Herpes zoster and risk of cancer in the elderly US population
Couplée aux données des registres américains des cancers et portant sur 1 108 986 cas et 100 000 témoins, cette étude évalue l'association entre une infection par le virus herpès zoster et le risque de cancer chez une population âgée de plus de 65 ans
Background: Herpes zoster (HZ) arises in older people due to age-related decline in immunity. We assessed whether HZ, as a marker of immune suppression, is associated with increased cancer risk. Methods: We conducted a case-control study in US adults aged ≥ 65 years using the SEER-Medicare linked database. Cases (n=1,108,986) were people with first cancers identified in cancer registries (1992-2005). Controls (n=100,000) were cancer-free individuals frequency-matched to cases on age, sex, and year of selection. We identified HZ diagnosis using Medicare claims. Logistic regression models were constructed to determine adjusted associations between cancer and HZ. Results: HZ prevalence was modestly higher in cases than controls (1.4% vs. 1.2%). We identified significant associations between HZ and oral cavity/pharyngeal (adjusted odds ratio [aOR]=1.21), colon (aOR=1.10), lung (aOR=1.11), and non-melanoma skin (aOR=1.46) cancers; myeloma (aOR=1.38); diffuse large B cell lymphoma (aOR=1.30); lymphoplasmacytic lymphoma (aOR=1.99); and chronic lymphocytic leukemia/small lymphocytic lymphoma (aOR=1.55). Among solid cancers, HZ was mostly associated with regional and/or distant stage tumors. Associations were strongest when HZ was diagnosed 13-35 months before cancer diagnosis/selection; they were significant for some cancers in the 36-59-month period, and 60+ months for lymphoplasmacytic lymphoma (OR=1.99). Conclusion: HZ is associated with modestly increased risk of a few cancers, particularly hematological malignancies. Associations were strongest at short latency intervals for many cancers, and for regional/distant stages among solid cancers, perhaps reflecting reverse causality. Impact: Age-related immune decline does not play a major role in cancer development in older people, but it may be important for some lymphomas.