Prevalence of human papillomavirus among oesophageal squamous cell carcinoma cases: systematic review and meta-analysis

Background:

Oncogenic human papillomavirus (HPV) has been hypothesised as a risk factor for oesophageal squamous cell carcinoma (OSCC), but aetiological research has been limited by the varying methodology used for establishing HPV prevalence. The aims of this systematic review and meta-analysis were to estimate the prevalence of HPV DNA detected in OSCC tumours and the influence of study characteristics.

Methods:

Study-level estimates of overall and type-specific HPV prevalence were meta-analysed to obtain random-effects summary estimates.

Results:

This analysis included 124 studies with a total of 13 832 OSCC cases. The average HPV prevalence (95% confidence interval) among OSCC cases was 0.277 (0.234, 0.320) by polymerase chain reaction; 0.243 (0.159, 0.326) by in situ hybridisation; 0.304 (0.185, 0.423) by immunohistochemistry; 0.322 (0.154, 0.490) by L1 serology; and 0.176 (0.061, 0.292) by Southern/slot/dot blot. The highest HPV prevalence was found in Africa and Asia, notably among Chinese studies from provinces with high OSCC incidence rates.

Conclusions:

Future research should focus on quantifying HPV in OSCC cases using strict quality control measures, as well as determining the association between HPV and OSCC incidence by conducting large, population-based case–control studies. Such studies will provide a richer understanding of the role of HPV in OSCC aetiology.     

Human papillomavirus and oral squamous cell carcinoma: A review of HPV-positive oral squamous cell carcinoma and possible strategies for future

Oral squamous cell carcinoma (OSCC) is a common cancer worldwide. Besides tobacco use and alcohol consumption, human papillomavirus (HPV) infection has also been identified as a risk factor for OSCC recently. The OSCC incidence has increased in recent years, especially among younger women. The purpose of this article is to review clinical and epidemiological studies on the association between HPV infection and OSCCs, and the efficacy of HPV vaccine, so as to provide possible policy implications for preventing HPV-positive OSCC. It is necessary to review the present related body of knowledge to determine whether the association between HPV infection and OSCC has been thoroughly studied. The study was based on literature review. Studies were identified using electronic databases including MEDLINE, PubMed, EMBASE, etc. The inclusion and exclusion criteria were based on consultation from a panel of experts in this area and carefully designed. Based on a systematic review of literatures, HPV infection is a possible cause for the incidence of HPV-positive OSCCs. The prevalence of HPV infection possibly contributed to the increasing trends of HPV-positive OSCCs. Oral HPV infection is a form of HPV transmission. Oral sex behaviors and open-mouthed kissing are probably reasons for oral HPV infection. We also have some epidemiological evidences proving that HPV vaccine provides a possible solution for preventing oral HPV infection. Increased awareness of HPV-positive OSCCs is essential due to the severity of this problem. Biological and epidemiological data regarding the link between sexual behavior and HPV-associated cancers indicate a probable connection, although definitive data are needed. Future studies are needed to investigate the mechanisms of how HPV infection causes HPV-positive OSCCs, whether HPV vaccine provides a prevention for OSCCs, and other important issues.     

Viral load of HPV in esophageal squamous cell carcinoma

We previously reported the presence of HPV DNA in esophageal squamous cell carcinoma (ESCC) cases from Hong Kong and Sichuan. The role of HPV in the carcinogenesis of ESCC remains unclear, partly due to the large variations in infection rates reported by different studies. While some of these variations may truly reflect different HPV infection rates in ESCC among different geographic regions, differences in sensitivity and specificity of the detection methods used also contribute. In the present study, we used quantitative real-time PCR to determine the copy numbers of HPV-16 and HPV-18 in ESCC from 5 different regions of China with different incidence rates of ESCC. Conforming to our previous reports, HPV infection was detected in 2-22.2% of samples. Infection with HPV-16 was again shown to be more common than that with HPV-18 among Chinese ESCC patients. The copy number of HPV-16 in these ESCC cases ranged from < or =1 to 157 copies/genome equivalent, with 65% of samples harboring fewer than 10 copies/genome equivalent. The median copy number of HPV-18 was 4.9/genome equivalent. Assays were validated using cervical carcinoma cell lines with known copy numbers of HPV-16 or HPV-18. The relatively low HPV copy number and infection rate in ESCC suggest that HPV is unlikely to play as essential a role in the carcinogenesis of ESCC as in cervical cancer. However, with the consistent detection of oncogenic HPVs in ESCC from some regions of China, the possibility of HPV infection being one of the multiple risk factors of ESCC in some geographic areas cannot be excluded.     

