Shinobu Masuda

Interobserver concordance of Ki67 labeling index in breast cancer: Japan Breast Cancer Research Group Ki67 Ring Study

The standardized assessment of Ki67 labeling index (LI) is of clinical importance to identify patients with primary breast cancer who could benefit from chemotherapy. In this study, we evaluated the interobserver concordance of Ki67 LI assessment. Six surgical pathologists participated and all the slides were prepared from archival breast cancer tissues fixed in 10% buffered formalin for 24 h and stained with MIB‐1. Three independent studies were conducted. In the first study, 30 stained slides were assessed using two different methods: the scoring system, with a positive rate scored from 1 (0–9%) to 10 (90–100%) by visual estimate; and the counting method, with approximately 1000 cells counted in hot spots. In the second study, 20 tumors with Ki67 LI 5–25% were assessed, and in the third study, 15 printed photographs of stained slides were assessed to avoid variations by selecting different fields. In study 1, the counting system (intraclass correlation coefficient [ICC], 0.66 [95% confidence interval 0.52–0.78]) demonstrated a better correlation than the scoring system (ICC, 0.57 [0.42–0.72]). In study 2, the assessment for Ki67 LI of 5–25% demonstrated a correlation (ICC, 0.68 [0.50–0.81]) similar to that of study 1 (unrestricted range of Ki67 LI). In study 3, the assessment of Ki67 LI by counting yielded a good concordance (ICC, 0.94 [0.88–0.97]). In conclusion, there was better concordance with the counting system, and concordance was high when the assessed field was predetermined, indicating that the selection of the evaluation area is critical for obtaining reproducible Ki67 LI in breast cancer.

Immunohistochemical Ki67 labeling index has similar proliferation predictive power to various gene signatures in breast cancer.

The objective of this study was to examine the association between the immunohistochemical Ki67 labeling index (IHC Ki67), Ki67 mRNA expression level, and first‐generation gene signatures in a cohort of breast cancer patients. We assessed associations between IHC Ki67 and first‐generation gene signatures in a panel of 39 tumor samples, using an oligonucleotide microarray. Gene expression analyses included Ki67 alone (MKi67), 21‐gene signature, mitosis kinome score signature, and genomic grade index. Correlation coefficients were calculated by Spearmans rank correlation test. In all cases, IHC Ki67, MKi67, and three genetic markers were highly correlated (ρ, 0.71–0.97). Estrogen receptor (ER)‐positive cases showed strong correlations between IHC Ki67 and other signatures (ρ, 0.79–0.83). The ER‐negative cases showed slightly lower correlations (ρ, 0.58–0.73). In ER‐positive cases, the low IHC Ki67 group showed significantly longer relapse‐free survival than the high IHC Ki67 group (P = 0.007). This difference was confirmed by multivariate analysis. Our data indicate that IHC Ki67 shows similar predictive power for proliferation in ER‐positive cancers as genomic markers. Further study of IHC Ki67 is needed to define prognostic factors and predictive factors for chemotherapy using central laboratory assessment. (Cancer Sci, doi: 10.1111/j.1349‐7006.2012.02319.x, 2012)

Differing deregulation of HER2 in primary gastric cancer and synchronous related metastatic lymph nodes

BackgroundThe aim of this study was to investigate how differences in expression of HER2 between primary gastric cancers (PGCs) and their corresponding metastatic lymph nodes (LMNs) might affect its potential as a prognostic indicator in treatments including anti-HER2 agents.MethodsThe analysis was conducted in 102 patients who underwent surgical resection for primary gastric cancers (PGCs; adenocarcinoma, intestinal type) with synchronous LNMs. HER2 gene status and protein expression were investigated by immunohistochemistry (IHC) in all patients; fluorescence in situ hybridization (FISH) was performed in 22 patients. The correlation between HER2 gene status in PGCs and their LNMs was evaluated.ResultsPositive HER2 expression as detected by IHC + FISH was observed in 27/102 PGC samples (26.5%) and 29/102 LNM samples (28.4%). HER2 amplification status in 102 paired PGC and LNM samples as evaluated by FISH + IHC was concordant in 92 patients (90.2%), 69 (67.6%) were unamplified and 23/102 (22.5%) were amplified at both sites, and discordant in 10 patients (9.8%), 4 (3.9%) were positive for PGC and negative for LNM, while 6 (5.9%) were positive for LNM and negative for PGC. The results of FISH + IHC showed very strong concordance in HER2 status between the PGC and LNM groups (k = 0.754).ConclusionThe high concordance between HER2 results for PGCs and their LNMs indicates that assessment of HER2 status in the primary cancer alone is a reliable basis for deciding treatment with anti-HER2 agents in patients with LNMs from gastric adenocarcinoma.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9365749431029643.

