RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells.

PURPOSE: Phase II trial to study the effectiveness of gemcitabine plus cisplatin in treating patients with malignant mesothelioma of the pleura that cannot be removed by surgery.

OBJECTIVES: I. Estimate overall survival and confirmed and unconfirmed complete and partial response in patients with unresectable malignant mesothelioma of the pleura treated with gemcitabine plus cisplatin. II. Evaluate the qualitative and quantitative toxicities of this regimen in this patient population.

OUTLINE: Patients receive gemcitabine IV over 30 minutes, immediately followed by cisplatin IV over 30 minutes on days 1, 8, and 15. Courses are repeated every 28 days. Treatment continues in the absence of unacceptable toxicity or disease progression. Patients with a complete response receive 2 additional courses of therapy. Patients are followed every 6 months until death.

PROJECTED ACCRUAL: A total of 50 patients will be accrued for this study within 25 months.

• Drug: cisplatin
• Drug: gemcitabine hydrochloride

DISEASE CHARACTERISTICS: Histologically confirmed diagnosis of unresectable malignant mesothelioma of the pleura Epithelial, fibrosarcomatous, or mixed type Bidimensionally measurable disease No CNS metastases

PATIENT CHARACTERISTICS: Age: Over 18 Performance status: SWOG 0-2 Life expectancy: Not specified Hematopoietic: WBC at least 3,000/mm3 Platelet count at least lower limit of normal Hepatic: Bilirubin no greater than 2.0 mg/dL SGOT or SGPT no greater than 2.5 times upper limit of normal (ULN) Renal: Creatinine no greater than 2 times ULN AND Creatinine clearance at least 60 mL/min Other: Not pregnant or nursing Fertile patients must use effective contraception No other prior malignancy within the past 5 years except adequately treated basal or squamous cell carcinoma of the skin, carcinoma in situ of the cervix, or adequately treated stage I or II cancer currently in complete remission Must have chest x-ray within the past 28 days

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy No other concurrent chemotherapy Endocrine therapy: Concurrent hormones for non-disease-related conditions allowed Concurrent steroids for antiemesis, adrenal failure, or septic shock allowed Radiotherapy: No prior radiotherapy No concurrent radiotherapy Surgery: At least 4 weeks since prior major surgery and recovered