Final Results of the First Randomized Trial Comparing Balloon Kyphoplasty (BKP) to Non-Surgical Management Among Cancer Patients with Vertebral Compression Fractures: Marked Improvement in Back Function, Quality of Life and Pain in the BKP Arm.

Abstract 2873

Poster Board II-849

Destructive vertebral lesions are a common source of morbidity for patients with cancer. Balloon kyphoplasty (BKP) is a minimally invasive surgical procedure for patients with painful vertebral compression fractures (VCFs) with the goal of reducing pain and disability. We report the final results of the first randomized trial among cancer patients with VCFs to assess the efficacy and safety of BKP. Twenty-two multinational sites enrolled 134 patients after consent and ethical review board approval. Adult patients diagnosed with cancer and ' 3 painful VCFs were randomly assigned to BKP or nonsurgical management (NSM) and followed for 12 months. Patients were excluded with primary bone tumors, osteoblastic tumors or solitary plasmacytoma at the fracture site, or spinal cord compression. The primary objective was to determine the change in the Roland-Morris Disability questionnaire (RMDQ), a 0- (no disability) to 24-point (maximum disability) instrument validated for assessing back-specific physical functioning, at one month. Following this assessment, cross-over to BKP was allowed in the NSM arm. Patients were randomized to BKP (N=70) or NSM (N=64). Five patients withdrew early from the study without significant baseline data; the 3 patients assigned to BKP did not undergo the procedure. Thus, 68 BKP and 61 control patients were evaluable. Mean patient age was 64 years, 58% were female, and tumor types included multiple myeloma (38%), cancers of the breast (22%), lung (8.5%), prostate (6.2%) and other sites (26%). At baseline, 35% of patients were currently on daily corticosteroids, 50% had received bisphosphonates within 12 months of study entry, 49% had received prior radiation (52 % to the spine), and 67% of patients were previously treated with chemo/hormonal therapies. VCFs were identified in a single (34%), two (26%) or three (40%) sites. Mean baseline RMDQ scores were similar between the groups; 17.6 and 18.2 points for BKP and NSM patients, respectively. However, at one month, there was an improvement for patients randomized to BKP of −8.3 points (95% CI −6.4 to −10.2) whereas those receiving NSM showed no significant change (0.1 points, 95% CI 1.0 to −0.8; p<0.0001). At one week, BKP-treated patients also showed significant improvement in their back pain (−3.8 points, 95%CI, −3.1 to −4.6) whereas those patients treated with NSM had no change (−0.3 points, 95%CI, 0.1 to −0.7; p<0.0001). Similar results for pain were obtained at one month (BKP: −3.9 [95%CI, −3.1 to −4.7]; NSM: −0.6 [95%CI, −0.1 to −1.1]; p<0.0001). The greater pain relief observed in the BKP group was accompanied by a greater reduction in the usage of any analgesics to control pain relief within one month (p=0.002). BKP patients also reported fewer days (compared to NSM) within two weeks where their activity was limited due to back pain (6.3 fewer days per 2 weeks; 95%CI, 5.8 to 6.8; p<0.0001) and greater improvements in quality of life as measured by the SF-36 physical component summary score (8.4 points higher; 95%CI, 7.7 to 9.1; p<0.0001). Thirty-eight of the 61 patients in the NSM group crossed over and underwent BKP with 21 (58%) occurring within 1 week of the 1-month visit. These cross-over patients were also assessed for safety and efficacy at 1 month following the procedure and through the study period. They showed similar benefits in regards to back disability, back pain relief, analgesic use, activity level, and quality of life as those originally assigned to BKP. Among all patients treated with BKP, these improvements were sustained throughout the 12-month study period. Adverse events were similar between the two groups. One serious adverse event in the form of an intra-operative non-Q-wave myocardial infarction resolved and was attributed to anesthesia. One patient with a cement leakage to the disc had an adjacent fracture occur 1 day after the index procedure; the local investigator judged this to be device-related. This randomized study demonstrates that cancer patients with VCFs treated with BKP have a superior outcome compared to NSM as measured by the primary endpoint, the RMDQ score. BKP also resulted in a marked reduction in back pain, improved quality of life and fewer days with limitation of daily activities; these outcomes were both clinically and statistically significant and these effects were maintained throughout the 12 month study period. This study supports the benefits of BKP in the management of cancer patients with VCFs.