Immunohistochemical demonstration of human papilloma virus antigen in human colon neoplasms

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.

Human papillomavirus infection and colorectal cancer in the Chinese population: a meta-analysis

AIM

Human papillomavirus (HPV) infection has been reported in colorectal cancer in many studies. We conducted a meta-analysis to assess the association between HPV infection and colorectal cancer/adenomas in the Chinese population.

METHOD

Relevant studies up to January 2018 were searched in PubMed, EMBASE, China National Knowledge Infrastructure and the Wanfang database. We used a random effects model to determine the prevalence of HPV and odds ratios (ORs) with 95% confidence intervals (CIs). The I² statistic and P-value from the Cochrane Q-test were used to describe the heterogeneity.

RESULTS

Ten case-control studies involving 766 colorectal cancer patients and 470 controls were included in the meta-analysis. Among the colorectal cancer patients, the pooled prevalence was 0.45 (95% CI 0.36-0.53). The pooled estimate for OR was 10.78 (95% CI 4.22, 27.53). Among the 193 patients with colorectal adenoma, the pooled prevalence and OR were 0.31 (95% CI 0.24-0.37) and 2.03 (95% CI 0.79, 5.26), respectively. The prevalence of HPV 16 and HPV 18 among HPV-positive cancers ranged from 57.9% to 100% and 0% to 39.7%, respectively.

CONCLUSION

The results indicated that HPV infection, especially HPV 16 and HPV 18, is associated with colorectal cancer in the Chinese population.

A viral map of gastrointestinal cancers

Cancers of the gastrointestinal tract (GIT) are expected to account for approximately 20% of all cancers in 2017. Apart from their high incidence, GIT cancers show high mortality rates, placing these malignancies among the most prominent public health issues of our time. Cancers of the GIT are the result of a complex interplay between host genetic factors and environmental factors and frequently arise in the context of a continued active inflammatory response. Several tumor viruses are able to elicit such chronic inflammatory responses. In fact, several viruses have an impact on GIT tumor initiation and progression, as well as on patients' response to therapy and prognosis, through direct and indirect mechanisms. In this review, we have gathered information on different viruses' rates of infection, viral-driven specific carcinogenesis mechanisms and viral-related impact on the prognosis of cancers of the GIT (specifically in organs that have an interface with the environment - esophagus, stomach, intestines and anus). Overall, while some viral infections show a strong causal relation with specific gastrointestinal cancers, these represent a relatively small fraction of GIT malignancies. Other types of cancer, like Esophageal Squamous Cell Carcinoma, require further studies to confirm the carcinogenic role of some viral agents.

Detection of human papillomavirus infection by molecular tests and its relation to colonic polyps and colorectal cancer

Objectives:

To prospectively examine the association between human papilloma virus (HPV) colonization of the colonic mucosa and the development of colorectal polyps (CRPs), and colorectal cancer (CRC) in Saudi Arabia.

Methods:

A case control study was performed between January 2013 and December 2014. All eligible patients underwent standard diagnostic colonoscopy. Patients with polyps or colorectal cancer were considered cases, while those with any other endoscopic findings were controls. Biopsy samples from polyps and tumors, and/or from normal colonic mucosa were acquired. Human papilloma virus colonization was detected using a hybrid capture technique of samples taken from both normal tissue, and CRPs and CRC. The association between HPV and CRPs/CRC was evaluated.

Results:

A total of 132 patients were recruited. The mean age was 53 (±15.9) years. Sixty patients had endoscopically detectable CRPs/CRC, and 72 had either inflammation or normal endoscopic evaluations. Only 4 (0.8%) of the 132 samples that were collected and analyzed were positive for the HPV gene. Statistical analysis did not identify any significant association between HPV colonization and the presence of CRPs/CRC. The only significant predictor of detecting CRPs/CRC on colonoscopy was symptomatic presentation (odds ratio=11.072, 95% confidence interval 4.7-26.2, p<0.001).

Conclusion:

Human papilloma virus colonic colonization is rare in Saudi Arabia. An association between HPV colonization and CRP/CRC development could not be identified in this cohort of patients.

Presence of Human Papillomavirus DNA in Colorectal Cancer Tissues in Shiraz, Southwest Iran

BACKGROUND

Colorectal cancer is one of the most common cancers worldwide. Viruses including human papillomavirus (HPV) have been reported to be associated with different cancers but any association with colorectal cancers remains controversial.

AIM

To evaluate any association between HPV infection and adenocarcinoma of the colon and adenomatous polyps.

MATERIALS AND METHODS

Paraffin-embedded tissue specimens of 70 colorectal adenocarcinomas, 70 colorectal adenomatous polyps, and 70 colorectal normal tissues were subjected to DNA extraction. The quality of the extracted DNA was confirmed by amplification of a β-globin fragment using polymerase chain reaction (PCR). PCR using specific primers were performed to detect HPV DNA. Specific primers targeting the E6 region of the HPVs 16 and 18 were used for genotyping.

RESULTS

HPV DNA was detected in 2 (2.85%) out of 70 adenocarcinoma colorectal tissues and 4 (5.71%) out of 70 adenomatous colorectal tissues. All normal colorectal tissues were negative for HPV DNA. HPV-16 was the most predominant genotype (5 sample) followed by HPV-18 (4 sample). Despite the above observations, statistical analyses indicated no significant differences in the frequencies of HPV positive subjects between the cancerous and normal samples.

CONCLUSIONS

Although the differences observed in the frequencies of HPV positive cases in our study was not significant relative to those of control subjects, the fact of 6 positive samples among cancerous tissues, may still suggest a role of HPV in colorectal carcinogenesis. The study collectively indicated that some colorectal cancerous tissues are infected with high risk HPV genotype. The findings merit more investigation.

Human papillomavirus infection and colorectal cancer risk: a meta-analysis

AIM

Human papillomavirus (HPV) infection is associated with cervical cancer, but whether it is involved in colorectal carcinogenesis is controversial. We conducted a meta-analysis to evaluate the association between HPV and colorectal adenocarcinoma.

METHOD

A search of the MEDLINE database was performed using the MESH terms 'HPV', 'human papillomavirus', and 'colon cancer', 'rectal cancer', 'colorectal cancer'. The prevalence of HPV infection in colorectal cancer was estimated by pooling data from 16 studies (involving 1436 patients) published up to July 2012, taking into consideration methodological heterogeneity between studies. The association of HPV with colorectal cancer risk was estimated from case-control studies.

RESULTS

The HPV overall prevalence was 31.9% (95% CI: 19.3-47.9). It was lowest in Europe (14.1%, 95% CI: 4.9-34.1) and highest in South America (60.8%, 95% CI: 42.7-76.4). Eight studies presented the results of HPV typing in 302 HPV-positive colorectal carcinomas. HPV 18 was the virus more frequently found in colorectal cancer cases from Asia (73.34%, 95% CI: 44.9-90.7) and Europe (47.3%, 95% CI: 34.5-60.4). In contrast, HPV 16 was more prevalent in colorectal tumours from South America (58.3%, 95% CI: 45.5-69.9). The analysis of five case-control studies showed an increase in colorectal carcinoma risk with HPV positivity (OR = 10.04; 95% CI: 3.7-27.5).

CONCLUSION

The results provide quantitative evidence for an association between HPV infection and colorectal cancer risk.

Human papillomavirus and colorectal cancer: evidences and pitfalls of published literature

PURPOSE

The aim of this study is to review published literature regarding a possible role of human papillomavirus (HPV) infection in colorectal cancer in order to understand if HPV infection plays an active role in colorectal carcinogenesis and to highlight evidences and pitfalls of published studies.

METHODS

We reviewed literature by searching PubMed, Ovid, and the Cochrane databases for published series investigating HPV and colorectal cancer from 1988 to date.

