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Old 03-03-2007, 01:14 AM
gdpawel gdpawel is offline
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Default Functional Tumor Cell Profiling

Functional profiling consists of a combination of a (cell morphology) morphologic endpoint (DISC) and one or more (cell metabolism) metabolic endpoinsts (MTT, ATP, resazurin). It studies cells in small clusters or microspheroids (microclusters). The combination of measuring morphologic (structural) effects and metabolic effects constitutes the measuring of a profile at the whole cell level.

Functional profiling with cell culture assays that predicts for patient survival in ovarian cancer

There is Functional Profiling that shows data indicating a near doubling in the survival of patients with platinum-resistant ovarian cancer, striking correlations between platinum activity and patient survival in previously-untreated ovarian cancer, and a comprehensive meta-analysis of scores of studies reporting response and survival correlations in thousands of patients.

With relapsed, platinum-resistant ovarian cancer, every clinical trial in history has just shown a 10-12 month median survival in this setting. However, background data (680 fresh surgical specimens) for the design of a cliinical trial to determine the efficacy of assay-directed therapy of platinum-resistant ovarian cancer, submitted to the 2003 Society of Gynecologic Oncology meeting, had a 27 month median survival and a fair number of long-term survivors. All specimens were tested with two separate Medicare-approved cell culture assays (DISC and MTT) having cell-death endpoints.

Cell culture drug resistance testing in platinum-resistant ovarian cancer
Sub-category: Translational research
Category: Ovarian
Control/Tracking Number: 2004-AB-171-SGO
Activity: Abstract Richard H. Nalick, Hospital of the Good Samaritan, Los Angeles, CA; Larry M. Weisenthal, Weisenthal Cancer Group, Huntington Beach, CA

Objectives: Obtained background data required for the design of a clinical trial to determine the efficacy of assay-directed therapy of platinum-resistant ovarian cancer.

Methods: 680 fresh surgical specimens of ovarian cancer were submitted from outside hospitals for the purpose of obtaining cell culture assay data to assist in the choice of chemotherapy on a non-investigational basis. Virtually all surgical specimens were tested with two separate Medicare-approved cell culture assays (DISC and MTT) having cell-death endpoints.

Results: Validation of cell culture assays for identifying platinum resistance was as follows.

1. Surgical specimens from platinum-treated patients had significantly greater in vitro resistance to platinum than surgical specimens from untreated patients.
2. Untreated patients without in vitro resistance to platinum had significantly better long-term, overall survival than patients with in vitro resistance to platinum (2775 vs 713 days, P2=0.0066).
3. Surgical specimens obtained within 6 months of platinum-based therapy had significantly greater in vitro resistance to platinum than surgical specimens obtained more than 6 months after the last platinum-based therapy.
4. In patients more than 6 months after the last platinum-based therapy, in vitro resistance to platinum predicted for significantly inferior long-term, overall survival (950 days vs median not reached, P2<0.05).

Comparing early relapse surgical specimens with untreated surgical specimens, the following regimens showed significantly inferior activity in early relapse surgical specimens: cisplatin, carboplatin, oxaliplatin, melphalan, thiotepa, mitomycin, paclitaxel, and the topotecan + cicplatin combination. The following did not show significantly inferior activity in ER surgical specimens: gemcitabine, etoposide, vinorelbine, fluorouracil, epirubicin, pegylated doxorubicin, topotecan, irinotecan, docetaxel, and all 3 gemcitabine + platinum combinations. Although the gemcitabine + platinum combination was the only active regimen in 25% of the early relapse surgical specimens, in 30% there was at least one active single agent, and in another 20%, other drug combinations were superior to gemcitabine + platinum, some of these being irinotecan + mitomycin, paclitaxel + cyclophosphamide, cyclophosphamide + etoposide, platinum + topotecan, and gemcitabine + melphalan. With a minimum follow-up of 3 years post-assay, early relapse (primary refractory and first relapse) patients had a median long-term, overall survival of 849 days, while all early relapse patients (including multiple relapse) had a median survival of 612 days. All late relapse patients had a median long-term, overall survival of 1244 days.

Conclusions: These results support a 3-armed, prospective randomized trial in early relapse patients to compare physician's choice chemotherapy, assay-directed therapy, and the 3 gemcitabine + platinum combination.