Human papillomavirus 16 and head and neck squamous cell carcinoma

Evidence suggests that human papillomavirus (HPV)16 seropositivity reflects past HPV16 exposure and is associated with risk for head and neck squamous cell carcinoma (HNSCC). Our objectives were to test the hypothesis that HPV16 seropositivity is associated with risk for HNSCC, to correlate HPV16 seropositivity with HPV16 tumor DNA, and to correlate HPV16 seropositivity and HPV16 DNA with sexual history and patient survival. In a case-control study of approximately 1,000 individuals, we assessed serology to the HPV16 L1 protein and in cases only, assayed tumors for HPV16 DNA. HPV16 seropositivity was associated with 1.5- and 6-fold risks for tumors of the oral cavity and pharynx, respectively. There was a dose response trend for HPV16 titer and increasing risk of HNSCC (p < 0.0001) and HPV16 tumor DNA (p < 0.0001). In cases, HPV16 DNA and seropositivity were significantly associated with sexual activity; odds ratios (ORs) of 12.8 and 3.7 were observed for more than 10 oral sexual partners and ORs of 4.5 and 3.2 were associated with a high number of lifetime sexual partners, respectively. Finally, HPV16 seropositivity and HPV16 tumor DNA were associated with hazard ratios of 0.4 and 0.5, respectively, indicating better survival for HPV positive individuals. HPV16 seropositivity was associated with risk for HNSCC, with greatest risk for pharyngeal cancer. We observed dose response relationships between serology titer and both risk for HNSCC and HPV16 tumor DNA. In cases, HPV16 tumor DNA and positive serology were associated with sexual history and improved disease free survival.     

Human papillomavirus tumor infection in esophageal squamous cell carcinoma

The association between human papillomavirus (HPV) and esophageal squamous cell carcinoma (ESCC) has been recognized for over three decades. Recently, multiple meta-analyses have drawn upon existing literature to assess the strength of the HPV-ESCC linkage. Here, we review these analyses and attempt to provide a clinically-relevant overview of HPV infection in ESCC. HPV-ESCC detection rates are highly variable across studies. Geographic location likely accounts for a majority of the variation in HPV prevalence, with high-incidence regions including Asia reporting significantly higher HPV-ESCC infection rates compared with low-incidence regions such as Europe, North America, and Oceania. Based on our examination of existing data, the current literature does not support the notion that HPV is a prominent carcinogen in ESCC. We conclude that there is no basis to change the current clinical approach to ESCC patients with respect to tumor HPV status.     

Dietary patterns and oesophageal squamous cell carcinoma: a systematic review and meta-analysis

Background/Objective:

Dietary patterns, which represent a complex integration of food and nutrients, have been used to explore the association between dietary factors and the risk of oesophageal cancer. However, the association remains unclear. This systematic review was performed to evaluate the relationship between dietary patterns and oesophageal squamous cell carcinoma (ESCC) by pooling available data from existing studies.

Methods:

Pertinent articles published up to the end of 2013 were systematically searched and retrieved. The most common dietary patterns with high loadings of foods/nutrients were selected. Adjusted odds ratios (ORs) were derived by comparing the highest with the lowest categories of dietary pattern scores and by using a random-effect model. Heterogeneity was tested using I² statistic.

