Combination of Carboplatin, Gemcitabine, and Capecitabine in Patients With Carcinoma of Unknown Primary Site

Inclusion Criteria:

* Histologic or cytologic diagnosis of carcinoma, with clinical evidence of metastasis and the primary site not clear after the following work-up:

  * Complete history and physical
  * Laboratory evaluation including serum beta-human chorionic gonadotropin (HCG), serum alpha-fetoprotein for undifferentiated or poorly differentiated carcinomas and serum prostate specific antigen (PSA) in men.
  * Directed radiologic evaluation including, at a minimum, computerized tomography (CT) of chest, abdomen and pelvis and bilateral mammography for female patients.
  * Pathologic immunohistochemistry studies of the surgical or biopsy specimen, including studies for estrogen receptor/progesterone receptor and PSA stains when clinically appropriate.
* Patients must be at least 18 years of age and have a Zubrod performance status 0-2.
* Adequate organ function, defined as absolute neutrophil count (ANC) \> 1500/ul, platelet count of \> 100,000/ul, serum creatinine less than or equal to 2.0 mg/dl, serum bilirubin less than or equal to 1.5 mg/dl.
* Patients must have measurable disease. (Partial response \[PR\] - at least a 30% decrease in the sum of LD of target lesions taking as reference the baseline sum LD.)
* Patients may be previously untreated or have received one chemotherapy regimen provided it did not include carboplatin, gemcitabine or capecitabine.
* Patients must have no serious intercurrent medical or psychiatric illness that would limit their ability to provide informed consent or receive protocol therapy.
* Patients must be informed of the investigational nature of this study and provide written informed consent in accordance with institutional and federal guidelines prior to the initiation of therapy.

Exclusion Criteria:

* Patients with previous invasive malignancy within the preceding 5 years are ineligible unless clinicopathologic information regarding the current neoplasm is clearly discordant from prior disease. Patients with non-melanoma skin cancer or in situ cancer of any site are eligible.
* Patients with brain metastasis are not eligible.
* No concurrent chemotherapy, biological or radiotherapy is allowed.
* Pregnant or lactating women are not eligible. Women and men of childbearing potential must agree to use effective contraception throughout the treatment period, and for six months after treatment has been discontinued.
* The following groups of patients will not be eligible for the study as they represent populations of patients with CUP for whom more specific treatment approaches are available:

  1. Patients presenting with squamous carcinoma isolated to middle and high cervical lymph nodes
  2. Women presenting with isolated axillary lymphadenopathy
  3. Women presenting with predominant peritoneal carcinomatosis
  4. Men \< 50 years of age presenting with predominant mediastinal and/or retroperitoneal nodal involvement and biopsy showing undifferentiated or poorly differentiated carcinoma.