Pathological non-response to chemotherapy in a neoadjuvant setting of breast cancer: an inter-institutional study

To identify markers of non-response to neoadjuvant chemotherapy (NAC) that could be used in the adjuvant setting. Sixteen pathologists of the European Working Group for Breast Screening Pathology reviewed the core biopsies of breast cancers treated with NAC and recorded the clinico-pathological findings (histological type and grade; estrogen, progesterone receptors, and HER2 status; Ki67; mitotic count; tumor-infiltrating lymphocytes; necrosis) and data regarding the pathological response in corresponding surgical resection specimens. Analyses were carried out in a cohort of 490 cases by comparing the groups of patients showing pathological complete response (pCR) and partial response (pPR) with the group of non-responders (pathological non-response: pNR). Among other parameters, the lobular histotype and the absence of inflammation were significantly more common in pNR (p < 0.001). By ROC curve analyses, cut-off values of 9 mitosis/2 mm(2) and 18 % of Ki67-positive cells best discriminated the pNR and pCR + pPR categories (p = 0.018 and < 0.001, respectively). By multivariable analysis, only the cut-off value of 9 mitosis discriminated the different response categories (p = 0.036) in the entire cohort. In the Luminal B/HER2- subgroup, a mitotic count < 9, although not statistically significant, showed an OR of 2.7 of pNR. A lobular histotype and the absence of inflammation were independent predictors of pNR (p = 0.024 and < 0.001, respectively). Classical morphological parameters, such as lobular histotype and inflammation, confirmed their predictive value in response to NAC, particularly in the Luminal B/HER2- subgroup, which is a challenging breast cancer subtype from a therapeutic point of view. Mitotic count could represent an additional marker but has a poor positive predictive value

Nodal-Stage Classification in Invasive Lobular Breast Carcinoma: Influence of Different Interpretations of the pTNM Classification

Purpose Application of current nodal status classification is complicated in lobular breast carcinoma metastases. The aim of this study was to define the optimal interpretation of the pTNM classification in sentinel node (SN) -positive patients to select patients with limited or with a high risk of non-SN involvement. Patients and Methods SN metastases of 392 patients with lobular breast carcinoma were reclassified according to interpretations of the European Working Group for Breast Screening Pathology (EWGBSP) and guidelines by Turner et al, and the predictive power for non-SN involvement was assessed. Results Reclassification according to definitions of EWGBSP and Turner et al resulted in different pN classification in 73 patients (19%). The rate of non-SN involvement in the 40 patients with isolated tumor cells according to Turner et al and with micrometastases according to EWGBSP was 20%, which is comparable to the established rate for micrometastases. The rate of non-SN involvement in the 29 patients with micrometastases according to Turner et al and with macrometastases according to EWGBSP was 48%, which is comparable to the established rate for macrometastases. Therefore, the EWGBSP method to classify SN tumor load better reflected the risk of non-SN involvement than the Turner et al system. Conclusion Compared with the guidelines by Turner et al, the EWGBSP definitions better reflect SN metastatic tumor load and allow better differentiation between patients with lobular breast carcinoma who have a limited or a high risk of non-SN metastases. Therefore, we suggest using the EWGBSP definitions in these patients to select high-risk patients who may benefit from additional local and/or systemic therapy

Validation of clinical prediction rules for a low probability of nonsentinel and extensive lymph node involvement in breast cancer patients

BACKGROUND: Two recently developed clinical prediction rules aim to anticipate the lack of nonsentinel lymph node metastases and the involvement of less than 4 lymph nodes in breast cancer patients with positive sentinel lymph nodes (SLNs). METHODS: The University of Louisville Breast SLN Study clinical prediction rules were validated on an independent set of SLN-positive patients with tumors < or = 15 mm. RESULTS: The data on 475 and 473 patients, respectively, were used for the validation. The areas under the receiver operating characteristic curves were similar to the originals for both predictive tools (.70 and .76). The lowest score of 1 identified 5 of 7 patients with disease limited to the SLNs and 161 of 165 as having less than 4 involved lymph nodes. CONCLUSIONS: A subset of patients with SLN-only involvement and less than 4 metastatic lymph nodes can probably be identified by means of the Louisville clinical prediction rules, but prediction of the lack of non-SLN metastasis seems less reliable

Sentinel lymph node biopsy in staging small (up to 15 mm) breast carcinomas. Results from a European multi-institutional study.

Sentinel lymph node (SLN) biopsy has become the preferred method for the nodal staging of early breast cancer, but controversy exists regarding its universal use and consequences in small tumors. 2929 cases of breast carcinomas not larger than 15 mm and staged with SLN biopsy with or without axillary dissection were collected from the authors' institutions. The pathology of the SLNs included multilevel hematoxylin and eosin (HE) staining. Cytokeratin immunohistochemistry (IHC) was commonly used for cases negative with HE staining. Variables influencing SLN involvement and non-SLN involvement were studied with logistic regression. Factors that influenced SLN involvement included tumor size, multifocality, grade and age. Small tumors up to 4 mm (including in situ and microinvasive carcinomas) seem to have SLN involvement in less than 10%. Non-SLN metastases were associated with tumor grade, the ratio of involved SLNs and SLN involvement type. Isolated tumor cells were not likely to be associated with further nodal load, whereas micrometastases had some subsets with low risk of non-SLN involvement and subsets with higher proportion of further nodal spread. In situ and microinvasive carcinomas have a very low risk of SLN involvement, therefore, these tumors might not need SLN biopsy for staging, and this may be the approach used for very small invasive carcinomas. If an SLN is involved, isolated tumor cells are rarely if ever associated with non-SLN metastases, and subsets of micrometastatic SLN involvement may be approached similarly. With macrometastases the risk of non-SLN involvement increases, and further axillary treatment should be generally indicated

Sentinel lymph node biopsy and non-sentinel node involvement in special type breast carcinomas with a good prognosis.

This study aimed at identifying factors related to sentinel lymph node (SLN) involvement in patients with tubular, cribriform, mucinous or papillary breast carcinoma and those related to non-SLN metastases if an SLN was positive. Multivariate analyses involved logistic and stepwise regressions. The SLNs harboured metastases in 85 of 572 cases, 78 of whom underwent axillary dissection; 19 presented non-SLN positive disease. Lack of lymphovascular invasion, a tumour size < or = 10 mm and a single SLN removed were the factors predicting an SLN metastasis rate &lt;10%, and patients with these features could be candidates for no surgical axillary staging. A positive SLN proportion of < or = 50% and no lymphovascular invasion were associated with a &lt;10% rate of non-SLN invasion; patients with a positive SLN and these features could be candidates for the omission of completion axillary dissection. The opposite presentation of these factors would mandate SLN biopsy and axillary dissection, respectively