Results:

From nine available case–control studies, in which smoking and other confounding factors were considered, three most common dietary patterns were selected: western pattern, healthy pattern, and drinker/alcohol pattern. Healthy pattern was significantly associated with a decreased risk of ESCC (OR=0.36, 95% confidence interval (CI): 0.23, 0.49); drinker/alcohol pattern was related to a significantly increased risk (OR=2.34, 95% CI: 1.22, 3.45), while no significant association with western pattern was observed (OR=1.29, 95% CI: 0.83, 1.75).

Conclusions:

Based on available studies, though limited in number, this meta-analysis suggests that some dietary patterns may be associated with the risk of ESCC.     

Human papillomavirus infection and squamous cell carcinoma of the conjunctiva

Background:

Squamous cell carcinoma of the conjunctiva (SCCC) is associated with HIV-related immunosuppression, but human papillomavirus virus (HPV) is also suspected to have a role. We carried out a case–control study to assess the role of cutaneous and mucosal HPV types in SCCC, conjunctival dysplasia, and their combination (SCCC/dysplasia) in Uganda.

Methods:

We compared HPV prevalence in frozen biopsies from 94 SCCC cases (79 of whom were found to be HIV-positive), 39 dysplasia cases (34 HIV-positive), and 285 hospital controls (128 HIV-positive) having other eye conditions that required surgery. Highly sensitive PCR assays that detect 75 HPV types were used. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed, adjusting for, or stratifying by age, sex, and HIV status.

Results:

Cutaneous HPV types were detected in 45% of SCCC cases, 41% of dysplasia cases and 11% of controls. Human papillomavirus virus 5 and 8 were the most common types in SCCC, and most often occurred in combination with other types. Associations were observed between SCCC/dysplasia and detection of both single (OR=2.3; 1.2–4.4) and multiple (OR=18.3; 6.2–54.4) cutaneous HPV types, and were chiefly based on findings in HIV-positive patients. Cutaneous HPV infections were rarely observed among HIV-negative patients and the association with SCCC/dysplasia was not significant (OR=2.4; 0.6–9.6) among them. Squamous cell carcinoma of the conjunctiva/dysplasia risk and mucosal HPV types were not associated in either HIV-positive or HIV-negative patients.

Conclusions:

We detected cutaneous HPV types in nearly half of SCCC/dysplasia cases and often multiple types (HPV5 and 8 being most common). The role of HIV (confounder or strong enhancer of cutaneous HPV carcinogenicity) is still uncertain.     

Support vector machine-based nomogram predicts postoperative distant metastasis for patients with oesophageal squamous cell carcinoma

Background:

We aim to develop effective models for predicting postoperative distant metastasis for oesophageal squamous cell carcinoma (OSCC) for the purpose of guiding tailored therapy.

Methods:

We used data from two centres to establish training (n=319) and validation (n=164) cohorts. All patients underwent curative surgical treatment. The clinicopathological features and 23 immunomarkers detected by immunohistochemistry were involved for variable selection. We constructed eight support vector machine (SVM)-based nomograms (SVM1–SVM4 and SVM1''–SVM4''). The nomogram constructed with the training cohort was tested further with the validation cohort.

Results:

The outcome of the SVM1 model in predicting postoperative distant metastasis was as follows: sensitivity, 44.7% specificity, 90.9% positive predictive value, 81.0% negative predictive value, 65.6% and overall accuracy, 69.5%. The corresponding outcome of the SVM2 model was as follows: 44.7%, 92.1%, 82.9%, 65.9%, and 70.1%, respectively. The corresponding outcome of the SVM3 model was as follows: 55.3%, 93.2%, 87.5%, 70.7%, and 75.6%, respectively. The SVM4 model was the most effective nomogram in prediction, and the corresponding outcome was as follows: 56.6%, 97.7%, 95.6%, 72.3%, and 78.7%, respectively.Similar results were observed in SVM1'', SVM2'', SVM3'', and SVM4'', respectively.

