Nonmelanoma Skin Cancer Linked to Other Cancers, Especially in Young Survivors
A study by Ong et al has found that people who had nonmelanoma skin cancer were at an increased risk for subsequently developing melanoma and a spectrum of 29 other cancer types. The risk was especially high among people who develop nonmelanoma skin cancer before the age of 25. The findings are published in Cancer Epidemiology, Biomarkers & Prevention.
Researchers analyzed data from an all-England record-linked hospital and mortality data set collected between 1999 and 2011. They constructed two cohorts: one that comprised 502,490 people with a history of nonmelanoma skin cancer and a control cohort of 8,787,513 people. The researchers followed the two cohorts electronically for 5 to 6 years to determine observed and expected numbers of people with primary cancers in each group based on person-years at risk and calculated standardized risk ratios (RRs).
Study Findings
The scientists found that 67,148 patients from the nonmelanoma skin cancer cohort and 863,441 patients from the control cohort subsequently developed cancers. For those who had nonmelanoma 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 over time.
Comparing the nonmelanoma skin cancer cohort with the control cohort, the risk ratio for all subsequent malignant cancers combined was 1.36 (95% confidence interval [CI] = 1.35–1.37]. Significant increased risk ratios (P < .05) were found for 26 of the 29 cancer types studied, in particular for salivary gland, melanoma, bone, and upper gastrointestinal tract cancers. The risk ratios were also especially high when comparing younger people with and without a history of nonmelanoma skin cancer.
Increased Risk for Younger Patients
For example, the study found that those who had nonmelanoma 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.
The risk for developing any cancer subsequent to nonmelanoma skin cancer decreased with advancing age: 23 times higher risk for those under 25 years of age, 3.52 for those 25 to 44 years of age, 1.74 for those 45 to 59 years of age, and 1.32 for those older than 60 years. While the risk decreased with increasing age, it remained higher compared with individuals who never had nonmelanoma skin cancer.
“Our study shows that nonmelanoma skin cancer susceptibility is an important indicator of susceptibility to malignant tumors and that the risk is especially high among people who develop nonmelanoma skin cancer at a young age,” Rodney Sinclair, MBBS, MD, a senior author of the study and Director of Dermatology at Epworth HealthCare and Professor of Medicine at the University of Melbourne, said in a statement. “The risk increases for a large group of seemingly unrelated cancers. However, the greatest risk relates to other cancers induced by sunlight, such as melanoma.”
Further studies to determine why people with nonmelanoma skin cancer, especially young people, are at increased risk of developing other malignancies could lead to a more fundamental understanding of carcinogenesis, concluded the study authors.
Eugene Liat Hui Ong, BMBCh, of the University of Oxford, is the corresponding author for the Cancer Epidemiology, Biomarkers & Prevention article.
The study was funded by the English National Institute for Health Research. The study authors reported no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
