Cancer Antigen Expression Associated With Prognosis in Ovarian Cancer

Patients with ovarian cancer who express the NY-ESO-1 testis antigen have significantly shorter overall survival than those who do not, according to a new study. These patients may benefit from immunotherapy agents.

“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,” said J. Brian Szender, MD, MPH, of Roswell Park Cancer Institute in Buffalo, New York, in a press release. Cancer testis antigens, of which there are more than 100 identified, have high expression levels in adult male germ cells, low expression in other tissues, and variable expression in cancer cells. Previous work has suggested NY-ESO-1 in particular may be important in ovarian cancer.

The new study included 1,002 patients with ovarian cancer, and NY-ESO-1 expression was assessed with immunohistochemistry (IHC), reverse-transcription polymerase chain reaction (PCR), and quantitative PCR. The results were published online ahead of print in Gynecologic Oncology.

Among the full cohort, 40.7% of tumors were considered NY-ESO-1-positive by either IHC or the PCR methods. Those with positive tumors were 3 years older (P < .001), and were more likely to be advanced in stage, have a higher histologic grade, and be of serous histology.

NY-ESO-1-positive tumors were associated with shorter progression-free survival, at 22.2 months vs 25 months for negative tumors (P  = .009). The same was true for overall survival, at 42.9 months vs 50 months (P = .002). An analysis that adjusted for stage, grade, and residual disease yielded a difference in overall survival that was still significant (P = .013), but progression-free survival was no longer significantly difference (P = .088).

A subset analysis showed extended survival among NY-ESO-1-positive patients who enrolled in cancer vaccine trials, compared with those who did not.

“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,” said senior study author Kunle Odunsi, MD, PhD, also of Roswell Park Cancer Institute. “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.”