Gemcitabine, Docetaxel, and Capecitabine in Treating Patients With Cancer of Unknown Primary Origin

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed malignancy for which no primary origin has been identified despite routine workup, including the following:
• History and physical examination
• Chemistry profile and other blood work, including tumor markers with follow up on any positive findings
• CT scan or MRI of the chest, abdomen, and pelvis
• Mammography (for female patients)
• Prostate examination (for male patients)
• Stool guaiac
• Measurable disease
• Previously irradiated lesions are not considered measurable disease unless there is documented clear tumor progression in these lesions after completion of radiotherapy
• The following tumor types or presentations are excluded:
• Resectable disease
• Tumors consistent with germ cell primary, as indicated by any of the following:
• Midline tumor
• Elevated beta human chorionic gonadotropin
• Elevated alpha-fetoprotein
• i12p chromosomal alteration
• Prostate primary with elevated prostate-specific antigen
• Females with axillary nodes as the primary disease site
• Tumors limited to the peritoneal cavity consistent with primary peritoneal carcinoma
• Neuroendocrine tumors
• Squamous cell carcinoma involving cervical or inguinal lymph nodes
• No symptomatic brain metastases
• Prior brain metastases allowed provided patient completed definitive treatment with brain irradiation with or without resection

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• More than 3 months

Hematopoietic

• Hemoglobin ≥ 9.0 g/dL
• Granulocyte count > 1,500/mm^3
• Platelet count > 100,000/mm^3

Hepatic

• Bilirubin normal
• Meets 1 of the following criteria:
• Alkaline phosphatase (AP) normal AND AST and ALT ≤ 5 times upper limit normal (ULN)
• AP ≤ 2.5 times ULN AND AST and ALT ≤ 1.5 times ULN
• AP ≤ 5 times ULN AND AST and ALT normal
• Albumin ≥ 3.0 g/dL

Renal

• Creatinine ≤ 1.5 mg/dL

Gastrointestinal

• Able to take oral medication
• Intestinal absorption intact
• No uncontrolled diarrhea and/or daily emesis

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier contraception during and for 3 months after completion of study treatment
• No other malignancy within the past 5 years except curatively treated carcinoma in situ of the cervix or basal cell skin cancer
• No severe medical or psychiatric illness that would preclude study treatment
• No peripheral neuropathy > grade 1
• No history of severe hypersensitivity reaction to docetaxel or other drugs formulated with polysorbate 80

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• No prior chemotherapy for this malignancy

Endocrine therapy

• Not specified

Radiotherapy

• See Disease Characteristics
• Recovered from prior radiotherapy
• Prior palliative radiotherapy to areas of bony metastases allowed provided there is measurable disease outside the radiotherapy port
• At least 4 weeks since prior radiotherapy
• No prior radiotherapy to ≥ 25% of the bone marrow

Surgery

• See Disease Characteristics

Other

• No concurrent antiviral therapy