RATIONALE: It is not yet known whether the supplement creatine is effective in increasing weight and improving appetite and quality of life in patients who have cancer.

PURPOSE: This randomized phase III trial is studying how well creatine works in increasing weight and improving appetite and quality of life in patients with weight loss caused by cancer.

OBJECTIVES:

• Compare weight-gain effects of creatine vs placebo in patients with cancer-associated weight loss and/or anorexia.
• Determine the effect of these regimens on quality of life in these patients.
• Compare the toxic effects of these regimens in these patients.
• Compare survival rates of patients treated with these regimens.

OUTLINE: This is a randomized, double-blind, placebo-controlled study. Patients are stratified according to primary cancer type (lung vs gastrointestinal vs other), weight loss severity (< 10 lbs vs ≥10 lbs), age (< 50 years vs ≥ 50 years), planned concurrent chemotherapy (yes vs no), gender, and prognosis. Patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients receive oral creatine daily.
• Arm II: Patients receive oral placebo daily. In both arms, treatment continues in the absence of unacceptable toxicity as long as treatment is considered beneficial.

Patients are followed every 6 months for up to 5 years.

PROJECTED ACCRUAL: A total of 300 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed cancer other than primary brain cancer

  • Considered incurable with available therapies

• History of weight loss ≥ 5 lbs in 2 months or fewer AND/OR estimated intake of < 20 cal/kg daily

• Determination by attending physician that weight gain would benefit patient

• Perception by patient that weight loss is a problem

• No symptomatic or untreated brain metastases

• No clinical evidence of ascites

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• At least 3 months

Renal

• Creatinine normal

Cardiovascular

• No poorly controlled congestive heart failure
• No poorly controlled hypertension

Other

• Able to reliably receive oral medication
• Must be alert and mentally competent
• No known obstruction of the alimentary tract, malabsorption, or intractable vomiting
• No diabetes that is controlled by insulin
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Chemotherapy

• Concurrent chemotherapy allowed

Endocrine therapy

• No other concurrent adrenal corticosteroids, androgens, or progestational agents within 30 days after study entry
• Concurrent short-term dexamethasone for chemotherapy-associated emesis is allowed
• Concurrent inhalant, topical, or optical steroids allowed

Radiotherapy

• No concurrent radiotherapy to the bowel or stomach
• Other concurrent radiotherapy allowed

Other

• No prior creatine use
• No concurrent tube feedings or parenteral nutrition