More information is available at [url]http://weisenthalcancer.com/Home.html

Assay Results and Bayes' Theorem

[url]http://cancerfocus.org/forum/showthread.php?t=3721

Last edited by gdpawel : 10-24-2013 at 01:08 AM. Reason: corrected url address
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Old 11-12-2007, 11:10 AM
gdpawel gdpawel is offline
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Default Functional Profiling Offers New Platform for Cancer Drug Discovery and Therapeutics

Ex-Vivo Analysis Recreates Human Tumor Cell Microenvironment

Long Beach, Calif. and San Diego (AACR Meeting) -- April 12, 2008 – Investigators at Rational Therapeutics and the Nagourney Institute (Long Beach, Calif.) report that ex-vivo analysis of the chemotherapeutic response of human tumors can provide clinically relevant predictive information, so long as the tumors remain within their natural micro-environment or “micro-ecosystem.” Their findings will be reported during a poster session presentation on Sunday, April 13th at the American Association for Cancer Research (AACR) Annual Meeting in San Diego.

As outlined in the presentation titled, “Functional Profiling of Human Tumors in Primary Culture: A Platform for Drug Discovery and Therapy Selection,” (AACR: 08-AB-1546), ex-vivo analysis (EVA) of human tumors provides a novel, real-time view of how such tumors act within their natural microenvironment. This information can, in turn, accelerate the drug development process and improve clinical therapy.

Led by Robert Nagourney, MD, medical director of Rational Therapeutics and the Todd Cancer Institute at Long Beach Memorial Medical Center, the investigators have applied a human tumor micro-spheroid platform that measures both apoptotic and non-apoptotic cell death events and other cellular responses following exposure to a variety of agents.

“With its capacity to measure genetic and epigenetic events, this platform provides a functional, real-time adjunct to static genomic and proteomic platforms,” said Dr. Nagourney. “By examining small clusters of cancer cells [microspheroids] in their native state, we provide a snapshot of the response of tumor cells to drugs, combinations and targeted therapies.”

He explains that what makes his research team’s analysis unique is the fact that each micro-spheroid examined contains all the complex elements of tumor bio-systems found in the human body and that have a major impact on clinical response.

“Our system for ex-vivo analysis is a conduit that connects novel drugs to clinicians and patients in need,” Dr. Nagourney added. “Appropriate use of this platform has the potential to save the pharmaceutical industry millions of dollars, shave years off the drug development cycle and improve clinical therapy.”

In recent years, Dr. Nagourney’s EVA/PCD platform has proven capable of identifying activity for signal transduction inhibitors and other classes of “targeted” agents, including a 100% response rate reported in previously untreated non-small cell lung cancer patients selected for 1st line treatment with the EGFr-TKIs.

About Rational Therapeutics Founded in 1995, Rational Therapeutics is a pioneering oncology research and testing center specializing in individualized therapy based on ex-vivo analysis of human tumors. More information is available at [url]www.rationaltherapeutics.com

http://www.rational-t.com/patient-stories/default.aspx?id=13

Last edited by gdpawel : 05-03-2012 at 07:35 PM. Reason: correct url address
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Old 03-07-2010, 08:06 AM
gdpawel gdpawel is offline
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Default Cell Culture Assay Testing Has Been Proven

In 1983, medical publications introduced assays based on cell-death (not cell-growth). This was a good five years before understanding the concept of apoptosis (apoptosis is a genetically programmed cell death pathway which exists in all cells, which is supposed to cause them to commit suicide if they become functionally deranged, but doesn't function properly in cancer cells, allowing them to grow abnormally without committing suicide, which can be triggered to occur by effective anti-cancer drugs).

Because clinical oncologists did not understand apoptosis then, the pioneering publications with cell-death (instead of cell-growth) endpoints were ignored, and neither clinical trials nor the application of cell-death assays were supported by academic and private practice clinical oncologists. The clinical utility and clinical accuracy of cell culture assay testing with cell-death endpoints have been proven.

There was a summary paper from a National Cancer Institute study, presented at the American Society of Clinical Oncologists (ASCO) Annual Conference in 1998, which looked at thirteen different studies that searched into "in vitro" (chemosensitivity assay) drug sensitivity testing for patients with cancer. It was noted that with the many different cancers represented in these studies, chemotherapy response rates went up from 3 to 66% (using standard chemotherapy drugs and procedures) and from 21 to 81% (using "in vitro" testing for the most responsive drug) and patient survival increased from 4.5 to 11.2 months (using standared procedures) and from 6.2 to 38.5 months (using "in vitro" testing).

A prospective, randomized clinical trial of physician's choice chemotherapy versus ATP assay-directed chemotherapy in non-surgically debulked, platinum-resistant ovarian cancer was presented by Ian Cree, M.D., Ph.D., Director, Translational Oncology Research Centre, Portsmouth, England at the May, 2005 ASCO meeting in Orlando, Florida. The results were highly suggestive of an effect due to the assay, and the most successful drug regimens used were nearly all developed using the assay. UK results in cancer are always lower than in the US for a variety of reasons. Part of this is probably lead time bias, but data on surgical debulking may be part of the explanation. Patients in the US get a whole lot more surgery along the way than in Germany and England, and it's not sure that it's our chemo which is doing the job or our surgery.

