OBJECTIVES:

• Determine the maximum tolerated dose of oxaliplatin when combined with fluorouracil and external beam radiotherapy in patients with locally advanced adenocarcinoma of the rectum. (Phase I closed to accrual effective 03/27/2003).
• Determine the pathological response rate in patients treated with this preoperative regimen and surgical resection.
• Determine the late toxicity of this preoperative regimen in these patients.
• Determine, in a preliminary manner, the progression-free survival, local control, and overall survival in patients treated with this regimen.

OUTLINE: This is a dose-escalation, multicenter study of oxaliplatin.

Patients receive oxaliplatin IV over 1 hour on day 1, fluorouracil IV continuously on days 1-7, and radiotherapy on days 1-5. Treatment repeats weekly for a maximum of 6 courses in the absence of disease progression or unacceptable toxicity.

Cohorts of 3-6 patients receive escalating doses of oxaliplatin until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients experience dose-limiting toxicity. Once the MTD is determined, additional patients are treated at that dose level in the phase II portion of the study. (Phase I closed to accrual effective 03/27/2003).

Patients may undergo radical resection of rectal tumor within 4-6 weeks after completion of chemoradiotherapy.

Patients are followed every 3 months for 2 years and then every 6 months for 3 years.

PROJECTED ACCRUAL: A total of 9-24 patients will be accrued for phase I of the study (phase I closed to accrual effective 03/27/2003) and a total of 19 patients will be accrued for phase II of the study within 12-18 months.

DISEASE CHARACTERISTICS:

• Histologically proven previously untreated adenocarcinoma of the rectum that begins within 12 cm of the anal verge by sigmoidoscopy and/or colonoscopy

  • Locally advanced disease defined as any of the following:

    • Fixed or immovable tumor on physical exam
    • T4 disease with invasion of adjacent structures (e.g., pelvic sidewall, sacral pelvis, bladder, or prostate) by CT scan, rectal ultrasound, or MRI
    • T3 disease with invasion through the wall of the muscularis propria by transrectal ultrasound, CT scan, or MRI
• No distant metastatic disease

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Granulocyte count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin no greater than upper limit of normal (ULN)
• SGOT/SGPT no greater than 2.5 times ULN

Renal:

• Creatinine no greater than 1.5 mg/dL OR
• Creatinine clearance at least 60 mL/min

Other:

• No active second malignancy except nonmelanomatous skin cancer or carcinoma in situ of the cervix
• Patients are not considered to have an active second malignancy if they have completed therapy and are at less than 30% risk of relapse
• No prior or concurrent evidence of neuropathy
• No history of allergy to platinum compounds or antiemetics
• Not pregnant or nursing
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• No prior fluorouracil or platinum-based therapy for any malignancy
• No other concurrent chemotherapy

Endocrine therapy:

• Hormonal therapy allowed only for non-disease related conditions (e.g., insulin for diabetes) OR intermittently as an antiemetic (e.g., dexamethasone)

Radiotherapy:

• No prior pelvic irradiation

Surgery:

• Not specified

Other:

• No concurrent antiretroviral therapy (HAART) for HIV positive patients