Nobue Kumaki

Prediction of malignant behavior of pheochromocytomas and paragangliomas using immunohistochemical techniques

Pheochromocytomas and paragangliomas arise from the adrenal glands and extraadrenal paraganglia, respectively. Malignant behavior of these tumors is uncommon and is, in part, dependent on their sites of origin, such as extraadrenal location. Morphologic criteria for malignancy of pheochromocytoma and paragangliomas have not been clearly defined. In this study, to clarify the histologic features that distinguish the benign from malignant pheochromocytomas and paragangliomas, we examined metastatic and nonmetastatic tumors using immunohistochemical techniques. A total of eight cases, five pheochromocytomas from the adrenal glands (four benign and one malignant tumor) and three paragangliomas with invasion or metastasis, were studied. The markers used in this study were chromogranin A, synaptophysin, NCAM (CD56), SNAP25, neuron-specific enolase, S-100 protein, and MIB-1. Our results suggest that MIB-1 immunostaining is a useful adjunct marker to predict malignant behavior in these tumors.

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)

Overexpression of fatty acid binding protein-7 correlates with basal-like subtype of breast cancer.

Fatty acid binding protein-7 (FABP-7) is normally expressed in the mammary gland. The aim of this study was to clarify the phenotype of breast cancers with respect to the overexpression of FABP-7. Reverse transcription PCR (RT-PCR) analysis was carried out on 16 cases, including 4 ER(+)/HER2(-), 2 ER(+)/HER2(+), 3 ER(-)/HER2(+), and 5 ER(-)/HER2(-) samples, and 2 non-neoplastic mammary glands as control tissue. Breast cancers categorized as ER(-)/HER2(-) revealed a high cDNA level of FABP-7 as compared to other groups of breast cancer (p=0.004). An immunohistochemical study carried out on 88 cases showed that FABP-7 overexpression had a strong relationship with triple-negative cases (45.8%, p=0.001) and the basal-like subtype (37.5%, p=0.001). Estrogen receptor (ER) and progesterone receptor (PgR) expressions had reverse correlation with FABP-7 overexpression (p=0.003, p<0.0001), but no significant associations can be identified between human epidermal growth factor receptor-2 (HER2) and FABP-7 (p=0.219). In conclusion, this study is the first to demonstrate overexpression of FABP-7 in triple-negative breast cancers [ER(-), PgR(-)/HER2(-)], especially in basal-like breast cancer, and to give a probable interpretation of the high histological grade and poor prognosis of basal-like breast cancer.

Comparison of tumor-infiltrating lymphocytes between primary and metastatic tumors in breast cancer patients

The presence of tumor‐infiltrating lymphocytes (TILs) is associated with favorable long‐term outcome in breast cancer. However, little is known about changes in TILs during metastatic progression. To confirm our hypothesis that malignant tumors escape from the host immune system during metastasis, we evaluated the percentage of TILs in paired samples of primary and metastatic breast tumors. We retrospectively identified 25 patients with human epidermal growth factor receptor‐2 (HER2+, n = 14) and triple negative (TN, n = 11) early breast cancer diagnosed between 1990 and 2009 at Tokai University Hospital (Isehara, Japan) and who subsequently experienced regional or distant recurrence confirmed by tumor biopsy/resection. Hematoxylin–eosin‐stained slides of these paired samples were evaluated for stromal TILs. Immunohistochemical staining was carried out using primary antibodies against CD4, CD8, Foxp3, programmed cell death ligand 1 (PD‐L1), PD‐L2, and HLA class I for characterizing the TILs and breast tumors. The percentage of TILs in the primary tumors was significantly higher (average 34.6%) than that in metastatic tumors (average 15.7%) (paired t‐test, P = 0.004) and that of CD8+ and CD4+ T cells significantly decreased from primary to metastatic tumors (paired t‐test, P = 0.008 and P = 0.026, respectively). The PD‐L1, PD‐L2, and HLA class I antibody expression changed from positive to negative and vice versa from the primary to the metastatic tumors. Tumors at first metastatic recurrence in HER2+ and TN breast cancers have a lower percentage of TILs and CD8+ and CD4+ T cells compared to primary tumors, which indicates that immune escape plays a role in tumor progression.

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.

Alteration of immunohistochemical biomarkers between pre- and post-chemotherapy: hormone receptors, HER2 and Ki-67

The immunohistochemical (IHC) biomarkers of breast cancer, especially hormone receptors and HER2, are very important because the pharmacological therapeutic strategy is generally decided by biomarker expression patterns. Biomarkers are examined on pre-chemotherapeutic biopsy materials from patients in whom neoadjuvant chemotherapy is planned. Statistically significant changes between pre- and post-chemotherapeutic markers have been reported; however, the alterations in biomarkers are poorly understood. Fluctuation of the Ki-67 labeling index (LI) between pre- and post-neoadjuvant therapy is associated with chemotherapeutic effects and with the prognosis of patients. It has been shown that IHC evaluation of Ki-67 LI is useful as a predictive and a prognostic factor. There are issues to be considered surrounding the use of the IHC Ki-67 LI in routine practice, including the standardization of staining procedures and a cutoff point for Ki-67 LI detection. The current understanding of IHC evaluation of biomarkers for breast cancer under neoadjuvant chemotherapy is reviewed based on the literature.

