Association of clinical/pathological parameters with axillary involvement in early breast cancer in patients with limited sentinel node involvement after neoadjuvant chemotherapy (NACT)

Background:

The association of clinical/pathological parameters and residual axillary involvement after NACT is still not sufficiently defined. We used data from the SENTINA trial to analyze this association in a patient population with limited sentinel lymph node (SLN) involvement.

Methods:

Patients were included if before NACT they presented with a clinically negative axilla but showed involvement of < 3 SLNs prior to NACT (Arm B). The association between clinical/pathological parameters and axillary involvement after NACT was analyzed.

Results:

265 of the 360 patients in arm B of the SENTINA were included. After NACT 66/265 (24.9%) patients had involved SLNs or non-SLNs; 71/265 (26.8%) achieved a pCR in the breast. We observed a significant association between pCR in the breast and ER negativity (p < 0.0001), PR negativity (p < 0.0001) and triple negative (TN) status (p = 0.001). However, no statistically significant association between residual axillary involvement after NACT and ER (p = 0.381), PR (p = 0.52), HER2 (p = 0.771), TN status (p = 0.937), grade (G) 1 (p = 0.081), G 2 (p = 0.335), G 3 (p = 0.747), age (p = 0.789), tumor size before NACT (p = 0.761) and pCR in the breast (p = 0.136) could be demonstrated.

Conclusion:

We found no association between residual axillary involvement after NACT and clinical/pathological parameters and we could not identify a subset of patients for whom axillary treatment after NACT could be safely omitted if SLNs were positive prior to therapy even in cases of limited SLN involvement.