Study identifies expression of tumor antigen as marker for aggressive ovarian cancer

Patients who expressed the tumor antigen NY-ESO-1 had more aggressive cancers and were more likely to die early from their disease, according to a large study conducted by Roswell Park Cancer Institute researchers and published online ahead of print in the journal Gynecologic Oncology.

"This is the largest study of NY-ESO-1 expression in ovarian cancer patients, and the first time that expression of this antigen has been identified as a marker for more aggressive disease," says the study's first author, J. Brian Szender, MD, MPH, Fellow in the Department of Gynecologic Oncology at Roswell Park.

NY-ESO-1 is one of the few tumor antigens that have restricted expression in normal tissue but become aberrantly expressed in epithelial ovarian cancers and other solid tumors. From January 2002 to June 2016, more than 1,000 patients with ovarian cancer were tested at Roswell Park for NY-ESO-1 expression. Their median age at diagnosis was 61 years, and most patients were diagnosed with stage IIIC or stage IV disease. The research team found that NY-ESO-1 expression was associated with shorter duration of both progression-free survival (22 months versus 25 months) and overall survival (42 months versus 50 months).

During the study period, the Roswell Park scientists enrolled a total of 68 ovarian cancer patients with NY-ESO-1-positive tumors to cancer vaccine trials targeting NY-ESO-1. The researchers found that patients with NY-ESO-1-expressing tumors who were enrolled in cancer vaccine trials had significantly improved overall survival compared to patients with NY-ESO-1 who did not participate in the cancer vaccine trials, and with patients without NY-ESO-1-expressing tumors.

"We suggest that NY-ESO-1 be a high-priority target for future immunotherapy studies, given the high prevalence of NY-ESO-1 expression in ovarian cancer and the association of this tumor antigen with adverse clinical outcomes," says Kunle Odunsi, MD, PhD, FRCOG, Deputy Director of Roswell Park and Chair of the Department of Gynecologic Oncology. "It is possible that in the coming years, NY-ESO-1 expression in ovarian cancer will be as important to the treating oncologist as HER2 expression is for the treatment of breast cancer."​