[Clinical course of bone metastases by prostatic cancer studies with conventional X-ray]

The clinical courses of bone metastases in 81 cases of prostatic cancer were examined using conventional X-ray. All patients received endocrine therapy as the initial treatment; castration and estrogen were given to 46 cases, castration and antiandrogen to 19, LH-RH analog to 11, flutamide to 5. The response to endocrine therapy was evaluated every 6 months after the start of the treatment according to National Prostatic Cancer Project criteria. The prognosis was calculated by cause-specific survival. The types of untreated bone metastases on X-ray were classified into five: sclerotic in 12 cases (15%), mixed but mainly sclerotic in 25 (31%), mixed but mainly lytic in 14 (17%), lytic in 8 (10%) and undetermined with positive scintigraphy in 22 (27%). Two mixed types showed more spread metastases and tendency of elevated prostatic acid phosphatase when compared with other types. Temporary enlargement of sclerotic area within 6 months after start of the treatment did not correlate with deterioration of disease. Remodeling of metastatic areas occurred 6-36 months after start of the treatment showed curative course and the prognosis of these groups were favorable. Most of lytic areas tended to sclerotic finding following endocrine therapy regardless of effects by endocrine therapy. Sclerotic and two mixed types showed better and worse tendencies, respectively. On viewpoint of remodeling, change of metastatic area and newly appearance of metastases, an evaluation criteria of response to the therapy was proposed, which showed good correlation with prognosis. From these observations, it was concluded that bone metastases tended from lytic to sclerotic changes and that lytic-sclerotic cycles occurred repeatedly along with disease progression regardless of effect to therapy. Remodeling seemed to be curative signs of metastatic area.