Dinh Tran

Low oestrogen receptor α expression in normal breast tissue underlies low breast cancer incidence in Japan

Among white Australians without breast cancer, the median of the percentage of oestrogen receptor alpha positive cells was 12% for women younger than 50 years and 17% for those 50 years or older; among Japanese women who had no breast cancer and are generally at low risk for this disease, the corresponding values were both significantly lower and around 9%.

Suggestions for HER-2/neu testing in breast carcinoma, based on a comparison of immunohistochemistry and Fluorescence in situ hybridisation

Summary The arrival of Herceptin (Trastuzumab), an antibody against the HER‐2 oncogene found in a proportion of breast carcinomas and other carcinomas, has emphasised the need for a standardised technique for demonstrating overexpression of HER‐2. We compared the Dako A485 antibody and Dako HercepTest kit (HT) on a series of 122 breast carcinomas. Fluorescence in situ hybridisation (FISH) (Vysis) was performed on all cases with positive or equivocal immunohistochemical results. The Dako A485 showed HER2 overexpression in 53% of carcinomas, while the HT showed 21% positive (HT 2 + 8%, HT 3 + 13%) and 79% negative (HT 0 67%, HT 1 + 12%). FISH for HER‐2 gene amplification on all the HT 1 + and HT 2 + cases was negative, whereas FISH analysis of all HT 3 + cases was positive, with the exception of one case which could not be analysed for technical reasons. When histological subtype was analysed, only grade 3 infiltrating duct carcinomas were FISH‐positive, suggesting that histological grading and subtyping may be able to triage carcinomas suitable for HER‐2 testing. We suggest that the HT or a similar standardised immunohistochemical study for HER‐2 can be used to screen breast carcinomas. We then recommend FISH where the carcinoma is HT 2 +. FISH may also be appropriate in high grade, HT 1 + carcinomas where there are doubts regarding optimal tissue fixation or block storage conditions.

From Bittner to Barr: a viral, diet and hormone breast cancer aetiology hypothesis

It is hypothesized that the human homologue of the mouse mammary tumour virus (HHMMTV) and other viruses, such as human papillomavirus (HPV) and Epstein-Barr virus (EBV), act as cofactors with diet, oestrogens and other hormones in the initiation and promotion of some types of breast cancer in genetically susceptible women. It is further hypothesized that diet influences the risk of breast cancer, through its influence on oestrogen metabolism and that of other hormones, in combination with genetic and infectious agents.

Breast cancer incidence and estrogen receptor α in normal mammary tissue—An epidemiologic study among Japanese women in Japan and Hawaii

We have undertaken a study to examine whether the difference in breast cancer incidence between 2 populations of similar genetic background is reflected in a similar pattern of estrogen receptor α expression in normal mammary gland. Study participants were 92 Japanese women from Sapporo, Japan (mean age 48.2 years) and 49 Japanese women from Honolulu, Hawaii (mean age 45.4 years), who underwent biopsy indicating normal breast tissue or benign, nonproliferative breast disease in hospitals in Sapporo, Japan and Honolulu, Hawaii. The breast tissue samples were formalin‐fixed and paraffin‐embedded. The estrogen receptor immunohistochemistry assays were conducted using Dako kits. Japanese women in Hawaii, who have a higher incidence of breast cancer compared with Japanese women in Sapporo, also had, as predicted, higher mean percentage of estrogen receptor α‐positive normal mammary cells (2‐tailed test, p ∼ 0.09). The results of our study are compatible with the hypothesis that estrogen receptor α expression in normal mammary tissue increases breast cancer risk and they also indicate that the expression of these receptors is dependent, at least in part, on nongenetic factors.

Presence of mouse mammary tumour-like virus gene sequences may be associated with morphology of specific human breast cancer

