Primary chemotherapy effect in sentinel node detection in breast cancer

Area of Science:

• Oncology
• Surgical Pathology

Background:

• Sentinel node (SN) biopsy is a standard method for breast cancer staging, offering an alternative to axillary dissection.
• Preoperative chemotherapy, while beneficial for tumor reduction, may alter lymphatic pathways and affect SN biopsy accuracy.

Purpose of the Study:

• To evaluate the effectiveness of lymphoscintigraphy and hand-held probe detection for SN biopsy after preoperative chemotherapy.
• To correlate SN biopsy findings with axillary lymph node histology in patients who received neoadjuvant chemotherapy.

Main Methods:

• Prospective study of 83 early-stage breast cancer patients (TNM stage I).
• Patients were divided into two groups: 37 received preoperative chemotherapy (G1), and 46 did not (G2).
• Lymphoscintigraphy was performed using Tc-99m dextran-70, followed by SN biopsy and axillary dissection.

Main Results:

• Sentinel nodes were detected in 94% of patients.
• The rate of false-negative SN biopsies, indicating missed axillary metastases, was significantly higher in the preoperative chemotherapy group (G1) compared to the no-chemotherapy group (G2) (P=0.01).

Conclusions:

• Preoperative chemotherapy appears to negatively impact the reliability of sentinel node biopsy for axillary staging in breast cancer.
• Caution is advised when using SN biopsy for axillary evaluation in patients undergoing neoadjuvant chemotherapy.