Breast cancer pathology: The impact of molecular taxonomy on morphological taxonomy

The concept of having an ‘intrinsic subtype,’ or a molecular taxonomy, lets us clearly recognize that breast cancers have characteristically different patterns of gene expression, thus giving newfound significance to morphological taxonomy. In this review, the concept of the ‘intrinsic subtype’ is discussed, research questions are introduced to refine the significance of morphological taxonomy, and a corresponding example is presented between microarray analysis and ‘immunohistochemical subtype,’ or histological taxonomy.

Prognostic Significance of the Ki67 Scoring Categories in Breast Cancer Subgroups

BACKGROUND Immunohistochemical (IHC) expression of Ki67 has a prognostic and predictive value for breast cancer, and the IHC Ki67 labeling index is estimated by counting the number of positive and negative cells. It has not been clarified whether IHC Ki67 estimated using a semiquantitative scoring system has a prognostic value. We aimed to estimate the usefulness of scoring categories of IHC Ki67 as a prognostic factor for breast cancer subgroups. PATIENTS AND METHODS We retrospectively identified patients in the Tokai University breast cancer database for whom IHC Ki67 data were available between January 1, 2000 and December 31, 2010. Survival curves were calculated using the Kaplan-Meier method and compared using the log-rank test. RESULTS Of the 1331 primary breast cancer patients included in the study, In patients with estrogen receptor (ER)-positive and HER2-negative tumors (n = 971), high and intermediate Ki67 scores were associated with poorer relapse-free survival than low Ki67 scores (P < .001 and P = .002, respectively). Furthermore, in the multivariate analyses of this subgroup, progression-free survival (PFS) was significantly longer in patients with low Ki67 scores than in patients with high Ki67 scores (hazard ratio, 0.387; 95% confidence interval, 0.233-0.643; P < .001). In the multivariate analyses, the Ki67 score was not significantly associated with PFS in the ER-positive and HER2-positive, ER-negative and HER2-positive, or ER-negative and HER2-negative subgroups. CONCLUSION Our data demonstrated that low, intermediate, and high Ki67 scores have a prognostic value in breast cancer patients with ER-positive and HER2-negative tumors.

Analysis of gene alterations of mitochondrial DNA D-loop regions to determine breast cancer clonality

Background:It has been a challenge to determine breast cancer clonality accurately. The aim of the present study was to assess methods using formalin-fixed paraffin-embedded (FFPE) tissue to differentiate new primary tumours from true recurrences that are associated with poorer prognoses and often require more aggressive treatment.Methods:We investigated the novel method of analysing gene alterations of mitochondrial DNA D-loop region (GAMDDL) and compared it with the conventional method of analysing the X-chromosome-linked human androgen receptor (HUMARA). The FFPE sections of primary and secondary breast cancers, the non-neoplastic mammary gland, and lymph nodes were examined.Results:Informative rates for HUMARA, GAMDDL, and combined analyses were 42.1%, 76.9%, and 89.5%, respectively. All of the 10 contralateral breast cancers were determined to be non-clonal. In contrast, 3 out of 8 (37.5%) of the ipsilateral secondary tumours shared a clonal origin with the primary tumour and were classified as true recurrences, whereas 4 out of 8 (50%) were classified as new primary tumours.Conclusion:GAMDDL analysis represents a novel and useful molecular method for examining the precise cell lineages of primary and secondary tumours, and was more accurate than HUMARA in determining clonality.

The cell cycle profiling-risk score based on CDK1 and 2 predicts early recurrence in node-negative, hormone receptor-positive breast cancer treated with endocrine therapy.

The Cell Cycle Profiling - Risk Score (C2P-RS) based on CDK1 and CDK2 specific activities was significantly associated with relapse in breast cancers. We evaluated the prognostic value of the C2P-RS classification using a Japanese cohort including node-negative, hormone receptor-positive breast cancers treated with adjuvant endocrine therapy alone as systemic therapy. Of 266 patients, 22 (8.3%) relapsed within 5 years after surgery. The distribution of each C2P-RS group was 71.8% in the low group, 12.0% in the intermediate group, and 16.2% in the high group. The 5-year relapse-free survival rate in the low C2P-RS group (97.3%) was significantly higher than that in the intermediate C2P-RS group (84.3%) or the high C2P-RS group (74.4%) (P < 0.001). The univariate analysis demonstrated that age, tumor size, histologic grade, and HER2 had no significant correlations with relapse but the C2P-RS classification (P < 0.001) and Ki-67 (P = 0.009) were significantly associated with relapse. Multivariate analysis showed only that the C2P-RS classification was a significant independent prognostic indicator. The C2P-RS classification might be a significant predictor of earlier recurrence in node-negative, hormone receptor-positive breast cancers treated with endocrine therapy.

