Prevalence of human papillomavirus in breast cancer: a systematic review

Breast cancer causes and treatment: where are we going wrong?

This discussion paper seeks to provoke thoughts about cancer research in general, and why breast cancer in particular is not yet "curable". It asks the question - are we looking at the disease in the right way? Should we regard cancer as a progressive state, which is part of aging? Should we tailor treatment to "reset" the system or slow progression rather than try using toxic and aggressive therapy to kill every cancer cell (and sometimes also the patient)? The thesis is presented that we need to revisit our fundamental beliefs about the disease and then ask why we cling to beliefs that clearly are no longer valid. The paper also questions the role of ethics boards in hampering research and discusses the concept that breast cancer is an industry with vested interests involving profiteering by preventive, diagnostic, and therapeutic players. Finally, the paper suggests some ways forward based on emerging concepts in system biology and epigenetics.

Prevalence and correlation of human papilloma virus and its types with prognostic markers in patients with invasive ductal carcinoma of the breast in kuwait

OBJECTIVES

This study aimed to document the association of human papilloma virus (HPV) and its types in breast carcinoma tissues in Kuwaiti women, and correlate this with known prognostic markers.

METHODS

The clinicopathological data of archived tissue from 144 cases of invasive ductal breast carcinoma were studied (age, histological grade, size of tumour, lymph node metastases, oestrogen/progesterone receptors and human epidermal growth factor receptor 2 status). HPV frequency was documented using immunohistochemistry (IHC) and chromogenic in-situ hybridisation (CISH). HPV types were documented by CISH using HPV probes. CISH and IHC techniques were compared and HPV correlated with prognostic parameters.

RESULTS

The HPV prevalence as determined by CISH and IHC was 51 (35.4%) and 24 (16.7%) cases, respectively. The sensitivity of HPV by IHC was 37.3% and specificity was 94.6%. The sensitivity and specificity of HPV-CISH compared to HPVIHC was statistically significant (P <0.001). HPV-CISH was seen in 51 cases. A combination of HPV 6 and 11, and 16 and 18 was seen in 2 (3.9%) cases, and a combination of HPV 6, 11, 31 and 33 was seen in 7 (13.7%) cases. All three HPV probes: 6 and 11, 16 and 18, as well as 31 and 33 were present in 2 (3.9%) cases. The prevalence of HPVCISH in the Kuwaiti and non-Kuwaiti populations was 27 (52.9%) and 19 (37.2%), respectively. No correlation was observed with the prognostic parameters.

CONCLUSION

The frequency of HPV in breast carcinoma cases in Kuwait was 35.4% (CISH). Of those, 52.9% were Kuwaitis in whom both low- and high-risk HPV types were detected.

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.

Detection of high-risk human papillomaviruses in fresh breast cancer samples using the hybrid capture 2 assay

The etiology of breast cancer remains unknown and the role of human papillomavirus (HPV) in breast carcinogenesis is controversial. This study investigated the prevalence of high-risk HPV infections in Chinese women with breast cancer and the possible relationship between high-risk HPV infection and the clinicopathological characteristics of breast cancer. Tumor cells from 224 fresh breast cancer samples and 37 fresh breast fibroadenomas were collected for hybrid capture 2 (HC2) assay. HC2 was the only technique approved by the United States Food and Drug Administration for screening for high-risk HPV infection in 2008. The prevalence of high-risk HPV infection in breast cancer samples was 21.4%, which was slightly higher than the 16.2% observed in breast fibroadenomas. Age and menopausal status were not risk factors for high-risk HPV infection among breast cancer patients. The clinical and pathological characteristics of breast cancer showed no significant correlation with high-risk HPV infection. Although the prevalence of 13 subtypes of high-risk HPV infections was similar in breast cancer and nonmalignant breast samples, the presence of high-risk HPVs in both malignant and benign breast samples implies that a possible causal role in breast cancer carcinogenesis could not be ruled out. Clarifying the possible link between high-risk HPVs and breast cancer might benefit women vaccinated against HPV and could decrease the incidence of HPV-related breast cancer.

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.

Presence of human papilloma virus in a series of breast carcinoma from Argentina

Background

The etiology and the molecular mechanisms related to breast carcinogenesis remain poorly understood. Some recent reports have examined the role of Human Papillomavirus (HPV) in this disease. The purpose of this study was to determine the prevalence of HPV in breast cancer.

Methods

Sixty one fresh frozen breast cancers samples were analyzed. Samples were tested for HPV by PCR, and products were automatically sequenced. Findings were correlated with clinical and pathological characteristics.

Results

The HPV DNA prevalence in the breast cancer samples was 26% (16/61). Clinical parameters were not statistically associated with HPV presence (p>0.05 χ² test). Sequence analysis in a subgroup of cases indicates the prevalence of low risk HPV11, followed by high risk HPV16. We found no HPV transcriptional activity.

Conclusion

The present study demonstrated for the first time in Argentina the presence of HPV in a proportion of the malignant breast tissues. This finding suggests that HPV may have a biological significance in breast carcinogenesis.

HexaPrime: a novel method for detection of coronaviruses

Despite intense efforts to develop novel and better tools to identify known viruses and to discover new viruses, establishing etiological roles for viruses in human disease is challenging. In large part, this may be attributed to the high variability of viral species and the difficulties in developing broad-spectrum, yet specific, diagnostic assays. To overcome this problem, a novel method for the detection of viruses is described in the current manuscript. The technique relies on the addition of synthetic oligonucleotides to both termini of RNA fragments in a sequence-dependent manner during first- and second-strand DNA synthesis; these oligonucleotides are used subsequently for amplification of the viral nucleic acids of interest. The recognition of the target sequence by the oligonucleotides is mediated by short (6–8 nt) conserved regions, which facilitates development of broad–spectrum assays. The method has been tested for coronaviruses, although it may be also adopted for other RNA viruses.

Lack of evidence for an association between seminoma and human papillomavirus infection using GP5+/GP6+ consensus primers

Testicular germ cell tumors account for about 1% of all cancers. The incidence of these tumors is increasing and they represent the most common solid malignancies of young men aged 15-40 years with seminoma being one of the most common histotype. Pathogenesis of testicular germ cell tumors remains unknown and, although cryptorchidism is considered the main risk factor, there is evidence of an association with environmental and genetic risk factors. Human papillomaviruses (HPV) are a family of DNA viruses and represent a major risk factor for cervical cancer. In addition, they have been associated with other human non-malignant and malignant diseases, including breast and head and neck cancer. HPV sequences have been detected throughout the male lower genitourinary tract as well as in seminal fluid and an increased testicular tumorigenesis has been reported in HPV transgenic mice. Aim of this study was to evaluate the potential involvement of HPV in human testicular tumorigenesis. Real-time PCR employing GP5+/GP6+ consensus HPV primers was used to examine the presence of HPV sequences in a subset of human seminoma (n = 61) and normal testicles (n = 23). None of the specimens tested displayed the presence of HPV DNA. These findings do not support an association between HPV and human seminoma and warrant further studies to assess definitively the role of these viruses in human testicular tumorigenesis.