DISEASE CHARACTERISTICS: Histologically confirmed advanced malignancy involving the peritoneal cavity, excluding leukemia and lymphoma Patients with ovarian cancer must have received prior standard therapy Predominantly small tumor metastases less than 1.0 cm in diameter including: Ovarian cancer with epithelial histology Other gynecological tumors Breast cancer Gastric cancer Colorectal cancer Appendiceal cancer Pancreatic cancer Unknown primary cancer Other malignancies with predominantly intraperitoneal manifestation No extensive intraperitoneal adhesions that cannot be easily lysed laparoscopically or by laparotomy No symptomatic disease outside the peritoneal cavity Asymptomatic disease outside the peritoneum considered (e.g., bone lesions)

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 3 months Hematopoietic: Neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 2.0 mg/dL AST no greater than 2 times upper limit of normal Renal: Creatinine no greater than 2.0 mg/dL Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: See Disease Characteristics At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas and/or mitomycin) Endocrine therapy: Not specified Radiotherapy: At least 3 weeks since prior radiotherapy Surgery: See Disease Characteristics