Background: Mouse mammary tumour virus (MMTV) has a proven role in breast carcinogenesis in wild mice and genetically susceptible in-bred mice. MMTV-like env gene sequences, which indicate the presence of a replication-competent MMTV-like virus, have been identified in some human breast cancers, but rarely in normal breast tissues. However, no evidence for a causal role of an MMTV-like virus in human breast cancer has emerged, although there are precedents for associations between specific histological characteristics of human cancers and the presence of oncogenic viruses. Aim: To investigate the possibility of an association between breast cancer and MMTV-like viruses. Methods: Histological characteristics of invasive ductal human breast cancer specimens were compared with archival MMTV-associated mammary tumours from C3H experimental mice. The presence of MMTV-like env DNA sequences in the human breast cancer specimens was determined by polymerase chain reaction and confirmed by Southern hybridisation. Results: MMTV-like env gene sequences were identified in 22 of 59 (37.3%) human breast cancer specimens. Seventeen of 43 (39.5%) invasive ductal carcinoma breast cancer specimens and 4 of 16 (25%) ductal carcinoma in situ specimens had some histological characteristics, which were similar to MMTV-associated mouse mammary tumours. However, these similarities were not associated with the presence or absence of MMTV-like gene sequences in the human breast tumour specimens. A significant (p = 0.05) correlation was found between the grade of the human breast cancer and similarity to the mouse mammary tumours. The lower the grade, the greater the similarity. Conclusion: Some human breast cancer specimens, in which MMTV-like env DNA sequences have been identified, were shown to have histological characteristics (morphology) similar to MMTV-associated mouse mammary tumours. These observations are compatible with, but not conclusive of, an association between the presence of MMTV-like env DNA sequences and some human breast cancers.

Dendritic Cells in Barrett’s Esophagus and Esophageal Adenocarcinoma

BackgroundLike other premalignant conditions that develop in the presence of chronic inflammation, the development and progression of Barrett’s esophagus is associated with the development of an immune response, but how this immune response is regulated is poorly understood. A comprehensive literature search failed to find any report of the presence of dendritic cells in Barrett’s intestinal metaplasia and esophageal adenocarcinoma and this prompted our study.Material and MethodsWe used immunohistochemical staining and electron microscopy to examine whether dendritic cells are present in Barrett’s esophagus and esophageal adenocarcinoma. Immunohistochemical staining with CD83, a specific marker for dendritic cells, was performed on paraffin-embedded sections of Barrett’s intestinal metaplasia (IM, n = 12), dysplasia (n = 11) and adenocarcinoma (n = 14).ResultsCD83+ cells were identified in the lamina propria surrounding intestinal type glands in Barrett’s IM, dysplasia, and cancer tissues. Computerized quantitative analysis showed that the numbers of dendritic cells were significantly higher in cancer tissues. Double immunostaining with CD83, CD20, and CD3, and electron microscopy demonstrated that dendritic cells are present in Barrett’s esophagus and form clusters with T cells and B cells directly within the lamina propria.ConclusionsThese findings demonstrate that dendritic cells are present in Barrett’s tissues, with a significant increase in density in adenocarcinoma compared to benign Barrett’s esophagus. Dendritic cells may have a role in the pathogenesis and immunotherapy treatment of Barrett’s esophagus and adenocarcinoma.

Dendritic Cell-Associated Immune Inflammation of Cardiac Mucosa: A Possible Factor in the Formation of Barrett’s Esophagus

BackgroundThe development of Barrett’s esophagus is poorly understood, but it has been suggested that cardiac mucosa is a precursor of intestinal type metaplasia and that inflammation of cardiac mucosa may play a role in the formation of Barrett’s esophagus. The present study was undertaken to examine the presence and distribution of immune-inflammatory cells in cardiac mucosa, specifically focusing on dendritic cells because of their importance as regulators of immune reactions.Material and MethodsEndoscopic biopsy specimens were obtained from 12 patients with cardiac mucosa without Barrett’s esophagus or adenocarcinoma and from 21 patients with Barrett’s esophagus without dysplasia (intestinal metaplasia). According to histology, in nine of the 21 specimens with Barrett’s esophagus, areas of mucosa composed of cardiac type epithelium-lined glands were present as well. Immunohistochemical staining and electron microscopy were used to examine immune-inflammatory cells in paraffin-embedded sections.ResultsImmune-inflammatory cells, including T cells, B cells, dendritic cells, macrophages, and mast cells, were present in the connective tissue matrix that surrounded cardiac type epithelium-lined glands in all patients with cardiac mucosa. Clustering of dendritic cells with each other and with lymphocytes and the intrusion of dendritic cells between glandular mucus cells were observed. In the Barrett’s esophagus specimens that contained cardiac type glands, computerized CD83 expression quantitation revealed that there were more dendritic cells in cardiac mucosa than in intestinal metaplasia.ConclusionImmune-inflammatory infiltrates containing dendritic cells are consistently present in cardiac mucosa. The finding of a larger number of dendritic cells in areas of cardiac mucosa in Barrett’s esophagus biopsies suggests that the immune inflammation of cardiac mucosa might play a role in modifying the local tissue environment to promote the development of specialized intestinal type metaplasia.

