Metastatic cancer from an undetermined primary site.

The charts of 285 patients diagnosed as metastatic cancer from an undetermined primary site were reviewed. An attempt was made to characterize this disease entity more specifically, and to evaluate the various modes of therapy utilized in such patients. Adenocarcinoma is the most common histologic type overall; squamous cell carcinoma is most common in 5-year survivors. Lymph nodes are the most common metastatic site overall and in 5-year survivors. The mean overall survival is 8.69 months with 8.7% 2-year survivors and 2.8% 5-year survivors. Surgery alone, radiation alone or in combination, and chemotherapy alone or in combination were utilized in these patients with 5-year survivals of 11, 3.7, and 1.1%, respectively. The 5-year survivors all had therapy initiated immediately after histologic diagnosis and medical workup, and all of their tumors were less than 8 cm in diameter. In view of this data, patients with metastatic cancer from an undetermined primary site should always be considered for early, aggressive therapy.