Those with skin cancer by age 25; higher risk of other cancers

MELBOURNE, March 7 (UPI) -- People with non-melanoma skin cancer by age 25 and younger have a higher risk of developing melanoma or other cancers later in life, Australian researchers say.

Rodney Sinclair, a professor at the University of Melbourne and director of Dermatology at Epworth HealthCare, said the risk decreased significantly with increasing age, but it remains higher compared with individuals who have never had non-malignant skin cancer.

Non-malignant skin cancer is considered the most common type of skin cancer, relatively easy to treat if detected early, and rarely spreading to other organs, Sinclair said.

"The risk for developing any cancer subsequent to non-malignant skin cancer decreases significantly with increasing age: 23 times higher risk for those age 25 and younger; 3.52 for those ages 25 to 44; 1.74 for those ages 45 to 59; and 1.32 for those age 60 and older," Sinclair said in a statement.

"Our study shows that non-malignant skin cancer susceptibility is an important indicator of susceptibility to malignant tumors and that the risk is especially high among people who develop non-malignant skin cancer at a young age."

Sinclair and colleagues Dr. Eugene Ong and Dr. Michael Goldacre hypothesized people who developed skin cancers later in life did so as a result of accumulated sun exposure, while those who developed skin cancer at a younger age might do so as a result of an increased susceptibility to cancer in general.

The researchers collected hospital admission and death data from the All England Record-linked Hospital between 1999 and 2011, and constructed two groups: one of 502,490 people with a history of non-melanoma skin cancer, and another group of 8,787,513 as controls. Both groups were tracked for five to six years.

The study, published in the journal Cancer Epidemiology, Biomarkers & Prevention, found for those who had non-melanoma skin cancer, the relative risk for developing cancers of the bladder, brain, breast, colon, liver, lung, pancreas, prostate, and stomach remained consistently elevated for the entire period of the study, and the risk for cancers of the brain, colon and prostate increased with time.

The study also found those who had non-melanoma skin cancer before age 25 were 53 times more likely to get bone cancer, 26 times more likely to get blood cancers, 20 times more likely to get brain cancer and 14 times more likely to get any cancer excluding those of the skin.

Skin cancer survivors younger than age 25 years were 23 times more likely to develop any cancer other than non-melanoma skin cancer. In particular, they were 94 times more likely to get melanoma and and 93 times more likely to get salivary gland cancer, the study said.