Background Systemic lupus erythematosus (SLE) or its treatment might increase the risk of cervical neoplasia as evidenced by previous studies, although inconclusive. Cervical screening can detect subclinical cervical intraepithelial neoplasias and, in turn, offers effective protection against cervical cancer.
Objectives To examine the risk of cervical neoplasia among women with SLE and across different treatment exposures incorporating findings from cervical screening.
Methods By linking national Swedish registers we assembled a cohort of women with SLE and matched general population comparators. SLE patients were identified using the National Patient Register. Using the Prescribed drug register, two SLE subcohorts were defined by use of antimalarials and other immune-suppressive treatments (with or without antimalarials). Data on cervical screening came from the Swedish National Cervical Screening Registry, which gathers data on all Pap smears. A composite outcome of cervical dysplasia and invasive cervical cancer during follow-up (2006–2012) was defined using the Cervical Screening Registry and the Swedish Cancer Register. Secondary outcomes considered CIN 1, 2–3, and invasive malignancy separately. Cox models estimated hazard ratios (HR) adjusted for age, sex, education level, healthcare utilization, number of children, marital status, family history of cervical cancer, and prior cervical screening.
Results Compared to the general population, there was a doubled rate of cervical dysplasia or invasive cancer among women with SLE (HR=2.12 95%CI 1.65–2.71). The rate was higher among those treated with systemic immune-suppressives than among those with only antimalarials (Table). Among women with SLE, immunosuppressive treatment was associated with an increased rate of cervical dysplasia or neoplasms compared to those on antimalarial therapy without additional immunosuppressive treatment (HR=1.83 95% CI 1.15–2.91). Results were generally similar for the secondary outcomes, however limited due to number of events and follow-up time, particularly in the antimalarial treated group.
Conclusions SLE is a risk factor for cervical neoplasia, even after adjusting for important risk determinants such as previous cervical screening. The clinical implication of our findings is that SLE patients treated with immune-suppressives are at increased risk of cervical neoplasia and should be adequately monitored, regardless of whether the risk increase is due to disease severity or treatment.
Disclosure of Interest None declared