The role of human papillomavirus infection in breast cancer

The association between infectious agents and breast cancer: a review of the epidemiologic evidence

PURPOSE

Several viruses have been casually linked to human cancers, including cervical, nasopharyngeal, liver, sarcoma, and Merkel cell carcinomas. However, the etiologic contribution of viral infections to breast cancer, the number one incident cancer among women worldwide, is not well established. Among studies exploring associations of viruses with breast cancer, potential linkages have been identified between breast cancer and five viruses: beta retrovirus, (i.e., mouse mammary tumor virus), human papillomavirus, Epstein Barr virus. bovine leukemia virus, and human cytomegalovirus.

METHODS

In this review, we provide a comprehensive evaluation of epidemiological ecologic, case-control, case-only, and cohort studies investigating these associations. We discuss results from several existing reviews and meta-analyses, evaluate epidemiological studies published in the past five years, and assess the relationship between these viruses and breast tumor clinicopathological factors.

RESULTS

The strongest epidemiological evidence for a viral role in breast cancer exists for MMTV and HPV, though limitations include lack of prospective studies for MMTV and potential detection bias in HPV studies. Viral detection challenges have limited studies of EBV and HCMV. Fewer studies have evaluated BLV, and though it has been associated with higher risk of breast cancer, sample sizes are quite small.   CONCLUSION: While epidemiologic evidence exists for an association between these five viruses and breast cancer, various methodological issues and lack of prospective studies preclude robust conclusions. Future research should prioritize establishing a temporal relationship between infection and disease, minimizing misclassification of detection assays, and further exploring the influence of co-infections.

HPV Detection in Breast Tumors and Associated Risk Factors in Northeastern Brazil

Breast cancer risk factors include lifestyle, genetic-hormonal influences, and viral infections. Human papillomavirus (HPV), known primarily as the etiological agent of cervical cancer, also appears active in breast carcinogenesis, as evidenced in our study of 56 patients from northeastern Brazil. We assessed the clinical and sociodemographic characteristics, correlating them with various breast cancer tumor types. HPV detection involved amplifying the L1 region, with viral load measured using the E2/E6 ratio and viral activity indicated by E5 oncogene expression. Predominantly, patients over 56 years of age with healthy lifestyles showed a high incidence of invasive ductal carcinoma and triple-negative breast cancer. HPV was detected in 35.7% of cases, mostly HPV16, which is associated with high viral loads (80 copies per cell) and significant E5 expression. These results hint at a possible link between HPV and breast carcinogenesis, necessitating further studies to explore this association and the underlying viral mechanisms.

An updated systemic review and meta-analysis on human papillomavirus in breast carcinogenesis

Background

Breast Cancer (BC) stands out as the widely prevalent malignancy among all the types of cancer affecting women worldwide. There is significant evidence that the pathogenicity of BC may be altered by Human Papillomavirus (HPV) infection; however, conclusive data are not yet available.

Methods

By searching five databases, including EMBASE, IBECS, PubMed, Scopus, Science Direct, Google Scholar, and Web of Science, a thorough systematic analysis was conducted on the prevalence of HPV in BC patients from 1990 to June 30, 2022. After applying extensive eligibility criteria, we selected 74 publications for further analysis based on the prevalence of HPV infections in breast tissues. All of the data were analyzed using a random-effects meta-analysis, Cochran Q test and I2 statistic were used to calculate the heterogeneity of the prevalence among these studies using subgroup analysis. Variations in the HPV prevalence estimates in different subgroups were evaluated by subgroup meta-analysis.

Results

In total, 3156 studies were initially screened, resulting in 93 full-text studies reviewed, with 74 meeting inclusion criteria. Among a total of 7156 BC biopsies, the pool prevalence of HPV was 25.6% (95% CI= 0.24-0.33, τ2 = 0.0369 with significant heterogeneity between estimates (I 2 = 97% and p< 0.01). Consequently, 45 studies with available controls were further studied, and the prevalence of HPV in case-control studies was 26.2% with overall odds 5.55 (95% CI= 3.67-8.41, I 2 = 38%, τ2 = 1.4878, p< 0.01). Further subgroup analysis of HPV revealed HPV-16 had a maximum prevalence of 9.6% (95% CI= 3.06-11.86, I 2 = 0%, τ2 = 0.6111, p< 0.01). Among different geographical regions, Europe reported the maximum prevalence of HPV, i.e., 39.2% (95% CI=1.29-7.91, I 2 = 18%, τ2 = 1.2911, p< 0.01). Overall distribution showed HPV-18 was a frequent HPV subtype reported in Australia.

Conclusion

Current study provides a global estimate of HPV prevalence in BC patients and demonstrates a significant association between this virus and BC etiology. Nevertheless, we recommend further investigation into the underlying mechanism is essential to validate this hypothesis.

Identification of monotonically expressed long non-coding RNA signatures for breast cancer using variational autoencoders

As breast cancer is a multistage progression disease resulting from a genetic sequence of mutations, understanding the genes whose expression values increase or decrease monotonically across pathologic stages can provide insightful clues about how breast cancer initiates and advances. Utilizing variational autoencoder (VAE) networks in conjunction with traditional statistical testing, we successfully ascertain long non-coding RNAs (lncRNAs) that exhibit monotonically differential expression values in breast cancer. Subsequently, we validate that the identified lncRNAs really present monotonically changed patterns. The proposed procedure identified 248 monotonically decreasing expressed and 115 increasing expressed lncRNAs. They correspond to a total of 65 and 33 genes respectively, which possess unique known gene symbols. Some of them are associated with breast cancer, as suggested by previous studies. Furthermore, enriched pathways by the target mRNAs of these identified lncRNAs include the Wnt signaling pathway, human papillomavirus (HPV) infection, and Rap 1 signaling pathway, which have been shown to play crucial roles in the initiation and development of breast cancer. Additionally, we trained a VAE model using the entire dataset. To assess the effectiveness of the identified lncRNAs, a microarray dataset was employed as the test set. The results obtained from this evaluation were deemed satisfactory. In conclusion, further experimental validation of these lncRNAs with a large-sized study is warranted, and the proposed procedure is highly recommended.

Innate Immune Program in Formation of Tumor-Initiating Cells from Cells-of-Origin of Breast, Prostate, and Ovarian Cancers

Tumor-initiating cells (TICs), also known as cancer stem cells (CSCs), are cancer cells that can initiate a tumor, possess self-renewal capacity, and can contribute to tumor heterogeneity. TICs/CSCs are developed from their cells-of-origin. In breast, prostate, and ovarian cancers, progenitor cells for mammary alveolar cells, prostate luminal (secretory) cells, and fallopian tube secretory cells are the preferred cellular origins for their corresponding cancer types. These luminal progenitors (LPs) express common innate immune program (e.g., Toll-like receptor (TLR) signaling)-related genes. Microbes such as bacteria are now found in breast, prostate, and fallopian tube tissues and their corresponding cancer types, raising the possibility that their LPs may sense the presence of microbes and trigger their innate immune/TLR pathways, leading to an inflammatory microenvironment. Crosstalk between immune cells (e.g., macrophages) and affected epithelial cells (e.g., LPs) may eventually contribute to formation of TICs/CSCs from their corresponding LPs, in part via STAT3 and/or NFκB pathways. As such, TICs/CSCs can inherit expression of innate-immunity/TLR-pathway-related genes from their cells-of-origin; the innate immune program may also represent their unique vulnerability, which can be explored therapeutically (e.g., by enhancing immunotherapy via augmenting TLR signaling).

HPV-Associated Breast Cancer: Myth or Fact?

Some estimates place the proportion of human malignancies attributable to viruses at between 15 and 20 percent. Viruses including the human papillomavirus are considered an interesting but controversial etiological risk factor for breast cancer. HPV infection is anticipated to be an early trigger in breast cancer carcinogenesis, followed by cumulative alterations over time ("hit and run" mechanism) through synergy with other environmental factors. The association between HPV and breast cancer has not yet been verified. There are very conflicting data on the presence of HPV DNA in breast cancer samples, and we lack a clarified, exact mode of HPV transmission to the breast. In our review article we analyzed the up-to-date knowledge about the association of HPV and breast cancer. Furthermore, we summarized the available original research published since 2010. In conclusion, the complexity and inconsistency of the available results together with the relatively low prevalence of HPV infection requires extensive research with much larger studies and exact and unified diagnostic methods are required to better understand the role of the HPV in breast carcinogenesis.

