• BREAKING NEWS ABC shows live and on-demand -- Download the WATCH ABC app!

DNA treatment effective against melanoma

June 14, 2011 12:00:00 AM PDT
Melanoma is the deadliest form of skin cancer. But up until now there haven't been very effective options to treat advanced cases of the disease. Now patients with advanced melanoma have new hope as researchers try to stop it in its tracks using DNA.

There are new, gene-based treatments for people with late-stage melanoma. Now we're learning more about how those drugs work and how doctors are targeting this deadly form of skin cancer in a whole new way.

Michael Sosnowicz, 63, never imagined that something he did when he was his children's age could kill him decades later. Sosnowicz spent years in the sun at his family's marina.

"The way I looked at things, you can't hurt Superman," said Sosnowicz.

Thirty years ago, doctors removed a cancerous tumor from Sosnowicz's leg and told him he was cured.

"Last April or May, I was driving home, and I put my hand on my thigh. Right here, next to the excision spot, I felt what I thought was a lipoma -- a fatty tumor," said Sosnowicz.

Dr. Lynn Schuchter is a melanoma expert at the University of Pennsylvania. She says the biggest breakthrough in decades may lie within a patient's DNA. Forty percent of patients with melanoma have a broken gene called the BRAF gene.

"What's really exciting is that there are new drugs, new inhibitors, that target these genes. They can put the brakes on these rapidly dividing cells," said Schuchter.

In some patients whose tumors have a broken BRAF gene, the inhibitors even shrink tumors by 50 percent or more.

"Three days after taking the drug, I wake up on my left-hand side, and I don't have this discomfort in my stomach. I move over to my right, and I don't have it," said Sosnowicz.

Schuchter says while patients have had tremendous results, eventually, the melanoma cells may become resistant. The next step? Combining the BRAF inhibitor with other therapies and ultimately find a cure.

Hope keeps Michael Sosnowicz strong -- hope and his family.

"I want them to be fighters just like me," he said.

The drug is now called vemurafenib.

The BRAF inhibitor is still being tested in clinical trials, but the Food and Drug Administration is expected to consider it for approval by the end of this year.


Melanoma, the most serious type of skin cancer, develops in the cells that produce melanin, the pigment that gives skin its color. Melanoma can also form in eyes and, rarely, in internal organs, such as intestines. Melanoma accounts for less than 5 percent of skin cancer cases but a majority of skin cancer deaths. Melanoma is the fifth most common cancer among men and the seventh most common cancer in women. Sometimes, melanoma is found in children and teenagers. The exact cause of all melanoma is not clear, but exposure to ultraviolet (UV) radiation from sunlight or tanning lamps and beds increases risk of developing the cancer. Other factors, such as genetic makeup, likely also play a role.

STANDARD TREATMENT: People with melanoma may have surgery, chemotherapy, biological therapy, or radiation therapy. Patients may have a combination of treatments. At any stage of disease, people with melanoma may have treatment to control pain and other symptoms of the cancer to relieve the side effects of therapy and to ease emotional and practical problems. This kind of treatment is called symptom management, supportive care, or palliative care.

NEW ANSWERS: Scientists from The Institute of Cancer Research (ICR) showed that in human cancer cells and mice, a gene called BRAF -- which is damaged in about half of all skin cancer cases -- triggers a cell signaling pathway that ultimately "blocks the instructions" from a second gene called PDE5A. In healthy cells, PDE5A acts as a brake to stop cell movement. However, in cancer cells, BRAF turns PDE5A's signals off, removing its ability to block cancer spread. By blocking the activity of PDE5A, BRAF drives skin cancer cells to invade new tissues and spread further around the body, converting skin cancer into a more aggressive disease. BRAF is only expressed in 8 percent of cancer but 50 percent of melanomas. BRAF inhibitors like PLX4032 (vemurafenib) inhibited proliferation of tumor cell lines, a mutation found in several human cancers including melanoma. The compound also showed partial or complete tumor regression and improved survival in a dose-dependent manner in preclinical efficacy models in rodents, without associated toxicity.

Load Comments