The aim of the study was to assess the value of routine bone scintigrams, independent of the primary tumor stage or the presence of symptoms, in the postsurgical follow-up of breast cancer patients for the early detection of bone metastases. For this purpose 1,000 patients with postsurgical breast cancer without previous documentation of metastatic disease, who were admitted to the special oncology hospital, Onkologische Klinik Bad Trissl, entered a prospective study in 1987-1988. The parameters followed were the TNM stage of the primary tumor, the presence of pain, bone pain as revealed by a thorough physical examination, and the patient's history for the assessment of risk factors. In addition, a whole-body skeletal scintigram, supplementary X-rays, and additional diagnostic measures were performed, if necessary, to detect bone metastases. It was shown that in 856 of 894 patients (groups 1-6) without clinical symptoms, the clinical examination and radiological and scintigraphic diagnostic measurements, demonstrating the absence of bone metastases, gave matching results, but in 12 of the 894 patients the results of all examinations remained questionable. In another 12 of the 894 patients (groups 1-3) radiological and/or scintigraphical evidence for the presence of bone metastases was found. In 14 of 79 cases (groups 7-10) with clinically suspicious symptoms these were proven to be signs of metastases by subsequent scintigrams, supplementary X-rays, and additional diagnostic measures. In 65 of the 79 patients with clinically suspicious symptoms, bone metastases could not be confirmed by obtaining bone scintigrams or X-rays while in the other 14 patients (groups 9 and 10) evidence for the presence of bone metastases was found in the scintigrams and/or X-rays. However, 10 of these 14 patients were high-risk patients for developing bone metastases as they had axillary lymph node infiltration. The other 4 patients were of the low-risk group as they had positive receptor status or no axillary lymph node infiltration at the time of primary diagnosis. In 13 of 27 patients (groups 11-14) with clinical symptoms indicating the presence of bone metastases this diagnosis was confirmed by scintigrams and/or X-rays (groups 11 and 12), while it was possible to exclude the presence of bone metastases in spite of the symptoms in 11 of the 27 patients. In the other 3 patients the results of the additional examinations remained questionable.(ABSTRACT TRUNCATED AT 400 WORDS)