|The following article features coverage from the American Society of Clinical Oncology 2020 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
Undergoing secondary cytoreductive surgery resulted in an almost 6-month extension of progression-free survival compared with second-line chemotherapy in women with later recurrent ovarian cancer, according to results from SOC1/SGOG-OV2.
“Secondary cytoreduction is a practical, but controversial option for patients with platinum-sensitive recurrence,” said Rongyu Zang, MD, of Shanghai Gynecologic Oncology Group in China, who presented the data during the ASCO20 Virtual Scientific Program. “According to local practice secondary cytoreductive surgery has been standard of care for recurrent ovarian cancer and most patients prefer the surgery.”
To be eligible for the trial patients had to be in first relapse with a 6 month or longer platinum-free interval and predicted to be a potential R0. The study included 357 patients randomly assigned to surgery followed by chemotherapy or second-line chemotherapy alone. The coprimary endpoints were progression-free and overall survival.
According to Dr Zang, there was a 36.9% crossover rate from the no surgery arm to the surgery arm. The majority of patients on both arms received platinum-containing second-line therapy.
Complete resection rate was 76.7% overall. About 5% of patients had postoperative 30 day complications of grade 3 or worse.
With a median follow-up of 36.9 months, the median progression-free survival was 17.4 months in the surgery arm compared with 11.9 months in the chemotherapy alone arm (hazard ratio [HR}, 0.58; 95% CI, 0.45-0.74; P <.001). The researchers also conducted a subgroup analysis comparing R0, R1 status, and the chemotherapy alone arm. The median progression-free survival was 19.2 months for R0 patients, 12.6 for R1 patients, and 11.9 months for patients who did not receive surgery.
Patients who underwent surgery had a longer time to first subsequent therapy (18.1 months vs 13.6 months; HR, 0.59; 95% CI, 0.46-0.76).
Overall survival data is not yet mature.
Treatment-free survival (TFSa), defined as overall survival minus total treatment time, was a secondary endpoint. The median TFSa was unreached in the R0 subgroup of the surgery arm compared with 39.5 months in the no surgery arm.
“Interim analysis of treatment-free survival suggest secondary cytoreductive surgery might potentially contribute to long-term survival compared with chemotherapy alone,” Dr Zang concluded. “The evidence of overall survival and TFSa benefits from surgery need further follow-up.”
Read more of Cancer Therapy Advisor‘s coverage of the ASCO 2021 meeting by visiting the conference page.
Zang R, Zhu J, Shi T, et al. A randomized phase III trial of secondary cytoreductive surgery in later recurrent ovarian cancer: SOC1/SGOG-OV2. Presented at: ASCO20 Virtual Scientific Program. J Clin Oncol. 2020;38(suppl):abstr 6001.