Conclusion:

The SVM-based models integrating clinicopathological features and molecular markers as variables are helpful in selecting the patients of OSCC with high risk of postoperative distant metastasis.     

The contribution of smoking and smokeless tobacco to oesophageal squamous cell carcinoma risk in the African oesophageal cancer corridor: Results from the ESCCAPE multicentre case-control studies

Tobacco use is a well-established risk factor for oesophageal squamous cell carcinoma (ESCC) but the extent of its contribution to the disease burden in the African oesophageal cancer corridor has not been comprehensively elucidated, including by type of tobacco use. We investigated the contribution of tobacco use (smoking and smokeless) to ESCC in Tanzania, Malawi and Kenya. Hospital-based ESCC case-control studies were conducted in the three countries. Incident cases and controls were interviewed using a comprehensive questionnaire which included questions on tobacco smoking and smokeless tobacco use. Logistic regression models were used to estimate odds ratios (OR) and their 95% confidence intervals (CI) of ESCC associated with tobacco, adjusted for age, sex, alcohol use, religion, education and area of residence. One thousand two hundred seventy-nine cases and 1345 controls were recruited between August 5, 2013, and May 24, 2020. Ever-tobacco use was associated with increased ESCC risk in all countries: Tanzania (OR 3.09, 95%CI 1.83-5.23), and in Malawi (OR 2.45, 95%CI 1.80-3.33) and lesser in Kenya (OR 1.37, 95%CI 0.94-2.00). Exclusive smokeless tobacco use was positively associated with ESCC risk, in Tanzania, Malawi and Kenya combined (OR 1.92, 95%CI 1.26-2.92). ESCC risk increased with tobacco smoking intensity and duration of smoking. Tobacco use is an important risk factor of ESCC in Tanzania, Malawi and Kenya. Our study provides evidence that smoking and smokeless tobacco cessation are imperative in reducing ESCC risk.     

Prevalence and physical status of human papillomavirus in squamous cell carcinomas of the head and neck

Fresh-frozen biopsies were obtained from 61 patients at diagnosis of squamous cell carcinoma of the head and neck (HNSCC) for study of the prevalence and physical status of human papillomavirus (HPV) DNA. The frequency of HPV DNA and genotypes were determined by SPF10 PCR screening with a general probe hybridization and INNO-LiPA HPV genotyping assay. In addition, a single-phase PCR with primers FAP 59/64 and a nested PCR with primers CP 65/70 and CP 66/69 served to detect particularly cutaneous HPV types. By the sensitive SPF10 PCR and INNO-LiPA assay, 37 of 61 (61%) samples were positive for HPV. HPV-16 was the most frequently detected type (31 of 37, 84%). Multiple infections were found in 8 of 37 (22%) of the HPV-positive samples, and co-infection by HPV-16 and HPV-33 was predominant. No cutaneous HPV types were detected. Patients with HPV-positive tumors had similar prognosis as those with HPV-negative ones. Real-time PCR analysis of the HPV-16 positive samples indicated the presence of integrated (11 of 23, 48%), episomal (8 of 23, 35%) and mixed forms (4 of 23, 17%) of HPV DNA. The viral load of HPV DNA exhibited large variation. The median copy numbers of E6 DNA in tonsillar specimens were approximately 80,000 times higher than that in nontonsillar HNSCC ones. Patients with episomal viral DNA were more frequently found to have large (T3-T4) tumors at diagnosis than were those with integrated or mixed forms.     

