benefit of postoperative radiotherapy in high-risk premenopausal women with breast cancer who receive adjuvant chemotherapy

ABSTRACT

Postoperative radiotherapy has been known to reduce rates of loco regional recurrences in women with breast cancer, but whether it prolongs overall survival is still a controversial subject. This randomized trial was conducted to test the effect of postoperative radiotherapy in high-risk premenopausal women with breast cancer who also received adjuvant systemic chemotherapy. A total of 82 high-risk pre menopausal women with breast cancer were randomly assigned, after modified radical mastectomy to receive either chemotherapy plus radiotherapy or chemotherapy alone. Radiotherapy was given to the chest wall and regional lymph nodes between the third and fourth cycles of FAC chemotherapy [5-Flourouracil. Doxorubicin and Cyclophosphamide], each cycle was administered every 3 weeks for 6 cycles. The end points were loco regional recurrence, distant metastases, disease free survival and overall survival. After 5 years of follow up, the frequency of loco regional recurrence alone or with distant metastases was 9.5% among the women assigned to radiotherapy plus FAC and 35% among those treated only with FAC [P = 0.005]. The disease free survival was 61.9% among the women who received radiotherapy plus FAC and 40% among those treated only with FAC [P = 0.047]. The overall survival was 73.8% among those given radiotherapy and FAC and 52.5% among those who received FAC alone [P = 0.045]. Multivariate analysis demonstrated that post mastectomy radiation therapy significantly improved disease free survival and overall survival irrespective of tumor size, the number of positive nodes, or the histopathological grade [p0.042 and p=0.014 respectively]. The addition of radiotherapy to adjuvant chemotherapy after modified radical mastectomy reduces locoregional recurrences and prolongs survival in high risk premenopausal women with breast cancer