Adjuvant treatment of surgically treated bone metastasis patients: association with hospital characteristics and trends over time.

Patients with metastatic disease of the bone (MDB) often require surgical stabilization; however, there is not widespread consensus on subsequent adjuvant management. This study aimed to characterize utilization of perioperative adjuvant treatment among MDB patients. We identified 9413 surgically treated MDB patients with primary (breast, kidney, lung, prostate, or multiple myeloma) cancer from Surveillance, Epidemiology, and End Results (SEER)-Medicare data. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for receipt of chemotherapy, radiation, and bisphosphonates, respectively, in the adjuvant setting (90 days before or after surgery) by hospital characteristics-medical school affiliation, surgery volume, and Commission on Cancer (CoC) accreditation. Trends in treatment utilization by year of surgery were assessed via bar charts and Chi-square tests for trend. Patients surgically treated at major medical schools or high-volume facilities (compared to no medical school affiliation and low volume) had significantly higher odds of receiving radiation and chemotherapy, independent of patient and tumor characteristics (OR (95% CI); medical school: radiation 1.33 (1.19-1.49), chemotherapy 1.15 (1.02-1.30); and high volume: radiation 1.22 (1.11-1.34), chemotherapy 1.11 (1.02-1.22)). Patients surgically treated at CoC-accredited institutions, compared to non-accredited, had significantly higher odds of receiving radiation and bisphosphonates [radiation 1.24 (1.13-1.36); bisphosphonates 1.15 (1.04-1.28)]. Use of chemotherapy and bisphosphonates increased while radiation use declined over the study period from 1991 to 2014. Medical school affiliation, hospital volume, and CoC accreditation are associated with receipt of adjuvant treatment to prevent or manage pathologic fractures in MDB patients. Further investigation is needed to determine whether these associations reflect delivery of optimal care.