This month, Kimmel Cancer Center director William Nelson reviewed four major cancer research stories ranging from pets that sniff out cancer to a reminder of the dangers of cigarette smoking.
The first story is one that has been reported for several years. A variety of reports have shown that dogs can detect cancer in people by sniffing their breath, in the case of lung cancer, and urine, for genitourinary cancers. The question, says Nelson, is what cancer-related molecule(s) are the dogs detecting? If we can determine the specific marker the dogs are identifying, we can study these markers for broader use, he says. As for using Fido now as a detection tool, Nelson says these studies are small and have not been compared in studies to any other detection tool, so stick with the proven methods.
Nelson also discussed, what he calls, "extremely exciting" news for metastic melanoma. The drug, vemurafenib, marketed by the name Zelboraf, was recently approved by the FDA for metastatic melaoma. It works by interfering with a growth signal in cells that gets turned on by the BRAF gene. When the gene is defective, the signal becomes stuck in a chronic "on" state and leads to uncontrollable growth of cells, resulting in cancer. Vemurafenib interferes with this growth signal. In studies of the drug, half or more of patients had "tremendous shrinage of tumors," according to Nelson, who says the approval is a "giant first step." He says the drug may have potential as a treatment for earlier stage melanoma and possibly in combination with immune-stimulating drugs currently being studied.
In a recent study evaluating whether inherited genes affected the course of cancer, researchers identified five variant genes that seem to be associated with aggressive prostate cancer. Nelson says that understanding how these genes contribute to cancer could help define why some cancers are more deadly than others and help tailor aggressive therapies to patients at higher risk for it.
Finally, cigarette smoking remains one of the largest factors that drives cancer, according to Nelson, and the relationship between lung cancer and smoking has been well known, but it is also known that smoking increases the risk for other cancers, including bladder cancer in men. A recent study reveals that smoking-related risk for bladder cancer may be even higher than previously thought. The study also shows that people who quit smoking reduce their risk of bladder cancer significantly. Nelson says, as the number of women who smoke has risen throughout the years, the number of smoking-related bladder cancers in women also has increased. Study authors point out that changes in the contents of cigarettes may have contributed to the rise in bladder cancer risk.