Abstract: Background and purpose: The optimal strategy of maintenance therapy following first-line chemotherapy for metastatic colorectal cancer (mCRC) patients is controversial. This pilot study was to evaluate the efficacy and safety of metronomic chemotherapy with capecitabine as maintenance therapy in metastatic colorectal cancer. Methods: This was a single-arm, singlecenter trial, and patients received maintenance therapy of capecitabine 500 mg, twice per day as metronomic chemotherapy following 18-24 weeks of induction chemotherapy with XELOX, mFOLFOX6 or FOLFIRI and achieved clinical benefit. The primary end point was progression-free survival (PFS). The secondary end points included overall survival (OS) and toxicity. Results: Between 16th Oct., 2014 and 31st Dec., 2017, 37 patients were enrolled in the study from Shanghai Jiao Tong University School of Medicine in China. The median follow-up time was 15 months (4.0-41.4 months). The primary end point PFS (metronomic maintenance therapy) was 5.6 months (1.7-38.5 months). The PFS (from the induction chemotherapy following maintenance therapy to the first progression) was 11.4 months（6.8-44.3 months）. The most common toxicities were neutropenia, nausea, vomiting and hand-foot syndrome. None of the patients had 3-4 grade toxicity. Conclusion: Metronomic chemotherapy with capecitabine as maintenance therapy can be considered an appropriate option following the induction chemotherapy in mCRC patients with acceptable toxicities.

Key words: Colorectal cancer, Capecitabine, Metronomic chemotherapy, Maintenance therapy