With regard to cell-based analysis, data show conclusively that patients benefit both in terms of response and survival from drugs and drug combinations found to be "active" in the assay even after treatment failure with several other drugs, many of which are in the same class, and even with combinations of drugs found to have low or no activity as single agents but which are found in the assay to produce a synergistic and not merely an additive anti-tumor effect.

Patients receiving a drug that tested "sensitive" were 1.44 times [i.e. 44%] more likely to respond compared to all patients treated in studies, while patients testing "resistant" were 0.23 as likely to respond as all patients. Patients receiving treatment with drugs testing "sensitive" enjoyed a 6-fold advantage (1.44/0.23 = 6.23) over patients treated with drugs testing "resistant."

This data includes both patients with solid tumors (e.g., breast cancer, lung cancer) and hematological (blood system) tumors (e.g. leukemia, lymphoma). In the case of solid tumors only, the advantage to receiving sensitive versus resistant drugs was 9.3 fold. In the case of breast cancer, it was more than 10-fold. Furthermore, patients receiving "sensitive" drugs were shown in many studies to enjoy significantly longer durations of survival than patients treated with "resistant" drugs.

Patients treated with a "positive" (sensitive) drug would respond 79.1% of the time, while patients treated with a "negative" (resistant) drug would respond only 12.6% of the time. Once again, there would be a huge advantage to the patient to receive a "positive/sensitive" drug, compared to a "negative/resistant" drug.

Sources:

Cree IA, Kurbacher CM, Lamont A, et al. A prospective randomized controlled trial of ATP-based tumor chemosensitivity assay-directed chemotherapy versus physicians choice in patients with recurrent platinum-resistant ovarian cancer. BMC Cancer. 2003; 3:19.

Weisenthal Cancer Group, Huntington Beach, CA and Departments of Clinical Pharmacology and Oncology, Uppsala University, Uppsala, Sweden. Current Status of Cell Culture Assay Testing May, 2002.

Functional profiling with cell culture-based assays for kinase and anti-angiogenic agents Eur J Clin Invest 37 (suppl. 1):60, 2007

Functional Profiling of Human Tumors in Primary Culture: A Platform for Drug Discovery and Therapy Selection (AACR: Apr 2008-AB-1546)
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Last edited by gdpawel : 03-18-2010 at 08:49 PM.
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Old 09-24-2010, 05:21 PM
gdpawel gdpawel is offline
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Default Microspheroids - Microclusters

There are any number of variables that affect drugs. These include the rate of excretion of the drugs by the kidneys and liver, protein binding and a myriad of other biological factors.

Some anticancer drugs are actually pro-drugs: they need to be first activated in the liver before becoming biologically active. So in vitro testing must administer the active forms of these agents, not the pro-drug form that is given to patients.

In the body, these cells interact with and supported by other living cells, both malignant and non-malignant cells. That is why cell-death functional profiling assays study cancer cells in small clusters, or microspheroids.

Analysis of these microspheroids provides a snapshot of cancer's behavior within the human body and provides a more accurate representation of how cancer cells are likely to respond to treatment in the clinic.

It is crucial that there is no manipulation of isolated cancer cells to make them grow, which was an important point of distinction with earlier cell-growth assays.

Drs. Larry Weisenthal and Robert Nagourney adopted this concept and began applying the term microclusters.

Real-life cancers grow as a complex organism that includes both malignant and non-malignant components. It may include fibrous tissue, mesothelial cells, fibroblasts, endothelial cells, etc.

In order to exhibit its most characteristic behavior patterns, a cancer cell needs to be surrounded by a colony of other cells, both normal and malignant.

Human tumors represent micro-ecosystems composed of transformed cells, stroma, fibroblasts, vascular elements, extra-cellular protein matrices and inflammatory elements.

The behavior of human cancers and their reponse to therapy reflect the complex interplay between humoral, vascular, adhesion and cytokine-mediated events acting in concert.

Tumors are very complex organisms. Ignoring this complexity, most studies of human cancer in culture have focused upon individual tumor cells that have been removed from their complex microenvironoment.

Cells are routinely broken up by mechanical and enzymatic means, which alters their subsequent behavior. Some previous methods of assays limited their analysis only to isolated tumor cells and failed to incorporate the crucial contribution of non-tumorous elements to the cancer phenomenon.

When allowed to grow in vitro, living cancer cells develop into these tiny micro-spheroid clusters that form a complex biosystem in which each malignant cell reacts upon its fellow colonists in subtle but important ways.

Each of these microspheres contains all the complex elements of tumor biosytems that are found in the human body and which can impact clinical reponse.

