Shu Ichihara

Breast cancer prognostic classification in the molecular era: the role of histological grade

Breast cancer is a heterogeneous disease with varied morphological appearances, molecular features, behavior, and response to therapy. Current routine clinical management of breast cancer relies on the availability of robust clinical and pathological prognostic and predictive factors to support clinical and patient decision making in which potentially suitable treatment options are increasingly available. One of the best-established prognostic factors in breast cancer is histological grade, which represents the morphological assessment of tumor biological characteristics and has been shown to be able to generate important information related to the clinical behavior of breast cancers. Genome-wide microarray-based expression profiling studies have unraveled several characteristics of breast cancer biology and have provided further evidence that the biological features captured by histological grade are important in determining tumor behavior. Also, expression profiling studies have generated clinically useful data that have significantly improved our understanding of the biology of breast cancer, and these studies are undergoing evaluation as improved prognostic and predictive tools in clinical practice. Clinical acceptance of these molecular assays will require them to be more than expensive surrogates of established traditional factors such as histological grade. It is essential that they provide additional prognostic or predictive information above and beyond that offered by current parameters. Here, we present an analysis of the validity of histological grade as a prognostic factor and a consensus view on the significance of histological grade and its role in breast cancer classification and staging systems in this era of emerging clinical use of molecular classifiers.

Basal-like and triple-negative breast cancers: a critical review with an emphasis on the implications for pathologists and oncologists

Breast cancer is a heterogeneous disease encompassing a variety of entities with distinct morphological features and clinical behaviors. Although morphology is often associated with the pattern of molecular aberrations in breast cancers, it is also clear that tumors of the same histological type show remarkably different clinical behavior. This is particularly true for ‘basal-like cancer’, which is an entity defined using gene expression analysis. The purpose of this article was to review the current state of knowledge of basal-like breast cancers, to discuss the relationship between basal-like and triple-negative breast cancers, and to clarify practical implications of these diagnoses for pathologists and oncologists.

Real-time endobronchial ultrasound-guided transbronchial needle aspiration is useful for diagnosing sarcoidosis.

Background and objective:  Several studies of real‐time endobronchial ultrasound (EBUS)‐guided transbronchial needle aspiration (TBNA) have reported a sensitivity of approximately 90% in the diagnosis of mediastinal and hilar malignancies. However, few studies have addressed its role in the diagnosis of sarcoidosis. The aim of the present study was to assess the utility of EBUS‐TBNA in confirming a pathological diagnosis of sarcoidosis.

Prospective study of endobronchial ultrasound-guided transbronchial needle aspiration of lymph nodes versus transbronchial lung biopsy of lung tissue for diagnosis of sarcoidosis

OBJECTIVE Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been reported to be an accurate and safe method to confirm a pathologic diagnosis of sarcoidosis. However, only a few retrospective or small prospective studies have been published on EBUS-TBNA versus transbronchial lung biopsy (TBLB), which has been the standard method for making a pathologic diagnosis of sarcoidosis so far. The aim of this study was to compare the diagnostic yield of EBUS-TBNA and TBLB through a flexible bronchoscope in patients with stage I and II sarcoidosis. METHODS A total of 62 patients with suspected stage I and II sarcoidosis were included in this prospective study. EBUS-TBNA was performed (2 lymph nodes, 2 needle passes for each lymph node), followed by TBLB (5 biopsy specimens from multiple lung segments) in the same setting. The final diagnosis of sarcoidosis was based on clinicoradiologic compatibility and pathologic findings. RESULTS Of the 62 patients enrolled, 54 were given a final diagnosis of sarcoidosis. The diagnostic yield of EBUS-TBNA and TBLB for sarcoidois by showing noncaseating epithelioid cell granuloma was 94% (stage I, 97%; stage II, 88%) and 37% (stage I, 31%; stage II, 50%), respectively. The difference was statistically significant (P < .001). One case of pneumothorax and 3 cases of moderate bleeding (7%) resulted from TBLB, and 1 case of severe cough (2%) from EBUS-TBNA. CONCLUSIONS The diagnostic yield of EBUS-TBNA for stage I and II sarcoidosis is higher than for TBLB.

