[Unknown primary bone metastasis: therapeutic and diagnostic strategies]

The primary site remains unknown in 0.5-15% of patients with multiple metastases. In 5-20% of these patients bone metastases are the first sign of disease. Survival after diagnosis ranges 2 to 6 months and 1-year survival is less than 25%. First of all, this paper reviews the current diagnostic and therapeutic approaches to patients with bone metastases from an unknown primary site and then reports the 10-year experience with radiotherapy at the Radiotherapy Division of the Centro di Riferimento Oncologico (Aviano) and of the Pordenone General Hospital in this patient population. Seventy-nine patients with bone metastases were evaluated. In 33 patients histology confirmed the original diagnosis and in 46 patients diagnosis was based on radiological and clinical findings. With respect to pain relief, differences in irradiated areas and in the ages of the patients were not significant. The patient's sex, however, did make a difference both to the degree of pain relief achieved and to survival (more favorable in women). To conclude, this paper suggests the diagnostic procedures necessary for the correct follow-up of patients with bone metastases from an unknown primary site.