Human papillomavirus does not have a causal role in colorectal carcinogenesis

Human Papillomavirus and Risk of Colorectal Cancer: An Analysis of Nationwide Claims Data

Background and Objectives: Although human papillomavirus (HPV) is a major etiology of cervical and anogenital cancers, whether it is associated with colorectal carcinogenesis is yet undetermined. Materials and Methods: The longitudinal association of HPV infection with colorectal cancer (CRC) was evaluated using 2000-2013 data from a nationwide Taiwanese claims database. In this retrospective cohort study, 358 patients with primary HPV diagnoses (HPV-infected cohort) and 1432 patients without such a diagnosis (HPV-uninfected cohort) were recruited between 2000 and 2006. Both cohorts were followed up to identify CRC incidences from 2006 to 2013. Hazard ratios (HRs) and their 95% confidence intervals (CIs) derived from Cox proportional hazards models were used to estimate the association between HPV and CRC risk. Results: The HPV-infected cohort had a significantly higher cumulative incidence of CRC than the HPV-uninfected cohort. The presence of HPV was associated with an increased risk of CRC (adjusted HR, 1.63; 95% CI, 1.02-3.62). Furthermore, the significant HPV-CRC risk association was evident in both sexes. Conclusions: This population-based cohort study reveals longitudinal evidence that HPV is associated with an increased risk of CRC. Further studies are required to verify the role of HPV in colorectal carcinogenesis.

Human papilloma virus: A review study of epidemiology, carcinogenesis, diagnostic methods, and treatment of all HPV-related cancers

Background: Human papillomavirus (HPV) infection is considered as the most common viral sexually transmitted infection worldwide. This poses an increasingly interdisciplinary medical challenge. Since there is vast scattered information in databases about HPV and the correlated diseases, we decided to collect useful data so that the experts can get a more comprehensive view of HPV. Methods: In this article, HPV-associated diseases, prevalence, prevention, and new treatments are discussed. The retrieved articles reporting the latest data about the required information for our review were selected through searching in Web of Science, Scopus, Medline (PubMed), EMBASE, Cochrane Library, Ovid, and CINHAL with language limitations of English and German. Results: There are 2 groups of HPVs: (1) low-risk HPV types that can lead to genital warts, and (2) high-risk HPV types that are involved in HPV-associated oncogenesis. About 70% of all sexually active women are infected and most of these infections heal within many weeks or months. In the case of HPV-persistence, a risk of preneoplasia or carcinoma exists. These types of viruses are responsible for the existence of genitoanal, gastrointestinal, urinary tract, and head and neck tumors. There is still no definite successful treatment. The detection of HPV-related condylomata occurs macroscopically in women and men, and the diagnosis of the precursors of cervical carcinoma in women is possible by Pap smear. Conclusion: For extragenital manifestations, there is no structured early detection program. Meanwhile, studies on HPV vaccines confirm that they should be used for the primary prevention of HPV-dependent diseases. However, we need more research to find out the real advantages and disadvantages of vaccines.

Does human papillomavirus cause human colorectal cancer? Applying Bradford Hill criteria postulates

The role of human papillomavirus (HPV) in human colorectal cancer (CRC) has already been widely investigated worldwide with conflicting results. Although researchers have tried to establish the link between HPV and CRC through a statistical meta-analysis of the previous studies associating HPV with CRC, they failed to establish a more reliable link due to the shortcomings of the statistical meta-analysis. In the present study, we identified population-wide studies relating HPV with CRC through the PubMed search engine. Then, we examined the available data of HPV prevalence in CRC and normal/benign samples and applied the postulates of Bradford Hill criteria on the available evidence to investigate the association between HPV and CRC. The Bradford Hill criteria are very old, reliable and widely accepted for establishing a link between the cause and disease. In addition, to further enhance the reliability of the outcomes, we have also evaluated the methodologies of the previous studies to address the possibility of false-negative and false-positive results. After a careful evaluation of the extracted data against the postulates of Bradford Hill criteria, it was observed that none of the studies fulfil all the major postulates of Bradford Hill criteria for causation including temporality, consistency, biological gradient, experiment, coherence, specificity and analogy. Hence, no causal relationship has been suggested between HPV and CRC patients of the any included population. The results failed to prove the causal relationship between HPV and CRC and suggested HPV as a coparticipant in the pathogenesis of CRC.

