Paraneoplastic neurologic syndromes associated to nasopharyngeal carcinoma. Systematic review

Introduction and objectives: Paraneoplastic syndromes (PS) are a heterogeneous group of cancer-associated disorders caused by mechanisms other than metastases, metabolic, nutritional deficits, infections, or side effects of cancer treatment PS appear in 1-7.4 % of all cancer patients. Paraneoplastic neurological syndromes (PNS) associated with nasopharyngeal carcinoma (NC) are very rare. The objective of this review is to characterize the PNS associated with NC. Methods: A systematic review of cases of PNS associated to NC was carried out. The following databases were used for the search: Pubmed, Web of Science and Cochrane library. As search terms we used the keywords: “paraneoplastic syndrome” and “nasopharyngeal carcinoma”. Results: We included a total of 11 patients in the review. The PNS most frequently identified were cerebellar degeneration, limbic encephalitis, and opsoclonus-myoclonus syndrome. Auto antibodies against neural structures were identified in 5 cases (anti-Yo, anti-Hu and anti-RI). Regarding neurological prognosis, neurological symptoms did not improve or improved only partially after both primary tumor and steroids and immunoglobulins. Conclusions: Clinicians should consider the possibility of a paraneoplastic etiology when caring for patients with NC who present with subacute neurological symptoms. The prognosis of PNS after treatment is poor.