Reduced expression of Axin correlates with tumour progression of oesophageal squamous cell carcinoma

Axin is a negative regulator of the Wnt signalling pathway, and genetic alterations of AXIN1 have been suggested to be an important factor of carcinogenesis in some tumours. The objective of this study was to clarify the clinicopathologic and prognostic significance of Axin in oesophageal squamous cell carcinoma (SCC). Immunohistochemical staining for Axin was performed on surgical specimens obtained from 81 patients with oesophageal SCC. Western and Northern blottings were performed on proteins and RNA from oesophageal SCC cell lines. Then polymerase chain reaction-single-strand conformational analysis (PCR-SSCP) was performed on DNA from oesophageal SCC patients and cell lines. Axin expression was found to be correlated inversely with depth of invasion, lymph node metastasis, and lymphatic invasion. Although univariate analysis showed Axin to be a negative predictor, multivariate analysis showed that it was not an independent prognostic marker. In all but one of the seven cell lines examined, the levels of protein expression were equivalent to RNA expression. PCR-SSCP showed that five patients and three cell lines had polymorphisms in exon 4 or 5 of the AXIN1 gene, but none of the 81 patients with oesophageal SCC had mutations. Our findings suggest that reduced expression of Axin is correlated with tumour progression of oesophageal SCC. However, additional studies will be necessary to elucidate the mechanism responsible for loss of Axin expression in tumour cells.     

No role for human papillomavirus in esophageal squamous cell carcinoma in China

Certain regions of China have high rates of esophageal squamous cell carcinoma (ESCC). Previous studies of human papillomavirus (HPV), a proposed causal factor, have produced highly variable results. We attempted to evaluate HPV and ESCC more definitively using extreme care to prevent DNA contamination. We collected tissue and serum in China from 272 histopathologically‐confirmed ESCC cases with rigorous attention to good molecular biology technique. We tested for HPV DNA in fresh‐frozen tumor tissue using PCR with PGMY L1 consensus primers and HPV16 and 18 type‐specific E6 and E7 primers, and in formalin‐fixed paraffin‐embedded tumor tissue using SPF₁₀ L1 primers. In HPV‐positive cases, we evaluated p16^INK4a overexpression and HPV E6/E7 seropositivity as evidence of carcinogenic HPV activity. β‐globin, and thus DNA, was adequate in 98.2% of the frozen tumor tissues (267/272). Of these, 99.6% (95% confidence interval (CI) = 97.9–100.0%) were negative for HPV DNA by PGMY, and 100% (95% CI = 98.6–100%) were negative by HPV16/18 E6/E7 PCR. In the corresponding formalin‐fixed paraffin‐embedded tumor specimens, 99.3% (95% CI = 97.3–99.9%) were HPV negative by SPF₁₀. By PGMY, 1 case tested weakly positive for HPV89, a noncancer causing HPV type. By SPF₁₀, 2 cases tested weakly positive: 1 for HPV16 and 1 for HPV31. No HPV DNA‐positive case had evidence of HPV oncogene activity as measured by p16^INK4a overexpression or E6/E7 seropositivity. This study provides the most definitive evidence to date that HPV is not involved in ESCC carcinogenesis in China. HPV DNA contamination cannot be ruled out as an explanation for high HPV prevalence in ESCC tissue studies with less stringent tissue procurement and processing protocols.     

Aberrant activation of the mTOR pathway and anti-tumour effect of everolimus on oesophageal squamous cell carcinoma

Background:

The mammalian target of rapamycin (mTOR) protein is important for cellular growth and homeostasis. The presence and prognostic significance of inappropriate mTOR activation have been reported for several cancers. Mammalian target of rapamycin inhibitors, such as everolimus (RAD001), are in development and show promise as anti-cancer drugs; however, the therapeutic effect of everolimus on oesophageal squamous cell carcinoma (OSCC) remains unknown.

Methods:

Phosphorylation of mTOR (p-mTOR) was evaluated in 167 resected OSCC tumours and 5 OSCC cell lines. The effects of everolimus on the OSCC cell lines TE4 and TE11 in vitro and alone or in combination with cisplatin on tumour growth in vivo were evaluated.

