Paraneoplastic ataxic syndrome with anti-Yo antibodies in breast and ovarian cancer: A retrospective analysis.

Abstract

e18089 Background: Paraneoplastic cerebellar syndrome is a rare immunological reaction caused most commonly by Anti-Yo or Purkinje cell cytoplasmic antibody type 1(PCA1) to cerebellar degeneration protein 2(CDR2), found in the cerebellum and ectopically produced by tumor. Most cases are reported in women with HER2+ breast and ovarian cancers with underlying breast cancer patients having relatively better prognosis. Treatment initiation within one month of symptom onset has shown better outcomes. Methods: A retrospective analysis was conducted using a clinical database at a single institution and included 3 patients with a cancer diagnosis and ataxic symptoms diagnosed between 2016 and 2020. Data collection included age, gender, performance status, site of disease, pathology, diagnostic work up, treatment and overall survival (OS). Results: The study included 3 patients who presented with new onset ataxic symptoms with the median time of cancer diagnosis from onset of symptoms being 5 months (range 4-7). Median age was 62 years (range 59-83), all 3 patients were females and functionally independent before symptom onset. Out of 3 patients 2 had HER2+ breast cancer (one with IHC 3+ and one with equivocal IHC but 20 HER2 signals/nucleus) and the third had ovarian carcinoma. All 3 patients had stage IIIA disease as per AJCC 8th edition and presented with bilateral extremity weakness, ataxia, visual disturbances, vertigo and nausea/vomiting. Extensive neurological work up including MRI brain, CSF analysis, EEG were inconclusive except for high titres of anti- Yo antibodies in all patients. All patients were treated with cancer directed therapy and immunomodulation with plasma exchange, IVIG and steroids. The median OS being 22 months (range 12-28) with 2 patients with underlying breast cancer alive at the time of the analysis albeit there has been no neurological recovery, despite IVIG, steroids, and plasma exchange. Conclusions: The anti-Yo associated paraneoplastic ataxic syndrome most commonly associated with breast and pelvic tumors in women has a very poor prognosis despite anti-tumor and immunomodulating therapies, leaving most patients bed-ridden. The neurologic damage is irreparably incurred once the antibodies attack cerebellar cells. Thus, it is critical for clinicians to recognize the potential signs and symptoms as early as possible, so that treatment can be started, and long term symptoms are minimized. Further studies are needed to know the exact mechanism of this syndrome and provide evidence based treatment options.