Short-course Preoperative Chemoradiotherapy Followed by Delayed Operation for Locally Advanced Rectal Cancer

Radiotherapy using tomotherapy is delivered in 5 Gy daily fractions for a total of 25 Gy in 5 fractions.

A bolus injection of 5-fluorouracil (400 mg/m2/d)and leucovorin (20 mg/m2/d) is delivered concurrently on day 1-5 during radiotherapy.

Total mesorectal excision is performed within 6±2 weeks. The pathological response of downstaing is the study endpoint.

Inclusion criteria

• Pathologically proven diagnosis of adenocarcinoma of the rectum (located within 8㎝ above the anal verge)
• Locally advanced and curatively resectable tumor(cT3-4 classification) evaluated with magnetic resonance imaging(MRI) with or without transrectal ultrasonography(TRUS)
• Age ≥18
• Performance Status(ECOG) 0-2
• CBC/differential obtained within 14 days prior to registration on study, with adequate bone marrow function defined as follows: Hemoglobin ≥ 10 g/dl, Absolute neutrophil count(ANC) ≥ 1,500 cells/㎣, Platelets ≥ 100,000cells/㎣
• Metabolic panel within 14 days prior to registration on study, with adequate liver and renal function defined as follows: AST and ALT ≤ 60 IU/L, bilirubin ≤ 1.5 mg/dl, serum creatinine ≤ 1.5 mg/dl
• Patient must provide study-specific informed consent prior to study entry

Exclusion criteria

• Any evidence of distant metastases(M1)
• Prior invasive malignancy (except non-melanomatous skin cancer and uterine cervical cancer in situ) unless disease free to a minimum of 3 years
• Hereditary rectal cancer; Familial adenomatous polyposis(FAP), Hereditary non-polyposis colorectal cancer(HNPCC), etc.
• Impending obstruction (except the case with colostomy)
• Severe, active comorbidity inappropriate to CRT as follows; Acute bacterial or fungal infection, transmural myocardial infarction within the last 6 months, unstable arrhythmia, angina and/or congestive heart failure, unstable arrhythmia
• Pregnancy or women of childbearing potential who are sexually active and not willing/able to use medically acceptable forms of contraception
• Unresected synchronous colon carcinoma
• Clinically unresectable rectal cancer