Presence of Human Papillomavirus DNA in Malignant Neoplasia and Non-Malignant Breast Disease

Breast cancer is the leading cause of cancer death among women worldwide. Multiple extrinsic and intrinsic factors are associated with this disease’s development. Various research groups worldwide have reported the presence of human papillomavirus (HPV) DNA in samples of malignant breast tumors. Although its role in mammary carcinogenesis is not fully understood, it is known that the HPV genome, once inserted into host cells, has oncogenic capabilities. The present study aimed to detect the presence of HPV DNA in 116 breast tissue biopsies and classify them according to their histology. It was found that 50.9% of the breast biopsies analyzed were malignant neoplasms, of which 74.6% were histologically classified as infiltrating ductal carcinoma. In biopsies with non-malignant breast disease, fibroadenoma was the most common benign neoplasm (39.1%). Detection of HPV DNA was performed through nested PCR using the external primer MY09/11 and the internal primer GP5+/6+. A hybridization assay genotyped HPV. HPV DNA was identified in 20.3% (12/59) of malignant neoplasms and 35% non-malignant breast disease (16/46). It was also detected in 27.3% (3/11) of breast tissue biopsies without alteration. However, there are no statistically significant differences between these groups and the existence of HPV DNA (p = 0.2521). Its presence was more frequent in non-malignant alterations than in malignant neoplasias. The most frequent genotypes in the HPV-positive samples were low-risk (LR) HPV-42 followed by high-risk (HR) HPV-31.

Systematic review and meta-analysis of the papillomavirus prevalence in breast cancer fresh tissues

BACKGROUND

Although widely studied, the role of HPV in the genesis of breast carcinomas remains elusive due to the diversity of results across studies, possibly caused by the wide methodological heterogeneity, some of them with inadequate methods.

OBJECTIVE

To verify the association between HPV and breast cancer through the meta-analysis of studies that used the best-recognized techniques for viral detection and tissue conservation.

METHODS

A systematic review and meta-analysis restricted to studies that detected HPV by PCR in fresh and frozen tissue from breast cancer were conducted to obtain greater homogeneity. PubMed, Scopus, Science Direct, Cochrane Library, and SciELO were searched until December 14, 2019. Search terms included "breast cancer" and "HPV" without language restrictions. Eleven studies were included in the meta-analysis. The pooled relative risks and 95% confidence interval (95% CI) were calculated, and heterogeneity was assessed using the I-squared (I2).

RESULTS

The selected studies had very low heterogeneity (2%). There is a 2.15 times higher combined relative risk (95% CI = 1.60-2.89) of detecting HPV in breast cancer than in cancer-free breast controls with a statistically significant p-value (p < 0.0001).

CONCLUSION

Our data support the association of DNA-HPV with breast carcinomas. Further studies are needed to find out which breast cancer subtypes this association is most frequent.

Presence of high-risk HPVs, EBV, and MMTV in human triple-negative breast cancer

Breast cancer, the most frequent disease amongst women worldwide, accounts for the highest cancer-related mortality rate. Triple-negative breast cancer (TNBC) subtype encompasses ~15% of all breast cancers and lack estrogen, progesterone, and HER2 receptors. Although risk factors for breast cancer are well-known, factors underpinning breast cancer onset and progression remain unknown. Recent studies suggest the plausible role of oncoviruses including human papillomaviruses (HPVs), Epstein-Barr virus (EBV), and mouse mammary tumor virus (MMTV) in breast cancer pathogenesis. However, the role of these oncoviruses in TNBC is still unclear. In the current study, we explored the status of high-risk HPVs, EBV, and MMTV in a well-defined TNBC cohort from Croatia in comparison to 16 normal/non TNBC samples (controls) using polymerase chain reaction assay. We found high-risk HPVs and EBV present in 37/70 (53%) and 25/70 (36%) of the cases, respectively. The most common HPV types are 52, 45, 31, 58 and 68. We found 16% of the samples positive for co-presence of high-risk HPVs and EBV. Moreover, our data revealed that 5/70 (7%) samples are positive for MMTV. In addition, only 2/70 (3%) samples had co-presence of HPVs, EBV, and MMTV without any significant association with the clinicopathological variables. While, 6/16 (37.5%) controls were positive for HPV (p = .4), EBV was absent in all controls (0/16, 0%) (p = .01). In addition, we did not find the co-presence of the oncoviruses in the controls (p > .05). Nevertheless, further investigations are essential to understand the underlying mechanisms of multiple-oncogenic viruses' interaction in breast carcinogenesis, especially TNBC.

Detection of High- and Low-Risk HPV DNA in Archived Breast Carcinoma Tissues from Ethiopian Women

BACKGROUND

Human papilloma virus (HPV) is involved in the development of cancer of the cervix, mouth and throat, anus, penis, vulva, or vagina, but it has not been much considered as a cause of breast cancer. Recently, a number of investigations have linked breast cancer to viral infections. High-risk HPV types, predominantly HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59, are established as carcinogens in humans. In this study we aimed to detect 19 high-risk and 9 low-risk HPVs from archived breast tumor tissue among Ethiopian women.

METHODS

In this study, 75 breast cancer patients from Tikur Anbassa Specialized Hospital in Addis Ababa (Ethiopia) were included. HPV detection and genotyping were done using the novel Anyplex™ II HPV28 Detection Assay at the Orebro University Hospital, Sweden. The Anyplex™ II PCR System detects 19 high-risk HPV types (16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 69, 73, and 82) and 9 low-risk HPV types (6, 11, 40, 42, 43, 44, 54, 61, and 70). IHC for p16 was done using an automated system, the Dako Autostainer Link.

RESULTS

Out of the 75 valid tests, two were found to be positive (2.7%) for HPV. One of the cases was positive for the high-risk HPV16 genotype while the other was positive both for the high-risk HPV39 and the low-risk HPV6. The cell cycle protein p16 was highly expressed in the case positive for the high-risk HPV16, but it was not expressed in the case positive for HPV39.

CONCLUSION

The prevalence of HPV is low in Ethiopian breast cancer patients, but the role played by HPV in breast carcinogenesis among Ethiopian breast cancer patients cannot be commented based on these observations.

High-risk human papillomaviruses and Epstein-Barr virus in breast cancer in Lebanese women and their association with tumor grade: a molecular and tissue microarray study

Background

High-risk human papillomaviruses (HPVs) are present and can cooperate with Epstein–Barr virus (EBV) to initiate and/or enhance the progression of several types of human carcinomas including cervical as well as head and neck; in parallel, it has been recently pointed out that these oncoviruses can be detected in human breast cancers. Thus, we herein explored the presence/co-presence of high-risk HPVs and EBV in breast cancer in Lebanese women.

Methods

A cohort of 102 breast cancer samples and 14 normal breast tissues were assessed for the presence of HPVs and EBV. Polymerase chain reaction (PCR) and immunohistochemistry (IHC) analysis in addition to tissue microarray (TMA) platform were used in this study.

Results

We found the presence of HPV in 66/102 (65%) of our samples, while EBV is present in 41/102 (40%) of the cohort. Additionally, our data showed that high-risk HPV types (52, 35, 58, 45, 16 and 51) are the most frequent in breast cancer in Lebanese women. Meanwhile, we report that high-risk HPVs and EBV are co-present in 30/102 (29%) of the samples; more significantly, our results indicate that their co-presence is associated with tumor grade (p = 0.03).

Conclusion

Our data revealed that HPVs and EBV are present/co-present in human breast cancer where they may play an important role in its development and/or progression; thus, we believe that further investigations are essential to confirm and elucidate the presence/co-presence of these oncoviruses and the underlying mechanisms of their interaction in breast carcinogenesis.

Oncogenic human papillomavirus in breast cancer: molecular prevalence in a group of Congolese patients

Background

Since the work of Band et al. in 1990 (Proc. Natl. Acad. Sci. USA 87:463–467), several studies have suggested a possible link between the pathogenesis of breast cancer and viral infection. Infection with oncogenic HPV has been one of the viruses implicated in breast cancer cases worldwide.

Objective

To investigate the presence of HPV DNA in archived paraffin-embedded breast cancer cases at the University Hospital of Brazzaville and to assess the association between viral HPV infections and clinicopathological features.

Methods

A total of 40 formalin-fixed paraffin-embedded (FFPE) biopsies were retrospectively collected and available information was recorded. HPV detection and genotyping were performed by real-time PCR by GeneXpert technology (Cepheid, Sunnyvale, USA).

