MONDAY, April 16 (HealthDay News) -- Surgery for non-melanoma skin cancer in the United States increased substantially from 2001 to 2006, mainly due to the increased use of a specific surgical procedure, a new study suggests.

Non-melanoma skin cancer forms in the outer layer of the skin or in skin squamous cells, but not in the cells that make pigment, according to the U.S. National Cancer Institute.

More than 3 million non-melanoma skin cancers are diagnosed in the United States each year. Treatment options include surgical excision (removal) and Mohs micrographic surgery, which examines the entire surgical margin during the procedure.

According to the American College of Mohs Surgery, the procedure "treats skin cancer through a highly specialized and precise technique that removes the cancer in stages, one tissue layer at a time."

The new study, by Dr. Kate Viola of the Albert Einstein College of Medicine in New York City and colleagues, analyzed the medical records of nearly 27,000 Medicare patients who had either surgical excision or Mohs micrographic surgery. The findings are published in the April issue of the journal Archives of Dermatology.

There is debate about whether surgical excision or Mohs micrographic surgery is more effective for primary non-melanoma skin cancer and about the cost-effectiveness of the Mohs procedure, Viola pointed out in a journal news release.

Among the study patients, about 64 percent had surgical excision and 36 percent had Mohs micrographic surgery to treat these skin cancers between 2001 and 2006. During that time, the rate of surgical excision increased from 1.8 to 2.1 per 100 patients while the rate of the Mohs surgery doubled from 0.75 to 1.5 per 100 patients.

Mohs micrographic surgery was more likely than surgical excision to be used for skin cancers on the lip (60 percent versus 40 percent) and eyelid (57 percent versus 43 percent). Atlanta had the largest proportion of non-melanoma skin cancer patients treated with the Mohs procedure -- about 45 percent -- and a larger proportion were performed in younger patients, the study found.

"Patient age and lesion location were significantly associated with the type of surgery (Mohs micrographic surgery versus surgical excision), yet there were wide variations in regional [Mohs procedure] use and geographical disparity that warrant further investigation. Additional large, prospective studies are needed to further identify surgical treatment outcomes for non-melanoma skin cancer," the authors concluded.

More information

The U.S. National Cancer Institute has more about skin cancer.