ALNM in PMBC: Clinicopathologic & Ultrasonographic Features

Na Li and the team aimed to study the sonographic and clinicopathologic characteristics associated with axillary lymph node metastasis (ALNM) for pure mucinous carcinoma of breast (PMBC) a subtype of breast cancer (BC).

They performed an inclusive analysis on 176 patients diagnosed with PMBC following surgery. These patients were categorized into 2 groups based on ALNM: ALNM group (n = 15) and non-ALNM group (n = 161).

Clinical factors including patient age, tumor size, and location, as well as molecular biomarkers (ER, PR, HER2, and Ki-67) and sonographic features (shape, orientation, margin, echo pattern, posterior acoustic pattern, and vascularity) were analyzed between the two groups. This analysis aimed to elucidate the clinicopathologic and ultrasonographic characteristics associated with ALNM in PMBC.

About 8.5% of patients in the study exhibited ALNM. Tumors located in the outer side of the breast, comprising the upper outer quadrant and lower outer quadrant, demonstrated a significantly higher likelihood of lymphatic metastasis compared to other locations (86.7% vs. 60.3%, P = 0.043). There was no significant association between ALNM and patient age (P = 0.437). Although tumor size did not show a significant association with ALNM (P = 0.418), the average tumor size was larger in the ALNM group (32.3 ± 32.7 mm) compared to the non-ALNM group (25.2 ± 12.8 mm).

All tumors expressed progesterone receptor (PR) positively, and 90% expressed estrogen receptor (ER) positively. Human epidermal growth factor receptor 2 (HER2) was positive in two cases in the non-ALNM group. Ki-67 high expression was observed in 36 tumors (20.5%), with a higher proportion in the ALNM group compared to the non-ALNM group (33.3% vs. 19.3%), although this difference was not statistically significant (P = 0.338).

The study concluded that tumor location plays a significant role in ALNM in PMBC, with outer side locations showing a higher propensity for ALNM. Additionally, tumors with larger sizes and/or higher Ki-67 expression levels were more likely to present with lymphatic metastasis.

This study was supported by the National Nature Science Foundation of China.

Source: https://pubmed.ncbi.nlm.nih.gov/38745134/

Li N, Li JW, Qian Y, et al. (2024). “Axillary lymph node metastasis in pure mucinous carcinoma of breast: clinicopathologic and ultrasonographic features.” BMC Med Imaging. 2024 May 14;24(1):108. doi: 10.1186/s12880-024-01290-9. PMID: 38745134; PMCID: PMC11094983.