Natural history of malignant bone disease in renal cancer: Final results of an Italian bone metastases survey

4627 Background: bone metastases (mts) are an emerging clinical problem in renal cancer patients related to survival increase. We report the final data of largest survey never published in literature. Methods: 398 renal cancer patients (pts) with evidence of bone mts, all died at the moment of study inclusion, have been included. Clinico-pathological data, data on survival and Skeletal Related Events (SRE) data and skeletal related therapies have been collected and statistically analyzed. Results: 286 males/112 females; median age: 63 (16-87); pts with bone mts at the moment of renal cancer diagnosis: 31.4%; pts with single bone mts: 31.1%. Type: lytic 77%, mixed: 14.6%, blastic: 7.6 %. Sites: spine (65.8%), pelvis (38.4%), long bones (31.6%), other (18.8%). Median time to bone mts: 8 months (0-288) (all patients); 24 months (1-288) (pts without bone mts at diagnosis). Pts with at least 1 SRE: 71.1%. Types of SREs: pathologic fracture (12.6%), radiotherapy (61.8%), spinal compression (7.6%), bone surgery (14.8%), hypercalcaemia (3.2%). Median number of SRE for patient: 1 (0-4). Median time to first SRE: 2 (0-72), to second SRE: 4 (0-113), to third SRE: 11 (1-108). Median survival after bone mts diagnosis: 12 (1-178). Median survival after first SRE: 10 (0-144). Median survival in pts with at least one SRE: 14 (1-178); median survival in pts without SREs: 9 (0-62). In according with MKSCC criteria median time to skeletal disease was in patients with good prognosis was 24 (0-288), intermediate was 5 (0-180) and poor prognosis was 0 (0-77). A total of 168 pts received zoledronic acid until performance status worsening or death. 162 pts have been analysed as control group. The median time to first SRE in the zoledronic treated pts was 3 mths (0-101) compared with 1 mth (0 - 25) in the control group (p< 0.05). 5 cases of ONJ have been diagnosed. Conclusions: The present survey is the largest descriptive study concerning the natural history of bone disease in renal cancer patients. The effects of biological therpies on bone met will be presented during the meeting.