RESUMEN
Objective:To investigate the efficacy of postmastectomy radiotherapy (PMRT) for human epidermal growth factor receptor 2 (HER2)-positive T 1-2N 1M 0 breast cancer in the context of HER2-targeted therapy. Methods:This study collected the clinical data of 105 female patients with HER2-positive T 1-2N 1M 0 breast cancer who underwent modified radical mastectomy in the First Affiliated Hospital of Bengbu Medical College from January 2013 to December 2019. Then, the clinical outcomes of these patients were observed, and the prognostic factors and the efficacy of PMRT were analyzed. Results:The median follow-up time was 50 months (ranging from 14 to 107 months), and the 5-year overall survival (OS), local-regional recurrence-free survival(LRFS), and disease-free survival (DFS) were 81.6%, 91.9%, and 76.2%, respectively. The multivariate analysis indicated that independent prognostic factors for OS and DFS include the age, pathologic grade, and tumor size; the independent risk factors for LRFS include positive lymph node ratio (LNR) and hormone receptor (HR) status; and the independent prognostic factor for DFS was PMRT (HR: 2.85, 95% CI: 1.10-8.80, P < 0.05). The subgroup analysis suggested that PMRT significantly improved the OS of various high-risk subgroups ( χ2=4.01-9.18, P < 0.05). However, the further stratified analysis indicated that PMRT only increased the OS of the patients who did not receive HER2-targeted therapy in various high-risk subgroups ( χ2=4.50-6.70, P < 0.05), while there was no statistical difference before and after PMRT for the individuals who received targeted treatment ( P > 0.05). Conclusions:PMRT is an independent prognostic factor for the DFS of patients with HER2-positive T 1-2N 1M 0 breast cancer who underwent modified radical mastectomy. PMRT can improve the OS of high-risk patients with ages < 45 years old, pathologic grade Ⅲ, tumor diameter ≥ 3 cm, LNR > 10%, and HR (-) who received no HER2-targeted therapy. However, the efficacy may be compromised to some extent in the context of the application of HER2-targeted therapy.
RESUMEN
Objective:To explore the effects of the deep inspiration breath-hold (DIBH) technique on cardiac dosimetry in internal mammary node irradiation with intensity-modulated radiation therapy (IMN-IMRT) for postoperative left breast cancer.Methods:Totally 23 left breast cancer patients in the First Affiliated Hospital of Bengbu Medical College from Octorber 2021 to July 2022 receiving postoperative IMN-IMRT were enrolled in this study. The changes in dosimetric parameters for their heart and left anterior descending coronary artery (LAD) in the DIBH mode were observed, and the potential factors affecting DIBH effects were analyzed.Results:Compared with the free breath (FB) mode, the DIBH mode manifested a heart volume decrease by 18% ( t = 10.47, P < 0.001), a left lung volume increase by 42% ( t = -14.55, P < 0.001), and significantly reduced dosimetric parameters ( Dmean, Dmax, V5- V30) for the heart and LAD, exhibiting statistically significant differences ( t=-13.38 to -3.30, P<0.05). As indicated by the Pearson correlation analysis, the relative ratio of cardiac dose reduction was positively correlated with that of left lung expansion ( r = 0.82, P < 0.001) and negatively correlated with the patient′age ( r = -0.56, P = 0.005). Conclusions:DIBH can effectively reduce the heart and LAD radiation doses in IMN-IMRT for postoperative left breast cancer and that the patient's age, and the DIBH effects might be affected by the vital capacity.
