History of Non-Melanoma Skin Cancer Doubles Melanoma Risk

[Editor-in-Chief]

History of Non-Melanoma Skin Cancer Doubles Melanoma Risk

By Jeff Minerd, MedPage Today Staff Writer
Reviewed by Zalman S. Agus, MD; Emeritus Professor at the University of Pennsylvania School of Medicine.
December 21, 2005

MedPage Today Action Points

• Recognize that a history of non-melanoma skin cancer is an independent risk factor for melanoma in older, white, postmenopausal women, regardless of sun exposure.
• Ask about a history of non-melanoma during routine physical exams of older, white, postmenopausal women.
• Monitor those at high risk for melanoma -- especially those with a history of non-melanoma -- with regular skin exams.

Review
CHICAGO, Dec. 21 - For older white women, a history of non-melanoma skin cancer outstrips sun exposure as the dominant risk factor for melanoma, researchers here reported.

These women were nearly twice as likely to develop melanoma as women with no such history, reported Carol A. Rosenberg, M.D., of Northwestern and colleagues in a study published online by the journal Cancer.

The finding emphasizes the need for physicians to ask about a history of non-melanoma skin cancer during routine physical exams and to monitor those with a history more closely, said the investigators.

Overall, women with a history of non-melanoma skin cancer were 2.4 times more likely than women with no history to develop melanoma over nearly seven years (95% confidence interval=1.82-3.20).

After adjusting for more than a dozen known risk factors, including sun exposure, geographical region by latitude, smoking, alcohol use, and family history of any cancer, women with a history of non-melanoma were still 1.7 times more likely to develop melanoma than those with no history (95% CI=1.18-2.44).

The study involved more than 67,000 white, postmenopausal women ages 50 to 79 participating in the Observational Study of the Women's Health Initiative. Of these women, about 5,500 had a history of non-melanoma skin cancer prior to enrollment. All women in this study were free of other cancers at enrollment.

Questionnaires administered at baseline and annually for a mean follow-up of 6.5 years assessed risk factors for cutaneous melanoma and new diagnoses. Reports of new diagnoses were confirmed by physician review of medical records.

"This study adds a history of the relatively favorable non-melanoma skin cancer -- in and of itself -- to the list of known risk factors for melanoma in both sun lovers and shade dwellers alike," Dr. Rosenberg said.

Because non-melanoma skin cancers are relatively common (1.3 million cases per year, according to the American Cancer Society) and carry a favorable prognosis, physicians are unlikely to ask about a history of this disease during a routine exam, she said.

However, because melanoma (about 60,000 cases per year) is so difficult to treat if not caught early, it is important for doctors and patients to talk about risk factors, especially a history of non-melanoma, she added.

For those at high risk, regular skin checkups are a must, Dr. Rosenberg advised.

The results of this study are "important not only for further defining melanoma risk in white postmenopausal women, but also for sensitizing the medical community to this risk and for developing new routines for follow-up and patient assessment by medical providers to promote the early detection of melanoma," the authors concluded.

Primary source: Cancer
Source reference:
Rosenberg CA et al. Cutaneous melanoma in postmenopausal women after nonmelanoma skin carcinoma. Cancer. Advanced online publication December 19, 2005.
Source