Non-genetic biomarkers and colorectal cancer risk: Umbrella review and evidence triangulation

Several associations between non-genetic biomarkers and colorectal cancer (CRC) risk have been detected, but the strength of evidence and the direction of associations are not confirmed. We aimed to evaluate the evidence of these associations and integrate results from different approaches to assess causal inference. We searched Medline and Embase for meta-analyses of observational studies, meta-analyses of randomized clinical trials (RCTs), and Mendelian randomization (MR) studies measuring the associations between non-genetic biomarkers and CRC risk and meta-analyses of RCTs on supplementary micronutrients. We repeated the meta-analyses using random-effects models and categorized the evidence based on predefined criteria. We described each MR study and evaluated their credibility. Seventy-two meta-analyses of observational studies and 18 MR studies on non-genetic biomarkers and six meta-analyses of RCTs on micronutrient intake and CRC risk considering 65, 42, and five unique associations, respectively, were identified. No meta-analyses of RCTs on blood level biomarkers have been found. None of the associations were classified as convincing or highly suggestive, three were classified as suggestive, and 26 were classified as weak. For three biomarkers explored in MR studies, there was evidence of causality and seven were classified as likely noncausal. For the first time, results from both observational and MR studies were integrated by triangulating the evidence for a wide variety of non-genetic biomarkers and CRC risk. At blood level, lower vitamin D, higher homeostatic model assessment-insulin resistance, and human papillomavirus infection were associated with higher CRC risk while increased linoleic acid and oleic acid and decreased arachidonic acid were likely causally associated with lower CRC risk. No association was found convincing in both study types.

Detection of Human papillomavirus and the role of p16INK4a in colorectal carcinomas

INTRODUCTION

Human papillomavirus (HPV) infection is associated with the development of anogenital and head and neck cancers. In recent years a potential role of HPV in colorectal cancer (CRC) has been suggested.

OBJECTIVE

To investigate the presence of HPV in colorectal carcinomas and to study the role of p16INK4a as a marker of transcriptionally active HPV infection. In addition, to investigate the correlation between these findings and the CRC prognostic factors.

METHODS

Case control study with 92 cases of colorectal cancers, 75 controls of normal tissue adjacent to the tumor, and 30 controls of precursor lesions, including polyps and colorectal adenomas. Paraffinized samples were used, HPV detection and genotyping were performed by PCR and reverse hybridization by using the INNO LIPA kit, with SPF10 plus primers. The expression of the p16INK4a protein was investigated using immunohistochemistry. Data analysis was performed using descriptive, univariate statistics and survival curves were calculated by using the Kaplan Meier and log-rank method.

RESULTS

HPV was detected in 13% of the cases and the most prevalent genotype was HPV 16. HPV DNA was not detected in either control groups. The high expression of p16INK4a was observed in 30% of the cases, but it was not associated to the presence of HPV. The overall survival was 53.3% and was influenced by prognostic factors such as later stage, lymph node and distant metastasis.

CONCLUSIONS

Based on these results, HPV is unlikely to be involved in colorectal carcinogenesis and p16INK4a expression is not a relevant marker of transcriptionally active HPV infection in CRC.

Human Papillomaviruses and Epstein-Barr Virus Interactions in Colorectal Cancer: A Brief Review

Human papillomaviruses (HPVs) and the Epstein-Barr virus (EBV) are the most common oncoviruses, contributing to approximately 10%-15% of all malignancies. Oncoproteins of high-risk HPVs (E5 and E6/E7), as well as EBV (LMP1, LMP2A and EBNA1), play a principal role in the onset and progression of several human carcinomas, including head and neck, cervical and colorectal. Oncoproteins of high-risk HPVs and EBV can cooperate to initiate and/or enhance epithelial-mesenchymal transition (EMT) events, which represents one of the hallmarks of cancer progression and metastasis. Although the role of these oncoviruses in several cancers is well established, their role in the pathogenesis of colorectal cancer is still nascent. This review presents an overview of the most recent advances related to the presence and role of high-risk HPVs and EBV in colorectal cancer, with an emphasis on their cooperation in colorectal carcinogenesis.

Putative Role of Circulating Human Papillomavirus DNA in the Development of Primary Squamous Cell Carcinoma of the Middle Rectum: A Case Report

Here we present the case of a patient affected by rectal squamous cell carcinoma in which we demonstrated the presence of Human Papillomavirus (HPV) by a variety of techniques. Collectively, the virus was detected not only in the tumor but also in some regional lymph nodes and in non-neoplastic mucosa of the upper tract of large bowel. By contrast, it was not identifiable in its common sites of entry, namely oral and ano-genital region. We also found HPV DNA in the plasma-derived exosome. Next, by in vitro studies, we confirmed the capability of HPV DNA-positive exosomes, isolated from the supernatant of a HPV DNA positive cell line (CaSki), to transfer its DNA to human colon cancer and normal cell lines. In the stroma nearby the tumor mass we were able to demonstrate the presence of virus DNA in the stromal compartment, supporting its potential to be transferred from epithelial cells to the stromal ones. Thus, this case report favors the notion that human papillomavirus DNA can be vehiculated by exosomes in the blood of neoplastic patients and that it can be transferred, at least in vitro, to normal and neoplastic cells. Furthermore, we showed the presence of viral DNA and RNA in pluripotent stem cells of non-tumor tissue, suggesting that after viral integration (as demonstrated by p16 and RNA in situ hybridization positivity), stem cells might have been activated into cancer stem cells inducing neoplastic transformation of normal tissue through the inactivation of p53, p21, and Rb. It is conceivable that the virus has elicited its oncogenic effect in this specific site and not elsewhere, despite its wide anatomical distribution in the patient, for a local condition of immune suppression, as demonstrated by the increase of T-regulatory (CD4/CD25/FOXP3 positive) and T-exhausted (CD8/PD-1positive) lymphocytes and the M2 polarization (high CD163/CD68 ratio) of macrophages in the neoplastic microenvironment. It is noteworthy that our findings depicted a static picture of a long-lasting dynamic process that might evolve in the development of tumors in other anatomical sites.