Results

The mean age was 51.1±11.4 years (range 22–75 years; median was 47). Overall, HPV DNA was detected in six (15%) breast carcinoma samples. HPV-16, the most common genotype was identified in 83.7 % of all samples. HPV porting with clinicopathological features showed no significant difference (P>0.05). However, a statistically significant difference was observed between HPV infection and SBR grade (P=0.05).

Conclusion

Our study described a high prevalence of HPV-HR in breast cancer cases in the Congolese woman. Future type case-control studies are necessary to better describe the potential role of HPV in the occurrence of breast cancer in Congo.

Human papillomavirus, gene mutation and estrogen and progesterone receptors in breast cancer: a cross-sectional study

Introduction

recent studies show a good relationship between breast cancer (BC) and human papillomaviruses (HPV) wich is responsible for about 18% of BC cases. This study aimed to assess the relationship between different genotypes of HPV and the expression of P53 and retinoblastoma (RB) genes and estrogen and progesterone receptors in BC among Sudanese women.

Methods

one hundred and fifty tissue blocks were obtained from females diagnosed with BC. Positive samples were used to determine genotypes with an applied biosystem (ABI 3730XL) genetic analyzer for sequencing and immunohistochemistry.

Results

13/150 samples showed HPV DNA. High-risk HPV-16 was detected in 5 cases, high-risk-HPV-58 was found in four cases, and HPV-18 was detected in three cases. Low-risk-HPV-11 was detected in a single invasive lobular carcinoma (ILC) case. P53 and RB gene mutations were detected in 35 and 30 BC cases, respectively. P53 gene mutation was frequently identified in grade (III) BC while RB gene mutation was positive in grade (II). Grade (II) BC had a higher incidence of HPV-16 and 58. On the other hand, HPV-18 had a higher incidence in grade (III). Estrogen and progesterone receptors were expressed in 94 and 79 HPV cases among the study group, respectively.

Conclusion

this study elucidates the associations between HPV genotypes and BC. A statistically significant association was observed among p53 and RB gene mutations and different BC histological types. On the other hand, there was a statistically insignificant association between HPV genotyping and different BC gradings, BC histological types, P53 and RB genes mutations, and estrogen and progesterone receptor expression. Also, there was a statistically insignificant association among estrogen and progesterone receptors expression and BC grading. RB gene mutation was significantly associated with different BC grades. On the other hand, there was a statistically insignificant association between progesterone receptor expression and BC.

The co-presence of high-risk human papillomaviruses and Epstein-Barr virus is linked with tumor grade and stage in Qatari women with breast cancer

High-risk human papillomaviruses (HPV) can be present and cooperate with Epstein–Barr virus (EBV) to promote the onset and/or progression of various cancers including cervical, breast, head and neck as well as colorectal. In this investigation, we explored the co-prevalence of high-risk HPV and EBV in 74 breast cancer tissues from Qatari women using polymerase chain reaction. We found that high-risk HPV and EBV are present in 48/74 (65%) and 36/74 (49%) of the cases, respectively. While we noted that the presence of HPV presence is associated with triple-negative breast cancer (TNBC) (p = .008), however, the presence of EBV did not correlate with any breast cancer subgroup. Moreover, our data revealed that high-risk HPV and EBV are co-present in 35/74 (47%) of the samples and their co-presence is significantly associated with tumor grade (p = .04) and tumor stage (p = .04). These data indicate that HPV and EBV are commonly co-present in breast cancer and their association could be linked with a more aggressive tumor phenotype. Thus, further investigations are essential to understand the underlying mechanisms of HPV and EBV cooperation in breast carcinogenesis.

Human papilloma virus (HPV) profiles in breast cancer: future management

Breast cancer (BC) is frequent among women in worldwide as well as in India. Several studies have reported a wide variation (1.6–86.2%) in the frequency of incidence of human papillomavirus (HPV) infection in BC with high prevalence of high risk HPV16 subtype. HPV infection in breast can occur through different routes like body fluid or by micro-lesion of breast skin from genital/agential sites, though the actual mode of HPV transmission is not yet known in details. Frequent integration and sequence variation with low copy number of HPV16 were seen in this tumour. In addition, high frequencies of methylation in p97 promoter region of HPV16 were evident in this tumour. Novel splice variants of E6/E7 along with other common variants and their protein expression were seen in the tumour. This indicates the importance of HPV in this tumor, its early diagnosis and prognosis. Thus, HPV may be targeted through vaccination to control the disease. However, detailed analysis of HPV associated molecular pathogenesis of BC is warranted for proper therapeutic intervention.

The scope of viral causation of human cancers: interpreting virus density from an evolutionary perspective

Most known oncogenic viruses of humans use DNA as their genomic material. Research over the past quarter century has revealed that their oncogenicity results largely from direct interference with barriers to oncogenesis. In contrast to viruses that have been accepted causes of particular cancers, candidate viral causes tend to have fewer viral than cellular genomes in the tumours. These low viral loads have caused researchers to conclude that the associated viruses are not primary causes of the associated cancers. Consideration of differential survival, reproduction and infiltration of cells in a tumour suggest, however, that viral loads could be low even when viruses are primary causes of cancer. Resolution of this issue has important implications for human health because medical research tends to be effective at preventing and controlling infectious diseases. Mathematical models may clarify the problem and help guide future research by assessing whether low viral loads are likely outcomes of the differential survival, reproduction, and infiltration of cells in a tumour and, more generally, the extent to which viruses contribute to cancer. This article is part of the theme issue 'Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses'.

Topological integration of RPPA proteomic data with multi-omics data for survival prediction in breast cancer via pathway activity inference

BACKGROUND

The analysis of integrated multi-omics data enables the identification of disease-related biomarkers that cannot be identified from a single omics profile. Although protein-level data reflects the cellular status of cancer tissue more directly than gene-level data, past studies have mainly focused on multi-omics integration using gene-level data as opposed to protein-level data. However, the use of protein-level data (such as mass spectrometry) in multi-omics integration has some limitations. For example, the correlation between the characteristics of gene-level data (such as mRNA) and protein-level data is weak, and it is difficult to detect low-abundance signaling proteins that are used to target cancer. The reverse phase protein array (RPPA) is a highly sensitive antibody-based quantification method for signaling proteins. However, the number of protein features in RPPA data is extremely low compared to the number of gene features in gene-level data. In this study, we present a new method for integrating RPPA profiles with RNA-Seq and DNA methylation profiles for survival prediction based on the integrative directed random walk (iDRW) framework proposed in our previous study. In the iDRW framework, each omics profile is merged into a single pathway profile that reflects the topological information of the pathway. In order to address the sparsity of RPPA profiles, we employ the random walk with restart (RWR) approach on the pathway network.

RESULTS

Our model was validated using survival prediction analysis for a breast cancer dataset from The Cancer Genome Atlas. Our proposed model exhibited improved performance compared with other methods that utilize pathway information and also out-performed models that did not include the RPPA data utilized in our study. The risk pathways identified for breast cancer in this study were closely related to well-known breast cancer risk pathways.

CONCLUSIONS

Our results indicated that RPPA data is useful for survival prediction for breast cancer patients under our framework. We also observed that iDRW effectively integrates RNA-Seq, DNA methylation, and RPPA profiles, while variation in the composition of the omics data can affect both prediction performance and risk pathway identification. These results suggest that omics data composition is a critical parameter for iDRW.

Robust pathway-based multi-omics data integration using directed random walks for survival prediction in multiple cancer studies

Background

Integrating the rich information from multi-omics data has been a popular approach to survival prediction and bio-marker identification for several cancer studies. To facilitate the integrative analysis of multiple genomic profiles, several studies have suggested utilizing pathway information rather than using individual genomic profiles.

Methods

We have recently proposed an integrative directed random walk-based method utilizing pathway information (iDRW) for more robust and effective genomic feature extraction. In this study, we applied iDRW to multiple genomic profiles for two different cancers, and designed a directed gene-gene graph which reflects the interaction between gene expression and copy number data. In the experiments, the performances of the iDRW method and four state-of-the-art pathway-based methods were compared using a survival prediction model which classifies samples into two survival groups.

Results

The results show that the integrative analysis guided by pathway information not only improves prediction performance, but also provides better biological insights into the top pathways and genes prioritized by the model in both the neuroblastoma and the breast cancer datasets. The pathways and genes selected by the iDRW method were shown to be related to the corresponding cancers.

