Researchers at the Johns Hopkins Kimmel Cancer Center have teased out two distinct sets of risk factors for head and neck cancers, suggesting that there are two completely different kinds of the disease.

In the Johns Hopkins study, head and neck tumors caused by the human papillomavirus (HPV), a common sexually transmitted virus, were most often linked to certain sexual behaviors and marijuana use, rather than tobacco and alcohol. The Johns Hopkins scientists also found that people with the viral-linked cancer were younger, more likely to be white, married, college-educated and have an annual income of $50,000 or higher. By contrast, those not caused by HPV, were associated with tobacco smoking, alcohol use and poor oral hygiene, which are the behaviors most often linked to head and neck cancer.

Patients with locally advanced laryngopharyngeal cancers who receive radical chemoradiation have significantly better voice outcomes during the 12 months following treatment when compared with patients who have undergone a total laryngectomy and surgical voice restoration, according to a study in the February 1 issue of the International Journal for Radiation Oncology*Biology*Physics, the official journal of the American Society for Therapeutic Radiology and Oncology.

The conventional treatment for patients with advanced squamous carcinomaterm of the larynx has traditionally been a total laryngectomy, which is the removal of the voice box, with or without radiation; however, this treatment has several serious side effectsterm, including natural-voice loss, altered food-swallowing function and a permanent opening in the trachea.

A simple blood test may be able to identify those most at risk for developing head and neck cancer as a result of smoking. This was the finding of a recent study by Prof. Zvi Livneh, Head of the Weizmann Institute's Biological Chemistry Department, Dr. Tamar Paz-Elizur of the same department, and their research team that worked in collaboration with Dr. Rami Ben-Yosef of Tel Aviv-Sourasky Medical Center, Prof. Laurence Freedman of Sheba Medical Center and Prof. Edna Schechtman of Ben-Gurion University of the Negev.

Livneh's research deals with repair mechanisms for DNA, the material of genes. Cells maintain sophisticated repair systems to prevent the accumulation of mutations that might lead to cancer. In these systems, molecular detectors scan the DNA for injury. A sort of local operation is then performed to cut out and dispose of the damaged segment and replace it with a new one. In their study, which appeared in Cancer Research, the scientists asked whether a reduced individual ability (non-inherited) to repair DNA damage increases chances of getting head and neck cancer. Smoking damages DNA and is known to be a major cause of this disease, which can affect the throat, mouth and larynx.

The cancer "Stem cell" theory comes from studies with blood cancers such as leukemiaterm, which are known to grow out of a subset of corrupted hematopoetic stem cells. In some studies, antibodies to the CD44 marker have been able to attach to these cells and block them from attaching to the bone marrow in a new mouse. Here Stanford and Michigan researchers seperated cancer cells from a solid tumor according to the CD44 marker using a technique known as Fluorescense Activated Cell Sorting in which a Flow Cytometerterm physically separates the cells.

Researchers have found a marker on head and neck tumor cells that indicates which cells are capable of fueling the cancer's growth. The finding is the first evidence of cancer stem cells in head and neck tumors.