DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed non-hematological cancer that is unresponsive to available therapies or for which there is no known effective treatment

• Measurable or evaluable disease

  • Clinical or radiological evidence of disease required
• No active brain metastases

PATIENT CHARACTERISTICS:

Age:

• 16 and over

Performance status:

• ECOG 0-2

Life expectancy:

• At least 3 months

Hematopoietic:

• Absolute neutrophil count at least 2,000/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin no greater than 1.5 mg/dL
• ALT and AST no greater than 2.5 times upper limit of normal

Renal:

• Creatinine less than 1.5 mg/dL

Cardiovascular:

• Ejection fraction at least 50%
• No significant arrhythmias
• No congestive heart failure

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No dementia or altered mental status
• No known HIV infection
• No active infection
• No other serious uncontrolled medical disorder that would preclude study participation
• No known allergies to soy products, rice flour, or gelatin (if receiving study dietary soy supplementation)

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 4 weeks since prior immunotherapy
• No concurrent prophylactic colony-stimulating factors

Chemotherapy:

• At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)
• Prior taxanes allowed
• No other concurrent chemotherapy

Endocrine therapy:

• No concurrent hormonal therapy except hormone replacement therapy or medication used to maintain castrate status for patients with progressive hormone-refractory prostate cancer

Radiotherapy:

• At least 4 weeks since prior radiotherapy
• No prior radiotherapy to more than 25% of bone marrow-containing areas
• No concurrent radiotherapy

Surgery:

• Not specified

Other:

• At least 4 weeks since prior investigational agents
• No other concurrent experimental anticancer therapy