Skin cancer often linked with more serious cancers
Monday, November 17, 2003
CHICAGO -- Women with common, usually nonfatal forms of skin cancer face double the risk of developing unrelated cancers, according to a large study, suggesting that the initial diagnosis may be more worrisome that previously thought.
The skin cancer link was found for several malignancies, including cancer of the brain, breasts, ovaries and uterus. It was even stronger for liver cancer, which had a five times higher risk, and lung cancer, which had triple the risk.
Previous studies have shown that men and women with skin cancer face an increased risk of skin cancer returning. Some also have found that people with non-melanoma skin cancer are prone to later developing non-skin cancers, but the earlier research didn't adequately consider other risk factors that might explain the connection, said the lead author, Dr. Carol Rosenberg of Evanston-Northwestern Healthcare, part of Northwestern University's medical school.
Her study, involving 92,835 post-menopausal women participating in a continuing federal study, considered other factors that influence cancer risk -- including smoking, weight and education level -- and still found an increased risk associated with skin cancer.
Rosenberg said she suspects her results would apply to men, too, since previous studies involved both genders.
The results appear in the January issue of Cancer, an American Cancer Society journal, being published online Monday.
Of the more than 85,000 women who did not have skin cancer, just over 11 percent, 9,927, reported having had other cancers.
Of the 7,665 women who reported having had a mild form of skin cancer, nearly 25 percent, 1,878, said they had also had other types of cancer.
The results are compelling, said Dr. Alexa Boer Kimball, an assistant dermatology professor at Stanford University.
Even though most patients with mild skin cancers won't develop other cancers, Kimball said, the results imply that they should still be vigilant about getting routine screening tests for other cancers.
Given previous research, the authors presumed that skin cancer preceded development of other cancers, though the study lacks information on which developed first, Rosenberg said.
The skin cancers implicated -- basal cell and squamous cell -- affect more than 1 million Americans each year. Those skin cancers grow more slowly than melanoma, the most serious skin cancer.
Study participant Luvie Owens, 70, said she had a skin cancer lesion removed last year and thought nothing of it. The doctor's message at the time was not to worry, she said.
Owens, of Winnetka, Ill., said she learned of the study results by phone last week.
"As soon as I hung up I made an appointment for a colonoscopy," she said. "It sure makes you want to keep up with your (medical) appointments."
The government-funded study involved participants in federal research examining factors that predict disease and death in postmenopausal women. Participants are being followed for an average of about seven years. At the outset, from 1994-98, they were asked numerous health-related questions.
Whether any women developed cancer since the initial questioning is still being studied, said Rosenberg, one of the researchers in the broader study.
Eugenia Calle, the American Cancer Society's director of analytical epidemiology, questioned whether the increased risk is as high as the study suggests, considering that earlier studies found lower risks.
Calle said the study design may have exaggerated the risk, since women with non-skin cancers might be more likely to remember having had mild skin cancer than women who have only had mild skin cancer, especially since it is often dismissed as a minor inconvenience, Calle said.
On the Net:
Cancer journal: http://www.interscience.wiley.com
American Cancer Society: http://www.cancer.org