Secretoglobin 3A2/uteroglobin-related protein 1 is a novel marker for pulmonary carcinoma in mice and humans

Secretoglobin (SCGB) 3A2, also called uteroglobin-related protein (UGRP) 1, is a downstream target for a homeodomain transcription factor NKX2-1, which is critical for the development of lung, thyroid and ventral forebrain. Both SCGB3A2 and NKX2-1 are expressed in airway epithelial cells and the latter also in alveolar Type II cells. NKX2-1 has been used clinically for diagnosis of human pulmonary tumors. Recently, the expression of SCGB3A2 was reported in human carcinomas, suggesting the use of this protein as a tumor marker. In this study, 28 lung tumors from aging B6;129 mice and nine lung adenocarcinomas from CC10TAg transgenic mice that express SV40 large T antigen under the mouse Scgb1a1 (CC10) gene promoter, were subjected to histopathological and immunohistochemical analyses for the expression of NKX2-1 and SCGB3A2. NKX2-1 was expressed in all types of tumors albeit more focally in carcinomas. In contrast, SCGB3A2 normally expressed in Clara cells, was negative in Type II cell hyperplasias and adenomas. However, it was expressed in alveolar Type II cell carcinomas and Clara cell adenocarcinomas. In these carcinomas, SCGB3A2 expression was observed in the portion of the tumor where NKX2-1 expression was reduced or almost abolished. As a comparison, the expression of SCGB3A2 and NKX2-1 from 23 human non-small cell lung carcinoma specimens was also examined. The results demonstrate that SCGB3A2 is a useful marker for diagnosis of pulmonary tumors both in mice and humans.

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.

Role of Indigenous Lactobacilli in Gastrin-Mediated Acid Production in the Mouse Stomach

ABSTRACT It is known that the stomach is colonized by indigenous lactobacilli in mice. The aim of this study was to examine the role of such lactobacilli in the development of the stomach. For a DNA microarray analysis, germ-free BALB/c mice were orally inoculated with 109 CFU lactobacilli, and their stomachs were excised after 10 days to extract RNA. As a result, lactobacillus-associated gnotobiotic mice showed dramatically decreased expression of the gastrin gene in comparison to germ-free mice. The mean of the log2 fold change in the gastrin gene was −4.3. Immunohistochemistry also demonstrated the number of gastrin-positive (gastrin+) cells to be significantly lower in the lactobacillus-associated gnotobiotic mice than in the germ-free mice. However, there was no significant difference in the number of somatostatin+ cells in these groups of mice. Consequently, gastric acid secretion also decreased in the mice colonized by lactobacilli. In addition, an increase in the expression of the genes related to muscle system development, such as nebulin and troponin genes, was observed in lactobacillus-associated mice. Moreover, infection of germ-free mice with Helicobacter pylori also showed the down- and upregulation of gastrin and muscle genes, respectively, in the stomach. These results thus suggested that indigenous lactobacilli in the stomach significantly affect the regulation of gastrin-mediated gastric acid secretion without affecting somatostatin secretion in mice, while H. pylori also exerts such an effect on the stomach.

Intratumoral heterogeneity of HER2 protein and amplification of HER2 gene in salivary duct carcinoma

Salivary duct carcinoma (SDC) is an aggressive adenocarcinoma of the salivary glands, and accounts for 1–3% of all malignant salivary gland tumors, resembling morphologically invasive ductal carcinoma (IDC) of the breast. In contrast to IDC of the breast and gastric carcinoma (GC), the study of human epidermal growth factor receptor 2 (HER2) in SDC has not progressed. Therefore, we investigated the relationship between HER2 protein expression and amplification of the HER2 gene, and compared them in terms of intratumoral heterogeneity (ITH) in 13 cases of SDC using immunohistochemistry and dual color in situ hybridization. We found seven cases with protein overexpression (53.8%) and five cases with gene amplification (38.5%) in accordance with ASCO/CAP guidelines. ITH of HER2 protein expression was seen in seven cases (53.8%). Interestingly, the ratio of the HER2 gene showed homogenous distribution with or without the presence of ITH of HER2 protein expression. SDC tends to have more ITH of HER2 protein similarly to GC, in contrast to IDC of the breast. ITH of HER2 protein in SDC has no heterogeneity of the HER2 gene amplification. The mechanism of HER2 protein expression in SDC might proceed through a more complex pathway relative to that of IDC of the breast.