Source: Nagourney RA, Kollin CA, Sommers B, Su Y-Z, Evans SS. Functional profiling of human tumors in primary culture: a platform for drug discovery and therapy selection, AACR abstract #1546, 2008
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  #5  
Old 11-17-2010, 11:12 AM
gdpawel gdpawel is offline
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Default Clinical Applications of Functional Profiling in Ovarian Cancer

Ovarian cancer is the leading cause of cancer death for gynecologic malignancies, afflicting 22,000 women in the US each year. The majority of ovarian cancer patients are diagnosed with advanced disease requiring chemotherapy. Experience shows that these patients typically respond well to available drugs, yet there has been no improvement in five-year survival for this disease in decades. And the standard of care platinum plus taxane has not changed in more than 15 years.

However, the clinical responsiveness of ovarian cancer renders it an ideal candidate for functional profiling. Using functional profiling, we were the first to use platinum and Gencitabine to treat this disease, showing its efficacy even in platinum-resistant patients. Clinical responses many very durable have been observed even in the most heavily pre-treated patients.

While there are many drugs active in this disease, microarray gene platforms have been unable to meaningfully distinguish subsets of patients and improve therapy selection. These limitations of DNA-based techniques are not shared by functional profiling, which has the unique capacity to examine complex biological systems in their native state. By incorporating the interaction of tumor cells with their stroma, vasculature and inflammatory elements, functional profiling has been shown to provide highly validated predictive information.

Using functional profiling, we are now exploring novel drug combinations and the introduction of signal transduction inhibitors into the management of advanced ovarian cancer. The failure of large cooperative group clinical trials (like the GOG182) to improve clinical outcomes in the first line setting can now be seen as a failed paradigm of patient randomization.

Using functional profiling to examine untreated ovarian cancers, we have shown that no standard combination is best for the majority of patients. Instead, patients manifest unique patterns of sensitivity and resistance that can only be recognized through the individualization of treatment. Functional profiling has the capacity to match patients to available drugs and combinations, thereby improving the odds of good response and minimizing exposure to ineffective and toxic drugs.

[Dr. Nagourney is medical and laboratory director at Rational Therapeutics, Inc., in Long Beach, California, and an instructor of Pharmacology at the University of California, Irvine School of Medicine. He is board-certified in Internal Medicine, Medical Oncology and Hematology.]
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Old 07-13-2011, 01:11 AM
gdpawel gdpawel is offline
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Default Clinical correlations between assay results and progression-free survival in Ov Ca

In regards to chemoresponse assays with cell death endpoints in ovarian cancer, there are 20 studies reporting response correlations and 9 studies reporting survival correlations. Overall, patients treated with drugs which were active in cell death assays were 6-fold more likely to respond than patients treated with drugs which were inactive in cell death assays, and patients treated with assay-active drugs had significantly longer progression-free and overall survivals, compared to patients treated with assay-inactive drugs.

Bibliography

[1] Weisenthal LM, Marsden JA, Dill PL, Macaluso CK. A novel dye exclusion method for testing in vitro chemosensitivity of human tumors. Cancer Res l1983;43: 749-57.

[2] Carstensen H, Tholander,B. Chemosensitivity of ovarian carcinoma: in vitro/in vivo correlations using the dye exclusion assay of Weisenthal. In: 3rd European Conference on Clinical Oncology. Stockholm; 1985. p. 206.

[3] Blackman KE, Fingert HJ, Fuller AF, Meitner PA. The fluorescent cytoprint assay in gynecological malignancies and breast cancer. Methodology and results. Contrib Gynecol Obstet l1994;19: 53-63.

[4] Sevin BU, Perras JP, Averette HE, Donato DM, Penalver M. Chemosensitivity testing in ovarian cancer. Cancer l1993;71: 1613-20.

[5] Sargent J, Elgie A, Taylor CG, Wilson J, Alton P, Hill JG. The identification of drug resistance in ovarian cancer and breast cancer: application of the MTT assay. Contrib Gynecol Obstet l1994;19: 64-75.

[6] Sevin BU, Perras JP, Kochli OR. Current status and future directions of chemosensitivity testing. Contrib Gynecol Obstet l1994;19: 179-94.

[7] Taylor CG, Sargent JM, Elgie AW, Reid FD, Alton PA, Hill JG. The clinical relevance of chemosensitivity testing in ovarian cancer. Cancer Detect Prev l1998;22: 305-12.

[8] Ng TY, Ngan HY, Cheng DK, Wong LC. Clinical applicability of the ATP cell viability assay as a predictor of chemoresponse in platinum-resistant epithelial ovarian cancer using nonsurgical tumor cell samples. Gynecol Oncol l2000;76: 405-8.

