Do RA or TNF inhibitors increase the risk of cervical neoplasia or of recurrence of previous neoplasia? A nationwide study from Sweden

Objectives To examine screening patterns and the risk of cervical neoplasia in women with rheumatoid arthritis (RA) treated or not with tumour necrosis factor inhibitors (TNFi). Methods We performed a nationwide register-based cohort study in Sweden of women with RA who started a first TNFi (n=9629), biologics-naive women with RA (n=34 984) and general population comparators (matched 1: 10, n=300 331), followed up from 1999 to 2012. Outcomes were first cytology screening with normal outcome, first ever cervical intraepithelial neoplasia (CIN) grade 1, first ever CIN 2-3 or adenocarcinoma in situ and first ever invasive cervical cancer during follow-up. HRs were assessed through Cox regressions adjusted for age, educational level, prior cervical screens, comorbidities, marital status and prior hospitalisations. Results Biologic-naive women with RA had more screenings (HR 1.08, 95% CI 1.06 to 1.10), were at greater risk of CIN 1 (HR 1.53, 1.23 to 1.89) and CIN 2-3 (HR 1.39, 1.16 to 1.66), but not of invasive cervical cancer (HR 1.09, 0.71 to 1.65) compared with the general population. Patients who initiated TNFi therapy had similar screening patterns (HR 1.01, 0.98 to 1.05), were not at increased risk of CIN 1 (HR 1.23, 0.87 to 1.74), but were at increased risk of CIN 2-3 (HR 1.36, 1.01 to 1.82) and invasive cervical cancer (HR 2.10, 1.04 to 4.23) compared with biologics-naive women with RA. Estimates varied little with successive adjustments, but were attenuated/absent in sensitivity analyses restricted to 2006-2012 and a disease-modifying antirheumatic drugs-treated comparator. Conclusions Women with RA in general are at elevated risk of cervical dysplasia. Compared with biologics-naive patients, women treated with TNFi are at increased risk of cervical cancer. Whether this increase is causally linked with TNFi could not be fully disentangled