Diffusion of accelerated partial breast radiotherapy in the United States: physician-level and patient-level analyses

Radiotherapy Trends and Variations in Invasive Non-metastatic Breast Cancer Treatment in the Netherlands: A Nationwide Overview From 2008 to 2019

AIMS

This nationwide study provides an overview of trends and variations in radiotherapy use as part of multimodal treatment of invasive non-metastatic breast cancer in the Netherlands in 2008-2019.

MATERIALS AND METHODS

Women with invasive non-metastatic breast cancer were selected from the population-based Netherlands Cancer Registry. Treatments trends were presented over time. Factors associated with (1) boost irradiation in breast-conserving therapy and (2) regional radiotherapy instead of axillary lymph node dissection (ALND) in N+ disease were identified using multilevel logistic regression analyses.

RESULTS

Radiotherapy use increased from 61% (2008) to 70% (2016), caused by breast-conserving therapy instead of mastectomy, increased post-mastectomy radiotherapy, and increased regional radiotherapy (32% in 2011 to 61% in 2019) instead of ALND in N+ disease. Omission of radiotherapy after breast-conserving surgery (BCS) in 2016-2019 (4-9%, respectively), mainly in elderly, decreased overall radiotherapy use to 67%. Radiotherapy treatment was further de-escalated by decreased boost irradiation in breast-conserving therapy (66% in 2011 to 37% in 2019) and partial (1% in 2011 to 6% in 2019) instead of whole breast irradiation following BCS. Boost irradiation was associated with high-risk features: younger age (OR>75 vs <50:0.04, 95%CI:0.03-0.05), higher grade (OR grade III vs I:11.46, 95%CI:9.90-13.26) and residual disease (OR focal residual vs R0-resection:28.08, 95%CI:23.07-34.17). Variation across the country was found for both boost irradiation use (OR South vs North:0.58, 95%CI:0.49-0.68), and regional radiotherapy instead of ALND (OR Southwest vs North:0.55, 95%CI:0.37-0.80).

CONCLUSION

Overall radiotherapy use increased in 2008-2016, while a decreasing trend was observed after 2016, caused by post-BCS radiotherapy omission. Boost irradiation in breast-conserving therapy became omitted in low-risk patients, and regional radiotherapy use increased as an alternative for ALND in N+ disease.

New Breast Cancer Radiotherapy Technology Confers Higher Complications and Costs Before Effectiveness Proven: A Medicare Data Analysis

A new breast cancer treatment, brachytherapy-based accelerated partial breast radiotherapy (RT), was adopted before long-term effectiveness evidence, potentially increasing morbidity and costs compared with whole breast RT. The aim of this study was to estimate complication rates and RT-specific and 1-year costs for a cohort of female Medicare beneficiaries diagnosed with breast cancer (N = 47 969). We analyzed 2005-2007 Medicare claims using multivariable logistic regression for complications and generalized linear models (log link, gamma distribution) for costs. Overall, 11% (n = 5296) underwent brachytherapy-based RT; 9.4% had complications. Odds of any complication were higher (odds ratio [OR]: 1.62; 95% confidence interval [CI]: 1.49-1.76) for brachytherapy versus whole breast RT, similarly to seroma (OR: 2.85; 95% CI: 1.97-4.13), wound complication/infection (OR: 1.72; 95% CI: 1.52-1.95), cellulitis (OR: 1.48; 95% CI: 1.27-1.73), and necrosis (OR: 2.07; 95% CI: 1.55-2.75). Mean RT-specific and 1-year total costs for whole breast RT were $6375, and $19 917, $4886, and $4803 lower than brachytherapy ( P < .0001). Multivariable analyses indicated brachytherapy yielded 76% higher RT costs (risk ratio: 1.76; 95% CI: 1.74-1.78, P < .0001) compared with whole breast RT. Brachytherapy had higher complications and costs before long-term evidence proved its effectiveness. Policies should require treatment registries with reimbursement incentives to capture surveillance data for new technologies.