Postmastectomy Radiotherapy and Chemotherapy in Patients with Breast Cancer

Ahn, Sung Ja; Chung, Woong Ki; Nam, Taek Keun; Nah, Byung Sik; Song, Ju Young; Park, Seung Jin

Abstract

PURPOSE: To evaluate the treatment outcomes after postmastectomy radiotherapy (PMRT) and chemotherapy in patients with breast cancer.
MATERIALS AND METHODS
The PMRT were retrospectively analyzed in 83 patients with stage II-III female breast cancer treated between 1989 and 1995. The median age was 46 years (range, 23-77); Seventy- seven patients had modified radical mastectomies, 5 radical mastectomies and 1 simple mastectomy. Three patients (4%) had pathologically negative axillae, and the remaining 80 (96%) had positive axillae. Eleven, 23, 44 and 5 patients had pathological stages IIA, IIB, IIIA, and IIIB, retrospectively. Eighty (96%) patients were treated with hockey-stick fields. The median dose of PMRT was 50.4 Gy, in 1.8 Gy fractions. Adjuvant systemic chemotherapy was given to 74 patients (89%). CMF-based or doxorubicin-containing regimens were given to 54 patients (65%). The median follow-up time was 82 months (range, 8-171) after the mastectomy.
RESULTS
The 5 and 10-year overall survival rates for all patients were 65 and 49%, respectively. The univariate and multivariate analyses of the factors affecting the overall survival revealed the stage to be the most significant prognostic factor (p=0.002), followed by the combination of chemotherapy. Thirteen patients (16%) developed a LRF, at an interval of 4-84 months after radiotherapy, with a median of 20 months. The only significant prognostic factor affecting LRF was the combination of chemotherapy, in both the univariate and multivariate analyses. With respect to the sequence of chemoradiation, the sequence had no statistical significance (p=0.90). According to the time interval from mastectomy to the onset of radiotherapy, the LRFR of the patients group treated by RT within or after 6 month postmastectomy 6 months were 14 vs. 27%, respectively (p=0.24). One third of the patients (26/83) developed distant metastasis, in 2-92 months, after radiotherapy, with a median of 21 months. The most commonly involved site was bone in 13 cases. The pathological staging was the only significant prognostic factor in both the univariate and multivariate analyses that affected distant failure. Radiological findingof radiation pneumonitis on a simple chest x-ray was shown in 20% (17/83), with a time interval ranging from 2 to 7 months post-radiotherapy, with a median of 3 months. The stable lung fibrosis settled in 11 patients (65%).
CONCLUSIONS
It was concluded through this analysis that the combination of PMRT with in chemotherapy resulted in better overall survival and local control than PMRT alone in patients needing PMRT.