Antibodies against early proteins of human papillomaviruses as diagnostic markers for invasive cervical cancer

Antibodies against high-risk human papillomavirus proteins as markers for noncervical HPV-related cancers in a Black South African population, according to HIV status

Human papillomavirus (HPV) proteins may elicit antibody responses in the process toward HPV-related malignancy. However, HPV seroepidemiology in noncervical HPV-related cancers remains poorly understood, particularly in populations with a high prevalence of human immunodeficiency virus (HIV). Using a glutathione S-transferase-based multiplex serology assay, antibodies against E6, E7 and L1 proteins of HPV16 and HPV18 were measured in sera of 535 cases of noncervical HPV-related cancers (anal (n = 104), vulval (n = 211), vaginal (n = 49), penile (n = 37) and oropharyngeal (n = 134)) and 6651 non-infection-related cancer controls, from the Johannesburg Cancer Study that recruited Black South African with newly diagnosed cancer between 1995 and 2016. Logistic and Poisson regression models were used to calculate adjusted odds ratios (aOR) and prevalence ratios (aPR) and 95% confidence intervals (CI) in cases versus controls. HPV16 E6 was more strongly associated with noncervical HPV-related cancers than HPV16 L1 or E7, or HPV18 proteins: anal (females (HPV16 E6 aOR = 11.50;95%CI:6.0-22.2), males (aOR = 10.12;95%CI:4.9-20.8), vulval (aOR = 11.69;95%CI:7.9-17.2), vaginal (aOR = 10.26;95%CI:5.0-21), penile (aOR = 18.95;95%CI:8.9-40), and oropharyngeal (females (aOR = 8.95;95%CI:2.9-27.5), males (aOR = 3.49;95%CI:1.8-7.0)) cancers. HPV16-E6 seropositivity ranged from 24.0% to 35.1% in anal, vulval, vaginal and penile cancer but was significantly lower (11.2%) in oropharyngeal cancer. After adjustment for HIV, prevalence of which increased from 22.2% in 1995-2005 to 54.1% in 2010-2016, HPV16 E6 seropositivity increased by period of diagnosis (aPR for 2010-2016 vs. 1995-2006 = 1.84;95%CI:1.1-3.0). Assuming HPV16 E6 seroprevalence reflects HPV attributable fraction, the proportion of certain noncervical-HPV-related cancers caused by HPV is increasing over time in South Africa. This is expected to be driven by the increasing influence of HIV.

Causal Link of Human Papillomavirus in Barrett Esophagus and Adenocarcinoma: Are We There Yet?

Esophageal cancer is a relatively common malignancy worldwide with a high mortality (5-year survival of <15%). Despite screening, surveillance, improved imaging and treatment, the exponential rise in OAC continues. The strongest risk factors for OAC are chronic heartburn and metaplastic transformation of the lower third of the esophagus (Barrett's esophagus). The risk profile includes Caucasian race, male gender older age, obesity and smoking. Although the tumor risk in BO has been progressively revised downwards, the exponential rise in OAC remains unchecked. This paradox points to an unidentified missing link. Relatively recently, we provided the world's initial data for a strong association of biologically relevant hr-HPV with BD and OAC. Since then, systematic reviews and meta-analysis have documented HPV DNA prevalence rates in OAC of between 13 to 35%. In this review, we provide some evidence for a probable causal relationship between hr-HPV and OAC. This is challenging given the multifactorial etiology and long latency. Increasingly, high-risk HPV (hr-HPV) is regarded as a risk factor for OAC. This discovery will aid identification of a sub-group of high-risk progressors to esophageal cancer by surveillance and the development of effective preventive strategies including vaccination.

Usefulness of high-risk HPV early oncoprotein (E6 and E7) serological markers in the detection of cervical cancer: A systematic review and meta-analysis

We reviewed the literature on the importance of selected anti-high-risk human papillomavirus (HR-HPV) antibodies (namely, 16/18 and early oncoproteins E6 and E7) as potential serological markers for early detection of individuals at high risk of cervical cancer. We searched for studies in PubMed and Embase databases published from 2010 to 2020 on antibodies against HR-HPV E6 and E7 early proteins and cervical cancer. Pooled sensitivity and specificity for HPV16 and HPV18 antibodies were calculated using a bivariate hierarchical random-effects model. A total of 69 articles were identified; we included three studies with 1550 participants. For the three HPV16/18 E6 and E7 antibody tests, enzyme-linked immunosorbent assay-based assays had a sensitivity of 18% for detecting CIN2+ (95% confidence interval [CI]: 15-21) and a specificity of 96% (95% CI: 92-98), for slot-blot, sensitivity was 28.9% (95% CI: 23.3-35.1) and specificity was 72% (95% CI: 66.6-77.0) for detecting CIN2+, and for multiplex HPV serology assay based on a glutathione S-transferase, sensitivity was 16% (95% CI: 8.45-28.6) and specificity was 98% (95% CI: 97-99) for detecting invasive cervical cancer. HR-HPV16/18 E6 and E7 serological markers showed high specificity, but sensitivity was suboptimal for the detection of cervical cancer in either population screening settings or as point-of-care screening tests.

