Improving survival in metastatic carcinoma of unknown origin

Metastatic carcinoma from an unknown primary site accounts for 3% to 5% of all newly diagnosed malignant lesions. Although 85% of patients who receive this diagnosis are dead within a year, 5% to 10% may be long-term survivors. Close cooperation between an experienced pathologist and the referring physician is essential in the management of these patients. One important task for the physician is to recognize those subgroups of patients who may have a better prognosis and thus may be treated in a different fashion. A second challenge is not to overinvestigate or overtreat patients who fall into the poor prognosis category. Empirical chemotherapy should not be given simply for the sake of doing something. Rather, proper emphasis should be placed on regional therapy, symptomatic treatment, and the best palliative care. Patients may be confused and frustrated when confronted with the news that the source of their tumor is not apparent. They should be reassured that this lack does not preclude development of a rational treatment plan and that those cancers for which highly effective systemic therapy exists have been excluded. A caring, informed physician may help empower the patient to make educated and informed choices.