ASCO GU 2018: Treatment Facility Volume and Survival in Patients with metastatic Renal Cell Carcinoma
As has been assessed in many other disease spaces, there is growing evidence that high-volume centers have better long-term outcomes in the management of these complex cases. In this abstract, the authors utilize population-level data to examine the association between treatment facility (TF) volume and overall survival (OS) in pts with metastatic renal cell carcinoma (mRCC).
They completed a population-level analysis using the National Cancer Database (NCDB) - while this database has been used frequently in the past few years, it is significantly limited by lack of cause-specific survival data – hence, all outcomes are based on overall survival.
It should be noted that an almost identical analysis was completed by the Cleveland Clinic (GU ASCO 2018, Abstract 590, Yu-Wei Chen), using the same database. However, the authors from this group defined treatment facility volume based on mRCC cases, which is an improvement on the Cleveland Clinic analysis. On the other hand, interestingly, the Cleveland Clinic group identified ~19000 cases of localized and mRCC from 2004-2012, which doesn’t quite match with the number of cases identified in this abstract. Which group is correct?
They identified all patients with mRCC between 2004 to 2013 (cohort A), but also subsequent narrowed their search to more stringent groups: cohort B = mRCC pts with active treatment; cohort C = mRCC pts with systemic therapy; cohort D = mRCC pts with systemic therapy at the reporting institution; cohort E = mRCC pts with systemic therapy at the reporting institution with liver and lung metastatic status known.
They defined high volume TFs as those in the top 20th percentile of mean number of mRCC patients treated per year (> 4.8 pts). They adjusted for patient (age, sex, race, ethnicity, insurance type, income, Charlson-Deyo Score), facility (location, practice setting) and clinical characteristics (histology, presence or absence of liver and lung metastasis).
There identified 41836 mRCC pts treated at 1,224 TFs. Median age 65, 66% were men and 79% had clear cell mRCC. Median TF volume was 2.2 pts/year (range 0.1-46.8) and high volume TFs treated 54% of all mRCC pts.
The unadjusted median overall survival of mRCC patients (cohort A) treated at high vs low volume TFs was 9.5 vs 6.5 months (P < 0.0001). This difference was maintained in all cohorts: cohort B = 13.7 vs 10.9, cohort C = 12.4 vs 10.0, cohort D = 12.5 vs 9.3, and cohort E = 13.3 vs 9.9 months (P < 0.0001 for all cohorts).
MVA confirmed that facility volume was associated with all-cause mortality after adjustment: HR = 0.85, [95% CI 0.82-0.88], P < 0.001. These results were consistent regardless of inclusion criteria, e.g. for cohort E: HR = 0.804, [95% CI 0.75-0.863], P < 0.0001. Considering the definition of high volume, all thresholds > 4.8 pts/year showed a survival benefit, with the largest effects at ≥20 pts/year.
High-volume TF’s were more likely to complete a cytoreductive nephrectomy and provide systemic therapy.
In this very nice analysis, it reaffirms the need for centralization of care for these advanced cases as the treatment options continue to bloom. With increasing number of treatment options and nuanced treatment decision making, centralized care will become more and more important.
Limitations / Discussion Points:
1. Overall survival is only one surrogate of response. CSS and PFS are not captured in this study. 2. Unfortunately, higher volume centers likely see more complex cases and may have artificially lower OS. Hence, the true difference may be more pronounced than captured here.
Speaker: Daniel Geynisman, MD
Co-Authors: Elizabeth Handorf, Matthew R. Zibelman, Elizabeth R. Plimack, Robert Uzzo, Alexander Kutikov, Marc C. Smaldone
Institution(s): Fox Chase Cancer Center, Philadelphia, PA
Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, Twitter: @tchandra_uromd at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA