Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed renal cell adenocarcinoma Disease
progression within 16 weeks after first-line therapy, which included interleukin-2 and/or
interferon Metastatic disease not amenable to surgery Measurable and/or evaluable disease
No more than one line of prior anticancer treatment for renal cell carcinoma No pure
papillary cell tumor, mixed tumor containing predominantly sarcomatoid cells, Bellini
carcinoma, medullary carcinoma, or chromophobe oncocytic tumor No brain metastases

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-1 Life expectancy:
More than 3 months Hematopoietic: Platelet count at least 100,000/mm3 WBC at least
2,500/mm3 Hemoglobin at least 8 g/dL (epoetin alfa allowed) Hepatic: Not specified Renal:
Calcium no greater than the upper limit of normal (ULN) (bisphosphonates allowed)
Creatinine no greater than 2 times ULN Other: No other prior malignancy within past 5
years except basal cell carcinoma of the skin or carcinoma in situ of the cervix No severe
allergy to fish or seafood No medical condition that would interfere with intake and/or
absorption of study medication (e.g., gastrectomy or major intestinal resection) No
significant medical or psychiatric condition that would preclude study Not pregnant
Negative pregnancy test Fertile patients must use adequate contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics At least 1 month
but no longer than 8 months since prior immunotherapy Chemotherapy: Not specified
Endocrine therapy: At least 1 week since prior systemic corticosteroids for symptomatic
treatment of renal cell carcinoma At least 28 days since prior medroxyprogesterone acetate
No concurrent medroxyprogesterone acetate Concurrent corticosteroids for symptomatic
treatment of neurological complications caused by renal cancer allowed Radiotherapy:
Concurrent radiotherapy to symptomatic lesions for symptom relief allowed Surgery: See
Disease Characteristics Concurrent surgical removal of symptomatic lesions for symptom
relief allowed Other: At least 28 days since other prior experimental therapeutic agents
At least 28 days since other prior shark cartilage products No other concurrent therapies
for metastatic renal cell carcinoma No other concurrent shark cartilage products