Combination Chemotherapy Plus Filgrastim in Treating Patients With Advanced Solid Tumors

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed advanced solid tumor that is not curable by surgery or radiotherapy * Sarcoma * Melanoma * Carcinoma of unknown primary * Pancreatic cancer * Lung cancer * Ovarian cancer * Breast cancer * Bladder cancer * Gastric cancer * Esophageal cancer * Prostate cancer * Head and neck cancer * No hematopoietic or lymphoid tumors * Measurable or evaluable disease PATIENT CHARACTERISTICS: Age: * Over 18 Performance status: * Karnofsky 60-100% * ECOG 0-2 Life expectancy: * Not specified Hematopoietic: * Absolute neutrophil count greater than 1,000/mm\^3 * Platelet count greater than 100,000/mm\^3 Hepatic: * Bilirubin normal * AST and/or ALT no greater than 5 times upper limit of normal (ULN) if alkaline phosphatase no greater than ULN OR * Alkaline phosphatase no greater than 5 times ULN if AST and ALT no greater than ULN OR * AST and/or ALT no greater than 1.5 times ULN if alkaline phosphatase no greater than 2.5 times ULN Renal: * Creatinine no greater than 2 times ULN OR * Creatinine clearance at least 50 mL/min Cardiovascular: * No congestive heart failure * No unstable angina Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No uncontrolled infection * No known sensitivity to E. coli-derived products PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * At least 2 weeks since prior cytotoxic anti-tumor therapy (4 weeks for nitrosourea or mitomycin) and recovered * No prior docetaxel or gemcitabine Endocrine therapy: * Not specified Radiotherapy: * See Disease Characteristics * At least 2 weeks since prior radiotherapy and recovered Surgery: * Not specified