HPV types 16/18 L1 E6 and E7 proteins seropositivity and cervical cancer risk in HIV-positive and HIV-negative black South African women

BACKGROUND

In populations with high rates of human immunodeficiency virus (HIV)-coinfection, the nature of the relationship between human papillomavirus (HPV)-16 and -18 (L1, E6 and E7) antibodies and cervical cancer is still uncertain. We measured the association between seropositivity to HPV (L1, E6 and E7) proteins and cervical cancer among black South African women with and without HIV co-infection.

METHODS

We used questionnaire data and serum collected from consecutively recruited patients with a newly diagnosed cancer from the Johannesburg Cancer Study from 1346 cervical cancer cases and 2532 controls (diagnosed with other non-infection related cancers). Seropositivity to HPV proteins was measured using a multiplex serological assay based on recombinant glutathione S-transferase (GST) fusion proteins. We measured associations between their presence and cervical cancer using unconditional logistic regression models and evaluated the sensitivity and specificity of these HPV biomarkers.

RESULTS

Among controls, HIV-negative women from rural areas compared to urban had significantly higher HPV seroprevalence, HPV16 E7 (8.6% vs 3.7%) and HPV18 E7 (7.9% vs 2.0%). HPV16 E6 and E7 antibodies were positively associated with cervical cancer in HIV-positive (Adjusted Odds Ratio (AOR) = 33; 95% CI 10-107) and HIV-negative women (AOR = 97; 95% CI 46-203). In HIV-positive women, HPV E6/E7 antibodies had low sensitivity (43.0%) and high specificity (90.6%) for cervical cancer detection. In HIV-negative women, HPV E6/E7 antibodies sensitivity was 70.6% and specificity was 89.7%.

CONCLUSIONS

Our data show that HPV (L1, especially E6 and E7) antibody positivity is associated with cervical cancer in both HIV-positive and HIV-negative women. Nonetheless, being HIV-positive plays an important role in the development of cervical cancer.

ePCL Electrospun Microfibrous Layers for Immune Assays: Sensitive ELISA for the Detection of Serum Antibodies Against HPV16 E7 Oncoprotein

Human papillomavirus (HPV) type 16 is the etiologic agent of more than 50% anal/cervical cancers and about 20% oropharyngeal cancers. HPV16 E6 and E7 oncogenes favor the transformation and are essential for maintaining the transformed status. Serum anti-E6 and anti-E7 antibodies appear to have prognostic significance for HPV-associated cancers. However, most of the previous attempts to establish diagnostic tools based on serum detection of E6 and/or E7 antibodies have been unsuccessful, mainly due to the low accuracy of applied tests. This paper reports on a feasibility study to prove the possibility to easily immobilize HPV16 E7 onto electrospun substrates for application in diagnostic tools. In this study, poly(ε-caprolactone) electrospun scaffolds (called ePCL) are used to provide a microstructured substrate with a high surface-to-volume ratio, capable of binding E7 proteins when used for enzyme-linked immunosorbent assay (ELISA) tests. ePCL functionalized with E7 exhibited superior properties compared to standard polystyrene plates, increasing the detection signal from serum antibodies by 5-6 times. Analysis of the serum samples from mice immunized with HPV16 E7 DNA vaccine showed higher efficiency of this new anti-E7 ePCL-ELISA test vs control in E7-specific antibody detection. In addition, ePCL-E7-ELISA is prepared with a relatively low amount of antigen, decreasing the manufacturing costs.

Blood-based biomarkers of human papillomavirus-associated cancers: A systematic review and meta-analysis

BACKGROUND

Despite the significant societal burden of human papillomavirus (HPV)-associated cancers, clinical screening interventions for HPV-associated noncervical cancers are not available. Blood-based biomarkers may help close this gap in care.

METHODS

Five databases were searched, 5687 articles were identified, and 3631 unique candidate titles and abstracts were independently reviewed by 2 authors; 702 articles underwent a full-text review. Eligibility criteria included the assessment of a blood-based biomarker within a cohort or case-control study.