Human papillomavirus and colorectal cancer

The involvement of human papillomavirus in carcinogenesis of colorectal cancer is a contentious issue. The presented meta-analysis was performed to systematize the currently available research results on the matter. The analysis was based on the data from 19 studies to assess the association of HPV infection with colorectal cancer. According to the obtained data, researchers determined the statistically significant level of HPV infection in tumor tissue of CRC and the resulting relative risk of developing CRC with HPV infection to be RR (95% CI) = 2.97 (1.42-6.22) with p = 0.0039.

Down-regulated miRs specifically correlate with non-cardial gastric cancers and Lauren's classification system

BACKGROUND AND OBJECTIVES

Gastric cancers are usually characterized using Lauren's classification into intestinal and diffuse types. We previously documented the down-modulation of miR31, miR148a, miR204, and miR375 in gastric cancers. We aimed this manuscript to investigate these miRs with the end-points of diagnosis, Lauren's classification and prognosis.

METHODS

A total of 117 resected non-cardial adenocarcinomas were evaluated for miRs' expressions. The performance of miRs' expressions for cancer diagnosis was tested using ROC curves. Logistic regression was conducted with the end-point of Lauren's classification. Kaplan-Meier and Cox analyses were performed for OS, DFS, and DSS. miRs' targets were reviewed using PRISMA method and BCL-2 was further investigated in cell lines.

RESULTS

ROC curves documented that miRs' down-modulation was significant in differentiating cancer versus normal tissues. Diffuse type cancers were associated with female sex, young age, and miR375 higher expression. We confirmed BCL-2 as a miR204 target. However, survival analyses confirmed the pathologic criteria (advanced stages, LNR, and low LNH) as the significant variables correlated to worse prognosis.

CONCLUSIONS

The down-modulation of miR31, miR148a, miR204, and miR375 is significantly associated with non-cardial gastric cancers and miR375 is specifically linked to Lauren's classification. Nevertheless, standard pathological features display as the independent variables associated with worse prognosis.

Human papillomaviruses in colorectal cancers: A case-control study in western patients

BACKGROUND

Colorectal cancer (CRC) is one of the most common cancers. As in other cancer locations, the involvement of human papillomaviruses (HPV) has been suggested but remains highly debated with wide differences among reported prevalence of HPV infection in CRCs.

AIM

To determine the actual prevalence of high risk HPV16 and 18 in a large case-control study.

METHODS

CRC specimens were used for analysis of both tumor and distant healthy tissue. As a non-malignant control group, samples from sigmoid diverticulosis resections were studied. Detection of HPV16 and HPV18 DNA was performed using a real time polymerase chain reaction (qPCR). Ten percent of tumor samples were also randomly subjected to a complete HPV genotyping using the INNO-LiPA technique.

RESULTS

467 samples were analyzed: 217 tumor samples from 210 CRCs, 210 distant healthy tissue samples, and 40 sigmoid samples. HPV18 DNA was never amplified and HPV16 was amplified only three times in tumor tissues with viral loads under or at the limit of quantification. New extraction from the same tumor blocks for these samples revealed no HPV with qPCR and INNO-Lipa assays.

CONCLUSION

With adequate procedures and reliable techniques, no HPV was detected in the largest case-control study so far, bringing more evidence on the absence of involvement of HPV in CRCs.

Human papillomavirus and gastrointestinal cancer: A review

Human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. Exposure to HPV is very common, and an estimated 65%-100% of sexually active adults are exposed to HPV in their lifetime. The majority of HPV infections are asymptomatic, but there is a 10% chance that individuals will develop a persistent infection and have an increased risk of developing a carcinoma. The International Agency for Research on Cancer has found that the following cancer sites have a strong causal relationship with HPV: cervix uteri, penis, vulva, vagina, anus and oropharynx, including the base of the tongue and the tonsils. However, studies of the aetiological role of HPV in colorectal and esophageal malignancies have conflicting results. The aim of this review was to organize recent evidence and issues about the association between HPV infection and gastrointestinal tumours with a focus on esophageal, colorectal and anal cancers. The ultimate goal was to highlight possible implications for prognosis and prevention.