Hormonal dependence and cancer in Systemic Lupus Erythematosus
Objective: To estimate the incidence and analyze any cancer-associated factors in patients with systemic lupus erythematosus (SLE), differentiating between hormone-sensitive (HS) and non-HS cancers. Methods: This was a retrospective multicenter study of a patient cohort from the Systemic Lupus Erythematosus Registry of the Spanish Society of Rheumatology. Included were the first cancer post-SLE diagnosis, clinical and sociodemographic information, cumulative damage, severity, comorbidities, treatments, and refractoriness. Cancers were classified as HS (prostate, breast, endometrium, and ovarian) and non-HS (the remainder). The standardized incidence ratio (SIR) was calculated and logistic regression models were built. Results: A total of 3,539 patients (90.4% women) were included, 154 of whom had cancer (91% female), and 44 had HS cancer (100% female). The cancer SIR was 1.37 (95% confidence interval [95% CI] 1.15-1.59), with higher values in women age <65 years (SIR 2.38 [95% CI 1.84-2.91]). The SIR in women with HS versus non-HS cancer was 1.02 (95% CI 0.13-1.91) and 1.93 (95% CI 0.98-2.89). In HS versus non-HS cancers, SLE diagnostic age (odds ratio [OR] 1.04 [P = 0.002] versus 1.04 [P = 0.019]), and period of disease evolution (OR 1.01 [P < 0.001] versus 1.00 [P = 0.029]) were associated with cancer. The Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (OR 1.27 [P = 0.022]) and angiotensin-converting enzyme (ACE) inhibitor prescriptions (OR 2.87 [P = 0.048]) were associated with non-HS cancers. Conclusion: Cancer incidence in patients with SLE was higher than in the Spanish population, particularly among young women. This increase might be due to non-HS cancers, which would be associated with SLE involving greater cumulative damage where more ACE inhibitors are prescribed. ; The RELESSER Registry was partially funded by GSK, Roche, UCB, Lilly and Novartis. The sponsors had no role in the study design, data collection, analysis or interpretation, in writing the report, or in the decision to submit the article for publication. Dr. Pego-Reigosa is supported by grant 316265 (BIOCAPS) from the European Union 7th Framework Program (FP7/REGPOT-2012- 2013.1). The FIS Grant PI11/02857 (Instituto Carlos III, Fondos FEDER) supported this study.