RESULTS

One hundred thirty-seven studies were included. Among all biomarkers assessed, HPV-16 E seropositivity and circulating HPV DNA were most significantly correlated with HPV-associated cancers in comparison with cancer-free controls. In most scenarios, HPV-16 E6 seropositivity varied nonsignificantly according to tumor type, specimen collection timing, and anatomic site (crude odds ratio [cOR] for p16+ or HPV+ oropharyngeal cancer [OPC], 133.10; 95% confidence interval [CI], 59.40-298.21; cOR for HPV-unspecified OPC, 25.41; 95% CI, 8.71-74.06; cOR for prediagnostic HPV-unspecified OPC, 59.00; 95% CI, 15.39-226.25; cOR for HPV-unspecified cervical cancer, 12.05; 95% CI, 3.23-44.97; cOR for HPV-unspecified anal cancer, 73.60; 95% CI, 19.68-275.33; cOR for HPV-unspecified penile cancer, 16.25; 95% CI, 2.83-93.48). Circulating HPV-16 DNA was a valid biomarker for cervical cancer (cOR, 15.72; 95% CI, 3.41-72.57). In 3 cervical cancer case-control studies, cases exhibited unique microRNA expression profiles in comparison with controls. Other assessed biomarker candidates were not valid.

CONCLUSIONS

HPV-16 E6 antibodies and circulating HPV-16 DNA are the most robustly analyzed and most promising blood-based biomarkers for HPV-associated cancers to date. Comparative validity analyses are warranted. Variations in tumor type-specific, high-risk HPV DNA prevalence according to anatomic site and world region highlight the need for biomarkers targeting more high-risk HPV types. Further investigation of blood-based microRNA expression profiling appears indicated.

Human papillomavirus infection in esophageal squamous cell carcinoma and esophageal adenocarcinoma: a concise review

The causal link between high-risk human papillomavirus (hr-HPV) infection and cervical, anogenital, and some oropharyngeal malignancies has been established by both molecular and epidemiological data. The association between HPV and esophageal squamous cell carcinoma (ESCC) remains controversial, as is the true prevalence of HPV infection in ESCC. The wide range in reported rates reflects variability in the primary literature, with some larger scale case-control studies suggesting the infection rates range from 0% to 78%. Interactions between HPV and the Barrett's metaplasia-dysplasia-carcinoma sequence have been explored, and these studies have shown some conflicting data. Overall, systematic reviews have reported the prevalence of HPV-positive DNA in esophageal adenocarcinoma patients of between 13% and 35%. Postulated reasons for discrepancies in HPV prevalence rates in esophageal cancer include variations in testing methodology and assay sensitivities; technical issues, including the lack of a gold-standard primer; types of specimens utilized (fresh-frozen versus formalin-fixed tissue); geographical variation; cross-contamination; and small sample sizes. Thus, efforts must be undertaken to (1) standardize HPV testing, ideally in a central laboratory and utilizing tests that detect viral transcriptional activity; (2) avoid cross-contamination; and (3) recruit large numbers of patients to accurately ascertain HPV rates in esophageal malignancy.

Immunology of HPV-mediated cervical cancer: current understanding

Human papilloma virus (HPV) has emerged as a primary cause of cervical cancer worldwide. HPV is a relatively small (55 nm in diameter) and non-enveloped virus containing approximately 8 kb long double stranded circular DNA genome. To date, 228 genotypes of HPV have been identified. Although all HPV infections do not lead to the development of malignancy of cervix, only persistent infection of high-risk types of HPV (mainly with HPV16 and HPV18) results in the disease. In addition, the immunity of the patients also acts as a key determinant in the carcinogenesis. Since, no HPV type specific medication is available for the patient suffering with cervical cancer, hence, a deep understanding of the disease etiology may be vital for developing an effective strategy for its prevention and management. From the immunological perspectives, the entire mechanisms of disease progression still remain unclear despite continuous efforts. In the present review, the recent developments in immunology of HPV-mediated cervix carcinoma were discussed. At the end, the prevention of disease using HPV type specific recombinant vaccines was also highlighted.

Development and validation of a multiplex immunoassay for the simultaneous quantification of type-specific IgG antibodies to E6/E7 oncoproteins of HPV16 and HPV18

