A retrospective, case-control study showed that optimal cytoreductive surgery is an independent predictor of overall survival, even when controlling for response to chemotherapy.
The findings were presented at the Society of Gynecologic Oncology’s Virtual Annual Meeting on Women’s Cancer (Abstract 10243).
Response to platinum-based chemotherapy is the strongest predictor of overall survival in advanced ovarian cancer, noted Nicholas Cardillo, MD, a gynecologic oncology fellow at the University of Iowa, Iowa City, who presented the findings at the meeting.
In recent years, a poor response to chemotherapy has sometimes been used as justification to forgo cytoreduction, Dr. Cardillo added.
He and his colleagues looked into this issue because evidence to support the practice is lacking. With their study, the researchers found that optimal cytoreduction – removing all disease of 1 cm or more – improved survival regardless of the response to chemotherapy.
“My advice right now is that debulking surgery should still be attempted in all patients with ovarian cancer because, as far as we know right now, optimal cytoreduction will improve survival,” Dr. Cardillo said in an interview. “Basically, this study argues to keep the status quo, which is to perform surgery.”
The status quo might change with future research, Dr. Cardillo acknowledged, “but as of right now, we have no evidence to support not pursuing cytoreduction in these patients.”
Study details and results
The researchers analyzed data on 234 patients who responded to platinum-based chemotherapy – meaning they had no evidence of disease for at least 6 months afterward – and 98 patients who did not respond – meaning they progressed during therapy, had stable disease, did not respond completely, or had a progression-free survival duration of less than 6 months. Subjects had stage III or IV high-grade serous ovarian cancer.
About three-quarters of responders and 57% of nonresponders had optimal surgery. Only seven patients in each group had fewer than six cycles of chemotherapy.
The mean age was 59 years in the responder group and 62 years among nonresponders. Stage IV disease, including upper-abdominal and chest involvement, was more common in the nonresponder group.
The median overall survival was 44.8 months in the responder group and 18.1 months among nonresponders (P < .001). The median overall survival was 34.2 months among patients who underwent optimal surgery and 24.8 months among those who did not (P < .001).
Predictors of survival
A multivariate analysis showed that response to chemotherapy had the greatest effect on survival, with a hazard ratio of 0.27 (P < .001).
“The second most significant predictor of overall survival was receipt of neoadjuvant chemotherapy [HR, 2.84; P < .001], which is intuitive as that is typically a marker for worse disease burden,” Dr. Cardillo said.
“But most importantly for our question is that optimal surgery is an independent significant factor in overall survival, even when controlling for other significant risk factors, including whether or not a patient responds to chemotherapy. The hazard ratio is 0.73 [P = .023], indicating a 25%-30% improvement in overall survival,” he added.
Based on these results, “surgical debulking should still be considered a component of the treatment algorithm in ovarian cancer patients who have a poor response to chemotherapy, if an optimal surgery is deemed feasible,” Dr. Cardillo concluded.
There was no funding for this study, and the investigators had no relevant disclosures.