Use of post-mastectomy radiotherapy in patients receiving completion axillary lymph node dissection after a positive sentinel lymph node biopsy
Menée sur 345 patientes atteintes d'un cancer du sein traité par mastectomie et ayant subi un curage ganglionnaire axillaire après une biopsie du ganglion sentinelle dont le résultat s'est avéré positif, cette étude évalue la proportion de patientes ayant reçu une radiothérapie après le curage ganglionnaire, puis évalue le risque de récidive loco-régionale en fonction du traitement reçu (radiothérapie ou non) et de la présence d'une atteinte ganglionnaire axillaire
Purpose : We sought to determine the rate of PMRT among women treated with ALND after a positive SLN biopsy and to establish the effect of a negative ALND and PMRT on local-regional recurrence (LRR) and overall survival (OS). Methods : All patients were treated with mastectomy and ALND after a positive SLN biopsy. All patients were clinical N0 or Nx at the time of mastectomy and received no neoadjuvant therapy. The presence of LVSI, multifocality, number of positive SLN and non-sentinel lymph nodes, clinical/pathologic stage, extranodal extension, age, and use of PMRT were evaluated for significance on the rates of OS and LRR. Results : A total of 345 patients were analyzed. ALND after positive SLN biopsy was negative in 235 patients (68.1%), and a total of 112 patients (32.5%) received XRT. On multivariate analysis, only pathologic stage III predicted for lower OS (HR 3.32, p<0.001). The rate of 10-year freedom from LRR was 87.9% and 95.3% in patients with positive and negative ALND, respectively. In negative ALND patients with >3 positive SLN, freedom from LRR was 74.7% compared to 96.7% in those with < 3 positive SLN (p=0.009). In patients with negative ALND, >3 positive SLN predicted for an increase in LRR on MVA (HR 10.10, p=0.034). Conclusions : A low proportion of cT1-2, N0 patients with positive SLNs who undergo mastectomy receive PMRT after ALND. Even in this low risk cohort, patients with >3 positive SLN and a negative ALND are at increased risk for LRR and may benefit from PMRT.