Original Article
In patients with micrometastases in sentinel lymph node biopsies, involvement of the non-sentinel lymph nodes cannot be predicted by clinicopathological variables
Abstract
Background: The sentinel lymph node biopsy (SLNB) procedure is long considered as an accurate method of staging the axilla for axillary involvement in early stage breast cancer. The question remains as to whether patients with micrometastases should undergo axillary clearance. We aimed to assess the indicators for positive non-sentinel lymph nodes (SLN) following completion axillary lymph node dissection (CALND).
Methods: We retrospectively analysed our experience of SLNB between July 2008 and July 2013. A total of 1,152 breast cancer patients underwent SLNB based on lymphoscintigraphy, intra-operative gamma probe detection, and blue dye mapping using 99m Tc-nanocolloid and Patent Blue V injected peri-areola. Statistical analysis was performed using Fisher’s exact and χ2 for categorical data.
Results: Out of 1,152 SLNBs performed, 224 (19.4%) were positive for metastatic disease; macrometastases in 150 (67.0%), micrometastases in 72 (32.1%) and isolated tumour cells (ITC) in 2 (0.9%). CALND was not performed in 20 cases (9 macrometastases, 10 micrometastases, and 1 ITC), largely due to concerns regarding fitness for anaesthesia. On univariate analysis, positive non-SLN in CALND for patients with micrometastases on SLNB was not predicted by grade (G0–G2, 6/43; G3; 3/19; P=0.565), size of primary breast tumour (<40 mm, 8/58; ≥40 mm, 1/4; P=0.475), lymph vascular invasion (5/30 vs. 4/31; P=0.503), age (<50 years, 3/24 vs. ≥50 years, 6/38; P=0.496), or number of positive SLNB.
Conclusions: In our series, 14.5% (9/62) of patients with micrometastases had positive non-SLN on CALND, which was not predicted by any clinicopathological characteristics. However, it is important to inform our patients that 14.5% of patients with micrometastases on SLNB may have positive non-SLN.
Methods: We retrospectively analysed our experience of SLNB between July 2008 and July 2013. A total of 1,152 breast cancer patients underwent SLNB based on lymphoscintigraphy, intra-operative gamma probe detection, and blue dye mapping using 99m Tc-nanocolloid and Patent Blue V injected peri-areola. Statistical analysis was performed using Fisher’s exact and χ2 for categorical data.
Results: Out of 1,152 SLNBs performed, 224 (19.4%) were positive for metastatic disease; macrometastases in 150 (67.0%), micrometastases in 72 (32.1%) and isolated tumour cells (ITC) in 2 (0.9%). CALND was not performed in 20 cases (9 macrometastases, 10 micrometastases, and 1 ITC), largely due to concerns regarding fitness for anaesthesia. On univariate analysis, positive non-SLN in CALND for patients with micrometastases on SLNB was not predicted by grade (G0–G2, 6/43; G3; 3/19; P=0.565), size of primary breast tumour (<40 mm, 8/58; ≥40 mm, 1/4; P=0.475), lymph vascular invasion (5/30 vs. 4/31; P=0.503), age (<50 years, 3/24 vs. ≥50 years, 6/38; P=0.496), or number of positive SLNB.
Conclusions: In our series, 14.5% (9/62) of patients with micrometastases had positive non-SLN on CALND, which was not predicted by any clinicopathological characteristics. However, it is important to inform our patients that 14.5% of patients with micrometastases on SLNB may have positive non-SLN.
