James S. Lawson

Human papilloma virus is associated with breast cancer

Background:There is increasing evidence that high-risk human papilloma virus (HPV) is involved in cancers in addition to cervical cancer. For example, it is generally accepted that HPV has a role in a significant proportion of head and neck tumours, and it has long been hypothesised that hormone dependent oncogenic viruses, such as HPV may have causal roles in some human breast cancers. A number of reports have identified HPV DNA in breast tissue and breast cancer specimens, but these rely on standard polymerase chain reaction (PCR), which is criticised for its propensity for contamination.Methods:We have used two different technologies, in situ and standard PCR (with sequencing), and histology based on light microscopy.Results:We unambiguously demonstrate the presence of high-risk HPV in the cells of breast cancer specimens and breast cancer cell lines. In addition, we also show that the oncogenic characteristics of HPV associated breast cancer are very similar to HPV-associated cervical cancer. Specifically, that putative koilocytes are present in some HPV associated breast cancers.Interpretation:The above observations indicate a likely causal role for high-risk HPV in human breast cancer and offer the possibility of primary prevention of some breast cancers by vaccination against HPV.

Identification of human papillomavirus DNA gene sequences in human breast cancer

Human papilloma viruses (HPVs) are accepted as being carcinogenic in human cervical and anogenital cancers. The suspicion that HPVs may also have a role in human breast cancer is based on the identification of HPVs in human breast tumours and the immortalisation of normal human breast cells by HPV types 16 and 18. For this investigation, DNA that had been previously extracted and fresh frozen at −70°C from 50 unselected invasive ductal breast cancer specimens were screened by polymerase chain reaction (PCR) for HPV type 16, 18 and 33 gene sequences. We show that HPV 18 gene sequences are present in DNA extracted from breast tumours in Australian women. Overall, 24 (48%) of the 50 samples were HPV positive. Overall no correlations with tumour grade, patient survival, steroid receptor status, ERB-2, p53 expression and mutation were observed. Human papilloma viruses may have a role in human breast cancer. We speculate that HPVs may be transmitted by hand from the female perineum to the breast.

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%.

Epstein-Barr Virus, Human Papillomavirus and Mouse Mammary Tumour Virus as Multiple Viruses in Breast Cancer

Background The purpose of this investigation is to determine if Epstein Barr virus (EBV), high risk human papillomavirus (HPV), and mouse mammary tumour viruses (MMTV) co-exist in some breast cancers. Materials and Methods All the specimens were from women residing in Australia. For investigations based on standard PCR, we used fresh frozen DNA extracts from 50 unselected invasive breast cancers. For normal breast specimens, we used DNA extracts from epithelial cells from milk donated by 40 lactating women. For investigations based on in situ PCR we used 27 unselected archival formalin fixed breast cancer specimens and 18 unselected archival formalin fixed normal breast specimens from women who had breast reduction surgery. Thirteen of these fixed breast cancer specimens were ductal carcinoma in situ (dcis) and 14 were predominantly invasive ductal carcinomas (idc). Results EBV sequences were identified in 68%, high risk HPV sequences in 50%, and MMTV sequences in 78% of DNA extracted from 50 invasive breast cancer specimens. These same viruses were identified in selected normal and breast cancer specimens by in situ PCR. Sequences from more than one viral type were identified in 72% of the same breast cancer specimens. Normal controls showed these viruses were also present in epithelial cells in human milk – EBV (35%), HPV, 20%) and MMTV (32%) of 40 milk samples from normal lactating women, with multiple viruses being identified in 13% of the same milk samples. Conclusions We conclude that (i) EBV, HPV and MMTV gene sequences are present and co-exist in many human breast cancers, (ii) the presence of these viruses in breast cancer is associated with young age of diagnosis and possibly an increased grade of breast cancer.

Viruses and human breast cancer

There are well-established risk factors for breast cancer, most of which relate to estrogens and growth hormones in females. These include early-age menarche, late-age menopause, postmenopausal obesity and use of hormone therapy. However, these factors do not account for the sixfold difference in breast cancer incidence and mortality between countries and the fact that these differences dramatically lessen after migration; nor do they account for male breast cancer. Accordingly, hormone-responsive viruses have become major suspects as etiological agents for human breast cancer. Human papillomaviruses, mouse mammary tumor virus and Epstein-Barr virus are the prime candidate viruses as causes of human breast cancer. Human papillomaviruses and the mouse mammary tumor virus have hormone responsive elements that appear to be associated with enhanced replication of these viruses in the presence of corticosteroid and other hormones. This biological phenomenon is particularly relevant because of the hormone dependence of breast cancer. Viral genetic material for each of these candidate viruses has been identified by polymerase chain reaction in breast tumors but rarely in normal breast tissue controls. Pooled data from controlled studies show substantial odds ratios for the presence of viral genetic material in breast tumors compared with normal controls. These and additional data provide substantial, but not conclusive, evidence that human papillomavirus, the mouse mammary tumor virus and Epstein-Barr virus may have a role in the etiology of human breast cancer. If conclusive evidence for a role of these viruses in breast carcinogenesis can be developed, there is a practical possibility of primary prevention.

