Studies in the past suggested SLE or its treatment to be a risk factor for cervical neoplasia. However, due to the relative rarity of the disease, patient numbers in the studies were low and the studies were inconclusive. ‘To examine the risk of cervical neoplasia among women with SLE we used data from the national Swedish patients and pharmacy registries to assemble a cohort of almost 5,000 women with SLE and a matched cohort of more than 28,000 women from the general Swedish population’, explained Hjalmar Wadström (student at the Karolinska Institute, Stockholm). The reference cohort was adjusted for age, sex, education level, healthcare utilisation, number of children, marital status, family history of cervical cancer and prior cervical screening. Data on cervical screening came from the Swedish National Cervical Screening Registry, which gathers data on all Pap smears.
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). SLE appeared to be a risk factor for cervical malignancies, even after adjusting for important risk determinants such as previous cervical screening. Results were similar for the risk of cervical dysplasia at different stages of severity, however, this comparison was less significant due to limited numbers of events and follow-up time.
‘Using the Prescribed drug register, we were able to define two SLE sub cohorts by use of hydroxychloroquine (n = 1783) and other immune-suppressive treatments with or without hydroxychloroquine (n = 1981).’ The rate of cervical neoplasia appeared to be much higher among the SLE women treated with systemic immune-suppressive compared to the SLE women treated with only antimalarials. The risk on cervical neoplasia in the “immune-supressive treated SLE women” was almost tripled compared to the reference group ( HR 2.72), whereas the risk in the “antimalarial treated SLE women” was less increased (HR 1.5).
‘Treatment may serve as a proxy for the severity of the disease’, Walström explained. ‘SLE is a heterogeneous disease with numerous phenotypes that span from mild local disease to life-threatening systemic disease. Patients treated with hydroxychloroquine tend to represent less severe cases, while more severe manifestations and organ involvement may necessitate potent cytotoxic immunosuppressive therapy.’
The clinical implication of these findings is that SLE patients, in particular if 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.
Author: Dr. Marten Dooper. All rights reserved by Medicom.
Source: ASCO Annual Meeting 2016