A new systematic review says that many skin cancer patients fare just as well when surgeons remove about one inch of normal-looking tissue around the lesion instead of a larger safety margin.
Cutaneous melanoma arises in pigment-producing cells and is associated with sun exposure, so primary tumors are often on the face and hands where patients have special concerns about unsightly scars.
The purpose of the safety margin is to remove both the primary tumor and any malignant cells that might have spread into the surrounding skin. Combined data from five studies suggested a slight benefit to wider surgical margins, but the difference was not statistically significant, the review says.
The bottom line for people with skin cancer is that individualized treatment is critical, say surgical oncologists who were not involved in the review.
"Patients should be sure they are being treated by physicians who are very knowledgeable about melanoma so they don''t get over- or under-treated," said Vernon Sondak, M.D., of the H. Lee Moffitt Cancer Center & Research Institute in Tampa, Fla. "They should seek out a very qualified team that includes pathologists as well as surgeons."
The review appears in the most recent issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
Melanoma is the most serious type of skin cancer, and the percentage of Americans who develop the disease has more than doubled in the past 30 years, according to the National Cancer Institute. Unlike many other common cancers, melanoma affects people across a wide age spectrum. While occurrence rates are highest among senior citizens, it is also one of the more common cancers in adolescents and young adults.
The systematic review analyzed five studies of patients with moderately severe melanoma, where the tumor has invaded the deeper layers of skin, but has not spread to other organs. Charles Balch, a review co-author, was lead author on one of the review studies.
The combined studies included about 3,300 participants, divided into two groups. One group had surgery with removal of 0.5 inches to one inch around the lesion, while the other had wider margins of 1.5 inches to two inches. Most of the studies tracked patient survival for five to 10 years. "Our meta-analysis showed there was no statistically significant difference in overall survival between the two groups," the review authors concluded.
Because the studies occurred some years ago, none included a newer procedure known as sentinel lymph node biopsy, said Michael Sabel, M.D., a surgical oncologist at the University of Michigan. This technique can help determine whether cancer cells have traveled to lymph nodes near the primary tumor. If the biopsy is positive, additional treatments can help control the spread of disease and improve survival rates.
Avoiding excessive sun exposure, especially during childhood when the skin is most sensitive, remains the single most effective way to prevent skin cancer. Experts recommend seeking shade during the midday hours and daily use of sunscreen, wide-brimmed hats and protective clothing.
Although melanomas can arise from an existing mole, most start in unmarked skin. The conventional warning signals for a sore or lesion are:
Diameter greater than one-quarter of an inch
Now, Sabel said, doctors include E for Evolution. "Any change in a lesion - such as itching, bleeding, change in size or change in color - should prompt a visit to a doctor," he said.