Changes in pulmonary function tests in breast carcinoma patients treated with locoregional post-mastectomy radiotherapy: results of a pilot study

Background: The aim of present pilot study was to evaluate the changes in pulmonary function tests (PFTs) after locoregional post-mastectomy radiotherapy (PMRT) in breast cancer patients. Materials and methods: Twenty consecutive patients with histopathologically confirmed breast carcinoma stages T1-T4, N1-N2, who were treated with modified radical mastectomy with neoadjuvant or adjuvant chemotherapy underwent PFTs, including forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced expiratory flow at 50%, and peak expiratory flow rate, maximum mid expiratory flow (MMEF25-75), maximal oxygen consumption (VO(2)max), and carbon monoxide diffusing capacity (DLCO) before, at 30 days, and at 90 days after locoregional PMRT. A two-tailed paired Student's t-test was used to compare mean values among the variables between the groups Results: A significant drop in FVC, FEV 1, and DLCO was noticed at day 90 after the completion of locoregional PMRT with P-values 0.033, 0.042, and 0.031, respectively, while MMEF25-75 and VO(2)max were not significantly affected (P-values 0.075 and 0.062, respectively) favoring a restrictive lung injury pattern. However, no patient was found to be symptomatic. Conclusion: A significant drop in reduction in PFTs occurred at day 90 after the completion of locoregional PMRT. PFTs shall be performed in all breast cancer patients receiving locoregional PMRT for early detection of radiation-induced lung toxicity as all patients in our cohort were found asymptomatic.