[9] Konecny G, Crohns C, Pegram M, Felber M, Lude S, Kurbacher C, Cree IA, Hepp H, Untch M. Correlation of drug response with the ATP tumor chemosensitivity assay in primary FIGO stage III ovarian cancer. Gynecol Oncol l2000;77: 258-63.

[10] Ohie S, Udagawa Y, Kozu A, Komuro Y, Aoki D, Nozawa S, Moossa AR, Hoffman RM. Cisplatin sensitivity of ovarian cancer in the histoculture drug response assay correlates to clinical response to combination chemotherapy with cisplatin, doxorubicin and cyclophosphamide. Anticancer Res l2000;20: 2049-54.

[11] O'Meara AT, Sevin BU. Predictive value of the ATP chemosensitivity assay in epithelial ovarian cancer. Gynecol Oncol l2001;83: 334-42.

[12] Nagourney RA, Brewer CA, Radecki S, Kidder WA, Sommers BL, Evans SS, Minor DR, DiSaia PJ. Phase II trial of gemcitabine plus cisplatin repeating doublet therapy in previously treated, relapsed ovarian cancer patients. Gynecol Oncol l2003;88: 35-9.

[13] Taylor CG, Sargent JM, Elgie AW, Williamson CJ, Lewandowicz GM, Chappatte O, Hill JG. Chemosensitivity testing predicts survival in ovarian cancer. Eur J Gynaecol Oncol l2001;22: 278-82.

[14] Ness RB, Wisniewski SR, Eng H, Christopherson W. Cell viability assay for drug testing in ovarian cancer: in vitro kill versus clinical response. Anticancer Res l2002;22: 1145-9.

[15] Flick MB, O'Malley D, Rutherford T, Rodov S, Kamsteeg M, Hao XY, Schwartz P, Kacinski BM, Mor G. Apoptosis-based evaluation of chemosensitivity in ovarian cancer patients. J Soc Gynecol Investig l2004;11: 252-9.

[16] Tian HM, Shi XY, Fu J, Chao DY, Zhang K, Wu LY, Wang JW, Zhang W. [Correlation between ATP bioluminescence tumor chemosensitivity assay and clinical response in ovarian cancer]. Zhonghua Zhong Liu Za Zhi l2005;27: 296-8.

[17] Nakada S, Aoki D, Ohie S, Horiuchi M, Suzuki N, Kanasugi M, Susumu N, Udagawa Y, Nozawa S. Chemosensitivity testing of ovarian cancer using the histoculture drug response assay: sensitivity to cisplatin and clinical response. Int J Gynecol Cancer l2005;15: 445-52.

[18] Han SS, Choi SH, Lee YK, Kim JW, Park NH, Song YS, Lee HP, Kang SB. Predictive value of individualized tumor response testing by ATP-based chemotherapy response assay in ovarian cancer. Cancer Invest l2008;26: 426-30.

[19] Zhao D, Wu LY, Li XG, Wang XB, Li M, Li YF, Tian HM, Song PP, Liu J, Chang QY, Zhang W. [Application of ATP-tumor chemosensitivity assay in recurrent epithelial ovarian cancer]. Zhonghua Zhong Liu Za Zhi l2010;32: 855-8.

[20] Zhao D, Wu LY, Wang XB, Li XG, Li M, Li YF, Tian HM, Zhang W. [Application of ATP tumor chemosensitivity assay in primary epithelial ovarian cancer]. Zhonghua Zhong Liu Za Zhi l2010;32: 368-72.

[21] Gallion H, Christopherson WA, Coleman RL, DeMars L, Herzog T, Hosford S, Schellhas H, Wells A, Sevin BU. Progression-free interval in ovarian cancer and predictive value of an ex vivo chemoresponse assay. Int J Gynecol Cancer l2006;16: 194-201.

[22] Herzog TJ, Krivak TC, Fader AN, Coleman RL. Chemosensitivity testing with ChemoFx and overall survival in primary ovarian cancer. Am J Obstet Gynecol l2010;203: 68 e1-6.

[23] Weisenthal LM WC, Smith ME, Sanchez CG, and Berglund RF. Platinum resistance determined by cell culture drug resistance testing (CCDRT) predicts for patient survival in ovarian cancer. In; 2003. p. Manuscript and two peer reviews of a correlation study of the activity of cisplatin and carboplatin in ovarian cancer with regard to long term, overall patient survival and the results of DISC and MTT primary cell culture assays.