More than 170 types of human papilloma viruses (HPV) exist with many causing proliferative diseases linked to malignancy in indications such as cervical cancer and head and neck squamous cell carcinoma. Characterization of antibody levels toward HPV serology is challenging due to complex biology of oncoproteins, pre-existing titers to multiple HPV types, cross-reactivity, and low affinity, polyclonal responses. Using multiplex technology from MSD, we have developed an assay that simultaneously characterizes antibodies against E6 and E7 oncoproteins of HPV16 and 18, the primary drivers of HPV-associated oncogenesis. We fusion tagged our E6 and E7 proteins with MBP via two-step purification, spot-printed an optimized concentration of protein into wells of MSD 96-well plates, and assayed various cynomolgus monkey, human and HPV+ cervical cancer patient serum to validate the assay. The dynamic range of the assay covered 4-orders of magnitude and antibodies were detected in serum at a dilution up to 100,000-fold. The assay was very precise (n = 5 assay runs) with median CV of human serum samples ~ 5.3% and inter-run variability of 11.4%. The multiplex serology method has strong cross-reactivity between E6 oncoproteins from human serum samples as HPV18 E6 antigens neutralized 5 of 6 serum samples as strongly as HPV16 E6. Moderate concordance (Spearman’s Rank = 0.775) was found between antibody responses against HPV16 E7 in the multiplex assay compared to standard ELISA serology methods. These results demonstrate the development of a high-throughput, multi-plex assay that requires lower sample quantity input with greater dynamic range to detect type-specific anti-HPV concentrations to E6 and E7 oncoproteins of HPV16 and 18.

Post-treatment human papillomavirus antibody kinetics in cervical cancer patients

Antibodies to the E6 and E7 oncoproteins of high-risk human papillomavirus (HPV) types are strongly associated with HPV-driven cancer, while antibodies against the capsid protein L1 are considered cumulative exposure markers. To test the hypothesis that L1 antibody levels are stable over time, whereas E6 and E7 levels undergo decay after cervical cancer (CxCa) treatment, we performed multiplex serology for HPV16 and 18 antigens E6, E7 and L1 in a post-treatment study of 184 patients with invasive CxCa that were characterized with a median follow-up time of 725 days, and 2-12 sera per patient. Antibody titers significantly decreased within the first six months for HPV16 E6 and E7 but not L1, and stabilized for the following 12 months on a high level, with few patients showing seroreversion. Of 67 patients seropositive for HPV16 E6 at diagnosis, 28 (41.8%) showed a decrease in antibody titers of at least 50% within the first 18 months. Similarly, of 50 HPV16 E7 seropositives, 33 (66.0%) showed decreasing antibody levels, whereas antibody decay was less frequent for HPV16 L1 (12 of 47, 25.5%). Using a power-law mathematical model to characterize antibody decay kinetics, the mean (±s.e.) durations to a 50% reduction in antibody titers within individual patients were estimated to be 56.9 (±26.1) and 56.3 (±19.0) days for HPV16 E6 and E7, respectively. In summary, HPV16 E6 and E7 antibodies undergo a slow but significant decrease in antibody titers within the first 6-18 months following CxCa treatment. However, larger studies are needed to confirm the utility of serology for prediction of disease progression and time to relapse based on antibody decay kinetics. This article is part of the theme issue 'Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses'.

Antibodies against human papillomavirus proteins in Barrett's dysplasia and intramucosal esophageal adenocarcinoma

High-risk human papillomavirus (HPV) types 16/18 have been associated with Barrett's dysplasia (BD)/esophageal adenocarcinoma (EAC). Nevertheless, no data exist in relation to serological analysis for HPV antibodies in BD/EAC with site-specific viral DNA status. We prospectively examined antibodies to multiple HPV types in 438 patients representing hospital/reflux controls and Barrett's metaplasia (BM)/BD/intramucosal EAC. Antibody responses to HPV6/11/16/18/31/33/45/52/58 were analyzed using multiplex serology, including antibodies to E6/E7/E1/E2 and L1 antigens. Seropositivity for individual HPV proteins was infrequent in both cases and controls and was ≤10.2%. There was no difference in the seroprevalence of antibodies to any HPV antigen/antibody combination between reclassified cases (BD/EAC) and controls (hospital/reflux/BM) or between HPV16 or HPV18 DNA cases and controls, respectively. Among HPV16 DNA-positive BD/EAC cases, antibodies to HPV16 E7 were significantly more prevalent (3/26, 11.5%) than in hospital and reflux controls plus BM (5/328, 1.5%) (adjusted OR = 10.12, 95% CI: 1.61-63.73, P = 0.014). Among HPV18 DNA-positive cases, antibodies to HPV18 E1 were present in 3/6 (50%) cases versus 5/328 (1.5%) controls (adjusted OR = 44.28, 95% CI: 6.10-321.47, P = 0.0002). Although antibodies against HPV were generally uncommon in cases and controls, immune responses against two early proteins of HPV16/18 were significantly more frequent in viral DNA-positive BD/intramucosal EAC.

