Melanoma – maybe some progress

Melanoma, a cancer of the skin, can be deadly. There are probably over one million people diagnosed with skin cancer each year. Almost all of these are not dangerous and don’t kill anyone. The exception is melanoma. About 68,000 cases were diagnosed in the U.S. in 2010 and around 8700 people died of the disease. The number of cases has been rising each year, but fortunately the number of people dying hasn’t changed. Now we may even see that number go down.

One reason the number of deaths hasn’t increased is that public awareness has increased so we are more likely to see our doctor if we have a funny looking brown spot on our skin. People are diagnosed earlier and their melanomas are being removed at an early stage. Letting it spread is a recipe for disaster. When I was in practice, the only drug that had any effect, dacarbazine made a lot more people sick than better. I don’t think any of my patients with widespread disease ever responded.

Now we have some new ammunition to treat melanoma when it spreads beyond the skin. The drugs are a lot smarter than dacarbazine, which is a general cell poison. They attack specific sites on the melanoma cell that would cause it to grow. The first one of these, called vemurafenib, was the subject of a groundbreaking report in the New England Journal of Medicine online this week. The investigators studied 675 patients from all over the world. Most had seriously advanced melanoma. They gave half the patients the new drug vemurafenib along with dacarbazine and the other half only the dacarbazine. By 6 months, people treated with the vemurafenib were much more likely to be alive.

But, there is a downside to all this. By the end of one year, it looked like the drug stopped working and the patients who got the new drug were dying at the same rate as those who didn’t receive it. Also, the drug only works in certain patients. It blocks a certain molecule on melanoma cells, but not all patients with melanoma have this molecule in their cells. In fact, the researchers screened 2100 patients and found only 675 eligible to take the new drug. Also, needless to say, this drug isn’t without side effects, although these did not seem to be a big problem. Actually the main one was that some of the patients on the drug developed new skin cancers.

Another study was also published online at the New England Journal at the same time. In this study, patients were given a drug that would boost their T cells, an important part of the immune system. We know that there have been occasional patients with widespread melanoma whose cancer disappeared spontaneously. Doctors think that this may be due to activation of the immune system and the patent rejecting their melanoma. Indeed trying to boost the immune system using a drug called interleukin-2 has been a useful attempt at treating melanoma with some patients experiencing very long-term remissions.

But the new approach described in this study seemed to work, although the results were once again, not that spectacular. The good news is that all patients can be treated this way. But, the benefit was small. The drug extended patients’ lives by an average of two months compared with patients not receiving the drug. Still, it’s a start. The main side effect was an itchy rash in about a quarter of the patients.

Finally, there was a study published in the Journal of the American Medical Association on June 9 that looked for a mutation called KIT in patients’ melanoma cells. We know that cancers with this mutation will respond to imatinib, the drug used so successfully in chronic myelocytic leukemia. In this study, about 20 percent of the patients with widespread melanoma had the mutation. Although only a few of them responded to the drug, they had spectacular responses with their disease regressing for around two years or more.

Still, in spite of these advances it is better to avoid this deadly skin cancer altogether. We know it is more common in fair skinned and light haired people who have been in the sun a lot, usually enough so they get sunburned. The highest rate of this cancer is in Australia where there are a lot of fair skinned British descendants on a sunny continent. So when in the sun, cover up. Don’t rely on sunscreens if you are fair – they just keep you out there longer so that you burn anyway.