Annual Facility Treatment Volume and Patient Survival for Mycosis Fungoides and Sézary Syndrome.

BACKGROUND: Management of mycosis fungoides and Sézary syndrome (MF/SS) is complex, and randomized evidence to guide treatment is lacking. The institutional treatment volumes for MF/SS might vary widely nationally and influence patient survival.

PATIENTS AND METHODS: Using the National Cancer Database, we identified patients with a diagnosis of MF/SS from 2004 to 2011 in the United States who had received treatment at a reporting facility. The patients were grouped into quintiles according to their treatment facility's average annual treatment volume (ATV). The characteristics associated with ATV were identified and compared using χ2 tests. Overall survival (OS) was compared among the ATV quintiles using the Kaplan-Meier method with log-rank tests and multivariable Cox regression with hazard ratios (HRs). OS was also analyzed using the annual patient volume as a continuous variable.

RESULTS: A total of 2205 patients treated at 374 facilities were included for analysis. The ATV quintile cutoffs were 1, 3, 6, and 9 patients. With a median follow-up period of 59 months, the 5-year estimated OS survival increased with ATV from 56.7% in the lowest quintile (≤ 1 patient annually) to 83.8% in the highest quintile (> 9 patients annually; P < .001). On multivariable analysis, greater ATV was associated with improved survival when analyzed as a continuous variable (HR, 0.96 per patient per year; 95% confidence interval, 0.94-0.98; P < .001) and when comparing the highest quintile to the lowest quintile (HR, 0.46; 95% confidence interval, 0.39-0.55).

CONCLUSION: The present national database analysis demonstrated that higher facility ATV is associated with improved OS for patients with MF/SS. Further study is needed to determine the underlying reasons for improved survival with higher facility ATV.