Despite advances in the fight against many types of cancers, survival rates for people who have advanced melanoma have not improved in more than three decades, according to new research.
"There has not been a substantial change in survival [for people who have] metastatic melanoma," says Dr. Vijay Trisal, an assistant professor of surgical oncology at City of Hope Cancer Center in Duarte, California.
The Study
Researchers identified 822 patients who had been diagnosed and treated for stage III melanoma. None of the participants had been receiving experimental treatments, such as melanoma vaccines.
The researchers found no differences in survival except in the most recent group of patients, and that may have reflected improvements in staging rather than any real survival differences, says study author Dr. Shawn E. Young, a surgical oncology specialist at the John Wayne Cancer Institute in Santa Monica, California.
"It's disappointing, but it doesn't surprise me," says Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society.
Explanations
The finding stands in stark contrast to other cancers. But, as Trisal points out, the major advances in breast and colorectal cancers, along with other malignancies, have occurred with chemotherapy, radiation or biological therapies. In melanoma, there are no such proven treatments.
The only chemotherapy that works for melanoma is interferon, and that has, at best, only a 15% to 20% response rate. And that [only] means tumor shrinkage. It's not a cure rate," Trisal explains.
"We have produced a lot of (post-surgical] therapies, but they don't work," says Young.
And experimental therapies, such as vaccines, are so far not showing promise.
While there have been some improvements in the treatment of stage I and II melanoma, Trisal adds, melanoma that has spread has been more intractable.
According to the study authors, only 35% to 50% of people who have stage III melanoma will achieve long-term survival. Only 5% to 10% who have stage IV disease will survive. And surgery, they say, is still the only treatment that has stable and predictable success."
"I think the amount of research that went into melanoma development 15 years back was minimal. We had not recognized melanoma as a serious threat," Trisal says. But, the incidence of melanoma is increasing faster than any other cancer in the US
Early Detection Important
Melanoma is both preventable and detectable. When caught early, the five-year survival rate is at least 91%, according to the American Academy of Dermatology (ADA).
"It is highly detectable," Trisal says. "Stage I or II detection is the most important thing."
Researchers Detect Factor in Melanoma's Growth
Scientists at Dana-Farber Cancer Institute and Children's Hospital in Boston have identified a protein that plays a critical role in the growth of melanoma.
The Study
The researchers found that malignant melanoma cannot grow without a steady supply of the protein CDK2-a protein not needed by normal cells.
Using laboratory-grown melanoma cells, the scientists found that adding a chemical that suppressed the activity of the CDK2 gene, which produces CDK2 protein, significantly slowed the growth and spread of melanoma cells.
Implications
The findings suggest that it may be possible to develop drugs that cut off the supply of CDK2 to melanoma cells. This may be an effective way to halt the growth of melanoma without causing damage to other cells.
Study authors note that CDK2-inhibiting drugs already exist, and they hope their study results will lead to clinical trials of these drugs in people who have melanoma.