Phyllodes tumours of the breast: a consensus review.

Phyllodes tumours constitute an uncommon but complex group of mammary fibroepithelial lesions. Accurate and reproducible grading of these tumours has long been challenging, owing to the need to assess multiple stratified histological parameters, which may be weighted differently by individual pathologists. Distinction of benign phyllodes tumours from cellular fibroadenomas is fraught with difficulty, due to overlapping microscopic features. Similarly, separation of the malignant phyllodes tumour from spindle cell metaplastic carcinoma and primary breast sarcoma can be problematic. Phyllodes tumours are treated by surgical excision. However, there is no consensus on the definition of an appropriate surgical margin to ensure completeness of excision and reduction of recurrence risk. Interpretive subjectivity, overlapping histological diagnostic criteria, suboptimal correlation between histological classification and clinical behaviour and the lack of robust molecular predictors of outcome make further investigation of the pathogenesis of these fascinating tumours a matter of active research. This review consolidates the current understanding of their pathobiology and clinical behaviour, and includes proposals for a rational approach to the classification and management of phyllodes tumours.

Lobular neoplasia of the breast revisited with emphasis on the role of e-cadherin immunohistochemistry

Lobular neoplasia (LN) is a term that encompasses both lobular carcinoma in situ and atypical lobular hyperplasia. These lesions have been shown to constitute both risk indicators and nonobligate precursors of invasive breast cancer, they are relatively uncommon, and are most often identified in specimens taken for other reasons. Their incidence has increased in the last 2 decades, and novel variants, including a pleomorphic type, have been described. Loss of E-cadherin expression is recognized as a hallmark diagnostic feature of LN and invasive lobular carcinomas, and immunohistochemical (IHC) analysis using anti-E-cadherin antibodies has been proven to be a useful method to differentiate between lobular and ductal lesions. The frequent use of E-cadherin IHC analysis in routine diagnostic histopathology, however, has resulted in confusion with regard to the actual value of IHC with antibodies against E-cadherin and other proteins of the cadherin-catenin complex. This review provides an update on recent clinicopathologic and molecular data on LN and invasive lobular carcinoma and a discussion about the use and limitations of IHC with E-cadherin in diagnostic breast pathology.

The Role of Contrast-Enhanced MR Mammography for Determining Candidates for Breast Conservation Surgery

PurposeThe aim of this study was to assess the impact of preoperative magnetic resonance mammography (MRM) on the surgical determination of breast conservation treatment for breast cancer patients.MethodsFrom September 1997 to March 2000, 57 consecutive breast conservation treatment candidates were prospectively evaluated with conventional imaging studies (mammography and ultrasonography) and preoperative MRM.ResultsIn 47 of 54 (87%) breast cancer patients breast conservation surgery (BCS) was indicated on the basis of mammography (MMG) and ultrasonography (US). However in 40 of the 54 (74%) patients BCS was indicated on the basis of MRM. Thirty-eight of the 40 patients ultimately underwent BCS and only 1 showed a positive margin. There were 7 patients whose MRM findings suggested that more aggressive treatment than BCS was needed but for whom US/MMG suggested that BCS was appropriate. Five of the 7 patients underwent mastectomy rather than BCS based on the MRM findings, which were justified by post-surgical histological findings. Of the 2 remaining patients who underwent BCS, one had a positive histological margin and one had recurrence, both of which resulted in salvage mastectomy.ConclusionOur study suggests that high resolution preoperative MRM provides more accurate information compared with US and MMG for selecting candidates for BCS. Using MRM as a routine staging tool may reduce unnecessary repeated excisions. A larger study will be required to confirm these findings and to define the patients most likely to benefit from breast MR imaging.

