Maintenance Treatment With Capecitabine in Colorectal Cancer Patients

Colorectal cancer is one of the most common malignant tumors, with the morbidity of approximate 100 million cases per year. About 40% of patients present with metastatic (stage IV) colorectal cancer at the time of diagnosis, and about 25% of patients with local lesion will ultimately develop metastatic disease.
5-Fluorouracil（5-FU) was the only efficacious treatment for metastatic colorectal cancer before the nineties of the 20th century, and afterwards as the discovery of chemotherapy such as oxaliplatin, irinotecan and capecitabine, response rate as well as survival had been improved greatly.
Most of advanced colorectal cancer will progress after first-line treatment; therefore, seeking an efficient and low toxic maintaining regimen to prolong PFS becomes a hot topic in oncologic field. Some clinical researches demonstrated that maintaining treatment followed first-line treating advanced NSCLC could extend PFS and OS. In metastatic colorectal cancer, patients receiving 5-FU/leucovorin(LV) maintaining therapy experienced significantly longer PFS than that stopped chemotherapy after six cycles of FOLFOX4 in OPTIMOX2 study. One phase II study shown that median PFS was 13.9 months, and median OS was 31 months in 30 patients receiving first-line treatment of six- month FOLFOX4 followed by UFT as maintaining treatment . A non-randomized small sample study conducted in department of medical oncology of Sun Yat-Sen University Cancer Center indicated that patients receiving first-line treatment of XELOX followed by capecitabine as maintaining therapy has significantly prolonged median TTP, comparing with the non-maintaining treatment patients,(14months vs. 9 month, respectively).
Above all, so far, there is no data to demonstrate that regular 4-6 month chemotherapy followed by maintaining treatment could prolong TTP and OS for advanced colorectal cancer. Capecitabine is effective for colorectal cancer, and was approved as palliative treatment for advanced colorectal cancer and adjuvant chemotherapy; in addition, with its relative less frequency of side effects and convenient oral administration, capecitabine as maintaining regimen could be prone to be accepted by patients. Therefore, our study is designed to investigate that capecitabine as maintaining treatment after first-line palliative chemotherapy could improve TTP and OS for patients with advanced colorectal cancer through a perspective randomized clinical study.