[Relationship between extent of bone metastases and effect of endocrine therapy evaluated with bone scintigraphy in stage D2 prostatic cancer].

Bone scintigraphy of metastatic lesion on 128 patients with prostatic cancer were classified according to the proposal by Soloway et al (Cancer, 61; 195-202, 1988). Since all patients received endocrine therapy, the response to therapy and survival were examined in relation to bone lesion. In extent of disease (EOD) 1, main metastatic lesions were located in the pelvis, lumbar spine, and with increasing number of EOD, metastases in the upper spine, rib, and skull appeared. Longer survival were noticed in EOD 1, followed by EOD 2 and EOD 3, and EOD 4 revealed the shortest survival. The survival of EOD 2 was similar to thus of EOD 3. However, when grades of tumor were considered, moderately differentiated cancer showed longer survival than poorly differentiated cancer in EOD 2 and EOD 3. The response as assessed by bone scintigraphy following 6-month therapy was well correlated with the number of EOD. When individual items for evaluation of response were examined, the results of local response of the prostate and values of PAP showed good correlation with survivals, however, that of bone lesions with bone scintigraphy failed to show such a correlation with prognosis. Therefore, it is concluded that the therapeutic evaluation of bone lesions with bone scintigraphy is difficult to interpret 6 months after initiation of treatment.