Evaluation of the risk of cervical cancer in patients with Multiple Sclerosis treated with cytotoxic agents: A cohort study

Background: Since most patients with relapsing-remitting multiple sclerosis (RRMS) are women, the present study aimed to determine whether treatment of patients with MS by cytotoxic agents is associated with an increased risk of cervical dysplasia. Cancer screening is often neglected in the chronic diseases such as MS, so more attention in this field was needed. Decreasing morbidity and mortality due to cervical cancer is the most important goal of screening in female MS patients especially in child bearing age. Thus, it can be said that this is the first study which investigated this important issue. Methods: A total of 129 individuals participated in this cohort study. They were assigned into 3 groups including 43 patients with MS who were treated with cytotoxic drugs, 43 patients with MS on immunomodulators, and 43 normal healthy controls. Pap smears were performed following standard methods and the results obtained from the three groups were compared by statistical analysis. Demographic data, Expanded Disability Status Scale (EDSS), and Pap smear changes were analyzed by SPSS software. Results: The most commonly detected abnormality in all examined patients and healthy controls was inflammation. Five patients with MS who were treated with cytotoxic agents revealed benign cellular changes (BCC) in their Pap smear that were statistically significant in comparison with other groups (P = 0.03). Patients who took Mitoxantrone presented BCC more than other groups [Odds ratio (OR) = 9.44, 95% confidence interval (CI): 1.46-60.70]. There was no significant difference between mean duration of MS diagnosis (P = 0.12), mean duration of previous MS treatments (P = 0.25), and mean duration of current MS treatments (P = 0.21) in patients with BCC compared to normal healthy controls or inflammatory change. Conclusion: According to the results of present study, BCC is more frequently observed in patients with MS who were treated with cytotoxic agents with immunosuppressive effect. Since BCC is a ‘premalignant condition’, the authors suggest that mandatory annual Pap smear should be performed for patients with MS who are treated with cytotoxic agents irrespective of their age in order to detect early signs of malignancy.