Post-Breast Cancer Radiotherapy Bronchiolitis Obliterans Organizing Pneumonia.

BACKGROUND: Radiotherapy for breast cancer has been implicated in the development of bronchiolitis obliterans organizing pneumonia (BOOP). Patients may be asymptomatic or may have pulmonary and constitutional symptoms that are moderate or severe. Postradiotherapy BOOP usually develops during the 12 months after completion of radiotherapy and is characterized by ground-glass opacities in the radiation-exposed lung and frequently in the non-irradiated lung.

METHODS: An updated literature search and review was performed to update the systematic review we conducted in 2014. Ten new publications were identified: 2 Japanese epidemiological studies, 1 Japanese case series study, 6 case reports, and 1 review article.

RESULTS: The incidence of postradiotherapy BOOP was 1.4% in both Japanese epidemiological studies. Risk factors included increasing age, cigarette smoking, and increasing central lung distance. The case reports included 7 women who had breast cancer postradiation BOOP and 1 woman who had an ataxia telangiectasia mutated ( ATM ) gene mutation, which may increase radiation sensitivity.

CONCLUSION: Postradiotherapy BOOP in women with breast cancer occurs at a rate of 1.0-3.0% and may occur in women with immune system dysfunction and genetic mutations.