Adenomyoepithelioma with carcinoma of the breast: A report of two cases and a review of the literature.

We herein described two cases of adenomyoepithelioma (AME) with carcinoma of the breast. Both of them were Japanese women, and they presented with a mass in their breast. Post-operative specimens revealed encapsulated and well-circumscribed tumors with local invasion, necrosis, cytological atypia, and a high mitotic rate. In immunohistochemistry, coincidentally with the loose adhesion pattern of myoepithelial cells in both cases, the intensities of E-cadherin and beta-catenin were much weaker in myoepithelial than luminal epithelial cells, with almost negative finding of beta-catenin in one case. We first found deletion of CDH1 and polysomy of CEP16 in myoepithelial cells by double color-fluorescence in situ hybridization. The two cases have been followed up for 5-8 years, and both remained free from local recurrence and distant metastases. We also presented an overview of 47 cases of AME with carcinoma in English-language literatures.

Altered intracellular region of MUC1 and disrupted correlation of polarity-related molecules in breast cancer subtypes

MUC1 glycoprotein is overexpressed and its intracellular localization altered during breast carcinoma tumorigenesis. The present study aimed to clarify the relationship of cytoplasmic localization of MUC1 with the breast cancer subtype and the correlation of 10 molecules associated with cell polarity in breast cancer subtypes. We immunostained 131 formalin‐fixed and paraffin‐embedded breast cancer specimens with an anti‐MUC1 antibody (MUC1/CORE). For 48 of the 131 tumor specimens, laser‐assisted microdissection and real‐time quantitative RT‐PCR were performed to analyze mRNA levels of MUC1 and 10 molecules, β‐catenin, E‐cadherin, claudin 3, claudin 4, claudin 7, RhoA, cdc42, Rac1, Par3 and Par6. Localization of MUC1 protein varied among breast cancer subtypes, that is, both the apical domain and cytoplasm in luminal A‐like tumors (P < 0.01) and both the cytoplasm and cell membrane in luminal B‐like (growth factor receptor 2 [HER2]+) tumors (P < 0.05), and no expression was found in triple negative tumors (P < 0.001). Estrogen receptor (ER)+ breast cancers showed higher MUC1 mRNA levels than ER− breast cancers (P < 0.01). The incidence of mutual correlations of expression levels between two of the 10 molecules (55 combinations) was 54.5% in normal breast tissue and 38.2% in luminal A‐like specimens, 16.4% in luminal B‐like (HER2+), 3.6% in HER2 and 18.2% in triple negative specimens. In conclusion, each breast cancer subtype has characteristic cytoplasmic localization patterns of MUC1 and different degrees of disrupted correlation of the expression levels between the 10 examined molecules in comparison with normal breast tissue.

Complete Atrioventricular Block Complicating Mitral Infective Endocarditis Caused by Streptococcus Agalactiae

Patient: Male, 74 Final Diagnosis: Infective endocarditis Symptoms: Apetite loss • fever Medication: — Clinical Procedure: Transesophageal echocardiography Specialty: Cardiology Objective: Rare co-existance of disease or pathology Background: Infective endocarditis (IE) involving the mitral valve can but rarely lead to complete atrioventricular block (CAVB). Case Report: A 74-year-old man with a history of infective endocarditis caused by Streptococcus gordonii (S. gordonii) presented to our emergency room with fever and loss of appetite, which had lasted for 5 days. On admission, results of serologic tests pointed to severe infection. Electrocardiography showed normal sinus rhythm with first-degree atrioventricular block and incomplete right bundle branch block, and transthoracic echocardiography and transesophageal echocardiography revealed severe mitral regurgitation caused by posterior leaflet perforation and 2 vegetations (5 mm and 6 mm) on the tricuspid valve. The patient was initially treated with ceftriaxone and gentamycin because blood and cutaneous ulcer cultures yielded S. agalactiae. On hospital day 2, however, sudden CAVB requiring transvenous pacing occurred, and the patient’s heart failure and infection worsened. Although an emergent surgery is strongly recommended, even in patients with uncontrolled heart failure or infection, surgery was not performed because of the Child-Pugh class B liver cirrhosis. Despite intensive therapy, the patient’s condition further deteriorated, and he died on hospital day 16. On postmortem examination, a 2×1-cm vegetation was seen on the perforated posterior mitral leaflet, and the infection had extended to the interventricular septum. Histologic examination revealed extensive necrosis of the AV node. Conclusions: This rare case of CAVB resulting from S. agalactiae IE points to the fact that in monitoring patients with IE involving the mitral valve, clinicians should be aware of the potential for perivalvular extension of the infection, which can lead to fatal heart block.