Conclusions

In this study, we demonstrated the effectiveness of a directed random walk-based multi-omics data integration method applied to gene expression and copy number data for both breast cancer and neuroblastoma datasets. We revamped a directed gene-gene graph considering the impact of copy number variation on gene expression and redefined the weight initialization and gene-scoring method. The benchmark result for iDRW with four pathway-based methods demonstrated that the iDRW method improved survival prediction performance and jointly identified cancer-related pathways and genes for two different cancer datasets.

Reviewers

This article was reviewed by Helena Molina-Abril and Marta Hidalgo.

Human papilloma virus and breast cancer: the role of inflammation and viral expressed proteins

BACKGROUND

Breast cancer is currently the most common neoplasm diagnosed in women globally. There is a growing body of evidence to suggest that human papillomavirus (HPV) infection may play a key role in invasiveness of breast cancer. The aim of this study was to determine the presence of HPV in patients with breast cancer and its possible association with cancer progression.

METHODS

Breast specimens were collected from 72 patients with breast cancer and 31 healthy controls. The presence of HPV was investigated by polymerase chain reaction (PCR) and genotyping was performed for positive cases. We also evaluated the viral factors such as E6, E2, and E7 in HPV positive cases. Enzyme-linked immunosorbent assay (ELISA (and Real-time PCR techniques were used to measure the expression level of anti-carcinogenic genes, such as p53, retinoblastoma (RB), breast and ovarian cancer susceptibility gene (BRCA1, BRCA2) and inflammatory cytokines, including tumor necrosis factor α (TNF-α), transforming growth factor β (TGF-β), nuclear factor-kB (NF-kB), and different interleukins [ILs] (IL-1,IL6, and IL-17).

RESULTS

The HPV DNA was detected in 48.6% of breast cancer samples, whereas only 16.1% of controls were positive for HPV. We observed statistically significant differences between breast cancer patients and HPV presence (P = 0.003). HPV type 18 was the most prevalent virus genotype in patients. The expression of P53, RB, BRCA1, and BRCA2 were decreased in patients with HPV-positive breast cancer as compared to HPV-negative breast cancer and healthy controls. (All P-values were less than 0.05). The presence of the HPV was associated with increased inflammatory cytokines (IL-1, IL-6, IL-17, TGF-β, TNF-α, and NF-kB) and tumor progression.

CONCLUSION

The present study demonstrated that HPV infection may implicate in the development of some types of breast cancer.

Evidence of No Association Between Human Papillomavirus and Breast Cancer

Background

Globally, breast cancer is the most frequent cancer among women. Studies reported an increased risk of breast cancer among women with prior cervical dysplasia. This study aimed to describe the prevalence of human papillomavirus (HPV) in breast cancer and explore if women with prior cervical neoplasia carry an increased risk of HPV-positive breast cancer compared to women without.

Methods

This case–control study identified 193 Danish women diagnosed with breast cancer (1998–2012) at Aarhus University Hospital or Copenhagen University Hospital Herlev. Cases were 93 women with cervical intraepithelial neoplasia grade 3 or worse (CIN3+) prior to breast cancer. Controls were 100 women without prior cervical dysplasia. HPV testing and genotyping were done using SPF₁₀ PCR-DEIA-LiPA₂₅ and an in-house semi-Q-PCR assay.

Results

Overall HPV prevalence in breast cancer for the assays was 1.55% (95% CI 0.32–4.48) and 0.52% (95% CI 0.01–2.85). There was no difference in HPV prevalence between cases and controls (2.15 vs. 1.00%, p = 0.61 and 1.08 vs. 0.00%, p = 0.48). HPV prevalence in CIN3+ was 94.62% (95% CI 0.88–0.98). Concordance between the assays was 98.60%.

Conclusion

HPV prevalence in breast cancer is very low suggesting no etiological correlation between HPV and breast cancer.

Risks and protective factors for triple negative breast cancer with a focus on micronutrients and infections

Triple negative breast cancer (TNBC) is an aggressive form of breast cancer (BC) with a poor prognosis. Second, patients cannot benefit from targeted therapy, except for those with BRCA1/2 mutations, for whom poly (ADP-ribose) polymerase (PARP) inhibition therapy using olaparib has recently been approved. As global priorities continue to be epidemiological analysis of BC risk factors and early diagnosis, this review focuses on the risks and protective factors associated with TNBC. A PubMed keyword search for new knowledge on the risks and protective factors for TNBC was carried out. We also found statistical information from current online databases concerning the estimated incidence, prevalence and mortality worldwide of this cancer. Traditional risk factors for BC and TNBC are those related to reproduction such as the age of menarche, age of first birth, parity, breastfeeding and age at menopause. Attention needs to be paid to familial BC, weight control, alcohol consumption and regular physical activity. Epidemiological studies on TNBC provide evidence for protective factors such as regular consumption of soya, seafood, green tea, folic acid and vitamin D. Potential risk factors may include night work and viral infectious agents like human papillomavirus (HPV) and Epstein-Barr virus (EBV). Droplet digital methylation-specific PCR (ddMSP) is a possible new screening method for detection of BC including TNBC. Further research is necessary to validate these new factors.

Detection of human papillomavirus DNA in tumors from Rwandese breast cancer patients

BACKGROUND

During the last decades, a great interest was given to viral etiology of breast cancer. Indeed, due to recent technical improvements and some encouraging new results, it has been a resurgence of interest in the possibility that a substantial proportion of human breast cancers may be caused by viral infections. High-risk genotypes of human papillomavirus (HPV) have been found in breast cancer cases. In the present study, we aimed to assess the presence of HPV DNA in breast cancer cases from Rwanda and to evaluate the association between HPV infection and clinico-pathological features.

METHODS

Therefore, a total of 47 archived formalin-fixed paraffin-embedded biopsies were collected and complete information was recorded. HPV detection and genotyping were done by PCR amplification and DNA sequencing.

RESULTS

Overall, HPV DNA was found in 46.81% of cases, HPV16 being the most prevalent subtype (77.27%) followed by HPV33 (13.64%) and HPV31 (9.09%). Comparison of HPV with clinico-pathological features showed no significant difference between HPV infection and breast localization, histological subtype, clinical stage, tumor grade, and intrinsic molecular subtypes.

CONCLUSIONS

These findings provide evidence of high prevalence of high-risk HPV in Rwandese patients with breast cancer and suggest that high-risk HPV infections could be a risk factor associated with human breast cancer development.

HPV Status and Its Correlation with BCL2, p21, p53, Rb, and Survivin Expression in Breast Cancer in a Chinese Population

Despite recent evidence, the role of human papillomavirus (HPV) in breast carcinogenesis is controversial. The correlations of HPV infection with the clinicopathological features of breast cancer and the expression of cell cycle/apoptosis-associated proteins have not been well elucidated. In this study, we sought to determine the prevalence of high-risk HPVs (HR-HPVs) infection and BCL2, p21, p53, Rb, and survivin expression in breast cancer patients and to investigate the relationship of HPV with these cancer-related proteins, in an attempt to clarify the potential mechanism of HPV in breast cancer pathogenesis. HPV presence in 81 fresh breast cancer tissues was determined by hybrid capture 2 (HC2) assay, and expression of BCL2, p21, p53, Rb, and survivin was detected by immunohistochemistry. Here we showed that fourteen (17.3%) patients were HR-HPV positive. HPV infection demonstrated no significant correlation with the clinicopathological characteristics of breast cancer. HPV-positive tumors showed significantly higher BCL2 and lower p53 expression than HPV-negative tumors. Expression of p21, Rb, and survivin was not associated with HPV status. Our results suggest a possible role of HR-HPV in breast cancer carcinogenesis, in which BCL2 and p53 may be involved.

