Lymph node involvement in immunohistochemistry-based molecular classifications of breast cancer

Abstract

Background Prognosis and treatment options differ for each molecular subtype of breast cancer, but risk of regional lymph node (LN) metastasis for each subtype has not been well-studied. Since LN status is the most important predictor for prognosis, the aim of this study is to investigate the propensity for LN metastasis in each of the five breast cancer molecular subtypes. Methods Under an IRB-approved protocol, we retrospectively reviewed the charts of all pathologically confirmed breast cancer cases from 1/2004 to 6/2012. Five subtypes were defined as luminal A (hormone receptor +, Ki67 low), luminal B (hormone receptor+, Ki67 high), luminal-human epidermal growth factor receptor 2 (HER-2), HER-2-enriched (hormone receptor negative), and triple negative (TN). Results A total of 375 patients with complete data were classified by subtype: 95 (25.3%) luminal A, 120 (32%) luminal B, 69 (18.4%) luminal-HER-2, 26 (6.9%) HER-2-enriched, and 65 (17.3%) TN. On univariate analysis, age (<50), higher tumor grade, HER-2 + status, tumor size, and molecular subtype were significant for LN positivity. Molecular subtype correlated strongly with tumors size (X2; p=0.0004); therefore, multivariable logistic regression did not identify molecular subtype as an independent variable to predict LN positivity. Conclusions Luminal A tumors have the lowest risk of LN metastasis, while luminal HER-2 subtype has the highest risk of LN metastasis. Immunohistochemical-based molecular classification can be readily performed and knowledge of the factors that affect LN status may help with treatment decisions.

Correlation between p53 and epidermal growth factor receptor expression in breast cancer classification

“…In this study, the Expert Consensus of the 2013 St. Gallen International Breast Cancer Conference was used to analyze the subtypes of breast cancer and showed that luminal B was the most common subtype (37.5%) in this group of subjects, followed by TNBC (26.1%), luminal A (23.9%), and the HER2-enriched subtype (12.5%), findings consistent with the results from El Fatemi et al (2012), Howland et al (2013), andGoldhirsch et al (2013). In this study, the positive rate of CK5/6 was 52.2% in TNBC.…”

A histomorphologic predictive model for axillary lymph node metastasis in preoperative breast cancer core needle biopsy according to intrinsic subtypes

“…Although the small cell feature with crushing artifact is a characteristic finding of small cell lung carcinoma with a reported higher risk of annual mortality compared to non-small cell lung carcinoma [27], this feature cannot be applied to our results due to discordant results on immunohistochemical stains. In this study, invasive carcinoma with solid sheet growth frequently observed in basal-like intrinsic subtype showed weak correlations with nodal involvement, which is similar to the results from a previous study [28]. In our opinion, this finding might be related to the cohesive nature of the tumor nests found in basal-like subtype in contrast to other invasive carcinomas with small cell carcinoma-like growth composed of relatively less cohesive and scattered tumor cell growth with higher frequencies of LNM.…”

Mammographic tumour appearance and triple-negative breast cancer associated with long-term prognosis of breast cancer death: A Swedish Cohort Study

“…TNBCs comprise about 10-25% of all breast cancers [1,2,[7][8][9][10][11][12][13][14][24][25][26][27], and 14% of subjects had TNBC in our study. Previous studies have shown that large tumours are statistically significantly preponderant in TNBCs compared to NTNs.…”