Background Immunosuppressed cohorts experience an increased risk of Human Papilloma Virus (HPV) and other virus-associated malignancies (e.g. Hodgkins and non-Hodgkins lymphoma). Medication exposure may play a role.
Objectives To investigate the risk of HPV and other virus-associated malignancies in female arthritis patients treated with biological Disease Modifying Anti-Rheumatic drugs (bDMARDs) compared with 1) bDMARD naïve patients and 2) the general population.
Methods A cohort of 13 905 female arthritis patients (median age 54.8 years, interquartile range 43.1-65.1) with rheumatoid arthritis (72%), psoriatic arthritis (12%), ankylosing spondylitis (4%) or other arthritides (12%) registered in the nationwide DANBIO registry was followed up for any virus-associated malignancy1 by linkage to the Danish Cancer Registry (DCR), 2000-2011 according to bDMARD exposure. Cumulated follow-up time was 34 429 years. Using Cox regression analysis, hazard ratios (HR) for cancer in ever (N=5647) vs. never (N=10 331) bDMARD treated patients were calculated. In order to compare the incidence with that of the general population, standardized incidence ratios (SIR) were calculated.
Results HRs for virus-associated malignancies in bDMARD treated vs bDMARD naïve are presented in the Table. Compared with the general population, risk of cervical cancer was neither increased in ever (SIR 1.0, 95% CI 0.3-3.1) nor in never bDMARD-treated patients (SIR 1.1, 95% CI 0.5-2.5). Compared with the general population, SIR of non-Hodgkin's lymphoma was increased in bDMARD treated (1.54, 95% CI 0.6-3.4) and bDMARD naïve patients (1.7, 95% CI 1.0-3.0). For Hodgkin's lymphoma, the SIR was increased among bDMARD treated (3.1, 95% CI 0.4-21.7) and reached statistical significance for bDMARD naïve (5.6, 95% CI 1.8-17.3).
Conclusions In this cohort study including 13 905 female arthritis patients, no overall increased risk of virus-associated cancers in bDMARD-treated compared with never bDMARD-treated arthritis patients was found. However, the observed predominance of anal and oropharyngeal cancers in bDMARD-treated patients needs further investigation. Interestingly, we did not find the risk of cervical cancer to be increased compared with the general population. The risk of lymphomas was increased, but this was not associated with bDMARD-treatment per se.
IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. A review of human carcinogens. Part B: Biological agents 100B (2012).
Acknowledgements Thanks to departments of rheumatology in Denmark for reporting to the DANBIO registry and to The Danish Rheumatism Association and the Danish Cancer Society for financial support.
Disclosure of Interest None declared