Cancer Res Treat.  2019 Jan;51(1):12-23. 10.4143/crt.2017.273.

The Effect of Hospital Case Volume on Clinical Outcomes in Patients with Nasopharyngeal Carcinoma: A Multi-institutional Retrospective Analysis (KROG-1106)

• Ha B
• Cho KH
• Moon SH
• Lee CG
• Keum KC
• Kim YS
• Wu HG
• Kim JH
• Ahn YC
• Oh D
• Noh JM
• Lee JH
• Kim SH
• Kim WT
• Oh YT
• Kang MK
• Kim JH
• Kim JY
• Cho MJ
• Kay CS
• Choi JH

• KMID: 2437594
• DOI: http://doi.org/10.4143/crt.2017.273

Abstract

PURPOSE
The purpose of this study was to investigate the effect of hospital case volume on clinical outcomes in patients with nasopharyngeal carcinoma (NPC).
MATERIALS AND METHODS
Data on 1,073 patients with cT1-4N0-3M0 NPC were collected from a multi-institutional retrospective database (KROG 11-06). All patients received definitive radiotherapy (RT) either with three-dimensional-conformal RT (3D-CRT) (n=576) or intensity-modulated RT (IMRT) (n=497). The patients were divided into two groups treated at high volume institution (HVI) (n=750) and low volume institution (LVI) (n=323), defined as patient volume ≥ 10 (median, 13; range, 10 to 18) and < 10 patients per year (median, 3; range, 2 to 6), respectively. Endpoints were overall survival (OS) and loco-regional progression-free survival (LRPFS).
RESULTS
At a median follow-up of 56.7 months, the outcomes were significantly better in those treated at HVI than at LVI. For the 614 patients of propensity score-matched cohort, 5-year OS and LRPFS were consistently higher in the HVI group than in the LVI group (OS: 78.4% vs. 62.7%, p < 0.001; LRPFS: 86.2% vs. 65.8%, p < 0.001, respectively). According to RT modality, significant difference in 5-year OS was observed in patients receiving 3D-CRT (78.7% for HVI vs. 58.9% for LVI, p < 0.001) and not in those receiving IMRT (77.3% for HVI vs. 75.5% for LVI, p=0.170).
CONCLUSION
A significant relationship was observed between HVI and LVI for the clinical outcomes of patients with NPC. However, the difference in outcome becomes insignificant in the IMRT era, probably due to the standardization of practice by education.

Keyword

Nasopharyngeal neoplasms; Hospital; Low- or high-volume; Treatment outcome; Three-dimensional conformal radiotherapy; Intensity-modulated radiotherapy

MeSH Terms

Cohort Studies
Disease-Free Survival
Education
Follow-Up Studies
Humans
Nasopharyngeal Neoplasms
Radiotherapy
Radiotherapy, Intensity-Modulated
Retrospective Studies*
Treatment Outcome

Figure

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  Fig. 1. Kaplan-Meier survival curves of overall survival (OS) (A) and loco-regional progression-free survival (LRPFS) (B) for both groups in entire cohort and propensity score-matched cohort. The OS (C) and LRPFS (D) were significantly higher in high volume institutions (HVI) than in low volume institutions (LVI) for the cohort before and after propensity score matching.

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  Fig. 2. Kaplan-Meier survival curves of overall survival (OS) (A, C) and loco-regional progression-free survival (LRPFS) (B, D) for both groups in the subgroups of patients treated with three-dimensional-radiotherapy (3D-CRT) and intensitymodulated radiotherapy (IMRT) in the propensity score-matched cohort. Significant differences in OS (p < 0.001) and LRPFS (p < 0.001) were observed in the 3D-CRT group and not in the IMRT group.

Reference

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