Gemcitabine in Treating Patients With Metastatic Cancer of Unknown Primary

OBJECTIVES: * Evaluate the efficacy of gemcitabine hydrochloride in patients with metastatic cancer of unknown primary (CUP), in terms of improved quality of life (QOL) (as measured by the FACT Physical Well Being subscale \[FACT-G\]) and reduction of symptom distress (as measured by the Memorial Symptom Assessment Scale Short Form Global Distress Index \[MSAS-SF\]). * Define clinical benefit response using a QOL instrument in patients with CUP receiving gemcitabine hydrochloride. * Correlate objective and/or evaluable tumor response with symptom and QOL response in these patients. * Explore the association between symptom response, QOL response, and clinical benefit response in these patients. * Evaluate changes in QOL in patients who have no symptom or objective response after treatment with gemcitabine hydrochloride. * Correlate EuroQOL ratings with those using symptom instruments (MSAS-SF) and quality of life instruments (FACT-G). * Evaluate changes in perceived QOL, as measured by the EuroQOL instrument, and how these changes relate to symptom response and QOL response. * Evaluate the patient's assessment of treatment burden, as measured by a single question, and how this compares to symptom response and QOL response. OUTLINE: This is an open-label, multicenter study. Patients receive gemcitabine hydrochloride IV over 30 minutes on days 1, 8, 15, 22, 29, 36, and 43, followed by 1 week of rest (course 1). For all subsequent courses, patients receive gemcitabine hydrochloride IV over 30 minutes on days 1, 8, and 15. Treatment repeats every 4 weeks for up to 6 courses in the absence of disease progression or unacceptable toxicity. Quality of life (QOL) and symptom response are assessed at baseline and at weeks 8, 16, and 32 (end of treatment). Questionnaires include the Memorial Symptom Assessment Scale-Short Form, Functional Assessment of Cancer Therapy-General, Pain Visual Analog Scale, and EuroQOL. Patients' perception of symptom response and perception of treatment burden are also assessed. After completion of study treatment, patients are followed periodically for up to 3 years. PROJECTED ACCRUAL: A total of 52 patients will be accrued for this study.