Secondary cytoreduction before chemotherapy can significantly prolong progression-free survival (PFS), compared with chemotherapy alone, in patients with platinum-sensitive, relapsed ovarian cancer, according to a study published in The Lancet Oncology.

The randomized, controlled, phase 3 trial ( Identifier: NCT01611766) was conducted at 4 sites in China. Eligible patients were aged 18 years and older with platinum-sensitive, relapsed epithelial ovarian cancer, which was defined as a platinum-free interval of at least 6 months from the end of first-line platinum-based chemotherapy to disease progression.

A total of 357 patients were included and randomized to receive either secondary cytoreduction followed by chemotherapy (n = 182; median age, 55.2 years) or chemotherapy alone (n = 175; median age, 53.1 years) from July 19, 2012, to June 3, 2019.

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Recommended chemotherapy for both groups was a platinum-based regimen, with six 3-weekly cycles of intravenous paclitaxel (175 mg/m²) or docetaxel (75 mg/m²) combined with intravenous carboplatin. The no-surgery group received chemotherapy within 4 weeks after randomization.

A total of 11 participants (6%) in the no-surgery group had secondary cytoreduction during second-line therapy, and 48 of 130 participants (37%) who had disease progression crossed over and had cytoreductive surgery.

At a median follow-up of 36.0 months, 243 patients had disease progression — 113 in the surgery group and 130 in the no-surgery group. In all, 111 patients died — 55 in the surgery group and 56 in the no-surgery group.

In the final PFS analysis, the median PFS was 17.4 months in the surgery group and 11.9 months in the no-surgery group (hazard ratio [HR], 0.58, 95% CI, 0.45-0.74; P <.0001).

At the interim analysis, the median overall survival was 58.1 months in the surgery group and 53.9 months in the no-surgery group (HR, 0.82, 95% CI, 0.57-1.19).

At 30 days, 5% of patients in the surgery group had grade 3/4 surgical morbidity. The median length of hospital stay was 15.5 days.

The most frequent grade 3/4 adverse events (AEs) occurring during chemotherapy (in the surgery and no-surgery groups, respectively) were neutropenia (17% vs 12%), leukopenia (8% vs 5%), and anemia (6% for both).  

All 4 serious AEs occurred in the surgery group — 3 cases of neutropenia and 1 case of increased blood creatinine. No patients died within 60 days of assigned treatment, and no treatment-related deaths occurred in either group.

The investigators noted that the major limitation of this trial was the 37% crossover from the no-surgery group to surgery at subsequent relapses.

“All patients should be counseled about the options of secondary cytoreduction in specialized centers with high volumes of ovarian cancer surgery,” the investigators advised.

Disclosures: This research was supported by the Zhongshan Development Program. The authors declared no competing interests.


Shi T, Zhu J, Feng Y, et al. Secondary cytoreduction followed by chemotherapy versus chemotherapy alone in platinum-sensitive relapsed ovarian cancer (SOC-1): a multicentre, open-label, randomised, phase 3 trial. Lancet Oncol. 2021;22(4):439-449. doi:10.1016/S1470-2045(21)00006-1