(P011) Postmastectomy Radiotherapy for T3N0 Breast Cancers: A National Cancer Database Analysis

Value Analysis of Neoadjuvant Radiotherapy for Breast Cancer after Modified Radical Mastectomy Based on Data Mining

Over the last two generations, there has been a surge of interest in nonmutilating treatment for women with early breast cancer. Neoadjuvant radiation therapy, which is progressively being provided to breast cancer patients, could be used to decrease tumor burden while also providing an ability to examine treatment response. This paper aims to explore the effects of the initiation time of radiotherapy after modified adjuvant radical mastectomy on the prognosis of breast cancer. The EMR data can be used to mine hidden rules, which are of great significance for treatment and prognosis analysis. In collaboration with breast cancer, the appropriate prediction model and visualization method are selected and a visual analysis system for breast cancer group and treatment plan based on electronic medical record is constructed. Patients with multiple dimensions are reduced and clustered to form patient groups. The differences of characteristics among patient groups are intuitively displayed by using Nightingale diagram, word cloud, and time axis visualization methods. The support vector machine (SVM) model is used to predict the treatment scheme. The radiotherapy time after modified radical surgery in the two groups was within 15 weeks (observation group) and 15 weeks (routine group), respectively. The incidence of complications, local recurrence rate, progression-free survival, and quality of life scores of patients in the routine group and observation group were compared. The total incidence of complications differed significantly between the observation and routine groups. The physical function, material function, psychological function, and social function of the observation group were significantly higher than the routine group (P < 0.05). Radiotherapy within 15 weeks after modified radical mastectomy for breast cancer can not only reduce the local recurrence rate but also prolong the progression-free survival of patients, and the incidence of complications will not increase, which will greatly help improve the quality of life of patients.

Evaluation of the benefit of post-mastectomy radiotherapy in patients with early-stage breast cancer: A propensity score matching study

The present study aimed to evaluate the significance of post-mastectomy radiotherapy (PMRT) in patients with early stage (T1-2) breast cancer. The Surveillance, Epidemiology, and End Results database was searched, and data on female patients with early stage (T1-2) breast cancer with 1–3 positive axillary lymph nodes (LNs) were extracted. Patients were subdivided into two groups: Those who had received PMRT and those who had not (no PMRT). Data from the two groups were analyzed in order to identify associations between PMRT status, breast cancer-specific survival (BCSS) probability and overall survival (OS) probability using multivariate Cox proportional hazards regression and propensity score matching models. A total of 7,316 patients were included in the analysis. Prior to propensity score matching, outcome probabilities were increased in the PMRT group, compared with the no PMRT group (BCSS probabilities: 92.0 vs. 90.1%, respectively, P=0.015; OS probabilities: 89.8 vs. 86.0%, respectively, P<0.001). In multivariate analyses, tumor location was not identified as being a risk factor for BCSS (hazard ratio, 0.917; 95% confidence interval, 0.772–1.090; P=0.326). Following propensity score matching, differences between the two treatment groups (PMRT and no PMRT) in terms of their BCSS scores remained significant (93.7 vs. 90.1%, respectively; P=0.007). Compared with the no PMRT group, the OS probabilities of the PMRT group were increased (89.4 vs. 86.0%; P=0.025). In conclusion, the present results indicated that PMRT may benefit the prognosis of patients with breast cancer with early stage disease (T1-2), and those with one to three positive axillary LNs.