ADJUVANT RADIOTHERAPY FOLLOWING MASTECTOMY:EVALUATION OF 1494 CASES

Abstract

PURPOSE: To evaluate the treatment results and the prognostic factors after postmastectomy radiotherapy in patients with breast cancer.Materials and methods: One thousand four hundred ninety four patients treated with radiotherapy after mastectomy during January 1982-December 2002 were evaluated retrospectively. Radiotherapy was applied to the chest wall and also to the regional lymphatics in patients carrying high risk factors with 1.8-2 Gy daily fractions up to the total median dose of 50 Gy.RESULTS: Median age was 49. Twenty-two patients (1.5%) had Stage I, 222 (14.9%) had Stage IIA, 421 (28.2%) had Stage IIB, 607 (40.6%) had Stage IIIA, 174 (11.6%) had Stage IIIB disease, 48 patients (3.2%) could not be staged due to Tx or Nx status. During a median follow-up duration of 46 months (range:6-276 months) 73 patients (4.8%) developed locoregional recurrence and 439 patients (29.3%) developed distant metastases. Five-year local-recurrence- free, disease-free and overall survival rates were 94.2%, 65.5% and 82.9% respectively. In multivariate analysis the only prognostic factor influencing local control was the number of metastatic axillary lymph nodes (p=0.029) and the prognostic factors affecting disease-free survival were T stage (p=0.042), nodal stage (p=0.041) and number of metastatic axillary lymph nodes (p=0.000) and the factors influencing overall survival were T stage (p=0.008), nodal stage (p=0.005), number of metastatic axillary lymph nodes (p=0.001), lymphovascular invasion (p=0.004) and histologic grade (p=0.042).CONCLUSION: In the present study prognostic factors that affect loco-regional control, disease-free and overall survival after postmastectomy radiotherapy in patients with breast cancer were T stage, nodal stage, stage, the number of metastatic axillary lymph nodes, skin invasion and lymphovascular invasion.