Maintenance Metronomic Chemotherapy in Treatment of Metastatic Colorectal Cancer

Abstract

Treatment of metastatic colorectal cancer (mCRC) is one of the most challenging and important problems in oncology at present moment. This article presents the interim results of treatment of patients with colorectal cancer, who were enrolled from 2016 till 2019 (n=60) with the use of maintenance metronomic chemotherapy. Metronomic regimen consisted of oral capecitabine 500 mg 3 times a day and oral cyclophosphane 50 mg daily. The control arm consisted of mCRC patients who received the same induction chemotherapy without maintenance from 2011 till 2015 (n=70). Median follow-up time was 18.5 months. Median progression-free survival (PFS) was 9.0 and 7.4 months in the maintenance and control arms respectively. Median overall survival (OS), counted from the beginning of induction chemotherapy, is currently 22.9 months in the maintenance arm, and 14.7 months in control. High expression levels of genes, encoding enzymes TS (thymidylate synthetase), DPD (dihydropyrimidine dehydrogenase) and receptor VEGFR1, low expression level of gene TP (thymidylate phosphorylase), as well as low levels of tumor markers CEA and СА 19-9 are the prognostic factors of sensitivity to metronomic chemotherapy given to colorectal cancer patients. Based on these data, we identified a group of patients who are recommended to use this method of treatment.