Clinical applications of breast pathology: management of in situ breast carcinomas and sentinel node biopsy issues

The Role of Sentinel Lymph Node Biopsy and Factors Associated with Invasion in Extensive DCIS of the Breast Treated by Mastectomy: The Cinnamome Prospective Multicenter Study

Background

When invasive components are discovered at mastectomy for vacuum-assisted biopsy (VAB)-diagnosed ductal carcinoma in situ (DCIS), the only option available is axillary lymph node dissection (ALND). The primary aim of this prospective multicenter trial was to determine the benefit of performing upfront sentinel lymph node (SLN) biopsy for these patients. The secondary aim was to determine DCIS factors associated with microinvasion or invasion.

Methods

The SLN procedure was performed during mastectomy, and for positive SLN an ALND was performed during the same intervention. A tissue microarray containing DCIS lesions from the mastectomy specimens was subsequently performed.

Results

From May 2008 to December 2010, 228 patients were enrolled from 14 French cancer centers, including 192 eligible patients with pure DCIS on VAB and successful SLN procedures. ALND was avoided for 51 [67 %; 95 % confidence interval (CI), 56–77 %] of all the patients who had microinvasive DCIS or DCIS associated with invasive carcinoma at mastectomy and a negative SLN. Of the 192 patients, 76 (39 %) with VAB-diagnosed DCIS were upgraded after mastectomy to micro (n = 20) or invasive disease (n = 56). The rate of positive SLN for patients with DCIS on VAB was 14 %. High nuclear grade of DCIS was associated with greater risk of microinvasion and invasion, and HER2-amplified DCIS was associated with greater risk of invasion.

Conclusions

Underestimation of invasive components is high when DCIS is diagnosed by VAB in patients undergoing mastectomy. Upfront SLN for patients with VAB-diagnosed extensive DCIS avoids unnecessary ALND for two-thirds of patients with micro or invasive disease on mastectomy.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-015-4476-5) contains supplementary material, which is available to authorized users.

Basal cytokeratin as a potential marker of low risk of invasion in ductal carcinoma in situ

OBJECTIVES

Biological markers that predict the development of invasive breast cancer are needed to improve personalized therapy for patients diagnosed with ductal carcinoma in situ. We investigated the role of basal cytokeratin 5/6 in the risk of invasion in breast ductal carcinoma in situ.

METHODS

We constructed tissue microarrays using 236 ductal carcinoma in situ samples: 90 pure samples (group 1) and 146 samples associated with invasive carcinoma (group 2). Both groups had similar nuclear grades and were obtained from patients of similar ages. The groups were compared in terms of estrogen (ER) and progesterone receptor (PR) status, human epidermal growth factor receptor 2 (HER2) expression, cytokeratin 5/6 immunostaining, human epidermal growth factor receptor 1 (EGFR) membrane staining and molecular subtype, as indicated by their immunohistochemistry profiles.

RESULTS

ER/PR-negative status was predictive of invasion, whereas HER2 superexpression and cytokeratin 5/6-positive status were negatively associated with invasion. Among the high-grade ductal carcinoma in situ cases, a triple-positive profile (positive for estrogen receptor, progesterone receptor, and HER2) and cytokeratin 5/6 expression by neoplastic cells were negatively associated with invasion. In the low-grade ductal carcinoma in situ subgroup, only cytokeratin 5/6 expression exhibited a negative association with the probability of invasion.

CONCLUSION

The immunohistochemical expression of cytokeratin 5/6 by ductal carcinoma in situ epithelial cells may provide clinically useful information regarding the risk of progression to invasive disease.