Significance of serum antibodies against HPV E7, Hsp27, Hsp20 and Hp91 in Iranian HPV-exposed women

BACKGROUND

Among different types of human papillomavirus (HPV), types 16 and 18 were known to be high-risk agents causing mainly cervical cancer. Up to now, the potential of HPV E7 protein has been proved as a diagnostic marker of cervical cancer. Moreover, the levels of anti-heat shock protein (Hsp) and anti-high mobility group box-1 (HMGB1) antibodies in cancer patients have been useful in tumor diagnosis. The goal of the present study was to determine the efficiency of the potential serologic markers including HPV E7, Hsp20, Hsp27 proteins and Hp91 peptide in Iranian HPV-exposed women, for the first time.

METHODS

At first, the recombinant HPV E7, Hsp20 and Hsp27 proteins were expressed in E. coli system, and purified by affinity chromatography under native conditions. Then, antibody responses were detected against the recombinant proteins as well as Hp91 peptide as potential markers in 49 Iranian women who were seropositive for HPV-16 and 18 L1 capsids (i.e., HPV-exposed women) and 49 controls using indirect ELISA.

RESULTS

Our data indicated that the seroreactivities of women exposed to HPV16, HPV18 and both of them against the recombinant E7, Hsp20, Hsp27 proteins and Hp91 peptide were significantly higher than those in control group (p < 0.05 for HPV16 or HPV18; p < 0.01 for both of them versus all markers). HPV-exposed women with high antibody responses to HPV-16 and 18 L1 capsids as a commercial biomarker had significant seroreactivity to HPV-16 and 18 E7 and Hsp27 (p < 0.05). The recombinant E7 and Hsp27 proteins showed higher efficiency than Hsp20 and Hp91 for detection of individuals exposed to HPV infections (p < 0.05).

CONCLUSION

Generally, the levels of serum E7 and Hsp27 were increased in HPV-16 and 18 L1- seropositive women suggesting their potential value as a diagnostic marker for HPV infections.

Profiling of serum antibodies against human papillomavirus antigens in Korean women with cervical intraepithelial neoplasia and cervical cancer

Sero-epidemiological studies of human papillomavirus (HPV) have been undertaken over the last two decades. In this study, the prevalences of nine serum antibodies (anti-E6, E7 and L1 antibodies of HPV types 16, 18, and 58) were evaluated in normal (control) Korean women and women with cervical intraepithelial neoplasia (CIN) I, CIN II, CIN III, and cervical cancer. The frequencies of all types of anti-HPV antibodies were higher in the CIN stages and cervical cancer than in normal women, and those of anti-HPV16 E6 and E7, anti-HPV18 E6 and E7, and anti-HPV58 E7 antibodies were higher in the cervical cancer group than in the CIN stages. The frequencies of antibodies against HPV16, 18, and 58 E7 tended to increase with increasing severity of cervical lesions. However, there were few differences in the frequencies of antibodies against the L1 antigens of HPV16, 18 and 58 in cervical cancer versus CIN stages. The anti-HPV antibodies were detected in 26.5% of normal, 46.3% of CIN I, 62.5% of CIN II, 51.6% of CIN III, and 75% of cancers when any of the nine antigens was used as a criterion. Correlations between HPV DNA positivity and seropositivity for anti-HPV E6, E7, or L1 antibodies were found only in HPV16 DNA-positive cervical cancers for anti-HPV16 E6 and L1 antibodies. In addition, strong positive correlations in seropositivity were found between anti-HPV16 E7 and anti-HPV58 E7 antibodies, and between anti-HPV18 E6 and anti-HPV58 E6 antibodies. These findings should advance global profiling of the seroprevalences of antibodies against HPV antigens.

Evaluation of type-specific antibodies to high risk-human papillomavirus (HPV) proteins in patients with oropharyngeal cancer

OBJECTIVES

High risk human papillomavirus (HR-HPV) infection leads to a subgroup of oropharyngeal cancer (OPSCC) characterized by improved treatment response. However an universally accepted definition of an HR-HPV-attributable cancer is lacking.

METHODS

Detailed, type-specific HPV antibody responses were analyzed by multiplex serology in HR-HPV-attributable OPSCC patients, defined by p16^INK4A overexpression and HR-HPV DNA detection by PCR amplification and sequencing.

RESULTS

Fifty patients were prospectively enrolled. 26/50 (52%) tumor samples were positive for both p16^INK4A expression and HR-HPV DNA (22 HPV16, 4 HPV33). Seropositivity was present in 26/26 HPV-attributable OPSCC and one p16^INK4A-positive/HPV DNA-negative case. The sensitivity and specificity to diagnose an HR-HPV-attributable tumor was 100% and 96%, respectively for anti-E6 reactivity, 82% and 100%, respectively for anti-E2 reactivity, and clearly lower for anti-E7, anti-E1, anti-E4 and anti-L1-reactivity. 3yr-overall (OS) and disease specific survival (DSS) was higher in patients with HR-HPV-attributable tumors (OS 88% vs 64%, p=0.02; DSS 90% vs 80%, p=0.07) and seropositive patients (OS 88% vs 62%, p=0.01; DSS 92% vs 78%, p=0.05) than HR-HPV-negative or seronegative patients.

