Medical center treatment volume may have an impact on clinical outcomes in multiple myeloma (MM), according to researchers at the Mayo Clinic. In a recent study, these researchers evaluated annual MM treatment volume and all-cause mortality using the National Cancer Database. All patients were diagnosed with MM between 2003 and 2011; it was found that patients may beneﬁt from treatment at high-volume facilities.1
“One possibility is the ‘practice makes perfect’ adage. This is especially true for multiple myeloma for several reasons,” said study author Ronald Go, MD, associate professor of medicine at the Mayo Clinic in Rochester, Minnesota.
It is estimated that there are only 2 new MM cases per hematologist/oncologist annually. There have been an unprecedented number of new drugs approved for MM in recent years (9 in the past 10 years), and an exponential increase in MM publications and clinical trials.
The researchers classified facilities by quartiles, balancing for patient clustering within facilities. They adjusted for demographic, socioeconomic (income, education, insurance type), and geographic (area of residence, treatment facility location, travel distance) factors. They also adjusted for comorbidity and year of diagnosis. In total, the analysis included 94,722 patients who were treated at 1 of 1333 facilities; the median age at diagnosis was 67 years and 54.7% were male.
The median annual facility volume was 6.1 patients per year; the unadjusted median overall survival by facility volume was 26.9 months for the lowest quartile, 29.1 months for the second quartile, 31.9 months for the third quartile, and 49.1 months for the fourth quartile. Facility volume was independently associated with all-cause mortality.
According to Dr Go, high-volume may be a reflection of good practices, such as “uniform use care pathways, adherence to clinical practice guidelines, discussion of complex cases at a tumor board, upfront chemotherapy dose-adjustment for frail patients, and preemptive management of treatment side effects. Determining these characteristics may help improve the outcome in lower-volume treatment facilities,” Dr Go told Cancer Therapy Advisor.
The study has significant limitations, however, due to its inability to control for selection bias by referring physicians. The researchers were also unable to account for the annual volume per physician or cumulative physician experience. Dr Go noted that there were lower-volume facilities that had as good outcomes as higher-volume facilities, and that some higher-volume facilities had outcomes similar to lower-volume facilities with poor survival rates. Volume is not, in itself, a necessary predictor of clinical outcomes.
Other studies suggest, however, that volume is an important factor. One study evaluating bone marrow transplant (BMT) centers and outcomes found that high patient to physician ratios tended to yield better outcomes.2