[24] Cree IA, Kurbacher CM, Lamont A, Hindley AC, Love S. A prospective randomized controlled trial of tumour chemosensitivity assay directed chemotherapy versus physician's choice in patients with recurrent platinum-resistant ovarian cancer. Anticancer Drugs l2007;18: 1093-101.
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Old 10-06-2011, 11:08 PM
gdpawel gdpawel is offline
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Default Studies of Assay-Directed Chemotherapy in Ovarian Cancer

Background: Many studies have shown strong correlations between assay results, chemotherapy response, and patient survival in ovarian cancer and other neoplasms. Such correlations are the traditional criteria used to evaluate all laboratory and radiographic tests by the FDA, other regulatory agencies, and the medical profession in general. The following studies are, in fact, unprecedented attempts to determine the extent to which treatment outcomes may be improved through the use of laboratory tests.

Kurbacher and colleagues treated 25 previously-treated patients with ovarian cancer (in 1st through 5th relapse) with assay-directed chemotherapy and compared outcomes with 30 non-randomized but clinically well-matched controls (Kurbacher, CM, et al. Anticancer Drugs 9:51-57,'98). In the control group, there was a response rate of 37% (2 complete responders), with median progression-free survival of 5 months and median overall survival of 17 months. In the assay-directed group, there was a response rate of 64% (8 complete responders), with a median progression-free survival of 12.5 months (P2=0.003) and a median overall survival of 24 months (P2=0.145). Assay directed therapy also produced a greater benefit with respect to both response rate and progression-free survival in the subgroup of patients with platinum-resistant disease. In an update presented at the American Society of Clinical Oncology (ASCO) meeting in 2001, the authors reported treating 59 previously-treated patients, including 28 with initially platinum-resistant disease. Median survival for patients with platinum-sensitive disease (with 2nd through 5th line therapy) was 24 months and for platinum-resistant disease was 21 months. A current multi-institutional, international trial is currently in progress to further determine whether assay-directed therapy is superior to empiric therapy.

Loizzi and colleagues treated 50 ovarian cancer patients in their first recurrence following platinum-based therapy with assay-directed therapy and compared clinical outcomes with 50 additional non-randomized but well-matched patients who received chemotherapy without assay information (results presented at the 34th Annual Meeting of the Society of Gynecologic Oncologists New Orleans, 2003, Abstract 189). There were differences in the impact of assays between patients who had primary platinum-sensitive disease versus platinum-resistant disease (unlike the Kurbacher study, in which there were equal benefits to patients with platinum-sensitive and platinum-resistant disease). In the group with initial platinum-sensitive disease, response rates were 65% for assay-directed chemotherapy versus 35% for empiric chemotherapy (P=0.02). Overall and progression-free median survival times were 38 and 15 months, respectively, in the assay-directed group versus 21 and 7 months for empirically-treated control patients (P=0.005, P=0.0002). However, in the platinum-resistant group, there was no improvement for assay-directed therapy. Response rates were 21% versus 16% (not significant). Overall median survivals were 13 months versus 12 months (n.s.). Median progression-free survivals were 5 months versus 6 months (n.s.). (n.b. this study has now been published in full: Loizzi, V, et al. Am J Obstet Gynecol. 2003 Nov;189(5):1301-7).

Weisenthal, et al recently completed an analysis of the overall survival of 549 ovarian cancer patients with tumors submitted to our laboratory for testing between January, 1993 and January, 2001. Kaplan-Meier survival curve analysis shows median survivals of 44 months for 1st line chemotherapy of previously-untreated patients, 41 months for 2nd line chemotherapy of patients meeting the clinical definition of initially platinum sensitive-disease (platinum-free interval > 6 months), 27 months for platinum-resistant disease (platinum-free interval 6 months or less), 23 months for patients receiving 3rd, 4th, or 5th line therapy (chemotherapy-free interval > 6 months), and 7 months for patients receiving 3rd, 4th, or 5th line therapy (chemotherapy-free interval 6 months or less). Click here to view Survival Curves.

We have also recently performed an analysis of the long-term survival of ovarian cancer patients who had tumor biopsy specimens referred to our laboratory for cell culture drug resistance testing (CCDRT or "chemosensitivity testing"), with the data analyzed as a function of whether or not the attempted CCDRT was evaluable or inevaluable (note that approximately 95% of specimens submitted for testing do yield an evaluable result, while approximately 5% are inevaluable for reasons relating to poor viability of the specimen, insufficient yield of tumor cells in the specimen, or other reasons). Comparing the survival of patients with evaluable assays (which resulted in CCDRT data to guide therapy) versus inevaluable assays (in which CCDRT data to guide therapy were not available), there were significant differences favoring patients in whom CCDRT was evaluable and in which results were reported to the referring oncologists. Click here to review these studies.

