Ronald S. Go, MD, lead author: “Our research shows that, for rare cancers such as myeloma, it may be beneficial to either refer or co-manage with an institution or a clinician who specializes in myeloma. The better outcome we observed in high-volume institutions is likely multifactorial and could also be partly due to a better ‘system.’ For example, better supportive care to manage treatment complications (i.e., availability of specialized clinicians, such as infectious disease specialists, surgeons, or intensive care unit clinicians), greater availability of clinical trials providing access to novel agents, or better adherence to clinical practice guidelines.”
Multiple myeloma (MM) is a rare cancer, and the average hematologist-oncologist sees approximately two new cases of MM annually. Because previous research has shown that the medical management of rare cancers is influenced by volume, researchers, led by Ronald S. Go, MD, examined the association between facilities’ volume of MM cases and all-cause mortality.
Their findings, published in the Journal of Clinical Oncology, suggest that experience matters; patients treated at higher-volume facilities had a lower risk of death than patients treated at lower-volume facilities.
“Practice makes perfect,” Dr. Go, from the Division of Hematology at Mayo Clinic in Rochester, Minnesota, told ASH Clinical News. “For hematologist-oncologists in smaller group practices, it may help to divide practices into disease groups, especially for rare cancers such as hematologic malignancies, in order to increase the number of cases seen annually.”
Using the National Cancer Database, the authors identified 94,722 patients diagnosed with MM between 2003 and 2011 (median age at diagnosis = 67 years; range = 58-76 years) at 1,333 facilities.
The facilities were then classified into quartiles according to the mean number of patients with MM treated annually:
- Q1: <3.6 patients
- Q2: 3.6 to 6.1 patients
- Q3: 6.1 to 10.3 patients
- Q4: >10.3 patients
The median annual facility volume was 6.1 patients per year (range = 0.2-109.9 patients) and more than half of patients were seen at the highest-volume centers (Q1: 5.2%; Q2: 12.6%; Q3: 21.9%; Q4: 60.3%).
As the authors hypothesized, the unadjusted median overall survival by facility volume was significantly higher in the Q4 centers, compared with lower-volume facilities (p<0.001 for all comparisons):
- Q1: 26.9 months
- Q2: 29.1 months
- Q3: 31.9 months
- Q4: 49.1 months
This association persisted on multivariable analysis. After adjustment for year of diagnosis and demographic (sex, age, race, ethnicity), socioeconomic (income, education, insurance type), geographic, and comorbid factors, facility volume was independently associated with all-cause mortality. Compared with patients treated at the highest-volume facilities, patients treated at the lowest-volume facilities had a 22 percent higher risk of death (hazard ratio [HR] = 1.22; 95% CI 1.17-1.28; p value not reported), whereas patients treated at Q2 facilities had a 17 percent higher risk (95% CI 1.12-1.21), and those treated at Q3 facilities had a 12 percent higher risk (95% CI 1.08-1.16).
“For patients, this means that if there is an option to choose a cancer clinician, they might prefer to be seen at a center with a higher volume of myeloma cases annually,” Dr. Go said. “Similarly, choosing a high-volume transplant center is also important, since high-dose therapy and autologous hematopoietic cell transplantation remains an integral part of myeloma therapy in the younger population.”
Dr. Go noted potential limitations of the study, including the fact that researchers did not examine clinician volume – just institutional volume – because this information was not contained in the National Cancer Database. Because the association is likely to be multifactorial, Dr. Go added, “there could be low-volume institutions that have relatively better outcomes and high-volume institutions that have worse outcomes.”
Go RS, Bartley AC, Crowson CS, et al. Association between treatment facility volume and mortality of patients with multiple myeloma. J Clin Oncol. 2017;35:598-604.