Locally advanced breast cancer is the number of dissected nodes after neoadjuvant chemotherapy important?

To assess whether the number of lymph nodes (LN) in breast cancer (BC) patients undergoing axillary dissection (AD) after neoadjuvant chemotherapy affects disease-free survival (DFS) and overall survival (OS).

Descriptive, retrospective, longitudinal cut-off study (2011-2020).

391 patients, 176 patients in the <10 LNs group and 215 ≥10 dissected LGs. The mean number of dissected nodes was 6.2 and 13.8 in the < or ≥ 10 LN groups, respectively. The <10 LN group had a higher proportion of stage IIIB (p = 0.012) and ypN0 (p = 0.001) patients and higher frequency in the phenotypes: luminal A 23.5%, TN 24.1% and HER 2 18.7% when compared with patients with ≥10 LN. Patients with ≥10 LN retrieved had a higher mean OS compared to the group of patients <10 LN with no statistical association (p = 0.184) (hazard ratio = 1.91 95% CI: 0.73-4.98) and a survival probability at 120 months (both groups) of 96.2%. There was also no statistical difference in the DFS when comparing the two groups of patients, indicating that the number of nodes removed is not associated with a differential risk of relapse, with a survival probability at 120 months of 63.3%.

The results of the study indicate that the number of nodes removed during AD does not affect survival (OS and EFS) in patients with neoadjuvant (ypN0/ypN+) BC. Axillary staging remains a key factor in the management of BC; therefore, an individualised approach considering the response to triple negative breast cancer and tumour burden in therapeutic decision making is recommended.