Search This Blog

Thursday, July 14, 2011

Tumor Size

A tumor, as described by Wikipedia, is commonly used as a synonym for a neoplasm (a solid or fluid-filled (cystic) lesion that may or may not be formed by an abnormal growth of neoplastic cells) that appears enlarged in size. Tumor is not synonymous with cancer. While cancer is by definition malignant, a tumor can be benign, pre-malignant, or malignant, or can represent a lesion with no cancerous potential whatsoever.

What does the size of a tumor have to do with cancer and health? It is possible that we often develop tumors. Without a doctor around to tell us what they are, our body deals with them and we are none the wiser. Some tumors however grow and make people quite uncomfortable, such as the picture on Wikipedia. Besides discomfort, a tumor can be a threat to your health.

In 1971 Dr. Juhah Folkman formulated the idea of tumors being dependent on blood vessel formation. Researchers eventually warmed up to the idea and started looking for angiogenic factors that could be target by drugs. VEGF, Vascular endothelial growth factor became a target and it worked, some of the time. In cancers deliberately developed on the backs of mice, for example, blocking VEGF prevents tumors from growing. Clinical trials on human beings showed that it adds time to a cancer patients life when used in conjunction with chemotherapy on colon and non-small cell lung cancer. However, it did not add time to a patients if they had breast cancer. But science isn't always straight forward.

The FDA approved Bevacizumab in 2008 for use in breast cancer. A panel of outside advisers voted 5 to 4 against approval, but their recommendations were overruled. The panel expressed concern that data from the open label clinical trial did not show any increase in quality of life or prolonging of life. The trial did show that Bevacizumab reduced tumor volumes and showed an increase in progression free survival time. Based on this data the FDA chose to overrule the recommendation of the panel of advisers.

Two subsequent double blind studies showed little efficacy and some serious side effects. The first rule in medicine is to do no harm. It is a rule that is being ignored by scientists and doctors at Roche and Genentech. Careerism has them continuing to tout the drug in spite of the trial data. It may help some people just as it might result in the many side effects. Prescribing the drug by doctors (which they can still do) would be a random act. If the patient gets better... Eureka! If they get the side effects or they die on schedule, it was an act of compassion. None if it could be considered science. At $90,000 a year, Avastin is a money maker. It is the number one selling cancer drug in the world bringing in around 6 billion dollars a year. Removing the breast cancer indication will cut profits by a billion dollars.

Tumor size is biotech endpoint. Shrinking tumors means making money. The real question is whether or not it helps cancer patients feel better and live longer.

No comments: