Assessing lung function in women treated for breast cancer with radiotherapy. A comprehensive systematic review and...

Radiotherapy is associated with pulmonary fibrosis in 5-15% of cases, potentially impacting lung function and thus the quality of life of patients with breast cancer. This study aimed to assess short, middle, and long-term effects of radiotherapy on lung function in women treated for breast cancer.

A thorough literature search of databases (Medline, Web of Science, Scopus, and CENTRAL) up to October 2024 was conducted. Included were observational, experimental, and quasi-experimental studies assessing radiotherapy effects on lung function in women treated for breast cancer. A meta-analysis summarised findings, and risk of bias (Cochrane ROBINS-E) and quality of evidence (GRADE framework) were assessed.

Twenty-two studies totalled 1042 women, of median age 51 years [range 44-56]. Radiotherapy administered conventionally (46-58 Gy, 1.8-2.2 Gy/fraction, 23-28 sessions, 5 days/week, 5 weeks) or hypo-fractionated (40-43.2 Gy, 2.7-2.8 Gy/fraction, 15-16 sessions, 5 days/week, 3 weeks), resulted in significant declines in FEV₁%predicted, FVC%predicted, and DLCO%predicted at one-, three-, six-, and 12-months post-radiotherapy. Clinically relevant reductions (≥5%) were noted for FEV₁%predicted at one and 12 months (MD[95 %CI) = -7.94[-13.94; -1.93], -5.10[-8.81; -1.39], respectively), FVC%predicted at one, six, and 12 months (-5.98[-11.78; -0.17], -5.90[-9.01; -2.79], -5.58[-9.32;-1.83], respectively), and DLCO%predicted at one, three, and 12 months (-8.00[-15.66; -0.34], -5.51[-7.91; -3.11], -6.76 [-10.27; -3.25], respectively). Risk of bias was low in 64 %, moderate in 14 %, and high in 23 % of studies. GRADE assessment indicated moderate level of evidence.

Radiotherapy may affect lung function in women treated for breast cancer, especially in the absence of lung-sparing techniques, resulting in declines persisting up to 12 months post-radiation. However, heterogeneity in patient characteristics and treatment protocols among studies warrants cautious interpretation of these findings. This highlights the need for enhanced monitoring and supportive pharmacological and non-pharmacological interventions in this patient group.