In the Netherlands approximately 2300 new patients are diagnosed with rectal cancer each year. Standard treatment for patients with a T2 or T3 rectal cancer consists of preoperative short course of radiotherapy followed by surgery. In advanced cases long course of radiotherapy combined with chemotherapy is used instead of a short cause. In some of these advanced cases a complete remission is observed after a long course of radio-/chemotherapy. Patients who respond well to neo-adjuvant treatment carry a better prognosis.

Objective of this research is to evaluate whether neo-adjuvant chemo-/radiotherapy in small non-advanced rectal cancers can be used to obtain a complete or near complete remission. In these patients could a complete resection of the rectum as an organ be avoided by treating them with a local excision with the TEM-technique (Transanal Endoscopic Microsurgery) of the scar. The advantage for these patients is, that they do not need major abdominal surgery and in a substantial number of these patients the rectum can be preserved with a better function of continence.

Inclusion Criteria:

• Patients (aged >18 years) with histological proven adenocarcinoma of the distal part of the rectum (below 10 cm) without signs of distant metastases.
• T1-3 tumour without lymph nodes > 5 mm at CT, MRI and endoanal ultrasound.
• ANC > 1.5 x 109/l.
• Thrombocytes > 100 x 109/l.
• Creatinin clearance >50ml/min (according to the Cockcroft-Gault formula)
• Total serum bilirubin < 24 mol/l or below <1.5 times the upper limit of the normal.
• ASAT,ALAT: up to 5 times the upper limit.
• Colonoscopy, colonography or virtual colonoscopy should exclude synchronous colorectal lesions in other parts of the colon.
• ECOG performance score 0-2.
• Fertile women should have adequate birth control during treatment.
• Mental/physical/geographical ability to undergo treatment and follow-up.
• Written informed consent (Dutch language).

Exclusion Criteria:

• Patients with Grade 1-2 T1 tumors (can be treated with TEM surgery without chemoradiation therapy)
• Patients with circular rectal tumor or tumors who are by other means unacceptable for TEM surgery (e.g. intra anal tumors).
• Patients with faecal incontinence prior to the diagnosis of rectal cancer (complaints of soiling due to the tumor will not be an exclusion criterium).
• Severe uncontrollable medical or neurological disease.
• Patients with secondary prognosis determining malignancies.
• Patients who have been treated with radiotherapy on the pelvis.
• Use of Vitamin K antagonists.
• Fenytoine and Allopurinol use.
• Known DPD deficiency
• Uncontrolled active infection, compromised immune status, psychosis, or CNS disease.
• Pregnant or lactating women.
• Clinically significant (i.e. active) cardiovascular disease for example cerebrovascular accidents (≤ 6 months prior to randomisation), myocardial infarction (≤ 6 months prior to randomisation), unstable angina, New York Heart Association (NYHA) grade II or greater congestive heart failure, serious cardiac arrhythmia requiring medication.
• Evidence of other disease, metabolic dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that contraindicates use of Capecitabine or patients at high risk for treatment complications. History or evidence upon physical examination of CNS disease unless adequately treated (e.g., seizure not controlled with standard medical therapy).