Influence of treatment center and hospital volume on survival for locally advanced cervical cancer

Abstract

Objective: Procedural volume is associated with outcomes for many surgical interventions. Little is known about the association between volume and outcomes of radiation. We examined the association between treatment center and hospital volume and outcomes for women with locally advanced cervical cancer treated with radiation.

Methods: Women with stage IIB-IVA cervical cancer treated with primary radiation from 1998 to 2011 and recorded in the National Cancer Database were examined. Hospital volume was estimated as the mean annualized volume, while center-specific effects on care were examined using a hospital-specific random effect. Multivariable regression models adjusted for metrics of treatment quality were used to estimate survival.

Results: 20,766 patients treated at 1115 hospitals were identified. The median follow-up was 24.2months while 5-year survival was 36.5% (95% CI, 35.6-37.4%). Higher hospital volume was associated with receipt of brachytherapy (P<0.05), but had no effect on use of chemotherapy. In a multivariable model accounting for clinical and demographic factors as well as quality of care, hospital volume was not associated with survival (P=0.25). The specific hospital in which patients received care was the strongest predictor of survival (P<0.0001) followed by stage, year of diagnosis and treatment quality (P<0.0001 for all). The hospital-specific effect on mortality expressed as a hazard ratio, ranged from 0.66 to 1.53 across hospitals.

Conclusion: For locally advanced cervical cancer, hospital volume has a minimal impact on outcome; however, the specific center in which care is delivered is strongly associated with survival.

Keywords: Cervical cancer; Chemoradiation; Chemosensitization; Outcomes; Radiation; Volume.

Figure 1

A. Adjusted hazard ratio for death for each hospital ranked by lowest (0.66) to highest (1.53) hazard ratio with 95% confidence intervals. Hazard ratios derived from treatment-adjusted models and includes all clinical and demographic variables as well as treatment metrics. B. Adjusted hazard ratio for death for each hospital stratified by annualized volume quartiles. Within each quartile hospitals are ranked from the lowest to highest hazard ratio with 95% confidence intervals.