Hormone replacement therapy use dramatically increases breast oestrogen receptor expression in obese postmenopausal women

BackgroundIt is known that use of hormone replacement therapy (HRT) by postmenopausal women increases the risk of breast cancer.MethodIn this study, oestrogen receptor (ER)-α expression is examined using standard immunoperoxidase technique.ResultsNormal breast samples of 11 Australian postmenopausal women have been included in the ER-α study; the result showed a strong correlation (r2 = 0.80) between ER-α expression in normal breast epithelial cells and body mass index (BMI) in normal women who currently use HRT.ConclusionThis finding confirms that the possibility of increased risk of breast cancer associated with increased ER-α expression in normal breast epithelial cells, in turn associated with high BMI and the use of HRT.

Microcysts and Breast Cancer: A Study of Biological Markers in Archival Biopsy Material

Breast cysts are associated with an increased risk of breast cancer. Some biomarkers such as estrogen receptor alpha (ERa), progesterone receptor (PR), and cyclin D1, show similar patterns of expression in epithelial cells lining breast cysts as malignant epithelial cells in local and invasive ductal breast cancer. We have attempted to answer two questions: (1) Do epithelial cells lining breast microcysts (cysts which can only be seen with a microscope) express biomarkers in a similar pattern to breast ductal carcinoma in situ and invasive ductal carcinoma? (2) Are breast microcysts precursors of breast cancer or are they part of normal involution of the breast?Seventy two archival open breast biopsy specimens of ductal carcinoma in situ and invasive ductal carcinoma and 32 normal breast biopsies from Australian women who had breast reduction surgery were selected from hospital archives. All specimens were analysed by standard immunohistochemistry for ERa, PR, cyclin D1, bcl-2, p53 and erbB-2 expression.In the same specimens, the pattern of high biomarker expression was very similar for all the above biomarkers in epithelial cells lining microcysts and in both ductal carcinoma in situ and invasive ductal carcinoma c. ErbB-2 was not expressed in normal control specimens. ErbB-2 was expressed in the same specimens in an increasing proportion of normal breast acini, microcysts and cancer cells in 36% of specimens with breast cancer.An apparent progression was observed from normal breast acini, to proliferation of epithelial cells in microcysts, ductal carcinoma in situ and invasive ductal carcinoma in the same specimen.When these findings are considered with other reports we conclude: (1) that epithelial cells lining breast cysts highly express biomarkers in a similar pattern to ductal carcinoma in situ and invasive ductal carcinoma; (2) that some microcysts are not part of normal involution of the breast and in some women may be part of the transition from normal to cancer.

Human Papilloma Viruses and Breast Cancer

Purpose Human papillomaviruses (HPV) may have a role in some breast cancers. The purpose of this study is to fill important gaps in the evidence. These gaps are: (i) confirmation of the presence of high risk for cancer HPVs in breast cancers, (ii) evidence of HPV infections in benign breast tissues prior to the development of HPV-positive breast cancer in the same patients, (iii) evidence that HPVs are biologically active and not harmless passengers in breast cancer. Methods RNA-seq data from The Cancer Genome Atlas (TCGA) was used to identify HPV RNA sequences in breast cancers. We also conducted a retrospective cohort study based on polymerase chain reaction (PCR) analyses to identify HPVs in archival specimens from Australian women with benign breast biopsies who later developed breast cancer. To assess whether HPVs in breast cancer were biologically active, the expression of the oncogenic protein HPV E7 was assessed by immunohistochemistry (IHC). Results Thirty (3.5%) low-risk and 20 (2.3%) high-risk HPV types were identified in 855 breast cancers from the TCGA database. The high risk types were HPV 18 (48%), HPV 113 (24%), HPV 16 (10%), HPV 52 (10%). Data from the PCR cohort study indicated that HPV type 18 was the most common type identified in breast cancer specimens (55% of 40 breast cancer specimens) followed by HPV 16 (13%). The same HPV type was identified in both the benign and subsequent breast cancer in 15 patients. HPV E7 proteins were identified in 72% of benign breast specimens and 59% of invasive breast cancer specimens. Conclusion There were four observations of particular interest: (i) confirmation by both NGS and PCR of the presence of high-risk HPV gene sequences in breast cancers, (ii) a correlation between high-risk HPV in benign breast specimens and subsequent HPV-positive breast cancer in the same patient, (iii) HPVs in breast cancer are likely to be biologically active (as shown by transcription of HPV DNA to RNA plus the expression of HPV E7 proteins), (iv) HPV oncogenic influences may occur early in the development of breast cancer.