Objective:

A systematic review and meta-analysis was conducted in order to characterize the temporal relationship between the diagnosis of neuromyelitis optica spectrum disorder (NMOSD) and breast cancer.

Background:

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory and demyelinating disorder affecting the optic nerve and spinal cord more frequently than other parts of the central nervous system (CNS). NMOSD was recognized as a unique condition with a chronic, relapsing course after the identification of IgG-class antibodies that bind to the water channel aquaporin-4 (AQP4-IgG) in serum from individuals with NMO. Typically this is an idiopathic autoimmune disorder, although there is increasing evidence behind the expression of AQP4 antibodies in the setting of an underlying tumor with NMOSD manifesting as a paraneoplastic syndrome.

Design/Methods:

This systematic review and meta-analysis was completed in accordance PRISMA guidelines. A literature search was conducted on PubMed/PubMed Central/MEDLINE, Scopus, and ScienceDirect databases. The review was registered with PROSPERO (Registration ID: CRD42022352109).

Results:

The search strategy yielded a total of  10 records, from which 16 cases were identified. Triple-negative breast cancer was the most prevalent form of breast cancer. Seven cases recorded the presence of longitudinally extensive transverse myelitis (LETM) involving the cervical and thoracic cord. Five cases identified lesions on magnetic resonance imaging (MRI) within the brainstem. And four cases described lesions within the cerebrum and/or cerebellum.  Intravenous methylprednisolone (IVMP) was the most common agent used in the acute management of NMOSD. On average the diagnosis of NMOSD occurred 1.4 months before that of breast cancer.

Conclusions:

NMOSD is a rare autoimmune condition that can occur in a paraneoplastic manner. The diagnosis of NMOSD precedes that of breast cancer with a mean time of 1.4 months. Triple-negative breast cancer is the most commonly identified subtype. Common MRI findings include LETM of the cervical and thoracic cord as well as brainstem lesions.