Koilocytes indicate a role for human papilloma virus in breast cancer

Background:High-risk human papilloma viruses (HPVs) are candidates as causal viruses in breast cancer. The scientific challenge is to determine whether HPVs are causal and not merely passengers or parasites. Studies of HPV-related koilocytes in breast cancer offer an opportunity to address this crucial issue. Koilocytes are epithelial cells characterised by perinuclear haloes surrounding condensed nuclei and are commonly present in cervical intraepithelial neoplasia. Koilocytosis is accepted as pathognomonic (characteristic of a particular disease) of HPV infection. The aim of this investigation is to determine whether putative koilocytes in normal and malignant breast tissues are because of HPV infection.Methods:Archival formalin-fixed normal and malignant breast specimens were investigated by histology, in situ PCR with confirmation of the findings by standard PCR and sequencing of the products, plus immunohistochemistry to identify HPV E6 oncoproteins.Results:human papilloma virus-associated koilocytes were present in normal breast skin and lobules and in the breast skin and cancer tissue of patients with ductal carcinoma in situ (DCIS) and invasive ductal carcinomas (IDCs).Interpretation:As koilocytes are known to be the precursors of some HPV-associated cervical cancer, it follows that HPVs may be causally associated with breast cancer.

Progression from Normal Breast Pathology to Breast Cancer Is Associated with Increasing Prevalence of Mouse Mammary Tumor Virus-Like Sequences in Men and Women

Mouse mammary tumor virus (MMTV)-like sequences have been found in up to 40% of breast cancer samples but in <2% of normal breast tissue samples from Australian women studied by our group. Screening of a larger and more diverse cohort of female breast cancer samples has now shown a correlation of MMTV-like sequences with the severity (grade) of breast cancer. Thirty-two percent (43 of 136) of female breast cancer samples were positive for MMTV-like sequences when screened using PCR. A significant gradient of MMTV positivity was observed with increasing severity of cancer from 23% of infiltrating ductal carcinoma (IDC) grade I tumors to 34% of IDC grade II tumors (P = 0.00034) and 38% of IDC grade III tumors (P = 0.00002). We also report for the first time the detection of MMTV-like sequences in 62% (8 of 13) of male breast cancer samples and 19% (10 of 52) of male gynecomastia samples screened. MMTV-like sequences were demonstrated in various premalignant breast lesions of females, including fibroadenoma (20%) and fibrocystic disease (28%) samples, at a significantly higher prevalence than that seen in normal breast tissue (1.8%; P = 0.00001). Study of a longitudinal cohort of female breast cancer patients indicated that MMTV was co-incident with tumor but was not present when tumor was absent on histology. These results support the association of MMTV-like sequences with development of breast tumors in men and women and suggest association of MMTV with increasing severity of cancer.

Mouse Mammary Tumor Virus–like Sequences in Human Breast Cancer

Mouse mammary tumor virus (MMTV) sequences have been reported to be present in some human breast cancers, but it is unclear whether they have any causal role. In mice, MMTV promotes tumor formation indirectly by insertional mutagenesis of Wnt oncogenes that lead to their activation. In this study, we investigated the status of Wnt-1 in human breast cancers harboring MMTV-like sequences encoding viral envelope (env) genes. We confirmed the detection of env sequences in the nucleus of human breast cancer specimens that are similar in appearance to mouse mammary tumors expressing MMTV env sequences. MMTV env sequences in human breast cancers were also nearly indistinguishable from env sequences in mouse MMTV isolates. Further, Wnt-1 expression was higher in specimens of env-positive ductal carcinoma in situ and invasive ductal carcinoma, relative to env-negative specimens. Our findings extend the evidence that MMTV sequences found in naturally occurring mouse mammary tumors can be found in some human breast cancers, prompting further evaluation of causal roles in these settings.

Excessive alcohol use by non-elite sportsmen

This study was designed to first, provide a profile of alcohol consumption patterns of young Australian men aged 16 to 34 years who participate in non-elite sport and secondly, to explore the factors associated with excessive alcohol consumption by this group. There were 1613 male participants in the study. The type of sport played, smoking, age, whether their sporting team had a licensed club and country of birth were associated with drinking above safe recommended levels. The excessive levels of alcohol consumption by some non-elite sportsmen in this study suggest a need to educate sports administrators, coaches and participants about safe alcohol consumption. Men were more likely to drink excessively when socializing with sporting team mates compared to drinking on social occasions with other groups.

Human papillomavirus and Epstein Barr virus in prostate cancer: Koilocytes indicate potential oncogenic influences of human papillomavirus in prostate cancer†

The purpose of this study is to determine if high risk human papillomaviruses (HPV) and Epstein Barr virus (EBV) are both present in the same prostate cancer specimens.