The value of radiotherapy in patients with T1-2 N1 M0 triple-negative breast cancer after modified radical mastecomy

SUN Liyun; SHEN Zan

Abstract：Objective To analyze the prognosis of patients with T1-2 N1 M0 triple-negative breast cancer(TNBC) after modified radical mastectomy with or without postoperative radiotherapy. Methods One hundred and twenty-nine patients diagnosed with T1-2 N1 M0 TNBC after modified radical mastectomy from Jan. 2004 to Sep. 2010 were retrospectively reviewed. Of whom 61 cases received postoperative radiotherapy and 68 cases did not. The 5-year overall survival(OS), locoregional recurrence-free survival(LRFS)and dis-ease-free surviva(DFS) rates of the two groups were observed. The risk factors for LRFS were analyzed in combination with clinical and patholgical features. Results With a median follow-up of 67 months, 27 patients developed locoregional recurrence. The patients trea-ted with radiotherapy had significantly higher LRFS rates(88. 5% vs. 70. 6%, P= 0. 017) as well as slightly higher DFS rates(78. 7%vs. 63. 2%,P= 0. 068).The 5-year OS rates were 88. 5% and 82. 4%(P= 0. 068), respectively. The univariate analysis indicated that age, T stage, the number of positive lymph nodes and postoperative radiotherapy were significant influencing factors for LRFS( P<0. 05). The multivariate analysis showed that no radiotherapy(HR = 3. 432,P = 0. 010) and 3 positive lymph nodes(HR = 2. 915,P =0. 020)were independent prognostic factors for LRFS. Conclusion T1-2 N1 M0 TNBC after modified radical mastectomy patients may benefit from radiotherapy, which significantly improves locoregional recurrence-free survival. The local control rates of patients with 3 positive axillary nodes was worse, so increasing regional lymph node irradiation should be feasible.