RESULTS

Twenty-one studies investigating a possible correlation between HPV infection and colon cancer have been published. We reviewed 15 case-control studies and six studies investigating a possible role for HPV virus in colorectal carcinogenesis. HPV was detected in the majority of reported series with a significant difference in HPV infection between tumors and disease-free controls or tumor-adjacent tissue; the HPV mean detection rate within carcinomas was 41.7%, comparing to a mean detection rate of 32.8% in adjacent colic mucosae, and 5.8% in disease-free controls (Chi-square test, p = 0.001). The correlation between HPV infection and c-myc amplification, k-ras mutation, and p53 polymorphism or mutations has been investigated; however, the possible role of HPV in colorectal carcinogenesis was not defined.

CONCLUSIONS

HPV has been detected in the majority of reported series, but published literature lacks in definitive data regarding standard methods of investigation and stratification of groups and population. These data encourage further studies with the aim to investigate the presence of the virus in larger series, its possible role in oncogenesis, the integration in host genome, the expression of viral oncoproteins, the mutations in HPV positive cancers and routes of colon infection (hematologic/lymphatic spreading or perineal diffusion).

Vaccination against human papilloma virus (HPV): epidemiological evidence of HPV in non-genital cancers

Recently, the vaccine against human papillomavirus (HPV) was introduced in the national vaccination programmes of several countries worldwide. The established association between HPV and the progression of cervical neoplasia provides evidence of the expected protection of the vaccine against cervical cancer. During the last two decades several studies have also examined the possible involvement of HPV in non-genital cancers and have proposed the presence of HPV in oesophageal, laryngeal, oropharyngeal, lung, urothelial, breast and colon cancers. The possible involvement of HPV in these types of cancer would necessitate the introduction of the vaccine in both boys and girls. However, the role of HPV in the pathogenesis of these types of cancer has yet to be proven. Moreover, the controversial evidence of the possible impact of the vaccination against HPV in the prevention of non-genital cancers needs to be further evaluated. In this review, we present an overview of the existing epidemiological evidence regarding the detection of HPV in non-genital cancers.

Family history of cancer in children and young adults with colorectal cancer

BACKGROUND

Family history of colorectal cancer among adult patients has been reported in the literature. Although extremely rare in children, colorectal cancer in this population may represent a unique group in whom genetic factors play a significant etiologic role. The aim of the present study was to assess genetic contribution, as measured by family history, to the development of colorectal cancer in probands under 21 years of age at diagnosis.

PROCEDURE

Detailed family histories were obtained from surviving patients or their parents. The risk [standardized incidence ratio (SIR)] of cancer in the relatives was calculated by comparing the observed and the expected incidence based on rates in the general population and person-years at risk.

RESULTS

Twenty-five patients (median age at diagnosis 15 years) diagnosed with colorectal cancer at St. Jude Children's Research Center since 1964 or their surviving next of kin were available for interview. The 461 relatives contributed 18,908 person-years of follow-up. Statistically significant increased risk of colorectal cancer was present among all relatives (SIR = 6.0, 95% CI, 2.7-10.6), and the increased risk of colorectal cancer was confined to relatives of probands who were under 15 years of age at diagnosis (SIR = 10.0, 95% CI, 4.5-17.6). In addition, there was an excess of uterine/cervical cancer among all female relatives (SIR = 6.5, 95% CI, 3.2-10.9).

CONCLUSIONS

The observed excess of colorectal cancer, in relatives of younger probands, suggests the need to examine these kindreds for genetic instability resulting from defects in mismatch repair genes to characterize further the patterns of risk observed.

Clinical update on the role of HPV and cervical cancer

In the mid-1980s, a clear connection was made between infection by the human papillomavirus (HPV) and cervical cancer. This association led to the generation of a large body of literature about the diagnosis, testing, treatment, transmission and, virological life span of HPV-related neoplasms and cancers. Because of advances in virology, molecular biology, and biochemistry, more is known about HPV and its effects on cervical neoplasms than ever before. Because deaths from cervical cancer, while less common in the United States and western Europe, account for 20% of cancer deaths in women worldwide (1), accurate knowledge of the disease and its prevention is critical for nurses working with patients both with preinvasive and invasive disease.

