Abstract 3443: Associations of immune-related conditions with squamous cell and basal cell skin cancer risk

Elevated risk of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) of the skin has been identified in a number of clinical populations with conditions affecting the immune system, such as organ transplant recipients and non-Hodgkin lymphoma patients. However, because many other immune-related conditions are rare, their relationships with SCC and BCC have not been studied. We used Medicare claims to identify SCC and BCC cases in 2012 and to select controls in 2012 matched on sex and age with a 10:1 ratio. All subjects were of white race. For cases and controls, we used Medicare claims during 1999-2011 to identify 44 immune-related conditions (immunosuppressive conditions, autoimmune diseases, hematologic malignancies, and allergic diseases). The statistical significance of associations was determined after Bonferroni correction for multiple comparisons. In Medicare in 2012, there were a total of 470,756 SCC and 601,863 BCC cases. Of the 44 immune-related conditions included, SCC was associated with 41 (93%) and BCC was associated with 31 (70%). For most conditions, SCC was more strongly associated than BCC. We identified significant associations of SCC and BCC risk with well-characterized conditions, such as HIV, rheumatoid arthritis, and allergic rhinitis (SCC odds ratios (ORs) of 1.64, 1.29, and 1.29, respectively; BCC ORs of 1.60, 1.10, and 1.22; Table), as well as with poorly characterized or rare conditions, such as deficiency of cell-mediated immunity and polyarteritis nodosa (SCC ORs of 2.87 and 1.92; BCC ORs of 1.55 and 1.49). In conclusion, most immune-related conditions in our study indicated an elevated risk of non-melanoma skin cancer, particularly SCC. These findings provide evidence that immune dysfunction, as manifest across a wide range of conditions, may play an important role in development of SCC and BCC. Possible mechanisms could include direct effects of immune-related conditions or their treatments. Citation Format: Elizabeth L. Yanik, Ruth M. Pfeiffer, D. Michal Freedman, Eric A. Engels. Associations of immune-related conditions with squamous cell and basal cell skin cancer risk. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3443.