Results:

Mammalian target of rapamycin phosphorylation was detected in 116 tumours (69.5%) and all the 5 OSCC cell lines. Everolimus suppressed p-mTOR downstream pathways, inhibited proliferation and invasion, and induced apoptosis in both TE4 and TE11 cells. In a mouse xenograft model established with TE4 and TE11 cells, everolimus alone or in combination with cisplatin inhibited tumour growth.

Conclusion:

The mTOR pathway was aberrantly activated in most OSCC tumours. Everolimus had a therapeutic effect both as a single agent and in combination with cisplatin. Everolimus could be a useful anti-cancer drug for patients with OSCC.     

Human papilloma virus integration sites and genomic signatures in head and neck squamous cell carcinoma

A prevalence of around 26% of human papillomavirus (HPV) in head and neck squamous cell carcinoma (HNSCC) has been previously reported. HPV induced oncogenesis mainly involving E6 and E7 viral oncoproteins. In some cases, HPV viral DNA has been detected to integrate with the host genome and possibly contributes to carcinogenesis by affecting the gene expression. We retrospectively assessed HPV integration sites and signatures in 80 HPV positive patients with HNSCC, by using a double capture‐HPV method followed by next‐generation Sequencing. We detected HPV16 in 90% of the analyzed cohort and confirmed five previously described mechanistic signatures of HPV integration [episomal (EPI), integrated in a truncated form revealing two HPV‐chromosomal junctions colinear (2J‐COL) or nonlinear (2J‐NL), multiple hybrid junctions clustering in a single chromosomal region (MJ‐CL) or scattered over different chromosomal regions (MJ‐SC) of the human genome]. Our results suggested that HPV remained episomal in 38.8% of the cases or was integrated/mixed in the remaining 61.2% of patients with HNSCC. We showed a lack of association of HPV genomic signatures to tumour and patient characteristics, as well as patient survival. Similar to other HPV associated cancers, low HPV copy number was associated with worse prognosis. We identified 267 HPV‐human junctions scattered on most chromosomes. Remarkably, we observed four recurrent integration regions: PDL1/PDL2/PLGRKT (8.2%), MYC/PVT1 (6.1%), MACROD2 (4.1%) and KLF5/KLF12 regions (4.1%). We detected the overexpression of PDL1 and MYC upon integration by gene expression analysis. In conclusion, we identified recurrent targeting of several cancer genes such as PDL1 and MYC upon HPV integration, suggesting a role of altered gene expression by HPV integration during HNSCC carcinogenesis.     

Alcohol consumption and cigarette smoking in relation to high frequency of p53 protein accumulation in oesophageal squamous cell carcinoma in the Japanese

We investigated levels of p53 protein expression in Japanese patients with oesophageal squamous cell carcinoma. A significantly larger proportion of heavy alcohol drinkers and cigarette smokers was evident in the p53-positive group. The combination of drinking and smoking was associated with a high frequency of p53 protein accumulation.     

Human papillomavirus in esophageal squamous cell carcinoma of the high-risk Kazakh ethnic group in Xinjiang,China

Aims

To investigate human papillomavirus (HPV) genotype-specific prevalence in the high-risk Kazakh ethnic group with esophageal squamous cell carcinoma (ESCC).

Methods

Sixty-seven Kazakh patients with primary ESCC were studied. From each patient, two tissue samples were collected: one sample of the tumor and one sample of normal esophageal tissue from an area away from the tumor. Tissues were analyzed by INNO-LiPA HPV Genotyping test v2 assay allowing the detection of at least 24 different HPV genotypes.

Results

Twenty cancer patients (30%) had HPV DNA detected in collected specimens. Interestingly, 14 patients (21%) had HPV only in the tumor and six (9%) had HPV only in the normal esophageal tissue. Overall, HPV16 was the viral type most frequently detected being present in eight out of 20 positive cases (40%). No correlation between the presence of HPVs and the gender or ESCC grade was observed.

Conclusion

If the causative factors of esophageal carcinogenesis remain to be firmly established in the Kazakh population, HPV found in 30% of patients might play a role in the etiology of esophageal SCC.