Inclusion Criteria:

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for at least 3 months
after study treatment

- No other previous or concurrent malignancy except nonmelanoma skin cancer, breast
cancer in situ, carcinoma in situ of the cervix, or previously treated nonpelvic
cancer that has been disease-free for > 5 years

- Patients with a history of breast cancer (without evidence of disease) who remain on
hormonal therapy for > 5 years are eligible

- No active bleeding not related to the primary rectal tumor within the past 6 months

- No active inflammatory bowel disease or other serious medical illness which might
limit the ability of the patient to receive protocol therapy

- No active gastroduodenal ulcer determined by endoscopy

- No serious or nonhealing wound, skin ulcer, or bone fracture

- No clinically significant peripheral sensory or motor neuropathy >= grade 2

- No nonmalignant systemic disease (e.g., cardiovascular, renal, or hepatic) that would
preclude study treatment including, but not limited to, any of the following:

- New York Heart Association class III or IV congestive heart failure

- Concurrent symptomatic arrhythmia

- No transient ischemic attack or cerebrovascular accident

- No arterial thromboembolic event, unstable angina, or myocardial infarction within
the past 12 months

- No significant peripheral vascular disease

- No psychiatric or addictive disorders or other conditions that, in the opinion of the
investigator, would preclude study requirements

- Patients with a history of hypertension must have blood pressure < 150/90 mm Hg AND
be on a stable regimen of antihypertensive therapy

- No significant traumatic injury within the past 28 days

- No known allergy to platinum compounds

- No other prior chemotherapy or pelvic radiotherapy except as neoadjuvant treatment
for current diagnosis of rectal cancer

- No prior invasive procedure, including either of the following:

- Major surgical procedure or open biopsy within the past 28 days

- Core biopsy or other minor procedure, except placement of a vascular access
device, within the past 7 days

- Concurrent participation on protocol NSABP-R-04 allowed

- Histologically confirmed adenocarcinoma of the rectum meeting 1 of the following
clinical (e.g., before neoadjuvant therapy) or pathologic staging criteria:

- T3, N+, M0

- T3, N0, M0

- T4, N0, M0

- Any T, N1-2, M0

- T4, N0-2, M0 disease must meet 1 of the following criteria:

- Clinically fixed tumor on rectal examination with tumor adherent to the pelvic
sidewall or sacrum

- Hydronephrosis on CT scan or IVP

- Ureteric or bladder invasion as documented by cystoscopy and cytology or biopsy

- Invasion into prostate

- Vaginal or uterine involvement

- Must have undergone complete tumor resection >= 28 days ago and able to begin
treatment by day 56

- No evidence of metastatic disease on the surgical/intraoperative examination

- Must have undergone concurrent neoadjuvant chemoradiotherapy*

- Must have undergone prior radiotherapy at 40-55.8 Gy** AND received 1 of the
following chemotherapy regimens:

- Continuous infusion of fluorouracil with or without oxaliplatin; fluorouracil
and leucovorin calcium

- Capecitabine with or without oxaliplatin; capecitabine with or without
oxaliplatin OR a continuous infusion of fluorouracil with or without oxaliplatin
received on protocol NSABP-R-04

- NOTE: *Neoadjuvant chemoradiotherapy received on protocol NSABP-R-04 allowed provided
it met these criteria

- NOTE: **Intensity-modulated radiotherapy allowed

- No evidence of metastatic disease confirmed by CT scan, MRI, or ultrasound of the
liver or chest CT scan or chest x-ray within the past 6 months

- No evidence of tumor outside of the pelvis, including liver metastases, peritoneal
seeding, or metastatic inguinal lymphadenopathy

- ECOG performance status 0-1

- Platelet count >= 100,000/mm^3

- Absolute granulocyte count >= 1,500/mm^3

- Bilirubin normal (unless chronic grade 1 bilirubin elevation due to Gilbert's disease
or similar syndrome due to slow conjugation of bilirubin)

- Alkaline phosphatase (AP) < 2.5 times upper limit of normal (ULN) and AST < 1.5 times
ULN

- Hepatitis B and C negative (for patients with AP > normal) unless previously
vaccinated

- Serum creatinine =< 1.5 times ULN

- Urine protein:creatinine (UPC) ratio < 1.0 OR urine protein < 1 g on 24-hour urine
collection

- INR =< 1.5

- INR > 1.5 allowed provided patient is on full-dose anticoagulants AND meets all of
the following criteria:

- In-range INR (i.e., between 2 and 3) on a stable dose of warfarin or low
molecular weight heparin

- No active bleeding or pathological condition that is associated with a high risk
of bleeding

- No concurrent major surgery