The Role of Level III Dissection in Locally Advanced Breast Cancer following Neoadjuvant Chemotherapy-A Prospective Study.

Nisha Prasannan Breast cancer is the most common female cancer in India, with a significant number presenting as locally advanced breast cancer (LABC). Level III clearance is routinely performed in our institute in LABC following neoadjuvant chemotherapy (NACT). In our previous retrospective study, level III positivity rate was 15.5%. We aim to prospectively assess level III positivity rate in LABC patients post-NACT. This is a prospective study of female patients with LABC (defined as cT3N1-3M0 or cT4N0-3M0 or cT _any N2,3M0) who received NACT and underwent surgery including level III dissection from November 2019 to October 2021. Data collected included age, menopausal status, TNM stage at presentation, grade, hormone receptor and HER2 status, treatment response, ycT and ycN stage, and final histopathology. Univariate and multivariate analysis was undertaken. p -Value less than or equal to 0.05 was considered significant. Study recruited 598 patients. Level III node positivity rate was 8.4%. The clinical complete response rate (cCR) was 36% (215/598). On univariate analysis, significant association was present between level III node and cCR ( p  < 0.01), ycT0 stage ( p  = 0.001), ycN0 stage ( p  = 0.028), level II node positivity ( p  = 0.001), ypT stage ( p  = 0.001), and ypN stage ( p  = 0.001). On multivariate analysis, significant association was present between level III node and ycT stage ( p  < 0.001), ypT stage ( p  = 0.001), and ypN stage ( p  = 0.001). Level III positivity rate in LABC post-NACT is high. In patients with advanced ycT stage, it would be advisable to offer complete axillary dissection including level III. Level III dissection may be avoided in patients with ycT0 or ycN0 or with cCR.