Tumors of unknown origin.

The recognition of subsets of very treatable patients within the large heterogeneous population of carcinomas of unknown primary site represents an advance in the management of these patients. These patients with responsive tumors can be defined with appropriate clinical and pathologic evaluation. A summary of the subsets and an outline of the evaluation necessary for their identification is illustrated in Table 5. A therapeutic trial remains the only method to determine if patients have responsive tumors, and several patients who do not conform to a defined subset do respond to cisplatin-based chemotherapy. Unfortunately, there is still a large group of patients with relatively insensitive tumors. Improved therapy for these patients will probably await advances in the treatment of non-small cell lung cancer, pancreatic cancer, and the other gastrointestinal cancers, since the majority of insensitive carcinomas probably arise from these occult primary sites. We have a registry at Vanderbilt and are attempting to register patients of other physicians around the country. We request pathology material and clinical summaries and follow-up data on all these patients. An unstained slide bank has also been established so that special stains developed in the future may be rapidly evaluated. These data may eventually enable us to better determine the frequency and spectrum of these neoplasms and may allow for more specific diagnoses and therapy.