Higher-volume facilities associated with improved survival for NHL
ORLANDO, Fla. — Patients with non-Hodgkin’s lymphoma who are treated at facilities with a high volume of similar patients experienced prolonged OS compared with patients treated at low-volume facilities, according to study results presented at the ASH Annual Meeting and Exposition.
The incidence of non-Hodgkin’s lymphoma (NHL) is relatively uncommon, with approximately 70,000 cases per year, according to study background. However, there are more than 50 subtypes of NHL and they are treated at a variety of institutions.
Ronald S. Go
Ronald S. Go, MD, associate professor of medicine in the department of hematology at the Mayo Clinic in Rochester, Minnesota, and colleagues sought to determine the extent to which a facility’s volume of patients with NHL affects OS outcomes.
“Non-Hodgkin lymphoma is a relatively uncommon cancer, has a very diverse classification and is becoming more complex to treat,” Go told HemOnc Today. “Therefore, we explored the question of whether the volume of care is associated with patient outcome. This volume–outcome relationship has been extensively studied in surgical procedures including cancer surgeries but understudied in the medical management of cancers. We did find that higher volume of care by treatment facility translated into better survival.”
Using the National Cancer Data Base, the investigators identified 278,985 patients who were treated at 1,151 facilities between 1998 and 2006.
Researchers classified the facilities into quartiles (Q) based on the mean number of patients with NHL treated there per year. Q1 facilities treated between 2 and 13 patients a year (10.7% of the NHL population), Q2 facilities treated 14 to 20 patients (13.5%), Q3 facilities treated 21 to 32 patients (23.3%) and Q4 facilities treated 33 or more patients (52.5%).
Overall, 31.2% of the facilities were academic centers, 55.9% were comprehensive community centers, 10.6% were community centers and 2.3% were categorized as other centers.
The unadjusted median OS by volume was 61.8 months for Q1 facilities, 65.9 months for Q2 facilities, 71.4 months for Q3 facilities and 83.6 months for Q4 facilities.
Facility volume remained an independent predictor of all-cause mortality after multivariable adjustments for patient demographics, socioeconomic, geographic, disease-specific and facility-specific factors. Secondary and sensitivity analyses showed similar results.
Compared with patients treated at Q4 facilities, patients treated at lower-volume facilities had shorter OS (Q3, HR = 1.05; 95% CI, 1.04-1.06; Q2, HR = 1.08; 95% CI, 1.07-1.1; Q1HR = 1.14; 95% CI, 1.11-1.17).
The investigators also used smoothing splines and found a significant non-linear effect of hospital volume on OS (P < .001) with an average HR of 1 occurring at a facility volume of 59 patients per year.
“Owing to the relative rarity of hematologic cancers and the increasing complexity on how they are managed, we believe that the time is ripe to study whether a volume–outcome relationship exists,” Go said. “Not only do we have an opportunity to assess the quality of nonsurgical cancer care, we also have a chance to learn more about variations in practice that are tied to relevant outcomes.
“Similar to surgical volume–outcome studies performed in the past 2 decades, such investigations could be performed either at the level of the treatment facility or the oncologists by secondary analyses of large patient data sets from national cancer registries, private or public payers, and clinical trials,” Go added. – by Anthony SanFilippo
Go RS, et al. Abstract 266. Presented at: ASH Annual Meeting and Exposition; Dec. 5-8, 2015; Orlando, Fla.
Disclosure: The researchers report no relevant financial disclosures.