Prognostic factors of early breast cancer treated with radiation after radical mastectomy / 中华放射肿瘤学杂志

ABSTRACT

Objective To study whether post-operative radiotherapy is necessary for patients with early breast cancer after radical mastectomy. Methods In 1998, 270 early breast cancer patients with 0 -3 pathologically confirmed positive axillary lymph nodes after radical mastectomy were retrospectively ana-lyzed. There were 156 patients with negative lymph node and 114 with 1 -3 positive lymph nodes. The prog-nostic index (PI) was defined as the sum of scores of the tumor size, number of positive axillary lymph nodes, receptor status, surgical margin status, lymphatic thrombi status, pathological grading and age. The PI≥ 4 was considered as high-risk, and PI <4 as the low-risk. Numerical variables were compared using t test and categorical variables were compared using chi-square test. Kaplan-Meier method was used to calcu-late the survival rates, and the Log-rank test was used for the comparison of the survival curves between dif-ferent groups. Results Of the patients with lymph node negative and 1 - 3 positive, the survival rates were 75.0% and 63.2% (χ~2 = 4.40 ,P =0.036), respectively. The corresponding disease-free survival rate, lo-cal recurrence rate, distant metastasis rate were 71.2% and 9.6% (χ~2 = 3.90, P = 0.048), 7.7% and 16.7%(χ~2 =5.22,P=0.022),12.8% and 21.1%(χ~2=3.27,P=0.070), respectively. The mean dis-ease-free survival time of the two groups was 97.03 ± 2.53 months and 87.01 ± 3.80 months, respectively. In the high-risk group, the 10-year survival rates of patients with and without radiotherapy were 72% and 56% (χ~2 = 4.07, P = 0.044), the local recurrence rates were 5% and 24% (χ~2= 11.16, P = 0. 001), and the distant metastasis rates were 16% and 26% (χ~2= 2.18 ,P = 0. 140). In the low-risk group, the survival rate of patients with and without radiotherapy were 81% and 71% (χ~2 = 1.57 ,P = 0.210), the local recur-rence rates were both 11% (χ~2=0.01 ,P=0.975), and the distant metastasis rates were both 13% (χ~2 = 0.00,P = 1. 000). Conclusions Early breast cancer patients with 1 -3 positive axiilary lymph nodes should receive post-operative radiotherapy after radical mastectomy. The prognostic index may decrease the chance of unnecessary radiation by distinguishing the patients under low risk of recurrence from those under high risk.