Oral Metronomic Therapy: An Effective Palliative Treatment Option for Epithelial Ovarian Cancer

Introduction The majority of the patients with advanced-stage epithelial ovarian cancer relapse within three years of standard first-line treatment. Access to novel therapies like poly ADP-ribose polymerase (PARP) inhibitors and antiangiogenic agents is limited in low- and middle-income countries. Oral metronomic therapy (OMT) may be an effective alternative treatment option in resource-limited settings. Materials and methods A retrospective study was conducted among patients with epithelial ovarian cancer who received OMT. OMT consisted of cyclophosphamide 50mg per day and tamoxifen 40mg per day which was administered continuously until unacceptable toxicity or progression was reached. OMT was given to patients with relapsed ovarian cancer and to those newly diagnosed ovarian cancer patients who were unfit for cytoreductive surgery and/or standard first-line intravenous platinum-based chemotherapy. All patients who received OMT at our center between 01-01-2017 and 31-12-2021 were included for analysis. Relevant details, as needed for the study, were collected from medical records. SPSS version 24 (IBM Corp., Armonk, NY) was used for statistical analysis. Results A total of 61 patients received OMT during the study period. The median age at diagnosis of ovarian cancer was 59 years. The median age at the start of OMT was 61 years. The majority (n= 37, 60.7%) had high-grade serous carcinoma subtype. A total of 52 patients received OMT in the relapse setting while nine received it in the first-line setting. Among relapsed ovarian cancer patients, 13 patients (21.3%) experienced platinum-sensitive relapse, 16 patients (26.2%) experienced partial platinum-sensitive relapse, and 23 patients (37.7%) experienced platinum-resistant disease. The mean duration of treatment with OMT was 7.8 months. The clinical benefit rate was 59% and the overall response rate was 22.9%. Ca-125 response was seen in 40.4% of patients. The median PFS for the overall group was 6.7 months. Median PFS was longer in patients with Ca-125 response and platinum-sensitive relapse. Only five patients (8.1%) had significant toxicity. Conclusion OMT is a safe and effective palliative treatment option for epithelial ovarian cancer, worth consideration in low- and middle-income countries.