Effect of Hydrochloric Acid Decalcification on Expression Pattern of Prognostic Markers in Invasive Breast Carcinomas.

CONTEXT: In the United States, it is estimated that 100,000 people are living with metastatic breast cancer (BC) with bone representing the most common site of involvement. However, patients with isolated bone metastasis at presentation may have a longer survival. Therapeutic options for BC bone metastases often include systemic anticancer therapy (endocrine, chemotherapy, monoclonal antibodies, and/or other targeted therapies), which is largely dependent on the immunohistochemical (IHC) repertoire of the cancer for the prognostic markers [estrogen (ER) and progesterone receptors (PR), Ki-67, p53, and Her-2/neu] at its osseous metastatic site. Traditionally, specimens obtained from the bone metastasis require decalcification, which may affect the immunoreactivity of these prognostic markers. To the best of our knowledge, limited studies describe the effect of decalcification on immunoexpression of the above-mentioned markers. A detailed illustration of the effect of decalcification on BC specimens in a real-time manner is lacking in the literature. OBJECTIVE: Herein, we sought to determine the impact of decalcification on the IHC expression pattern of the above listed markers on BC tissue following decalcification. DESIGN: After Institutional Review Board approval, sections from the residual tumor specimens were collected prospectively from 15 BC excision specimens and 1 curetting from a BC bone metastasis. The sections (3 to 6 sections/case) for decalcification were collected following routine submission for pathologic evaluation. The sections were subjected to hydrochloric acid (HCl)-based Decal Stat decalcifying solution for 2, 12, 18, and 24 hours in each case. IHC studies for ER, PR, Ki-67, p53, and Her-2/neu were performed on 1 representative section of the regularly processed tumor block and 1 decalcified tumor block from each time point. Scoring of ER and PR were performed according to the Allred scoring system. Scoring of Her-2/neu was performed according to CAP/ASCO guidelines. RESULTS: The tumors comprised 11 grade 3 invasive ductal carcinomas, 2 grade 2 invasive ductal carcinomas, 2 grade 3 invasive lobular carcinoma, and 1 metastatic BC to bone. Nine cases showed Allred score 8 for ER, 1 case showed Allred score 4, 1 case showed Allred score 2, and the remaining 5 were ER negative. For PR, 1 showed Allred score 8, 2 Allred score 7, 4 Allred score 6, 1 each Allred score 5 and score 2 with the remainder negative for PR. Ki-67 ranged from 5% to 95%. Five cases showed p53 overexpression ranging from 35% to 95%. Five cases each showed 3+, 6 cases showed 2+ Her-2/neu, 3 cases showed 1+ Her-2/neu, and the remaining 2 were negative. All specimens demonstrated decline in ER, PR, Ki-67, and p53 immunoreactivity after 2 hours of decalcification, with additional decline up to 24 hours. The most significant declines in immunoreactivity occurred with Ki-67 and p53. Most of the Her-2/neu cases with an equivocal score declined to zero after 24 hours of decalcification. However, 3 out of 11 cases showing Her-2/neu overexpression remained at the baseline scoring even after extended (24 h) decalcification. CONCLUSIONS: Our results demonstrated that the decalcification process affects the immunoreactivity of the prognostic BC markers. There is progressive loss of reactivity at 2 hours and beyond for markers with lower degrees of expression. In addition, heterogeneity in marker distribution progressed from diffuse to more focal beyond 1 hour.

Mucinous Carcinoma with Neuroendocrine Differentiation of Salivary Gland Origin.

Primary mucinous adenocarcinomas of the salivary gland are rare malignancies defined by aggregates of epithelial cells suspended in large pools of extracellular mucin. We report a case of a giant mucinous adenocarcinoma of salivary gland origin, with low-grade cytoarchitectural features and neuroendocrine differentiation arising in the submental region. Grossly, the tumor measured 12.5 × 13.4 × 8.2 cm and replaced the bone and soft tissues of the anterior oral cavity. Microscopically, the neoplasm was composed of large extracellular pools of mucin, which contained papillary and acinar aggregates, and small nodules of ductal type epithelium with minimal nuclear enlargement, powdery chromatin and little pleomorphism. The nodules comprised 20 % of the tumor and showed morphologic and immunohistochemical evidence of neuroendocrine differentiation. Examination revealed histologic features comparable to mammary gland analogues in mucin predominance, ductal type morphology, expression of estrogen and progesterone receptors, and GATA-3 positivity. This is the first case reported of mucin-rich carcinoma of salivary gland origin exhibiting neuroendocrine differentiation.

Effects of tissue decalcification on the quantification of breast cancer biomarkers by digital image analysis.

BACKGROUND: Recent technical advances in digital image capture and analysis greatly improve the measurement of protein expression in tissues. Breast cancer biomarkers provide a unique opportunity to utilize digital image analysis to evaluate sources of variability that are caused by the tissue preparation, in particular the decalcification treatment associated with the analysis of bone metastatic breast cancer, and to develop methods for comparison of digital data and categorical scores rendered by pathologists. METHODS: Tissues were prospectively decalcified for up to 24 hours and stained by immunohistochemistry (IHC) for ER, PR, Ki-67 and p53. HER2 positive breast cancer sections were retrieved from the pathology archives, and annotated with the categorical HER2 expression scores from the pathology reports. Digital images were captured with Leica and Aperio slide scanners. The conversion of the digital to categorical scores was accomplished with a Gaussian mixture model and tested for accuracy by comparison to clinical scores. RESULTS: We observe significant effects of the decalcification treatment on common breast cancer biomarkers that are used in the clinic. ER, PR and p53 staining intensities decreased 15 - 20%, whereas Ki-67 decreased > 90% during the first 6 hrs of treatment and stabilized thereafter. In comparison with the Aperio images, pixel intensities generated by the Leica system are lower. A novel statistical model for conversion of digital to categorical scores provides a systematic approach for conversion of nuclear and membrane stains and demonstrated a high concordance with clinical scores. CONCLUSION: Digital image analysis greatly improves the quantification of protein expression in human tissues. Decalcification affects the accuracy of immunohistochemical staining results and cannot be reversed by image analysis. Measurement data obtained on a continuous scoring scale can be converted to categorical scores for comparison with categorical dataset that are generated by pathologists. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_213.