Differential receipt of sentinel lymph node biopsy within practice-based research networks

Abstract

Background: Practice-based research networks (PBRNs) are promising for accelerating not only research, but also dissemination of research-based evidence into broader community practice. Sentinel lymph node biopsy (SLNB) is an innovation in breast cancer care associated with equivalent survival and lower morbidity, as compared with standard axillary lymph node dissection. We examined the diffusion of SLNB into practice and whether affiliation with the Community Clinical Oncology Program (CCOP), a cancer-focused PBRN, was associated with more rapid uptake of SLNB.

Research design: Surveillance Epidemiology and End Results-Medicare data were used to study women diagnosed with stage I or II breast cancer in the years 2000-2005 and undergoing breast-conserving surgery with axillary staging (n=6226). The primary outcome was undergoing SLNB. CCOP affiliation of the surgical physician was ascertained from NCI records. Multivariable generalized linear modeling with generalized estimating equations was used to measure association between CCOP exposure and undergoing SLNB, controlling for potential confounders.

Results: Women treated by a CCOP physician had significantly higher odds of receiving SLNB compared with women treated by a non-CCOP physician (OR 2.68; 95% CI, 1.35-5.34). The magnitude of this association was larger than that observed among patients treated by physicians operating in medical school-affiliated hospitals (OR 1.76; 95% CI, 1.30-2.39).

Conclusions: Women treated by CCOP-affiliated physicians were more likely to undergo SLNB irrespective of the hospital's medical school affiliation, suggesting that the CCOP PBRN may play a role in the rapid adoption of research-based innovation in community practice.

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*Study period is from 12 months prior to diagnosis to 12 months after diagnosis or Medicare record of death, whichever comes first.