Gender and Sex Differences in Health-Related Quality of Life, Clinical Outcomes, and Survival After Treatment of Metastatic Spine Disease

Retrospective review of prospective, multicenter, and international cohort study. To describe the effect of gender on health-related quality of life (HRQoL), clinical outcomes, and survival for patients with spinal metastases treated with either surgery and/or radiation. Gender differences in health-related outcomes are demonstrated in numerous studies, with women experiencing worse outcomes and receiving lower standards of care than men; however, the influence that gender has on low HRQoL and clinical outcomes after spine surgery remains unclear. Patient demographic data, overall survival, treatment details, perioperative complications, and HRQoL measures including EuroQoL-5D, pain NRS, the short form 36 version 2, and the Spine Oncology Study Group Outcomes Questionnaire were reviewed. Patients were stratified by sex, and a separate sensitivity analysis that excluded gender-specific cancers ( i.e. breast, prostate, etc .) was performed. The study cohort included 207 female and 183 male patients, with age, smoking status, and site of primary cancer being significantly different between the two cohorts ( P <0.001). Both males and females experienced significantly improved Spine Oncology Study Group Outcomes Questionnaire, EuroQoL-5D, and pain NRS scores at all study time points from baseline ( P <0.001). Upon sensitivity analysis (gender-specific cancers removed from analysis), the significant improvement in Spine Oncology Study Group Outcomes Questionnaire physical, mental, and social subdomains and on the short form 36 version 2 domains disappeared for female. Males experienced higher rates of postoperative complications. Kaplan-Meier survival analysis of both the overall and sensitivity analysis cohorts showed females lived longer than males after treatment ( P =0.001 and 0.043, respectively). Both males and females experienced significantly improved HRQoL scores after treatment, but females demonstrated longer survival and a lower complication rate. This study suggests that gender may be a prognostic factor in survival and clinical outcomes for patients undergoing treatment for spine metastases and should be taken into consideration when counseling patients accordingly.