A new study from the US suggests that people who have had nonmelanoma skin cancer (NMSC) may be at increased risk of developing other cancers, including those that affect other parts of the body.
The study is the work of Dr Jiping Chen of the National Cancer Institute in Bethesda, Maryland, and Dr Anthony Alberg of the Medical University of South Carolina, and colleagues, and is published on August 26 in the online issue of the Journal of the National Cancer Institute.
Previous research has already shown a link between a history of NMSC and increased risk of developing melanoma, a rarer but more malignant form of skin cancer that causes most deaths from skin cancer, but it is not clear whether NSMC is also a risk factor for cancers that affect other parts of the body.
Chen and Alberg and colleagues analyzed data from a prospective cohort study known as CLUE II, which is based in Washington County, also in Maryland. They found 769 people in the cohort had been diagnosed with NMSC during a 16 year follow up period since the study started in 1989, and 18,405 people had no history of the disease over the same period. They then compared the risk of developing other types of cancer in the two groups.
The results showed that:
- The overall rate of cancer diagnosis was 293.5 cases per 10,000 person-years in the NMSC group and 77.9 per 10,000 in the non-NMSC group.
- After adjusting for other known cancer risk factors such as age, sex, body mass index (BMI), smoking status, and educational level, people with a history of NMSC were twice as likely to develop other cancers as people with no such history.
- The increased risk was unaffected by the removal of melanoma from the list of other cancers.
- The figures were the same for both types of NMSC, basal cell and squamous cell carcinoma.
- The strongest links between a history of NMSC and the risk of developing other cancers was in participants aged 25 to 44.
The authors concluded that:
“This community-based, prospective cohort study provides evidence for an association between an NMSC diagnosis and an increased risk of subsequent cancer, even after adjusting for individual-level risk factors.”
Speculating on the finding that the younger participants with a history of NMSC were the ones most likely to develop other cancers, the authors suggested it could be because of an inherited predisposition to cancer.
Discussing the limitations of the study, the editors suggested that people with a history of NMSC might be more likely to receive a diagnosis for another cancer because they are more closely monitored. Also, the people studied in this cohort were all from one county in Maryland and may not be representative of the population as a whole. And finally, the adjustments that were made to eliminate factors such as skin type and sunburn history had to include assumptions because a lot of the data was missing for those factors.
“Nonmelanoma Skin Cancer and Risk for Subsequent Malignancy.”
Jiping Chen , Ingo Ruczinski , Timothy J. Jorgensen , Gayane Yenokyan , Yin Yao , Rhoda Alani , Nanette J. Liégeois , Sandra C. Hoffman , Judith Hoffman-Bolton , Paul T. Strickland , Kathy J. Helzlsouer , and Anthony J. Alberg.
Journal of the National Cancer Institute Advance Access published on August 26, 2008.
DOI 10.1093/jnci/djn260
Sources: Journal Abstract, JNCI.
Written by: Catharine Paddock, PhD