57 Impact of metformin on survival outcome in advanced cervical cancer: a Korean and japanese gynecologic oncology group (KGOG & JGOG) collaboration study

Introduction/Background

More than 80% of cervical cancer incidence and mortality are concentrated in low- and middle-income countries (LMICs). Thus, most are diagnosed with locally advanced disease status, and the initial radiotherapy and concurrent chemo-radiation are primarily considered. New agents showed significant survival improvement in recent clinical trials. Paradoxically, same as the vaccines and screening programs, there is little chance in LMICs. Metformin, with established anticancer effects in preclinical experiments and its affordability and safety, theoretically can be an alternate substitute in LMICs. The survival benefit of metformin use in advanced cervical cancer patients was studied.

Methodology

The eligible patients in 66 Korean and Japanese institutions from 2013 to 2015 were identified and analyzed. These patients were categorized into metformin and none or non-metformin groups. Recurrence-free, overall, and cancer-specific survivals (RFS, OS, and CSS) were analyzed. The multivariate model included variables with P-values < 0.1 in the results of the univariate model. In addition, a backward variable selection method with an elimination criterion of 0.05 to the multivariate model.

Results

Among the eligible 197 study patients, 70 (35.5%) were metformin users. 105 (53.3%) were International Federation of Gynecology and Obstetrics (FIGO) stage II and 92 (46.7%) were stage III, and IV. 162 (82.2%) were squamous cell carcinoma. There were 88 (44.7%) recurrences and 75 (38.1%) deaths. Among the deaths, 59 (78.7%) patients died because of the disease itself. In Cox proportional hazard analysis, metformin use was not associated with improved RFS (hazard ratio [HR], 95% confidence interval [CI], 0.686 [0.440–1.071]; P = 0.0970), OS (HR, 95% CI, 0.965 [0.574–1.623]; P = 0.8935), and CSS (HR, 95% CI, 0.635 [0.337–1.194]; P = 0.1587). A higher dose of metformin medication or lower initial hemoglobin A1C at diagnosis were not associated with improved survival outcomes.

Conclusion

Metformin use did not improve the survival outcomes in advanced cervical cancer patients.

Disclosures

No COI.