Post-operative radiotherapy is beneficial for T1/T2 triple negative breast cancer patients with four or more positive lymph nodes

Abstract

The efficacy of adjuvant radiotherapy for the treatment of triple negative breast cancer patients with varying numbers of positive lymph nodes is not clear. We assessed the association between adjuvant radiotherapy and survival in 943 T1/T2 triple negative breast cancer patients treated at our institute between 2008 and 2012. We determined that post-operative radiotherapy improved overall survival (OS), disease-free survival (DFS), and local recurrence-free survival (LRFS) in patients with ≥ 4 positive nodes (p = 0.037, p = 0.035, and p = 0.012, respectively). Although Cox regression analysis demonstrated that radiotherapy was a significant prognostic factor in triple negative breast cancer with ≥ 4 positive nodes, post-operative radiotherapy had no clear effect on OS, DFS, or LRFS in patients with 1-3 positive nodes (p = 0.849, p = 0.860, and p = 0.162, respectively). The prognosis (i.e., OS, DFS, and LRFS) of triple negative breast cancer patients without lymph node metastasis who underwent breast-conserving surgery and post-operative radiotherapy was similar to that of patients who underwent mastectomy alone (p = 0.336, p = 0.537, and p = 0.978, respectively). Our findings demonstrate that post-operative radiotherapy is beneficial for T1/T2 triple negative breast cancer patients with ≥ 4 positive lymph nodes.

The effect of postmastectomy radiotherapy in node-positive triple-negative breast cancer

“…Adjuvant radiotherapy after mastectomy has been shown to reduce the 5-year LRR by 17% (6% vs. 23%) and the 15-year breast cancer mortality by 5.4% (54.7% vs. 60.1%, P < 0.001) when compared to those without radiotherapy for node-positive cancer [ 14 ]. The American Society of Clinical Oncology (ASCO) recommends that PMRT can be used as a standard essential treatment for patients with ≥4 positive axillary lymph nodes [ 15 ]; other researchers have accordingly shown that TNBC patients with positive lymph nodes are also equally eligible for PMRT [ 16 , 17 ]. However, the classification criteria of the number of lymph nodes is difficult to implement for some patients.…”

Survival following radiotherapy in young women with localized early‐stage breast cancer according to molecular subtypes

“…However, all of these do not mean that RT in TNBC is not important. Studies clarified that postoperative radiotherapy for TNBC patients could reduce the local recurrence rate, especially for the patients with ≥4 positive axillary lymph nodes . In addition, we could discover and target specific potential biomarkers to regulate the proliferation and radio‐sensitivity of TNBC cells.…”

“…Despite the limitations, our study has several of strengths. No previous study has focused on the survival benefit in young early‐stage breast cancer for RT, though many have shown improvement in local control and local‐regional recurrence with postoperative radiation . This is the first study comparing the RT benefit in young women with localized early stage breast cancer according to molecular subtypes via PSM to minimize potential bias.…”

Postmastectomy Radiotherapy Can Decrease Locoregional Recurrence in Triple Negative T1-2N1 Breast Cancer Patients

“…[8] The role of PMRT in patients with early-stage T1-2 disease with limited nodal metastasis (one to three positive nodes) is still controversial. [11,12] Some studies have shown that post-mastectomy radiotherapy is beneficial for patients with 1-3 positive nodes. [8, 9, 13-15] However, McBride et al reported that patients with 1-3 positive nodes without risk features had a low rate of locoregional recurrence, even without radiotherapy.…”