Startling melanoma rate jump spurs warnings and research
Next time you decide to head to the tanning salon to get that bronzed glow for beach season, think again. A recent study by the Mayo Clinic reported a significant escalation in skin cancer, especially among people under 40. Young women in particular are the most affected.
Although mortality rates from melanoma have improved largely due to early detection and immediate medical care, the rising rate of skin cancer in young women is alarming. The study observed first-time diagnoses of melanoma in patients aged 18 to 39 from 1970 to 2009, and found that the incidence of melanoma increased by eight times among young women and by four times among young men. Researchers believe that the use of indoor tanning beds is the chief cause of the rising cancer rate in young women.
According to a study cited by lead investigator Jerry Brewer, M.D., a Mayo Clinic dermatologist, people who use indoor tanning beds frequently are 74 percent more likely to develop melanoma. Despite the information available to the public about the dangers of tanning beds, young women in particular continue to use them. Nearly 30 million people tan indoors and an estimated 71 percent of tanning salon patrons are females aged 16-29. The results of the Mayo Clinic study highlight the need for improved intervention to decrease risk factors for skin cancer and more effective treatment options for advanced melanoma because of the larger patient pool.
Melanoma is the most serious type of skin cancer. It develops in the cells that produce melanin, the pigment that gives skin its color. Melanoma can also form in the eyes and, rarely, in internal organs. Exposure to ultraviolet (UV) radiation from the sun or tanning lamps increases the risk of melanoma, but genetic makeup can also be a factor.
Melanoma can develop anywhere on the body but most often develops in areas that receive frequent exposure to the sun, such as the back, legs, arms and face. The first symptoms include a change in an existing mole or the development of a new and unusual growth on the skin. Melanoma occurs when skin cells develop DNA damage, whether it be caused by UV radiation, environmental or genetic factors, causing new cells to grow out of control and form a mass of cancerous cells. While it can be successfully treated if detected early, advanced melanoma is more difficult, especially when the disease spreads to the lymph nodes or other areas of the body.
However, two new drugs approved by the US Food and Drug Administration (FDA), vemurafenib and ipilimumab, could slow the progression of melanoma and possibly extend survival in patients with advanced cancer. These therapies target abnormal genes in melanoma cells in an attempt to stop their out of control growth.
A gene called BRAF is mutated in 40 to 80 percent of melanoma cells, causing the cells to grow uncontrollably and cancer to form. When a BRAF mutation is present, the MAP Kinase Pathway gets locked into an ‘on’ position and cells begin to grow quickly. The drug vemurafenib targets the switch of this pathway, blocking the ‘on’ switch, and slowing the cell growth. Researchers found that the drug gave patients an average of 6.2 months without the melanoma getting worse. But some studies have shown that within six to 10 months, the melanoma cells develop resistance to the drug.
Ipilimumab blocks a specific molecule, which could allow the patient’s body to recognize, target and attack the melanoma cells. Patients generally lived about 10 months longer with this drug, but, for a few patients, cancer growth was stopped for as long as six years. Researchers are currently looking to use ipilimumab together with vemurafenib, hoping this will lessen the chances of drug resistance developing.
Another exciting avenue of melanoma research is immunotherapy. Mayo Clinic researchers have trained mouse immune systems to combat skin cancer from within, using a genetic combination of human DNA from melanoma cells and a cousin of the rabies virus. This method uses a genetically engineered version of the vesicular stomatitis virus to deliver genes derived from melanoma cancer cells into tumors, triggering an immune response against the cancer cells. The immune system thinks it is being invaded by viruses, which are expressing cancer-related antigens that should be destroyed. Cancers can adapt and hide from a normal immune system but seem to be unable to evade an immune system exposed to the genetically engineered vesicular stomatitis virus. Sixty percent of mice with tumors were cured in less than three months, and with minimal side effects, using this method.
Researchers are also studying how simple lifestyle changes could have drastic effects on cancer. A recent study showed that the combination of caffeine consumption and exercise has the potential to protect against skin cancer, as well as inflammation related to other cancers. Researchers at the Rutgers Ernest Mario School of Pharmacy studied the effects of caffeine and exercise on mice at high risk for skin cancer. The mice that consumed caffeine and exercised with a running wheel had 62 percent fewer skin tumors. The volume of tumors was also 85 percent less compared to the mice that did not consume caffeine or exercise.
These advancements in drug and skin cancer treatment should help relieve the growing number of melanoma cases. But prevention and awareness is key to effectively combat the risk of melanoma, especially when the risk of getting the disease could be lowered by taking the necessary measures and avoiding certain conditions.