Survival slightly higher at high-volume radiation treatment centers

We all know that prostate surgery results are significantly better at high-volume centers (see this link). Unsurprisingly, the same holds true for primary radiation treatment of high-risk patients.

Chen et al. analyzed the National Cancer Database to find data on 19,465 high-risk patients treated at 1,099 facilities between 2004 and 2006 and followed up through 2012. Patient data included age, race, insurance status, comorbidity, clinical stage, Gleason score, type of radiation, use of ADT, type of facility, household income, education level, and location. The 20% highest volume facilities treated half the patients, and that was arbitrarily chosen as the definition of “high volume.” After median 81 months of follow-up, they found:

• ·      High volume facilities treated 223 patients (median)
• ·      Low volume facilities treated 76 patients (median)
• ·      High volume facilities were more likely to be academic hospitals, in a metropolitan area.
• ·      Patients treated at high volume facilities were more likely to have higher Gleason scores, stage T3, and lower PSA. They were also twice as likely to receive brachy boost therapy (17% vs. 8%).
• ·      They adjusted for all patient data in their analysis.

They were only able to retrieve data on overall mortality, not prostate cancer-specific mortality. The key finding was that for every 100 patients treated, mortality risk was reduced by 3%. So, a typical high volume facility treating 223 patients in this time period had 4.4% fewer deaths per patient treated than a typical low volume facility treating 76 patients.

Incidental findings of mortality risk included:

• ·      33% lower risk among patients who received brachy boost therapy
• ·      17% lower risk among patients who received brachytherapy
• ·      Risk increased 5% for every year of age
• ·      30% lower risk among Hispanics compared to Anglos or African-Americans
• ·      40% higher risk among those using Medicaid
• ·      Higher risk among those with <$35,000 income and with less education
• ·      Higher risk among those with more co-morbidities, higher tumor stage, and Gleason score

Unfortunately, there were no available data in this analysis on physician experience.

While the effect of treatment volume is small, it is statistically significant. What is most striking, however, is the overwhelming effect of age, poverty, and other risk factors. There is an important interaction effect as well: brachy boost therapy, which requires the coordination of various specialists, is often only available at high volume centers. As we’ve seen both here and in recent clinical trials, oncological outcomes are significantly improved by the combination therapy.

Higher volume facilities tend to have the best equipment, attract the best doctors and have experienced treatment teams. However, the individual doctor’s experience and abilities is of much greater importance. With brachy boost therapy, it is not necessary that the external beam therapy and the brachytherapy be performed at the same facility, only that the radiation oncologists coordinate their treatments. Often, it is more convenient to travel to an experienced brachytherapist, but to have the time-consuming external beam portion of the treatment done locally. The patient should primarily find the most qualified doctor(s) for his treatment.