The effect of metformin on the early outcome of patients undergoing ovarian cancer chemotherapy

Abstract

Ovarian cancer is one of the most common malignancies among gynecological cancers and is the 7th most common cancer among women in the United States. The prognosis of ovarian tumors is highly dependent on the stage of disease and treatment. This study aimed to evaluate the effect of metformin on early outcomes in patients undergoing adjuvant chemotherapy for ovarian cancer after cytoreductive surgery. Materials and Methods: In this clinical trial, women over 18 years old who had epithelial ovarian cancer and CA-125 over 35 underwent laparotomy and surgical staging with the FIGO system. The diagnosis of epithelial ovarian cancer was confirmed by pathology, and they were candidates for adjuvant chemotherapy included in the study. Patients were divided in two groups; intervention (n = 26) and control (n = 24). Patients in both intervention and control groups received carboplatin-paclitaxel periodically for 3-9 cycles depending on the cancer stage (every 21 days). In addition to the above drugs, metformin was administered to patients in the intervention group, starting with a daily dose of 500 mg and increasing to 1,500 mg daily in three divided doses (500 mg every 8 hours) over a week. Results: The mean age of all women was 48.48±13.70 years. The mean gravid and parity of the patients were 2.55±1.54 and 2.28±1.39, respectively. Approximately half of the patients had a regular menstrual cycle (52%). 34% of patients had a history of OCP use, and most of them had a history of breastfeeding (84%). Only three patients had a previous history of cancer. Seven patients also had a history of underlying hypertension. The most common ovarian tumors were serous (92%), and patients were in Stage II and Stage III (88%), out of which 62 had high-grade tumors. The most common pre-surgery CT-Scan finding was ovarian or abdominal mass. Tumor refractory was 19 (38%) based on serum CA-125 level. The recurrence rate was 30.8% in the intervention group and 45.8% in the control group, statistically significant (p=0.003). The rate of disease-free survival was higher in the intervention group (61.5% vs. 45.8%). The mean of CA-125 in patients in the intervention and control groups at quarterly follow-up was 24.92 U/mL and 148.53 U/mL, respectively.