Add-on metformin of little benefit in advanced stage ovarian cancer

Using metformin in addition to first-line platinum/taxane-based chemotherapy does not appear to produce survival gains in patients with newly diagnosed advanced stage ovarian cancer, according to a study.

A total of 108 patients with pathologically confirmed advanced-stage ovarian cancer who were scheduled to undergo primary debulking or neoadjuvant platinum-based chemotherapy followed by surgery participated in the study.

The patients were randomly assigned to receive platinum/taxane-based chemotherapy with metformin 850 mg orally twice per day or placebo, followed by maintenance therapy with either metformin (n=54) or placebo (n=54) for 2 years from the date of randomization.

Of the patients, 71 (66 percent) received neoadjuvant therapy, 33 (31 percent) underwent primary debulking surgery, and 93 (88 percent) had tumours of high-grade serous histology.

Compared with placebo, add-on metformin was not associated with significant improvements in the primary endpoint of progression-free survival (PFS) (adjusted hazard ratio [HR], 0.87, 95 percent confidence interval [CI], 0.56–1.36; p=0.31). Median PFS was 15.4 months (95 percent CI, 11.2–23.5) with metformin vs 14.3 months (95 percent CI, 11.6–18.0) with placebo.

Likewise, overall survival (OS) did not significantly differ between the metformin and placebo group (adjusted HR, 1.49, 95 percent CI, 0.86–2.59; p=0.21). The median OS was 40.7 months (95 percent CI, 28.0–48.2) with metformin vs 43.8 months (95 percent CI, 35.3–57.2) with placebo.

In terms of safety, add-on metformin was well tolerated, with no significant between-group differences in toxicity.