The Effect of Hormonotherapy on the Development of Lung Fibrosis after Radiotherapy in Breast Cancer Patients

Abstract

This study aimed to investigate the effects of hormonotherapy on lung fibrosis in patients receiving adjuvant conformal radiotherapy with the diagnosis of breast cancer. Data of 876 patients were examined.469 patients who underwent computed tomography (CT) for any reason after radiotherapy and whose CT images were available at 6th month and 2nd years were included in the study. CT sections were evaluated by a radiologist blindly. Pulmonary fibrosis was graded according to RTOG/EORTC toxicity criteria. The effect of hormonotherapy (tamoxifen and aromatase inhibitors), age, menopause status, radiotherapy, lung volume receiving ipsilateral 5 Gy (V5), lung volume receiving ipsilateral 20 Gy (V20), ipsilateral mean lung dose (MLD) and taxane group chemotherapy on pulmonary fibrosis were investigated. The median age in the study group was 51 (27-83). 239 patients (51%) were premenopausal. As hormonotherapy, 159 patients (33.9%) used tamoxifen and 253 patients used aromatase inhibitors (53.9%). Hormonotherapy was not used in 57 patients (12.2%-control group). Grade 1 fibrosis developed in 273 (53.9%) patients and grade 2 in 18 (3.8%) patients at the 6th month.304 patients (64.8%) developed grade 1, and 37 (7.9%) developed grade 2 fibrosis in the second year. Grade 3 and grade 4 fibrosis were not detected. When early and late lung fibrosis was examined, there was an increase in grade 2 lung fibrosis at the end of the 2nd year (p<0,001). A significant relationship was found between 6th month lung fibrosis and V20 (p = 0.019), MLD (p = 0.020) and regional lymphatic irradiation (p = 0.030). V20 (p<0,001), MLD (p<0,001), regional lymphatic irradiation (p = 0,030) and use of hormonotherapy (p<0,001) were effective in the formation of lung fibrosis in the 2nd year. Patients who received tamoxifen had more grade 2 fibrosis at the end of the second year than the patients who received control and aromatase inhibitors evaluated of hormone therapy(p<0,001). No relation was found between menopause status, age and taxane group chemotherapy and lung fibrosis development. The use of tamoxifen in patients receiving adjuvant radiotherapy for breast cancer increases the early and late lung fibrosis more than the aromatase inhibitors. However, V20, MLD, and regional lymph node irradiation also contribute to the frequency of fibrosis.Abstract 2112; TableLung fibrosis (No) n (%)Lung fibrosis (Yes) n (%)p valueAge (y-median)50 (28-74)52(27-83)0,257V5 (%-median)33,31 (4,83-94,0)36,59(16,55-96,69)0,095V20 (%-median)20,47(1,46-35,78)23,43(6,5-35,98)<0,001MLD(Gy-median)11,24(1,73-18,62)12,34(4,87-23,28)<0,001Hormonotherapy No Aromatase Inhibitors Tamoxifen29(22,7) 66(25,8) 33(25,8)28(8,2) 187(54,8) 126(37)<0,001Menopausal status Premenopause Postmenopause71(55,5) 57(44,5)168(49,3) 173(50,7)0,255Irradiation of the regional lymph nodes No Yes53(41,4) 75(58,6)92(27) 249(73)0,030Taxane chemotherapy No Yes68(53,1) 60(46,9)161(47,2) 180(52,8)0,257 Open table in a new tab