CD109 expression in basal‐like breast carcinoma

Breast cancer can be classified into several subtypes based on gene expression profiling. Basal‐like breast carcinoma (BLC) has a triple negative phenotype, that is, the subtype lacks the estrogen receptor (ER), progesterone receptor (PgR) and human epidermal growth factor receptor 2 (HER2). It has been recently reported that CD109, a glycosylphosphatidylinositol (GPI)‐anchored cell surface protein, is a new breast myoepithelial marker. In the present study CD109 expression was investigated in invasive ductal carcinomas (IDC) of the breast on immunohistochemistry. Eighty‐eight formalin‐fixed, paraffin‐embedded breast carcinoma sections were immunostained with anti‐CD109, anti‐cytokeratin 5/6 (CK5/6), anti‐calponin, anti‐vimentin and anti‐p63 antibodies. CD109 expression was detected in 18 of 30 basal‐like breast carcinomas (BLC) but not in other types of 53 IDC (non‐BLC) that were positive for ER, PgR and/or HER2. The percentage of CD109‐positive tissues (60%) in BLC was similar to that of CK5/6 (63%) and higher than that of other myoepithelial markers including p63 (23%), calponin (33%) and vimentin (33%). Statistical analysis indicated that the CD109‐positive group in BLC, but not the CK5/6‐positive group in BLC, was associated with reduced fat invasion (P < 0.05). These findings indicate that CD109 is a useful diagnostic marker for BLC and that CD109 expression may affect biological properties of cancer cells.

Serous papillary adenocarcinoma of the female genital organs and invasive micropapillary carcinoma of the breast. Are WT1, CA125, and GCDFP-15 useful in differential diagnosis?

Serous papillary adenocarcinoma of the female genital organs and invasive micropapillary carcinoma of the breast have close histologic similarities. Thus, when these cancers occur synchronously or metachronously in the same patient, it is difficult to determine the primary site. We examined 23 serous papillary adenocarcinomas (16 ovarian, 5 endometrial, and 2 peritoneal) and 37 invasive micropapillary carcinomas of the breast (12 pure and 25 mixed types) on immunohistochemical expression of Wilms tumor antigen-1 (WT1), CA125, and gross cystic disease fluid protein-15 (GCDFP-15), which have been reported to be useful in the differential diagnosis of primary ovarian carcinomas versus metastatic breast cancer to the ovary. The positive rates of WT1, CA125, and GCDFP-15 in serous papillary adenocarcinomas were 78%, 78%, and 0%, respectively, and the corresponding rates in invasive micropapillary carcinomas were 3%, 40%, and 38%. The CA125-positive rate of invasive micropapillary carcinoma was higher than the rate reported for other types of breast carcinomas. We consider CA125 to be not always useful in the differential diagnosis of serous papillary adenocarcinoma and invasive micropapillary carcinoma. Although the positive rate of WT1 was significantly higher in serous papillary adenocarcinoma than in invasive micropapillary carcinoma, WT1 expression in endometrial serous papillary adenocarcinoma was infrequent (20%). WT1 and GCDFP-15 could be useful markers for the differential diagnosis of ovarian and peritoneal serous papillary adenocarcinoma versus breast invasive micropapillary adenocarcinoma. However, the availability of GCDFP-15 is limited because of the low positive rate of GCDFP-15 in invasive micropapillary carcinomas.

CD109, a new marker for myoepithelial cells of mammary, salivary, and lacrimal glands and prostate basal cells.

The CD109 gene encodes a glycosylphosphatidylinositol (GPI)‐anchored cell surface protein. Herein it is shown that CD109 is highly expressed in myoepithelial cells of mammary, salivary, and lacrimal glands; and in prostate basal cells. The anti‐CD109 antibody generated by the authors was available for formalin‐fixed paraffin section, and it strongly stained myoepithelial cells and basal cells but not ductal, acinar, and secretory cells in these glands. CD109 expression was negative in examined breast ductal carcinomas and prostate adenocarcinomas. These findings indicate that CD109 is a useful marker for the diagnosis of invasive breast and prostate carcinomas.