Risk factors for keratinocyte carcinomas, primarily pigment traits and sun sensitivity, were associated with the risk of developing non-Hodgkin lymphomas (NHL) and chronic lymphocytic leukemia (CLL) in an analysis of 92,097 women in France.
The presence of “many or very many nevi [moles]” was particularly associated with the risk of CLL among individuals in the E3N cohort, according to a report published online in Cancer Medicine. E3N is a prospective cohort of French women aged 40-65 years at inclusion in 1990. Researchers collected cancer data at baseline and every 2-3 years.
Hazard ratios and 95% confidence intervals for associations between patients pigmentary traits and sun exposure and their risk for CLL/NHL were estimated using Cox models, according to study author Louis-Marie Garcin, MD, of the Université Paris-Saclay, Villejuif, and colleagues.
Common etiology?
Among the 92,097 women included in the study, 622 incident cases of CLL/NHL were observed over a median of 24-years’ follow-up.
The presence of nevi was associated with CLL/NHL risk. The HR for “many or very many nevi” relative to “no nevi” was 1.56. The association with number of nevi was strongest for the risk of CLL, with an HR for “many or very many nevi” of 3.00 vs. 1.32 for NHL. In addition, the researchers found that women whose skin was highly sensitive to sunburn also had a higher risk of CLL (HR, 1.96), while no increased risk of NHL was observed. All HR values were within their respective 95% confidence intervals.
Relevant characteristics that were found to not be associated with added CLL/NHL risk were skin or hair color, number of freckles, and average daily UV dose during spring and summer in the location of residence at birth or at inclusion.
These observations suggest that CLL in particular may share some constitutional risk factors with keratinocyte cancers, according to the researchers.
“We report an association between nevi frequency and CLL/NHL risk, suggesting a partly common genetic etiology of these tumors. Future research should investigate common pathophysiological pathways that could promote the development of both skin carcinoma and CLL/NHL,” the researchers concluded.
The study was sponsored by the French government. The authors stated that they had no conflicts of interest.
SOURCE: Garcin L-M et al. Cancer Med. 2020. doi: 10.1002/cam4.3586 .