Utility of paraneoplastic antigens as biomarkers for surveillance and prediction of recurrence in ovarian cancer

BACKGROUND: Ovarian cancer is frequently diagnosed at an advanced stage and 70% of patients experience recurrence months to years from initial diagnosis. The expression of paraneoplastic antigens can result in the occurrence of onconeural autoantibodies in ovarian cancer that may be associated with neurological disorders that are clinically manifested in patients before diagnosis of ovarian cancer. These paraneoplastic antigens can serve as excellent biomarkers not only for early detection but also for monitoring ovarian cancer recurrence. OBJECTIVE: To assess the immunoreactivity of our previous 3 biomarkers along with 3 paraneoplastic antigens, HARS, Ro52 and CDR2 for the evaluation of their sensitivity in predicting recurrence before the clinical relapse of the ovarian cancer. METHODS: Western blot immunoassays were performed to assess the immunoreactivity of 6 antigens with 21 recurrent ovarian cancer patients. RESULTS: The results indicated that antibodies to HARS, Ro52, CDR2 and 5H6 antigens predicted ovarian cancer recurrence 5.03 months before the clinical or symptomatic relapse in 21 ovarian cancer patients with a sensitivity of 90.5% when CA125 levels were below the standard cutoff (35 U/ml). CONCLUSION: Our study suggests that appearance of onconeural antibodies prior to the rise in CA125 during post treatment surveillance can be a useful diagnostic to predict ovarian cancer recurrence.