Neuromyelitis optica spectrum disorder (NMOSD) associated with cancer: A systematic review

Abstract NMOSD is a disease shown to be highly associated with other diseases such as autoimmune diseases. There are a few reports of this association with cancer. So, this systematic review aimed to obtain a broad understanding on the cancers associated in NMOSD, including the source of common perceptions and assumptions in this regard. Methods in this study, we systematically searched the PubMed, EMBASE, SCOPUS, Web of Sciences, Proquest, Ovid, conference proceedings, and reference lists of the retrieved articles. All NMOSD cases who met the last version of criteria for its diagnosis, which reported the patients with a history of cancer before or after the onset of neurological symptoms without time limitations, and those who were referred as paraneoplastic neuromyelitis optica in articles published in English language (both the abstract & full text), were assessed. Finally, each study was critically appraised. Results Only 47 studies met the inclusion criteria, so they were assessed for qualitative synthesis. Considering the Euro network criteria, only 62 cases met this issue. The mean age of 52.21 ± 17.14 and 52.16 ± 17.21 was reported for cancer and NMOSD cases with female predominance (79%), respectively. The most reported organ in the cancer population were genitourinary (n = 14, 22.3%), breast (n = 12, 19.4%), lung (n = 12, 19.3%), gastrointestinal (n = 7, 11.3%), and hematology (n = 6, 9.7%), respectively. Conclusion In older NMOSD patients without suspicious symptoms, we recommend paying more attention to lung, breast and genitourinary (especially ovary) cancer screening. Also, cancer resection had positive effect on the attack numbers after receiving treatment and NMOSD recovery.