Conference Coverage

Secondary surgery extends OS in recurrent ovarian cancer


 

FROM ASCO 2020

In a phase 3 trial, combining cytoreductive surgery with chemotherapy significantly prolonged progression-free and overall survival among select patients with recurrent ovarian cancer who had a platinum-free interval of more than 6 months.

The trial, AGO DESKTOP III/ENGOT ov20, is the first prospective, randomized study showing an overall survival benefit for debulking surgery in patients with recurrent ovarian cancer.

Among 406 patients in first relapse, the median overall survival was 53.7 months for those randomized to cytoreductive surgery plus chemotherapy and 46 months for patients randomized to chemotherapy alone (P = .02).

“The overall survival benefit was highest and exclusively seen in the cohort with complete resection, indicating the importance of a thorough selection process of both the right patient and the right center,” said investigator Andreas du Bois, MD, of the Kliniken Essen-Mitte (Germany).

The median survival gain for patients with platinum-free intervals of more than 6 months who undergo complete resection is nearly 16 months “and is worth going for,” he added.

Dr. du Bois presented these results as part of the American Society of Clinical Oncology virtual scientific program (Abstract 6000).

In another trial, SOC-1, that was also presented in the virtual program, investigators reported a progression-free survival advantage of 5.5 months for patients with recurrent ovarian cancer who underwent debulking surgery, compared with those who did not (Abstract 6001).

Different trials, different results

The invited discussant for Dr. du Bois’s presentation was Robert L. Coleman, MD, chief scientific officer of the U.S. Oncology Network in The Woodlands, Tex., who was the principal investigator of the GOG-0213 trial (N Engl J Med. 2019;381:1929-39).

That trial did not show an overall survival advantage to secondary surgical cytoreduction followed by chemotherapy, compared with chemotherapy alone, among 485 women with platinum-sensitive recurrent ovarian cancer.

Referring to both AGO DESKTOP III and SOC-1, Dr. Coleman noted that, “while only DESKTOP III met its primary endpoint of improving overall survival, both demonstrated a benefit on PFS [progression-free survival].” Both trials also support a triage algorithm for selecting the approximately 75% of patients who are likely to benefit from secondary cytoreductive surgery.

“However, the price paid for being wrong is substantial, with no benefit seen in progression-free survival and possibly a detriment in overall survival. Because of these observations, both [presenters of SOC-1 and AGO DESKTOP III data] recommended that procedures be limited to select women having surgery performed at sites of excellence,” Dr. Coleman said.

Potential explanations for the differential findings of a secondary surgery benefit in DESKTOP III and SOC-1 versus GOG-0213 include the use of a selection algorithm in the former versus investigator selection based on clinical parameters and imaging in the latter.

In addition, “while platinum-based therapy was the rule in all trials, the use of concomitant and maintenance bevacizumab, a regimen found to improve overall survival in GOG-0213, was used in substantially higher numbers of patients in that trial relative to the two current trials,” Dr. Coleman said.

The GOG-0213 trial also demonstrated an advantage for adjuvant therapy with platinum-based chemotherapy and bevacizumab, which was given to 84% of patients in GOG-0213. That trial had a median overall survival for patients who did not undergo surgery of 65.7 months, compared with 46 months in AGO DESKTOP III and 53.9 months in SOC-1, Dr. Coleman said.

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