Molecular characterization, prevalence and clinical relevance of Phodopus sungorus papillomavirus type 1 (PsuPV1) naturally infecting Siberian hamsters (Phodopus sungorus)

Phodopus sungorus papillomavirus type 1 (PsuPV1), naturally infecting Siberian hamsters (Phodopus sungorus) and clustering in the genus Pipapillomavirus (Pi-PV), is only the second PV type isolated from the subfamily of hamsters. In silico analysis of three independent complete viral genomes obtained from cervical adenocarcinoma, oral squamous cell carcinoma and normal oral mucosa revealed that PsuPV1 encodes characteristic viral proteins (E1, E2, E4, E6, E7, L1 and L2) with conserved functional domains and a highly conserved non-coding region. The overall high prevalence (102/114; 89.5 %) of PsuPV1 infection in normal oral and anogenital mucosa suggests that asymptomatic infection with PsuPV1 is very frequent in healthy Siberian hamsters from an early age onward, and that the virus is often transmitted between both anatomical sites. Using type-specific real-time PCR and chromogenic in situ hybridization, the presence of PsuPV1 was additionally detected in several investigated tumours (cervical adenocarcinoma, cervical adenomyoma, vaginal carcinoma in situ, ovarian granulosa cell tumour, mammary ductal carcinoma, oral fibrosarcoma, hibernoma and squamous cell papilloma) and normal tissues of adult animals. In the tissue sample of the oral squamous cell carcinoma individual, punctuated PsuPV1-specific in situ hybridization spots were detected within the nuclei of infected animal cells, suggesting viral integration into the host genome and a potential etiological association of PsuPV1 with sporadic cases of this neoplasm.

Prevalence of Human Papillomavirus Infection in Breast Cancer Cells from Thai Women

Breast cancer is the leading female cancer worldwide and is the most frequently diagnosed in Thai women. Its potential etiologic has not been clearly identified. Several recent reports could detect human papillomavirus (HPV) infection in breast cancer or benign breast lesions. HPV infection considered suggests being one of many risk factors for cancer development. The aim of this study was to determine the frequency of HPV infection in both breast cancer and benign breast lesion/tumor tissues. Seven hundred samples from Thai women were collected during 2013-2015 and statistically correlation between HPV infection, sociodemographic and histopathological parameters were also analyzed. HPV DNA detection and genotyping were performed by polymerase chain reaction and enzyme immunoassay, respectively. The results demonstrated that mean age of the patients were 41.76±12.53 years and 52.73±11.68 years for benign breast lesions/tumor and breast cancer samples, respectively. HPV DNA was detected in 25/700 (3.57%) samples, in which 10/350 (2.857%) from benign breast lesion/tumor samples and 15/350 (4.285%) from breast cancer samples. HPV 16 is the predominant types of this study, follow by HPV 33, 18, 35, 52. Most of HPV type detection samples belong to the high risk types, except 1/25 sample could be detected low risk type; HPV 6 which was presented as co-infection with the other high risk type. From sociodemographic and histopathological correlation analysis, all of studied parameters such as breast cancer history, hormone receptors status etc. did not show statistically significant correlated with HPV infection (P>0.05). In conclusion, the low frequency detection in this study suggests that HPV did not play the main important role for breast cancer development and represented highly controversial, but it may be causative agents of only a relative small proportion of all breast cancer or non-malignant breast lesion and it is the interesting data for further study in virus-associated cancer.

Prevalence of EBV, HPV and MMTV in Pakistani breast cancer patients: A possible etiological role of viruses in breast cancer

BACKGROUND

Breast cancer being a multifactorial disease, the role of infectious agent in development of disease is of great interest. The high incidence of breast cancer around the world has woken the interest in a viral etiology of breast cancer. Despite decades of research, no etiologic factor(s) for human breast cancer has been known and the quest for a contributing cause has all but been abandoned during the past years. Recent investigations have linked breast cancer to viral infections, such as Epstein-Barr virus (EBV), Human papillomavirus (HPV) and mouse mammary tumor virus.

AIM

To investigate the possible association of EBV, HPV and MMTV infection with breast cancer development and progression.

METHODS

Screening of isolated genomic DNA from FFPE breast cancer tissue biopsies (n=250) using standard polymerase chain reaction and correlation of virus prevalence with BC disease outcomes using statistical analysis software (SPSS 16.0).

RESULTS

Our findings suggest the prevalence of EBV (24.4%), HPV (18.1%) and MMTV (29.3%), while coinfection of HPV and EBV was detected in 9.2% (23/250), co infection of HPV and MMTV in 3.2% (8/250) and coinfection of EBV and MMTV in 6% (15/250) of breast cancer samples. No virus was detected in 59.5% of the breast cancer samples. Mono infection of EBV and HPV do not statistically co-relate with the clinico-pathological outcomes of breast cancer disease, though MMTV infection does co-relate with age and grade of breast cancer disease. In our study, the prevalence of coinfection of HPV, EBV and MMTV in Pakistani breast cancer patients is rare, still there is a possibility of synergistic carcinogenic effect of different viruses in the development of breast cancer disease.

CONCLUSION

The significant percentage of virus prevalence shows potential role in breast cancer development. However, this study provides substantial but not conclusive evidence for the involvement of viruses in BC disease development and progressiveness.

Viral warts (Human Papilloma Virus) as a potential risk for breast cancer among younger females

INTRODUCTION

There have been several reports on the role of human papillomavirus (HPV) in the etiology of breast cancer. To our knowledge, this is first study to use disease-disease association data-mining approach to analyzing viral warts and breast cancer to be conducted in Taiwanese population.

MATERIALS AND METHODS

We analyzed the Taiwan's National Health Insurance database (NHIDM data comprising of 23 million patient data) to examine the association between viral warts and female breast carcinoma. The patients were categorized into three groups: breast cancer only, viral warts only, and those with both breast cancer and viral warts. The Cox proportion hazard regression analysis was used to measure the effect of HPV on the time to breast cancer diagnosis. Multivariable analyzes and stratified analyzes using hazard ratios (HRs) were presented with 95% confidence intervals (CIs) after adjusting for age, and CCI.

RESULT

Among 807,578 HPV population, we identified 6014 breast cancer cases. The HPV group was associated with a significantly higher risk of developing breast cancer (HR, 1.18; 95% CI, 1.15-1.21; p< 0.001) compared with the non-HPV group. HPV patients with age group 18-39 was slightly higher risk of breast cancer occurrence (HR, 1.07; 95% CI, 1.01-1.13; p<.05). The risk of breast cancer in 10-year incidence was 7% higher for females less than 40 years and 23% for over 40 year's patients when compared with non-HPV patients of the same age group.

CONCLUSION

Our study indicates that women who develop viral warts are at a significantly higher risk of developing breast cancer than women who have not diagnosed with viral warts. Thus, the presence of viral warts is a potential risk to breast cancer. Therefore, we suggest patients diagnosed with viral warts may get early screening for breast cancer.

Study of association and molecular analysis of human papillomavirus in breast cancer of Indian patients: Clinical and prognostic implication

OBJECTIVES

Human papillomavirus (HPV) causes tumors primarily Cervical cancer. Recently, inconsistent reports came up in Breast cancer (BC) too. In India, despite treatment 70,218 BC patients die each year. So, we explored the association of HPV, if any, with BC prognosis in Indian pre-therapeutic (PT) and Neo-adjuvant chemotherapy (NACT) patients with subsequent analysis of HPV profile.

METHODS

HPV prevalence was checked and analysis of physical status, copy number, genome variation, promoter methylation and expression (mRNA and protein) of the prevalent subtype was done.

RESULTS

High prevalence of HPV was observed in both PT (64.0%) and NACT (71.0%) cases with significant association with younger (20-45 yrs) PT patients. Interestingly, HPV infection was significantly increased from adjacent normal breast (9.5%, 2/21), fibro adenomas (30%, 3/10) to tumors (64.8%, 203/313) samples. In both PT and NACT cases, HPV16 was the most prevalent subtype (69.0%) followed by HPV18 and HPV33. Survival analysis illustrated hrHPV infected PT patients had worst prognosis. So, detailed analysis of HPV16 profile was done which showed Europian-G350 as the most frequent HPV16 variant along with high rate of integration. Moreover, low copy number and hyper-methylation of P97 early promoter were concordant with low HPV16 E6 and E7 mRNA and protein expression. Notably, four novel variations (KT020838, KT020840, KT020841 and KT020839) in the LCR region and two (KT020836 and KT020837) in the E6 region were identified for the first time along with two novel E6^E7*I (KU199314) and E6^E7*II (KU199315) fusion transcript variants.

CONCLUSION

Thus, significant association of hrHPV with prognosis of Indian BC patients led to additional investigation of HPV16 profile. Outcomes indicated a plausible role of HPV in Indian BC patients.

Detection of Human Papillomavirus in Korean Breast Cancer Patients by Real-Time Polymerase Chain Reaction and Meta-Analysis of Human Papillomavirus and Breast Cancer

Background

Human papillomavirus (HPV) is a well-established oncogenic virus of cervical, anogenital, and oropharyngeal cancer. Various subtypes of HPV have been detected in 0% to 60% of breast cancers. The roles of HPV in the carcinogenesis of breast cancer remain controversial. This study was performed to determine the prevalence of HPV-positive breast cancer in Korean patients and to evaluate the possibility of carcinogenic effect of HPV on breast.