CONCLUSIONS

Detection of HR-HPV type-specific antibodies highly correlated with HPV-attributable OPSCC and was associated with better survival. HR-HPV antibodies are promising diagnostic, prognostic and potentially screening markers in HR-HPV-attributable OPSCC.

Serum biomarkers of polyomavirus infection and risk of lung cancer in never smokers

BACKGROUND

Lung cancer in never smokers is a significant contributor of cancer mortality worldwide. In this analysis, we explored the role of nine human polyomaviruses, including JC virus (JCV), BK virus (BKV) and Merkel cell virus (MCV), in lung cancer development in never smokers as there are data to support that polyomaviruses are potentially carcinogenic in the human lung.

METHODS

We used multiplex serology to detect serum antibodies to polyomaviruses in a nested case-control design combining lung cancer cases and controls from four cohort studies - NYU Women's Health Study (NYU-WHS), Janus Serum Bank, Shanghai Women's Health Study and Singapore Chinese Health Study (SCHS).

RESULTS

The final analyses included 511 cases and 508 controls. Seroprevalence for each polyomavirus showed significant heterogeneity by study, but overall there were no statistically significant differences between cases and controls. In total, 69.1% of the cases and 68.7% of the controls were seropositive for JCV VP1 antibody. Seropositivity for BKV was higher at 89.0% in cases and 89.8% in controls and lower for MCV at 59.3% in cases and 61.6% in controls. Similar results were obtained after adding an additional retrospective case-control study (Xuanwei study) to the analysis.

CONCLUSIONS

Our results do not support the hypothesis that seropositivity for polyomaviruses is associated with increased lung cancer risk in never smokers. Future research to evaluate relationship between polyomavirus infection and lung carcinogenesis should focus more on evaluating the presence of virus or viral nucleic acids (DNA or RNA) in lung tumour samples.

Low prevalence of HPV-driven head and neck squamous cell carcinoma in North-East Italy

Objectives

To investigate the frequency of Human papillomavirus (HPV)-driven head and neck squamous cell carcinoma (HNSCC) among patients living in North-East Italy, by assessing HPV-DNA positivity in all tumors and additional markers whenever possible.

Material and methods

HPV types, viral load, viral RNA, HPV16/18 E6 protein and p16^INK4a and pRb expression were determined in primary tumor tissues from 247 HNSCC patients. Tumor-specific HPV seropositivity was analyzed in 102 patients.

Results

Tumor HPV-DNA prevalence was 8.5% overall (21/247) and 27% in oropharynx (17/63). HPV16 accounted for 95% of all HPV types found. Among HPV-DNA+ tumors, type-concordant HPV E6^*I RNA prevalence was 79%. HPV DNA+ RNA+ tumors showed high viral load, up-regulated p16^INK4a, down-regulated pRb and presence of HPV16 E6 protein. Eight cases showed tumor-specific HPV seropositivity, all type-concordant with the tumor. Tumors were defined as HPV-driven when positive for HPV-DNA plus 2 additional HPV transformation-related markers.

Conclusion

Relative prevalence of HPV-driven tumors (14 HPV16, 1 HPV58) was 6% overall and 20% among oropharyngeal cancers. In the oropharynx the HPV-driven group showed a trend for better survival versus the HPV-negative group.

The relative prevalence of HPV-driven oropharyngeal cancer is low in North-East Italy as compared to Western and Northern Europe.

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HPV DNA alone is not sufficient to demonstrate causality in HNSCC.

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Additional transformation markers are needed to correctly identify HPV-driven tumors.

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HPV prevalence in HNSCC shows large geographical variation, even within Europe.

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Few small studies investigated the relative prevalence of HPV in HNSCC in Italy.

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In North-East Italy 6% of HNSCC and 20% of OPSCC are HPV-driven.

Mucosal alpha-papillomaviruses are not associated with esophageal squamous cell carcinomas: Lack of mechanistic evidence from South Africa, China and Iran and from a world-wide meta-analysis