In considering the results of our own analysis (Weisenthal, et al, above), it is important to note that these survival outcomes were not obtained in the context of a formal clinical trial. Rather, these data represent the survival of patients for whom tumor biopsy specimens were submitted to our laboratory for cell culture drug resistance testing (CCDRT). We do not have any information regarding what forms of chemotherapy were actually administered to these patients. Since all of these specimens were submitted on a non-investigational basis and since patients (or their insurance companies) were charged an average of nearly $2,000 for the performance of the tests, one presumes that the results of the testing were considered in treatment planning, but it would not be surprising if all patients were not treated strictly according to the assay results, particularly in the cases of first line chemotherapy. This may or may not explain why the survival of both platinum-sensitive and resistant-patients receiving 2nd line chemotherapy were not significantly different than the survival of previously-untreated patients (i.e. if "2nd line" patients were treated more strictly according to assay results than were "1st line" patients, then this may have provided the "2nd line" patients with disproportional benefit, compared to the "1st line" patients).

One additional point to consider is the superior survival of the platinum-resistant patients in the Kurbacher study and in the Weisenthal series, compared to the Loizzi study. It is noteworthy that both Kurbacher and Weisenthal employed assays using cell death endpoints, while the Loizzi study employed a cell proliferation endpoint. As discussed elsewhere on this website, I believe (based on personal experience and on the basis of published data) that cell death assays may be more robust with respect to indentifying clinically-active drugs than are cell proliferation assays. In 1991-2, I proposed a clinical trial to make a head to head comparison between the cell death and cell proliferation endpoints in ovarian cancer to the Gynecologic Oncology Group (GOG). Despite great efforts (including the writing of a draft protocol), the GOG declined to do the study, in favor of performing dozens of studies of empiric chemotherapy which have not identified better chemotherapy treatment regimens in the ensuing 12 years.

It is time to abandon the empiric, "one sized fits all" treatment paradigm in favor of recognizing what has been known for more than 40 years, namely that ovarian and other forms of cancer represent heterogenous diseases, where the tumors of different patients have different responses to chemotherapy, and where important treatment advances will require individualizing treatment based on testing the individual properties of each patient's cancer.

Weisenthal Cancer Group
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Old 01-27-2012, 09:21 PM
gdpawel gdpawel is offline
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Default Functional profiling of clear cell ovarian cancer

J Clin Oncol 30, 2012 (suppl; abstr 5035)

Author(s):

Rowan Miller, Rachel Brough, Ilirjana Bajrami, Stanley B. Kaye, Christopher J. Lord, Alan Ashworth; The Institute of Cancer Research, London, United Kingdom; The Royal Marsden Hospital, Sutton, United Kingdom

Abstract:

Background:

Clear cell ovarian cancer represents up to 15% of epithelial ovarian cancers. In comparison to other subtypes, clear cell ovarian carcinomas have a poorer prognosis and are relatively resistant to standard platinum based chemotherapy. Recently, loss of function mutations in the tumour suppressor gene ARID1A were identified in up to 50% of ovarian clear cell carcinomas. We have adopted an integral functional and molecular profiling approach as a route to identify new genetic dependencies and therapeutic targets for this disease.

Methods:

Clear cell ovarian cancer cell lines were functionally profiled using high throughput screening with chemical and siRNA libraries. This has been integrated with molecular profiling data generated from exome and transcriptome sequencing to aid the discovery of novel targets.

Results:

Using functional screens we have now identified critical gene dependencies and potential therapeutics in a series of clear cell ovarian cancer models. The comparison of functional viability profiles for models characterized by ARID1A loss of function mutations is now enabling an analysis of synthetic lethal effects that could be used to target clear cell ovarian cancers carrying these mutations.

Conclusions:

The work undertaken so far provides the framework for the discovery of therapeutic targets for clear cell ovarian cancer using an integrated approach. Revalidation of these preliminary results is now underway to characterize new genetic dependencies for this disease.

[url]http://www.asco.org/ASCOv2/Meetings/Abstracts?&vmview=abst_detail_view&confID=114&abst ractID=98016

Note: connect t & r in abstractID

It's only a cell-line study -- still, it's gratifying to see that someone picked up on the "functional profiling" moniker!

Clear cell carcinoma of the ovary: [url]http://www.ncbi.nlm.nih.gov/pubmed/21276610
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Last edited by gdpawel : 03-02-2013 at 12:17 AM. Reason: corrected url address
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Old 10-18-2012, 05:39 PM
gdpawel gdpawel is offline
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Default FGF1 expression influences platinum resistance & progression-free survival in OvCa

British Journal of Cancer (2012) 107, 13271336. doi:10.1038/bjc.2012.410

Individuality in FGF1 expression significantly influences platinum resistance and progression-free survival in ovarian cancer

G Smith 1, M T H Ng 1,5, L Shepherd 1,5, C S Herrington 1, C Gourley 2, M J Ferguson 3 and C R Wolf 1,4

1. Division of Cancer Research, Medical Research Institute, University of Dundee, Dundee, UK
2. Edinburgh Cancer Research Centre, MRC IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH2 2XR, UK
3. Tayside Cancer Centre, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
4. CRUK Molecular Pharmacology Unit, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK

Abstract

Background:

Ovarian cancer is frequently advanced at presentation when treatment is rarely curative. Response to first-line platinum-based chemotherapy significantly influences survival, but clinical response is unpredictable and is frequently limited by the development of drug-resistant disease.