Methods

Meta-analysis was performed in 22 case-control studies for HPV infection in breast cancer. A total of 123 breast cancers, nine intraductal papillomas and 13 nipple tissues of patients with proven cervical HPV infection were tested by real-time polymerase chain reaction to detect 28 subtypes of HPV. Breast cancers were composed of 106 formalin-fixed and paraffin embedded (FFPE) breast cancer samples and 17 touch imprint cytology samples of breast cancers.

Results

The overall odds ratio between breast cancer and HPV infection was 5.43 (95% confidence interval, 3.24 to 9.12) with I² = 34.5% in meta-analysis of published studies with case-control setting and it was statistically significant. HPV was detected in 22 cases of breast cancers (17.9%) and two cases of intaductal papillomas (22.2%). However, these cases had weak positivity.

Conclusions

These results failed to serve as significant evidence to support the relationship between HPV and breast cancer. Further study with larger epidemiologic population is merited to determine the relationship between HPV and breast cancer.

No Significant Association between Human Papillomavirus and Breast Cancer, Sanandaj, Iran

Background and Objective:

Any role of human papillomavirus (HPV) in the development of breast cancer is conjectural. The aim of this study was to investigate possible links between HPV and breast cancer in women, Sanandaj, Iran.

Methods:

In this case-control study, 70 formalin fixed and paraffin embedded blocks of breast malignant tumors as a case group and 70 blocks of lesions without malignancy were selected as controls. Sections about 10 µm thick were prepared. After removing the paraffin, DNA was extracted. Samples were tested by PCR using general and high-risk specific HPV primers.

Results:

All 70 malignant breast tumors (cases) were invasive ductal carcinomas, and of the 70 controls, 17 (24.3%) were fibrocystic tumors and 53 (75.7%) fibroadenomas. The age range of women in the case group was 25-72 years old and in the control group It was13-66 years. Using HPV general primers two samples were positive in the case group, confirmed to be HPV-18 using high-risk specific primers.

Conclusion:

No statistically significant association was found between breast cancer and HPV. It is necessary to confirm this result by further investigations in other populations.

Detection of human papillomavirus-16 DNA in archived clinical samples of breast and lung cancer patients from North Pakistan

PURPOSE

Over the past few decades, human papillomavirus (HPV) has been recorded as a key player in the development of various genital cancers, most notably cervical cancer. It has also been associated with some non-genital cancers. A subset of oropharyngeal cancers are known to be caused by HPV. Its aetiological involvement has been suggested for breast and lung cancer as well. However, reports regarding the HPV DNA detection vary widely from different parts of the world. Due to scarcity of local data in this regard, the current study aimed at retrospective detection of HPV presence in the archival samples of breast and lung cancer patients from north part of the country.

METHODS

A total of 55 formalin-fixed paraffin-embedded tissue sections of invasive ductal carcinoma of breast (n = 46) and lung (n = 9) were collected for this study. Genotyping for HPV16 and 18 was carried out through PCR.

RESULTS

HPV16 DNA was found in both breast and lung carcinoma samples with the prevalence rate of 17 and 11 %, respectively. An interesting association was found between ER/PR (Oestrogen/Progesterone receptor) and HER2/Neu (Human epidermal growth factor receptor-2) positivity with HPV occurrence in breast tumours.

CONCLUSION

Current study shows the presence of HPV16 DNA in archived clinical biopsy sections from breast and lung cancers (17, 11 %), respectively. A positive correlation of HPV16 presence was found with ER/PR and HER2-positive breast cancers. These initial findings warrant further investigation in order to determine HPV prevalence and aetiological role in local cancers, especially in ER/PR/HER2-positive breast cancers on a larger scale.

Human papillomavirus infection and risk of breast cancer: a meta-analysis of case-control studies

Background

Although systematic reviews (SR) report that human papillomavirus (HPV) increases the risk of breast cancer, there are still disputes regarding this association. In particular, it has been argued that the risk level differs depending on nationality, type of tissue, subtype of HPV, and publication year. Considering that the searching year of publication for the previous SRs was June 2013, a renewal meta-analysis needs to be conducted.

Methods

Using articles selected in the previous SRs, we compiled a list of references, cited articles, and related articles from the PubMed and Scopus databases. Of these, only publications with data from case-control studies on HPV DNA-positivity in tissues were chosen. Summary odds ratio (SOR) and 95 % confidence interval (CI) were calculated through meta-analysis. Meta-regression analysis was performed for nationality, types of tissue, subtype of HPV, and publication year.

Results

Twenty-two case-control studies were selected, and the total number of individuals in the case and control group was 1897 and 948, respectively. According to the meta-analysis about the 22 publications, HPV infection increased the risk of breast cancer (SOR = 4.02, 95 % CI: 2.42–6.68; I-squared = 44.7 %). Statistical significance was not found in meta-regression performed on the four variables of nationality, type of tissue, subtype of HPV, and publication year which some researchers think sources of heterogeneity.

Conclusions

The results of the present study supported the argument that HPV infection increases the risk of breast cancer. Age-matched case-control studies are in need in the future.

Molecular diagnosis and phylogenetic analysis of human papillomavirus type-16 from suspected patients in Pakistan

Background

Human Papillomavirus (HPV) is well known pathogen that can cause benign and malignant tumors in humans, yet there is very little information regarding HPV types prevalent in Pakistan.

Methods

A total of 92 cervical secretions were collected from suspected married female patients and used for DNA isolation using a novel isolation method. The samples were tested through Polymerase Chain Reaction (PCR) using already reported primers MY09/MY11, GP5/GP6, GP5+/GP6+, CP65/CP70, CP66/CP69 and SPF1/SPF2 and with those developed in this study including HRT1 and HRT2 primer sets for typing HPV types and HACTB primer set for human beta actin gene as internal positive control. Sequencing and phylogenetic analyses were performed for two isolates to determine circulating HPV types.

Results

PCR with HRT1 and HRT2 indicated 2 (2.17 %) patients were positive for HPV type- 16 while 1 (1.08 %) with HPV type 18. Sequencing and phylogenetic analysis of isolates confirmed HPV type-16 in genus alpha 9 which have 99 % homology with already reported HPV from Japan and Costa Rica.

Conclusion

This is the first report of HPV type-16 genus alpha 9 in Pakistan and the reported assay and sequence data will serve as valuable tools in further epidemiological studies for HPV surveillance to improve public health, especially of females in Pakistan.

The role of human papillomavirus in head and neck squamous cell carcinoma: A case control study on a southern Chinese population

HPV plays a role in the development of a portion of head and neck squamous cell carcinoma (HNSCC), but only limited information on its role in southern Chinese population is available. A multicenter case-control study was conducted. HPV type, viral integration, E6/7 mRNA expression status, and TP53 mutation were determined. A total of 228 HNSCC were recruited including 137 (60.1%) oral SCC, 34 (14.9%) oropharyngeal SCC, 31 (13.6%) laryngeal SCC, 21 (9.2%) hypopharyngeal SCC, and 5 (2.2%) lip and paranasal sinus SCC. High-risk HPV infection was found in 7.5% (17/228) of HNSCC, but only a small proportion of samples had evidence of viral integration (5.3%, 12/228) or E6/7 mRNA expression (4.4%, 10/228). HPV infection with oncogenic phenotype (integration and E6/7 mRNA expression) was significantly more common in oropharyngeal SCC than controls (9/34, 26.5% vs. 0/42, 0.0%, P < 0.001). Smoking showed a significant association with HNSCC, oropharyngeal SCC, and laryngeal SCC. TP53 mutation was associated with HNSCC (P < 0.001). Older age, TP53 mutation, and HPV16 infection with oncogenic phenotypes were independently associated factors for HNSCC with odds ratios of 1.03 (1.02-1.05), 3.38 (1.71-6.66), and 9.19 (1.13-74.68), respectively. High-risk HPV infection of head and neck mucosa is not uncommon in the Hong Kong population. This study found that 26-30% of oropharyngeal carcinoma was associated with HPV infection, mostly HPV16, and that smoking which predisposes to TP53 mutations was another important risk factor.

