Medline ® Abstracts for References 1,2
Hospital volume and late survival after cancer surgery.
Birkmeyer JD, Sun Y, Wong SL, Stukel TA
Ann Surg. 2007;245(5):777.
CONTEXT: Although hospital procedure volume is clearly related to operative mortality with many cancer procedures, its effect on late survival is not well characterized.
OBJECTIVE: To examine relationships between hospital volume and late survival after different types of cancer resections.
DESIGN: Using the national Surveillance Epidemiology and End Results (SEER)-Medicare linked database (1992-2002), we identified all patients undergoing major resections for lung, esophageal, gastric, pancreatic, colon, and bladder cancer (n = 64,047). Relationships between hospital volume and survival were assessed using Cox proportional hazards models, adjusting for patient characteristics and use of adjuvant radiation and chemotherapy.
STUDY PARTICIPANTS: U.S. Medicare patients residing in SEER regions.
MAIN OUTCOME MEASURES: 5-year survival.
RESULTS: Although there were statistically significant relationships between hospital volume and 5-year survival with all 6 cancer types, the relative importance of volume varied markedly. Absolute differences in 5-year survival probabilities rates between low-volume hospitals (LVHs) and high-volume hospitals (HVHs) ranged from 17% for esophageal cancer resection (17% vs. 34%, respectively) to only 3% for colon cancer resection (45% vs. 48%). Absolute differences in 5-year survival between LVHs and HVHs fell between these ranges for lung (6%), gastric (6%), pancreatic (5%), and bladder cancer (4%). Volume-related differences in late survival could not be attributed to differences in rates of adjuvant therapy.
CONCLUSIONS: Along with lower operative mortality, HVHs have better late survival rates with selected cancer resections than their lower-volume counterparts. Mechanisms underlying their better outcomes and thus opportunities for improvement remain to be identified.
Michigan Surgical Collaborative for Outcomes Research and Evaluation, Department of Surgery, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI, USA. email@example.com
Long-term survival is superior after resection for cancer in high-volume centers.
Fong Y, Gonen M, Rubin D, Radzyner M, Brennan MF
Ann Surg. 2005;242(4):540.
BACKGROUND: A number of studies have demonstrated that surgical resection at high-volume centers is associated with improved short-term perioperative outcome. Whether long-term results after resection of visceral malignancies are superior at high-volume centers is largely unknown.
METHODS: All patients who were subjected to pancreatectomy or hepatectomy for cancer in the years 1995 and 1996 were identified in the National Medicare database. Data extracted and examined include demographics, comorbidities, and long-term survival. All survival was confirmed through 2001, providing actual 5-year survival. Long-term survival was examined as related to hospital volume.
RESULTS: In the study period, there were 2592 pancreatectomies and 3734 hepatectomies performed at 1101 and 1284 institutions, respectively. High-volume center was defined as>25 cases/y. By this definition, there were 10 high-volume centers for pancreatectomy and 12 centers for hepatectomy performing 11% (n = 291) of the pancreatectomies and 12% (n = 474) of the hepatectomies in this study period. Comparison by log-rank demonstrated superior survival for patients resected at high-volume centers (pancreatectomy: P = 0.001; hepatectomy: P = 0.02). This was confirmed by multivariate analysis. All analyses included an adjustment for within-center correlation.
CONCLUSION: Superior long-term survival is associated with complex visceral resections for cancer at high-volume centers.
Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. FongY@mskcc.org