The appearance of onconeural antibodies prior to an increase in CA125 levels can be a useful diagnostic tool to predict ovarian cancer recurrence, according to results of a study published in Cancer Biomarkers.
“Our results indicate that autoantibodies to HARS, R052, 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 (35U/ml),” wrote the study’s authors, led by Madhumita Chatterjee, PhD, Department of Oncology, Wayne State University School of Medicine, Detroit.
One of the unmet needs in ovarian cancer is a sensitive biomarker that can predict recurrence before the rise in CA125. This could allow patients to benefit from early therapeutic intervention that may prolong disease-free interval and improve overall survival.
Several studies have shown that tumor autoantibodies to tumor-associated antigens can be biomarkers for ovarian cancer diagnosis and recurrence before evidence of clinical symptoms. Paraneoplastic antigens can cause an immune response in cancer patients as antigens are expressed in the cells of the nervous system and the tumor. This can lead to neurological disorders called paraneoplastic syndromes, particularly dermatomyositis or polymyositis, which can precede ovarian cancer diagnosis.
Onconeural antibodies can occur without paraneoplastic symptoms, which could be helpful in diagnosing asymptomatic patients.
In this study, western blot immunoassays were performed to assess the immunoreactivity of six antigens (Ro52, CDR2, HARS, 4B7, 4H4, and 5H6) from 21 patients with recurrent ovarian cancer. Serial blood samples were collected at the time of surgery and every six months, for up to five years. Medical records were reviewed to determine CA125 levels, disease status, chemotherapy status, disease-free interval, and time to recurrence.
The researchers noted that a panel of three antigens—Ro52, CDR2, and 5H6—resulted in 90.5% sensitivity in predicting recurrence in the ovarian cancer patients. Although the addition of HARS into that panel did not improve the sensitivity, the authors felt it should be included because it showed high frequency and strong reactivity with the ovarian cancer patient serum samples and it is in the paraneoplastic antigen family.
“We propose that paraneoplastic autoantibodies occur in asymptomatic cancer patients and can be used for early detection of cancer,” the authors concluded.
They explained that early prediction of recurrence can give patients time to be treated and prevent progression.
To read more about this study, click here.