Inflammatory and Non-inflammatory Breast Cancer: A Potential Role for Detection of Multiple Viral DNAs in Disease Progression

BACKGROUND

Inflammatory breast cancer (IBC) is the most lethal form of breast cancer. Multiple viral infections in IBC tissues were found to be associated with disease pathogenesis.

OBJECTIVE

The aim of the present study was to correlate the incidence of viral DNA with breast cancer progression.

MATERIALS AND METHODS

Overall, 135 women diagnosed with breast cancer were enrolled in this study. Using polymerase chain reaction and sequencing assays, we determined the incidence of human papillomavirus types 16 and 18 (HPV-16 and -18), human cytomegalovirus (HCMV), Epstein-Barr virus, human herpes simplex virus type 1 and 2, and human herpes virus type 8 (HHV-8) in breast carcinoma tissue biopsies. We also assessed the expression of the cell proliferation marker Ki-67 by immunohistochemistry in association with the incidence of viral DNA.

RESULTS

HCMV and HPV-16 were the most detected viral DNAs in breast carcinoma tissues; however, the frequency of HCMV and HHV-8 DNA were significantly higher in IBC than non-IBC tissues. Moreover, the prevalence of multiple viral DNAs was higher in IBC than non-IBC tissues. The incidence of multiple viral DNAs positively correlates with tumor size and number of metastatic lymph nodes in both non-IBC and IBC patients. The expression of Ki-67 was found to be significantly higher in both non-IBC and IBC tissues in which multiple viral DNAs were detected.

CONCLUSIONS

The incidence of multiple viral DNAs in IBC tissues was higher compared with non-IBC tissues. The present results suggest the possibility of a functional relationship between the presence of multiple viral DNAs and disease pathogenesis.

EPMA position paper in cancer: current overview and future perspectives

At present, a radical shift in cancer treatment is occurring in terms of predictive, preventive, and personalized medicine (PPPM). Individual patients will participate in more aspects of their healthcare. During the development of PPPM, many rapid, specific, and sensitive new methods for earlier detection of cancer will result in more efficient management of the patient and hence a better quality of life. Coordination of the various activities among different healthcare professionals in primary, secondary, and tertiary care requires well-defined competencies, implementation of training and educational programs, sharing of data, and harmonized guidelines. In this position paper, the current knowledge to understand cancer predisposition and risk factors, the cellular biology of cancer, predictive markers and treatment outcome, the improvement in technologies in screening and diagnosis, and provision of better drug development solutions are discussed in the context of a better implementation of personalized medicine. Recognition of the major risk factors for cancer initiation is the key for preventive strategies (EPMA J. 4(1):6, 2013). Of interest, cancer predisposing syndromes in particular the monogenic subtypes that lead to cancer progression are well defined and one should focus on implementation strategies to identify individuals at risk to allow preventive measures and early screening/diagnosis. Implementation of such measures is disturbed by improper use of the data, with breach of data protection as one of the risks to be heavily controlled. Population screening requires in depth cost-benefit analysis to justify healthcare costs, and the parameters screened should provide information that allow an actionable and deliverable solution, for better healthcare provision.

Human papillomavirus 16 infection as a potential risk factor for prostate cancer: an adaptive meta-analysis

OBJECTIVES

Although an expert review published in 2013 concluded that an association between human papillomavirus (HPV) infection and prostate cancer (PCa) risk had not yet been firmly established, a 2011 systematic review of 14 articles revealed an increased prevalence of HPV-16 DNA in PCa tissues. Another meta-analysis of the related articles is needed to evaluate the potential link between HPV infection and PCa risk.

METHODS

A snowballing search strategy was applied to the previously cited articles in the above-mentioned expert review and systematic review. Additional articles selected for this meta-analysis should fulfill all following inclusion criteria: (a) evaluation of detected HPV-16 DNA in tissue samples and the PCa risk and (b) report of the HPV-16 prevalence in both cancer and control tissues. Estimated summary odds ratios (sOR) with 95% confidence intervals (CI) were calculated using fixed effect or random-effect models.

RESULTS

Hand searching identified 16 new articles. The sOR of the total 30 articles indicated a significant HPV-16 infection-related increase in the PCa risk (sOR, 1.851; 95% CI, 1.353 to 2.532, I(2)=37.82%).

CONCLUSIONS

These facts provide additional supportive evidence for a causal role of HPV-16 infection in prostate carcinogenesis. As the PCa incidence rates have increased rapidly in Asian countries, including Korea, during the last several decades, further studies of HPV-related PCa carcinogenesis may be necessary.

HPV infection and triple-negative breast cancers: an Italian case-control study

Background

Breast cancer is one of the most important neoplasia among women. To reduce its incidence and mortality impact it would be desirable to early identify risk factors associated with its development. It was recently suggested that biological agents could be the etiological cause, particularly Human Papilloma Virus (HPV). No specific relationship with different breast cancer types has been demonstrated until now. In particular, the triple-negative breast cancer (TNBC), characterized by a receptor negative pattern (ER/PgR/HER2–negative) and poor prognosis, can represent one of the most relevant clinical and public health priority in terms of observational research.

Findings

Aim of the study was to evaluate the HPV-positivity prevalence in two breast cancer series (TNBC vs. non-TNBC) in Northern Sardinia, Italy. The sample size of each group was represented by 40 formalin-fixed and paraffin-embedded specimens. The mean age was 60.3 years. The majority of the cancers were ductal (84%). The grading distribution was different: G2 was the most prevalent grade in the non-TNBC series, whereas G3 was the most frequent in the TNBC series (70% and 72%, respectively). Six biological samples were HPV-positive (7.5%): the positivity was assessed only in the TNBC group (15%; p-value: 0.026). The isolated genotypes were: 16, 31, 45, 52, 6, and 66. Only one co-infection was found (i.e., HPV-6 and -66).

Conclusions

The prevalence of HPV-positivity in TNBC specimens was 15%. On the basis of its carcinogenetic ability, an etiological role in the pathogenesis of the cancer could be supposed. This association should be confirmed with longitudinal studies to better assess the role of the HPV infection in TNBC and non-TNBC tumors.

A retrospective investigation on canine papillomavirus 1 (CPV1) in oral oncogenesis reveals dogs are not a suitable animal model for high-risk HPV-induced oral cancer

CPV1 (also called COPV) is a papillomavirus responsible for oral papillomatosis in young dogs. The involvement of this viral type in oral oncogenesis has been hypothesized in oral squamous cell carcinomas (SCCs), but has never been investigated in other neoplastic and hyperplastic oral lesions of dogs. Aim of this study was to investigate the presence of CPV1 in different neoplastic and hyperplastic lesions in order to assess its role in canine oral oncogenesis; according to the results obtained, a second aim of the study was to define if the dog can be considered a valid animal model for oral high risk HPV-induced tumors. Eighty-eight formalin-fixed, paraffin-embedded (FFPE) canine oral lesions including 78 oral tumors (papillomas, SCCs, melanomas, ameloblastomas, oral adenocarcinomas) and 10 hyperplastic lesions (gingival hyperplasia) were investigated with immunohistochemistry for the presence of papillomavirus L1 protein and with Real-Time PCR for CPV1 DNA. RT-PCR for RNA was performed on selected samples. All viral papillomas tested were positive for immunohistochemistry and Real-time PCR. In 3/33 (10%) SCCs, viral DNA was demonstrated but no viral RNA could be found. No positivity was observed both with immunohistochemistry and Real-Time PCR in the other hyperplastic and neoplastic lesions of the oral cavity of dogs. Even though the finding of CPV1 DNA in few SCCs in face of a negative immunohistochemistry could support the hypothesis of an abortive infection in the development of these lesions, the absence of viral RNA points out that CPV1 more likely represents an innocent bystander in SCC oncogenesis. The study demonstrates a strong association between CPV1 and oral viral papillomas whereas viral contribution to the pathogenesis of other oral lesions seems unlikely. Moreover, it suggests that a canine model of CPV1 infection for HPV-induced oncogenesis could be inappropriate.

Two hypotheses of dense breasts and viral infection for explaining incidence of breast cancer by age group in Korean women

Breast cancer, the second leading type of cancer in Korean women, has shown increasing incidence over the past 10 years. However, the curves of incidence by age group cast doubt on the birth cohort effect hypothesis. To explain the curves, here I suggest two alternative hypotheses of breast density and viral infection based on pre-existing evidences. Evaluating these hypotheses would require important clues to find unknown risk factors of breast cancer and to plan more effective strategies for breast cancer control in Korean women.

