Correlation Found Between Treatment Interruptions During Adjuvant Radiotherapy and Overall Survival Among Patients With Triple-Negative Breast Cancer

According to a data analysis, a correlation has been found between treatment interruptions and overall-survival (OS) among patients with triple-negative breast cancer undergoing adjuvant radiotherapy. 

“Currently, there are no data regarding the impact of treatment interruptions during radiotherapy for breast cancer,” stated Ronald Chow, MS, FRSPH, New York Proton Center, New York, New York, and coauthors. “In this study, we examine the correlation between treatment interruptions during radiotherapy and outcomes [among patients with] triple-negative breast cancer.” 

Using data from the National Cancer Database, 35 845 patients with triple-negative breast cancer who underwent radiotherapy treatment between 2010 and 2014 were included in the analysis. The number of interrupted treatment days was calculated based on the difference between total elapsed days from start to end of radiation treatment (including both initial treatment and boost treatment, when administered) and the total number of expected treatment days (the number of expected treatment days plus 2 weekends for every 5 treatment days). Binomial multivariate regression was used to detect correlates of treatment interruptions and propensity-score matched multivariable Cox proportional hazard models were used to evaluate the association between treatment interruptions and OS. 

When results were modeled as a continuous variable, longer treatment duration was associated with poorer OS (hazard ratio [HR], 1.023; 95% confidence interval [CI], 1.015 to 1.031). Additionally, results indicated that the likelihood of mortality was increased when patients experienced 0 to 1 days of interruption, 2 to 5 interrupted days (HR, 1.069; 95% CI, 1.002 to 1.140 interrupted days), 6 to 10 interrupted days (HR, 1.239; 95% CI, 1.140 to 1.348 interrupted days), and 11 to 15 interrupted days (HR, 1.265; 95% CI, 1.126 to 1.431 interrupted days). 

Dr Chow and coauthors concluded this study is “the first study of its kind [to] report a correlation between treatment interruptions during adjuvant radiotherapy in triple-negative breast cancer and OS.”

Source: 

Chow R, Hasan S, Choi JI, et al. Effect of treatment interruptions on overall survival in patients with triple-negative breast cancer. J Natl Cancer Inst.Published online July 3, 2023. doi:10.1093/jnci/djad127