Epidemiological and mechanistic evidence on the causative role of human papillomaviruses (HPV) in esophageal squamous cell carcinoma (ESCC) is unclear. We retrieved alcohol- and formalin-fixed paraffin-embedded ESCC tissues from 133 patients seropositive for antibodies against HPV early proteins, from high-incidence ESCC regions: South Africa, China and Iran. With rigorous care to prevent nucleic acid contamination, we analyzed these tissues for the presence of 51 mucosotropic human alpha-papillomaviruses by two sensitive, broad-spectrum genotyping methods, and for the markers of HPV-transformed phenotype: (i) HPV16/18 viral loads by quantitative real-time PCR, (ii) type-specific viral mRNA by E6*I/E6 full-length RT-PCR assays and (iii) expression of cellular protein p16(INK4a). Of 118 analyzable ESCC tissues, 10 (8%) were positive for DNA of HPV types: 16 (4 tumors); 33, 35, 45 (1 tumor each); 11 (2 tumors) and 16, 70 double infection (1 tumor). Inconsistent HPV DNA+ findings by two genotyping methods and negativity in qPCR indicated very low viral loads. A single HPV16 DNA+ tumor additionally harbored HPV16 E6*I mRNA but was p16(INK4a) negative (HPV16 E1 seropositive patient). Another HPV16 DNA+ tumor from an HPV16 E6 seropositive patient showed p16(INK4a) upregulation but no HPV16 mRNA. In the tumor tissues of these serologically preselected ESCC patients, we did not find consistent presence of HPV DNA, HPV mRNA or p16(INK4a) upregulation. These results were supported by a meta-analysis of 14 other similar studies regarding HPV-transformation of ESCC. Our study does not support the etiological role of the 51 analyzed mucosotropic HPV types in the ESCC carcinogenesis.

HPV Serum Antibodies as Predictors of Survival and Disease Progression in Patients with HPV-Positive Squamous Cell Carcinoma of the Oropharynx

PURPOSE

Oropharyngeal carcinoma positive for human papillomavirus type 16 (HPV16) has a significantly better prognosis than oropharyngeal carcinoma unrelated to HPV. Within HPV16-positive oropharyngeal carcinoma, biomarkers of prognosis are urgently needed to individualize care. We hypothesized that serum antibodies specific to HPV16, the major HPV type causing oropharyngeal carcinoma, have biologic relevance and are potential biomarkers for improved prognosis among patients with HPV16-positive oropharyngeal carcinoma.

EXPERIMENTAL DESIGN

IgG antibodies to the HPV16 antigens E1, E4-E7, L1, L2, and the N-terminal and C-terminal fragments of E2 (NE2, CE2) were quantified using a custom programmable enzyme-linked immunosorbent assay. Sera were obtained at diagnosis from 209 oropharyngeal carcinoma patients (96 HPV16-positive). The ratios of median fluorescent intensity (MFI) for each antigen to MFI for control GST protein were determined. Kaplan-Meier survival curves and Cox proportional hazards regression were used to determine survival differences between groups. ROC curves were used to determine the best combination of E antibodies to predict disease recurrence.

RESULTS

E1, NE2, and E6 antibody positivity were all strongly associated with improved overall and progression-free survival in the entire cohort and in patients with known HPV16-positive tumors (P < 0.05). For both overall and progression-free survival among HPV-positive patients, hazard ratios were 0.2 for NE2, 0.3 for E1, and 0.3 for E6 antibody positivity.

CONCLUSIONS

We identified three HPV16-specific antibodies that are associated with improved overall and progression-free survival in patients with HPV-related oropharyngeal carcinoma. These results suggest that differential serologic responses in patients may reflect differential biologic processes within the host and tumor and may have prognostic value.

Validation of Serological Antibody Profiles Against Human Papillomavirus Type 16 Antigens as Markers for Early Detection of Cervical Cancer

Cervical cancer (CC) is the second most frequent neoplasia among women worldwide. Cancer prevention programs around the world have used the Papanicolaou (Pap) smear as the primary diagnostic test to reduce the burden of CC. Nevertheless, such programs have not been effective in developing countries, thus leading to research on alternative tests for CC screening. During the virus life cycle and in the process toward malignancy, different human papillomavirus (HPV) proteins are expressed, and they induce a host humoral immune response that can be used as a potential marker for different stages of the disease. We present a new Slot blot assay to detect serum antibodies against HPV16 E4, E7, and VLPs-L1 antigens. The system was validated with sera from a female population (n = 485) aged 18 to 64 years referred to the dysplasia clinic at the General Hospital in Cuautla, Morelos, Mexico. To evaluate the clinical performance of the serological markers, the sensitivity, specificity, positive, and negative predictive values and receiver-operating characteristic curves (for antibodies alone or in combination) were calculated in groups of lesions of increasing severity. The results showed high prevalence of anti-E4 (73%) and anti-E7 (80%) antibodies in the CC group. Seropositivity to 1, 2, or 3 antigens showed associations of increasing magnitude with CC (odds ratio [OR] = 12.6, 19.9, and 58.5, respectively). The highest association with CC was observed when the analysis was restricted to only anti-E4+E7 antibodies (OR = 187.7). The best clinical performance to discriminate CC from cervical intraepithelial neoplasia 2 to 3 was the one for the combination of anti-E4 and/or anti-E7 antibodies, which displayed high sensitivity (93.3%) and moderate specificity (64.1%), followed by anti-E4 and anti-E7 antibodies (73.3% and 80%; 89.6% and 66%, respectively). In addition, the sensitivity of anti-E4 and/or anti-E7 antibodies is high at any time of sexual activity (TSA), which suggests they can be biomarkers for the early detection of CC. The sensitivity of anti-E4 antibodies was low (<10%) when the TSA was <10 years, and it increased up to 100% in relation to the TSA, suggesting that anti-E4 antibodies can be useful as HPV exposure markers at early stages of the disease.