Methods:

We used qRTPCR analysis to assess intertumour differences in the expression of fibroblast growth factor 1 (FGF1) and additional candidate genes in human ovarian tumours (n=187), and correlated individuality in gene expression with tumour histology, chemotherapy response and survival. We used MTT assays to assess platinum chemosensitivity in drug-sensitive and drug-resistant ovarian cell lines.

Results:

Marked intertumour differences in gene expression were observed, with each tumour having a unique gene expression profile. Nine genes, including FGF1 (P=1.7 10−5) and FGFR2 (P=0.003), were differentially expressed in serous and nonserous tumours. MDM2 (P=0.032) and ERBB2 (P=0.064) expression was increased in platinum-sensitive patients, and FGF1 (adjusted log-rank test P=0.006), FGFR2 (P=0.04) and PDRFRB expression (P=0.037) significantly inversely influenced progression-free survival. Stable FGF1 gene knockdown in platinum-resistant A2780DPP cells re-sensitised cells to both cisplatin and carboplatin.

Conclusion:

We show for the first time that FGF1 is differentially expressed in high-grade serous ovarian tumours, and that individuality in FGF1 expression significantly influences progression-free survival and response to platinum-based chemotherapy.

[url]http://www.nature.com/bjc/journal/v107/n8/full/bjc2012410a.html
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Old 10-18-2012, 05:40 PM
gdpawel gdpawel is offline
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Default

They had the right idea of using the MTT assay (one of the cell-death assay endpoints) to assess platinum chemosensitivity in drug-sensitive and drug-resistant ovarian cell-lines. It's a shame they did this with cell-lines.

Cell-lines are useful for experimentation in labs as they are always available to researchers as a product and do not require harvesting (acquiring of tissue from a host) every time cells are needed in the lab.

Problem is, cell-lines don't recapitulate drug response patterns which exist in the body. For drug selection, it is better to directly remove tumor microclusters straight from the body and immediately test them, before they change.

I remember NCI had a huge lab working on microarrays to look for patterns of mRNA and protein expression which were predictive of chemotherapy response. They spent 2 years trying to find patterns which correlated using the NCI's various established ovarian cell-lines.

They thought they had something, but when they started to apply them to fresh tumor specimens, none of the results in the cell-lines was applicable to the fresh tumors. Everything they'd worked out in the cell-lines was not worth anything and they had to start over from square one.

I also remember Potti at Duke was also doing what these guys are doing: cell culture assays in cell-lines as gold standards of "resistant" vs "sensitive" tumors. Trying then to identify gene expression patterns which correlated with "sensitivity" vs "resistance." Lots of scientists have done this and lots of failure. Maybe these guys will be successful, maybe not.

The best study using this approach I ever read was a NEJM publication in 2004. However, there has been no follow up whatsoever in the past 8 years. I presume the authors concluded that the gene expression patterns weren't helpful, or they'd probably have published something by now (N Engl J Med. 2004 Aug 5;(6):533-42;601-3 Gene-expression patterns in drug-resistant acute lymphoblastic leukemia cells and response to treatment).

The gene expression markers (assays) actually can be calibrated to provide information both about the possibility of recurrence and also chemosensitivity. The problem is dissecting one from the other. Studies to date have just looked at whether people had a recurrence.

You can identify gene expression patterns (via assays) which correlate with this. But it can be hard and even impossible to tell what exactly you are measuring: is it intrinsic aggressiveness of the tumor? sensitivity to drug A? sensitivity to drug B? sensitivity to drug C? sensitivity to drug D? You find a gene expression panel which correlates with something, but picking apart the pieces is hard.

You can begin to do this if you combine gene expression studies with cell culture studies. Use the cell culture as the gold standard to define the difference between sensitivity and resistance. Then see which pattern correlates with which for individual tumors and individual drugs. It can theoretically be done (and certainly will be done, over time), but it's not easy.

And this study is somewhat similar in that both were cell-line studies, but still, it was gratifying to see that someone is picking up on the "functional profiling" moniker.
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Last edited by gdpawel : 02-24-2013 at 07:14 PM. Reason: additional info
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