THE NEED TO CONSIDER SURVIVAL, OUTCOME, AND EXPENSE WHEN EVALUATING AND TREATING PATIENTS WITH UNKNOWN PRIMARY-CARCINOMA

Background: Patients who present with unknown primary carcinomas repre sent 10% to 15% of the patients with cancer who present to medical cen ters. Despite data in the literature indicating minimal success in det ermining the location of primary carcinomas, these patients continue t o be evaluated exhaustively. Additionally, identification of the locat ion of primary carcinomas does not often affect treatment. Clinical tr eatment and prognosis are only affected if a reevaluation of the patho logic findings yields a potentially curative diagnosis of an undiffere ntiated lymphoma, germ cell tumor, or a hormonally sensitive carcinoma . Methods: Tumor registry files from January 1, 1990, through December 31, 1992, were retrospectively retrieved to identify adult patients w ho presented with metastasis of an unknown primary site at the H. Lee Moffitt Cancer Center and Research Institute, a 162-bed tertiary care cancer center specialty hospital affiliated with the University of Sou th Florida College of Medicine, Tampa. Medical records were reviewed f or age, sex, histologic findings of previous malignant growth, types a nd duration of symptoms, and mode of presentation. Fifty-six of the 19 9 patients were included in the study; 31 were men (55.4%) and 25 were women (44.6%), with ages ranging from 33 to 83 years. Diagnostic eval uations were reviewed and included data from procedures conducted at b oth the H. Lee Moffitt Cancer Center and at outside facilities. Diagno stic studies performed included barium swallow; intravenous pyelogram; mammogram; abdominal ultrasound; chest x-ray film; bone scan; magneti c resonance imaging; computed tomography of the head, chest, abdomen, and pelvis; laparotomy; bronchoscopy; gastroscopy; and colonoscopy. In formation for the diagnostic test procedures was taken from the point of initial patient contact until the determination of metastatic disea se. Results: The primary cancer site was found in four (7.1%) of the 5 6 cases in the study and could not be classified as curable by systemi c means. The average cost of diagnosis was $17 971, with 19.6% of the patients surviving for more than 1 year. The mean survival period was 8.1 months. A total of 410 tests were performed with only four tests c orrectly identifying the location of the primary tumor. Conclusions: O nce a potentially curable malignancy has been excluded, there is littl e justification to support extensive diagnostic evaluation of the pati ent. Substantial costs are incurred and survival is often not signific antly affected. it was estimated that 1.2 million new cancer cases wou ld have occurred during 1994, with approximately 10% of these patients presenting with cancer of unknown primary origin. Based on cost asses sments, investigation of these patients would exceed $1.5 billion. Thi s clinical scenario is one where attention to outcome, clinical manage ment, and expense should be carefully considered.