Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed locally unresectable or metastatic malignancy that is
considered incurable

- Refractory to further treatment with known forms of effective therapy

- No clinically active CNS metastasis

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- 0-2

Life expectancy:

- At least 12 weeks

Hematopoietic:

- WBC at least 4,000/mm^3

- Platelet count at least 100,000/mm^3

Hepatic:

- Bilirubin normal

- SGOT no greater than 2.5 times upper limit of normal

Renal:

- Creatinine normal OR

- Creatinine clearance at least 60 mL/min

Other:

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for at least 6 months
after study participation

- Maintaining a reasonable state of nutrition consistent with weight maintenance

- No recent history of weight loss greater than 10% of current body weight

- No frequent vomiting/poor alimentation

- No other serious concurrent medical illness that would preclude study therapy

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- No concurrent immunotherapy

Chemotherapy:

- At least 4 weeks since prior chemotherapy (6 weeks for mitomycin and nitrosoureas)
and recovered

- No other concurrent chemotherapy

Endocrine therapy:

- No concurrent hormonal therapy

- Patients who have progressive disease while being treated with LHRH agonists,
antiestrogens, or antitestosterones for at least 3 months may remain on these
agents if in their best interest

Radiotherapy:

- At least 4 weeks since prior radiotherapy

- No concurrent radiotherapy

Surgery:

- See Disease Characteristics

- At least 21 days since prior major surgery