Treatment at a facility with a higher patient volume was associated with a lower risk of mortality for patients with multiple myeloma, even after adjustment for sociodemographic and geographic factors and comorbidities, a new study showed.
“Patients treated at the highest-quartile facilities (≥ 10 patients per year) had nearly a quarter lower risk of death compared with those treated at the lowest-quartile facilities (< 4 patients per year),” wrote Ronald S. Go, MD, of the Mayo Clinic in Rochester, Minnesota, and colleagues in the Journal of Clinical Oncology. “Although knowledge on how to manage rare malignancies such as multiple myeloma is now easily accessible, substantial gaps in clinical outcome continue to exist based on institutional volume of care.”
Go and colleagues identified 94,722 patients with multiple myeloma treated at 1,333 facilities from 2003 to 2011 using the National Cancer Database. They divided facilities into quartiles based on volume: < 3.6 patients with myeloma treated per year (Q1), 3.6 to 6.1 (Q2), 6.1 to 10.3 (Q3), and > 10.3 (Q4). The median age of patients at diagnosis was 67 years.
Across all facilities, the median annual volume was 6.1 patients per year. The majority of patients were treated at high-volume facilities (Q4, 60.3% of patients; Q3, 21.9%, Q2, 12.6%; and Q1, 5.2%). Only 18 of the 1,333 facilities treated more than 50 patients annually.
The researchers found a significantly longer unadjusted median overall survival for patients treated at the highest volume facilities compared with the lowest volume (Q4, 49.1 months; Q3, 31.9 months; Q2, 29.1 months; Q1, 26.9 months; P < .001). A multivariable analysis confirmed that facility volume was independently associated with all-cause mortality.
“To show that a volume-outcome relationship exists in the management of multiple myeloma should come as no surprise, considering that: on average, a hematologist-oncologist in the United States will see only two new multiple myeloma cases annually; an unprecedented number of new drugs are becoming available for multiple myeloma; and there is a surge of published biologic and clinical information on multiple myeloma in recent years,” the researchers wrote. “Keeping up with pertinent new knowledge in multiple myeloma, which comprises only 2% of all cancers, and at the same time maintaining proficiency in its management, is becoming more difficult, especially if one also has to stay current in all the other cancers.”
Compared with the highest quartile of treatment, patients treated at lower-quartile facilities had a higher risk for death (Q3 hazard ratio [HR], 1.12; Q2 HR, 1.17; Q1 HR, 1.22). In addition, compared with those facilities treating 10 patients per year, those facilities treating 20 patients had a 10% lower overall mortality rates; 30 patients per year, 15% lower mortality rates; and 40 patients per year, 20% lower overall mortality rates.