Joint infectious causation of human cancers

Joint infectious causation of cancer has been accepted in a few well-studied instances, including Burkitt's lymphoma and liver cancer. In general, evidence for the involvement of parasitic agents in oncogenesis has expanded, and recent advances in the application of molecular techniques have revealed specific mechanisms by which host cells are transformed. Many parasites evolve to circumvent immune-mediated detection and destruction and to control critical aspects of host cell reproduction and survival: cell proliferation, apoptosis, adhesion, and immortalization. The host has evolved tight regulation of these cellular processes-the control of each represents a barrier to cancer. These barriers need to be compromised for oncogenesis to occur. The abrogation of a barrier is therefore referred to as an essential cause of cancer. Alternatively, some aspects of cellular regulation restrain but do not block oncogenesis. Relaxation of a restraint is therefore referred to as an exacerbating cause of cancer. In this chapter, we explore past and current evidence for joint infectious causation of cancer in the context of essential and exacerbating causes. We stress that discovery of joint infectious causation may provide great improvements in controlling cancer, particularly through the identification of many additional nonhuman targets for synergistic interventions for prevention and treatment.

Detection and analysis of human papillomavirus (HPV) DNA in breast cancer patients by an effective method of HPV capture

Despite an increase in the number of molecular epidemiological studies conducted in recent years to evaluate the association between human papillomavirus (HPV) and the risk of breast carcinoma, these studies remain inconclusive. Here we aim to detect HPV DNA in various tissues from patients with breast carcinoma using the method of HPV capture combined with massive paralleled sequencing (MPS). To validate the confidence of our methods, 15 cervical cancer samples were tested by PCR and the new method. Results showed that there was 100% consistence between the two methods.DNA from peripheral blood, tumor tissue, adjacent lymph nodes and adjacent normal tissue were collected from seven malignant breast cancer patients, and HPV type 16(HPV16) was detected in 1/7, 1/7, 1/7and 1/7 of patients respectively. Peripheral blood, tumor tissue and adjacent normal tissue were also collected from two patients with benign breast tumor, and 1/2, 2/2 and 2/2 was detected to have HPV16 DNA respectively. MPS metrics including mapping ratio, coverage, depth and SNVs were provided to characterize HPV in samples. The average coverage was 69% and 61.2% for malignant and benign samples respectively. 126 SNVs were identified in all 9 samples. The maximum number of SNVs was located in the gene of E2 and E4 among all samples. Our study not only provided an efficient method to capture HPV DNA, but detected the SNVS, coverage, SNV type and depth. The finding has provided further clue of association between HPV16 and breast cancer.

Development of biomarker panel to predict, prevent and create treatments tailored to the persons with human papillomavirus-induced cervical precancerous lesions

Introduction

Human papillomavirus (HPV) induce many cancer conditions and cause cervical cancer, second in frequency of malignant disease in women.

The aim was to develop biomarker panel for HPV-induced cervical precancerous diseases in patients infected with herpes simplex virus (HSV).

Material and methods

The study involved 71 women with cervical precancerous diseases (mean age 26 ± 5 years) revealed by colposcopic, cytomorphological, and ultrasound signs which were assessed according to the following: first group, 44 patients infected with HPV; second group, 27 HPV-negative patients; and third group, 30 healthy patients (controls). In cervical specimen, we identified HPV DNA of different oncogenic risk types by polymerase chain reaction (PCR). Enzyme-linked immunosorbent assay (ELISA) kits (JSC SPC ‘DiaprofMed’) were used for detecting antibodies to HSV1 and/or HSV2 and for determining the avidity index. The production of pro-inflammatory cytokines, interferon-γ (IFN-γ), IFN-α, TNF-α, and interleukin-1β (IL-1β), and anti-inflammatory cytokines, IL-4, IL-10, and transforming growth factor-β1 (TGF-β1), were studied by ELISA.

Results

In HPV-induced cervix precancerous diseases, we identified low-avidity IgG antibodies to HSV serum of 20 patients; in the serum of 17 patients, we identified average-avidity antibodies, and high-avidity antibodies were found in 2 patients only. In 14 HPV-negative patients, we found low-avidity IgG antibodies to HSV; in 10 patients, medium avidity. Patients with low-avidity IgG antibodies to herpes virus showed high and medium oncogenic risk HPV types and a decrease of IFN-γ compared to patients with medium-avidity IgG antibodies. Production of IFN-γ was suppressed also in HPV-negative patients with cervical precancers, but we found low- and medium-avidity IgG antibodies to herpes virus. In patients with low-avidity antibodies, we observed increased level of IL-10. Level of IFN-α, IL-1β, IL-2, and IL-4 did not change in patients of all groups, but TGF-β1 increased.

Conclusions

In HPV-positive patients, those with low-avidity IgG antibodies to HSV had immunosuppression, confirmed by increased TGF-β1 and violation of IFN-γ production. Therefore, in pro- and anti-inflammatory cytokines and IgG antibodies to HSV, their avidity is an important diagnostic biomarker of HPV-induced precancerous cervical diseases. Low-avidity IgG antibodies may be an indication for treatment with immunomodulators and antiviral drugs.

Carcinogenic viruses and solid cancers without sufficient evidence of causal association

Viral infections are important risk factors for tumor development in humans. Selected types of cancers, either lymphomas or carcinomas, for which there is sufficient evidence in humans of a causal association with specific viruses, have been identified. Experimental and clinical data on the possible association of other tumor types and carcinogenic viruses are presently controversial. In this article, we review the current evidence on the relationship between breast, colorectal and lung cancers and carcinogenic viruses. The majority of the publications reviewed do not provide definitive evidence that the viruses studied are associated with breast, colon and lung cancers. However, since this association may be clinically relevant for some tumor subtypes (i.e., lung cancer and papillomaviruses), there is an urgent need for further investigation on this topic. Using innovative laboratory techniques for viral detection on well-defined tumor types, National and International networks against cancer should encourage and organize concerted research programs on viruses and solid cancer association.

Role of viruses in the development of breast cancer

The most common cancer worldwide among women is breast cancer. The initiation, promotion, and progression of this cancer result from both internal and external factors. The International Agency for Research on Cancer stated that 18-20% of cancers are linked to infection, and the list of definite, probable, and possible carcinogenic agents is growing each year. Among them, biological carcinogens play a significant role. In this review, data covering infection-associated breast and lung cancers are discussed and presented as possible involvements as pathogens in cancer. Because carcinogenesis is a multistep process with several contributing factors, we evaluated to what extent infection is significant, and concluded that members of the herpesvirus, polyomavirus, papillomavirus, and retrovirus families definitely associate with breast cancer. Detailed studies of viral mechanisms support this conclusion, but have presented problems with experimental settings. It is apparent that more effort needs to be devoted to assessing the role of these viruses in carcinogenesis, by characterizing additional confounding and synergistic effects of carcinogenic factors. We propose that preventing and treating infections may possibly stop or even eliminate certain types of cancers.

The ‘Trojan horse’ oncogenic strategy of HPVs in childhood

HPVs are considered to be the principal cause of cervical cancer worldwide. During the last decade, their possible oncogenic involvement has also been proposed in a substantial proportion of nongenital cancers, such as breast and lung cancer. The presence of high-risk HPVs in the neonatal oral mucosa supports the transmission of HPVs from the mother to her newborn. This review presents current evidence that supports the perinatal transmission of high-risk HPVs and suggests that this may be the initial step of the oncogenic strategy of high-risk HPVs in humans. The hypothesis that children are a unique reservoir of silent high-risk HPVs, analogously to the Trojan horse, should be investigated further.

Potential use of vaccines in the primary prevention of breast cancer in high-risk patients

Cancer vaccines are an emerging therapeutic and prophylactic modality that may play a more important role in cancer prevention and treatment in the future. Therapeutic cancer vaccines are designed to generate a targeted, immune-mediated antitumor response. Successful prophylactic vaccines are those against oncogenic viral infections, such as the human papillomavirus and cervical cancer. However, a tough challenge for the majority of tumor vaccines is the self-nature of tumor antigens. Ongoing studies are investigating methods to enhance vaccine strategies including immune-modulating agents. The present review analyzes the potential use of vaccines in the primary prevention of breast cancer, focusing on the recent extension of vaccine target selection to self-proteins that are overexpressed during the early stages of tumor development but whose expression no longer occurs as we age, a feature that may avoid clinically significant autoimmune sequelae.