Photo courtesy of the CDC
Patients with multiple myeloma (MM) are more likely to live longer if they are treated at a medical center where the staff has more experience with the disease, according to research published in the Journal of Clinical Oncology.
The study showed that patients treated at medical centers seeing 10 new MM patients per year had a 20% higher risk of death than patients treated at centers seeing 40 new MM patients per year.
Most cancer treatment centers in the US see fewer than 10 new MM patients per year.
“It is very difficult to be proficient when doctors are seeing only 1 or 2 new cases of multiple myeloma per year,” said study author Ronald Go, MD, of the Mayo Clinic in Rochester, Minnesota.
“Studies on cancer surgery have shown the more experience the center or practitioner has, the better the outcome. We wanted to see if volume matters when it comes to nonsurgical treatment of rare cancers such as multiple myeloma.”
To investigate, Dr Go and his colleagues used the National Cancer Database, examining outcomes for 94,722 newly diagnosed MM patients treated at 1333 facilities between 2003 and 2011.
The researchers grouped the facilities into quartiles according to the volume of MM patients treated there each year.
The mean number of MM patients treated per year was:
- Less than 3.6 for quartile 1 (Q1)
- 3.6 to 6.1 for Q2
- 6.1 to 10.3 for Q3
- More than 10.3 for Q4.
The majority of patients (60.3%) were treated in Q4 facilities. For all facilities, the median number of new MM patients per year was 6.1 (range, 3.6 to 10.3). The mean was 8.8 ± 9.9.
The researchers calculated the relationship between MM patient volume at these facilities and patient mortality, adjusting for demographic characteristics, socioeconomic factors, geographic factors, comorbidities, and year of diagnosis.
Outcomes
The unadjusted median overall survival was 26.9 months for patients treated at Q1 facilities, 29.1 months for Q2, 31.9 months for Q3, and 49.1 months for Q4 (P<0.001).
The 1-year mortality rate was 33.5% for patients treated at Q1 facilities, 32.3% for Q2, 30.7% for Q3, and 21.9% for Q4.
The researchers’ multivariable analysis showed that facility volume was independently associated with all-cause mortality.
Patients treated at the lower-quartile facilities had a higher risk of death than patients treated at Q4 facilities. The hazard ratios were 1.12 for patients at Q3 facilities, 1.12 for Q2, and 1.22 for Q1.
The researchers performed another analysis in which volume was treated as a continuous variable, and they compared various volume sizes to a reference volume of 10 patients per year.
Compared with facilities treating 10 new MM patients per year, facilities treating 20 MM patients per year had roughly 10% lower overall mortality rates.
Facilities treating 30 MM patients per year had about 15% lower mortality rates. And facilities treating 40 MM patients per year had 20% lower overall mortality rates.