Detection of human papillomavirus DNA in colorectal carcinomas by polymerase chain reaction

Human papillomaviruses (HPVs) are associated with a number of benign and malignant neoplasms. To substantiate the relationship between HPV DNA and colorectal carcinomas, 70 carcinomas and 37 adenomas were analysed in this study. Specific types of HPV DNA in colorectal tumours were detected by polymerase chain reaction (PCR) and Southern blot hybridisation. HPV DNA was detected in 11 of 37 (29.7%) adenomas and in 52.9% 37 of 70 (52.9%) of carcinomas. The expression of HPV DNA in adenomas and carcinomas, especially that of HPV 16 in HPV positive cases (4 of 11 v 26 of 37), was significantly different (p < 0.05). There was no correlation, however, between HPV and the location, differentiation, stage, or survival of malignant neoplasms. These data suggest that HPV DNA, especially type 16, is associated with colorectal carcinogenesis.

Serum antibody against unfused recombinant E7 protein of human papillomavirus type 16 in cervical cancer patients

Sera were examined for the presence of antibody against E7 protein of human papillomavirus type 16 (HPV-16) by Western blot analysis using the bacterially derived unfused protein. The occurrence rates of anti-E7 antibody against HPV-16 were 14.1% (10/71) in cervical cancer patients, 0% (0/48) in cervical intraepithelial neoplasia patients, and 0% (0/41) in female non-malignant patients. Three patients (one with endometrial cancer, one with breast cancer, and one male patient with colon polyp) out of 115 patients with tumors in organs other than the cervix, had antibody against E7 protein of HPV-16. The serum antibody, once positive, could be detected for a long time after surgical removal of the cancers in all cases that could be followed up. HPV-16 DNA could be detected in 50% (13/26) of cervical cancer patients. Sixty-nine percent (9/13) of patients with HPV-16 DNA in cancers had the antibody and all the patients with stages II, III, and IV cervical cancer (8/8) harboring HPV-16 DNA showed the presence of the antibody against E7 protein of HPV-16. In contrast, only 20% (1/5) of cervical cancer patients with stage Ia or Ib harboring HPV-16 DNA showed positive for the anti-E7 antibody in sera. These findings suggest that the presence of anti-E7 antibody in serum depends on the staging of cervical cancer and extent of HPV infection.

Confirmation of the association of human papillomavirus with human colon cancer

The human papillomavirus (HPV) has been shown to be associated with neoplasms of the human colon using immunohistochemistry and in situ hybridization. We now report our use of the polymerase chain reaction and Southern blotting to investigate that same association. We selected 38 carcinomas, 21 adenomas, and 24 normal mucosal samples for the current study. Tissue sections were prepared, and then DNA was extracted and subjected to 40 cycles of amplification using Thermus aquaticus DNA polymerase and a set of degenerate primers. Amplified products were analyzed by agarose gel electrophoresis and Southern blotting. The L1 region of the HPV genome was identified in 13 of 38 carcinomas (32%), 8 of 21 adenomas (38%), and 2 of 24 normal biopsy specimens (8%). These observations validate our previous results and confirm the presence of HPV in human colon mucosa and tumors of that mucosa.

Investigation of colon cancers for human papillomavirus genomic sequences by polymerase chain reaction

Two previous studies have reported the presence of human papillomavirus (HPV) genomic sequences in colorectal cancers. We examined DNAs from 50 colorectal tumors for HPV sequences by polymerase chain reaction (PCR), using HPV consensus L1 primers for amplification. The PCR products were screened with a generic HPV probe consisting of amplimers of HPV-16 and HPV-18. All tumor DNAs were negative for HPV sequences. These results call into the question the reported association of colorectal cancers with HPVs.