The Prevalence of Cancer in Patients with Multiple Sclerosis (MS) who were Under Treatment with Natalizumab (Tysabri): A Systematic Review and Meta-Analysis

Background: To determine the pooled prevalence of cancer in subjects with multiple sclerosis (MS) who received Natalizumab. Methods: Two researchers systematically searched PubMed, Scopus, EMBASE, Web of Science, google scholar, and gray literature including references of the included studies. The search strategy which was used in PubMed was ("Disseminated Sclerosis" OR "multiple sclerosis" OR "MS" OR "Acute Fulminating") AND ("Cancer" OR "Neoplasia*" OR "Neoplasm*" OR "Tumor*" OR "Malignancy" OR "Benign Neoplasm" OR "Malignant neoplasm") AND ("Tysabri" OR "Antegren" OR "natalizumab" OR "Modifying Therapy"). Results: We found 1,993 articles by literature search, and 1,573 studies remained after removing duplicate studies. For metaanalysis, we used the extracted data of eight studies. The pooled prevalence of cancer in patients who received Natalizumab was 2% (95%CI: 1-3%; I-2: 99.4%, P < 0.001). The pooled prevalence of basal cell carcinoma in patients with cancer was 12% (95%CI: 5-20%; I-2:50.3%, P = 0.13). Conclusions: The main finding of this systematic review and metaanalysis is that the pooled prevalence of cancer in subjects who suffer from MS and received natalizumab was 2%.