Colorectal cancer patients with metastases (mCRC) at response under first-line chemotherapy are candidates for an convenient maintenance treatment.

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.Therefore, our study is designed to investigate that colorectal cancer patients with metastases (mCRC) at response under first-line chemotherapy are candidates for an convenient maintenance treatment.

Inclusion Criteria:

- Age between 18 and 75 years Eastern Cooperative Oncology Group performance status (ECOG PS) 0-1 histologically confirmed colorectal cancer with inoperable locally advanced or recurrent and/or metastatic disease Life expectancy of at least 3 months Intact organ function, including complete blood counts (CBC) showing normal values or any toxicity limited to grade 1 and blood chemistry (SMA) showing liver and renal functions < 1.5 upper normal limit (UNL).

Patients who achieved objective response or stable disease after 16-24 weeks first line chemotherapy Signed informed consent

Exclusion Criteria:

- Known hypersensitivity to capecitabine Concurrent any other cancer (except BCC or squamous cell carcinoma of skin). Inability to adhere to monthly visits to the oncology unit for evaluation. Presence of brain metastases. Previous radiotherapy to the only site of measurable disease. Evidence of severe or uncontrolled systemic disease No previous chemotherapy for metastatic disease Positive serum pregnancy test in women of childbearing potential unresolved bowel obstruction or malabsorption syndrome