RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die.

PURPOSE: Phase II trial to study the effectiveness of capecitabine in treating older patients who have metastatic or recurrent colorectal cancer that cannot be surgically removed.

OBJECTIVES:

• Determine the feasibility of enrolling patients aged 70 and over with unresectable metastatic or recurrent colorectal cancer to a structured phase II study.
• Determine the anticancer efficacy of capecitabine, in terms of objective response rate (confirmed and unconfirmed, complete and partial responses) and 2-year survival, in these patients.
• Determine the toxicity and tolerability of this drug in these patients.
• Determine the feasibility of using standardized self-report measures of comorbidity, depression, and functional status of patients treated with this drug.
• Determine the clinical pharmacology of this drug in these patients.
• Determine whether patients under 60 years of age treated with this drug have clinical pharmacologic parameters similar to those reported in the literature.

OUTLINE: This is a multicenter study. Patients are stratified according to age (70 and over vs 18 to 59).

Patients receive oral capecitabine twice daily on days 1-14. Treatment repeats every 21 days for up to 18 courses in the absence of disease progression or unacceptable toxicity.

Patients are followed every 6 months for 3 years.

PROJECTED ACCRUAL: A total of 80 patients (60 patients aged 70 and over, 20 patients aged 18 to 59) will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed metastatic or recurrent colorectal cancer not amenable to surgical resection
• Measurable disease
• No known brain metastases by MRI or CT scan

PATIENT CHARACTERISTICS:

Age

• 70 and over OR
• 18 to 59

Performance status

• Zubrod 0-2

Life expectancy

• Not specified

Hematopoietic

• Absolute granulocyte count at least 1,000/mm^3
• Platelet count at least 100,000/mm^3

Hepatic

• Bilirubin no greater than 2 times upper limit of normal (ULN)
• SGOT (serum glutamate oxaloacetate transaminase) or SGPT (serum glutamate pyruvate transaminase) no greater than 2 times ULN

Renal

• Creatinine no greater than 2 times ULN
• Creatinine clearance greater than 50 mL/min

Other

• Not pregnant or nursing
• Fertile patients must use effective contraception
• HIV negative
• No known seizure disorder
• No other malignancy except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, adequately treated stage I or II cancer currently in complete remission, or any other cancer for which the patient has been disease free for 5 years

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• No prior chemotherapy for advanced cancer
• Prior adjuvant chemotherapy allowed provided recurrence occurred more than 1 year after the last treatment

Endocrine therapy

• Not specified

Radiotherapy

• Not specified

Surgery

• Not specified

Other

• At least 4 weeks since prior sorivudine or brivudine
• No concurrent sorivudine or brivudine