Humoral Immune Response Against Human Papillomavirus as Source of Biomarkers for the Prediction and Detection of Cervical Cancer

Cervical cancer (CC) is one of the main causes of death among women of reproductive age. Although there are different tests, the disease tends to be diagnosed at late stages. In recent years, the use of complementary tests or sequential diagnostic tests has been implemented. Nevertheless, the results are variable and not conclusive; therefore, more studies for improving the usefulness of these tests in diagnostics are necessary. The human papillomavirus (HPV) infection has been associated with both benign and malignant proliferation of skin and mucosal tissues. Furthermore, some HPV types have been classified as high risk due to their potential to cause cancer, and HPV16 is most frequently associated with this disease. Although between 70% and 80% of precancerous lesions are eliminated by the host's immune system, there is no available test to distinguish between regressive lesions from those that could progress to CC. An HPV infection generates a humoral immune response against L1 and L2 capsid proteins, which can be protective and a response against early proteins. The latter is not a protective response, but these antibodies can be used as markers to determine the stage of the infection and/or the stage of the cervical lesion. Up to now, the humoral immune response resulting from the HPV infection has been used to study the biology of the virus and the efficacy of the HPV vaccines. Although there are no conclusive results regarding the use of these antibodies for diagnosis, we hereby review the actual panorama of the antibody response against the HPV proteins during the development of the disease as well as their possible use as biomarkers for the progression of cervical lesions and of CC.

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.

Human papillomavirus antibodies and future risk of anogenital cancer: a nested case-control study in the European prospective investigation into cancer and nutrition study

PURPOSE

Human papillomavirus (HPV) type 16 (HPV16) causes cancer at several anatomic sites. In the European Prospective Investigation Into Cancer and Nutrition study, HPV16 E6 seropositivity was present more than 10 years before oropharyngeal cancer diagnosis and was nearly absent in controls. The current study sought to evaluate the extent to which HPV16 E6 antibodies are present before diagnosis of anogenital cancers within the same cohort.

METHODS

Four hundred incident anogenital cancers (273 cervical, 24 anal, 67 vulvar, 12 vaginal, and 24 penile cancers) with prediagnostic blood samples (collected on average 3 and 8 years before diagnosis for cervix and noncervix cancers, respectively) and 718 matched controls were included. Plasma was analyzed for antibodies against HPV16 E6 and multiple other HPV proteins and genotypes and evaluated in relation to risk using unconditional logistic regression.

RESULTS

HPV16 E6 seropositivity was present in 29.2% of individuals (seven of 24 individuals) who later developed anal cancer compared with 0.6% of controls (four of 718 controls) who remained cancer free (odds ratio [OR], 75.9; 95% CI, 17.9 to 321). HPV16 E6 seropositivity was less common for cancers of the cervix (3.3%), vagina (8.3%), vulva (1.5%), and penis (8.3%). No associations were seen for non-type 16 HPV E6 antibodies, apart from anti-HPV58 E6 and anal cancer (OR, 6.8; 95% CI, 1.4 to 33.1). HPV16 E6 seropositivity tended to increase in blood samples drawn closer in time to cancer diagnosis.

CONCLUSION

HPV16 E6 seropositivity is relatively common before diagnosis of anal cancer but rare for other HPV-related anogenital cancers.

Human papillomavirus serology and tobacco smoking in a community control group

Background

HPV infection is an established risk factor for oropharyngeal cancer, and it has been proposed that cigarette smoking may potentiate HPV infection in the oral epithelium. We sought to test the hypothesis that cigarette smoking increases HPV infection in an HPV16 serology study of cancer-free individuals.

Methods

Subjects were participants in a risk factor study for head and neck cancer, and were required to have no prior history of either HNSCC or any other cancer. Tobacco use and other risk factor data were gathered through interviewer-assisted questionnaires, while serology was conducted in a blinded fashion using a glutathione S-transferase capture enzyme-linked immunosorbent assay (ELISA) to detect antibodies against HPV16 L1, E1, E2, E4, E6 and E7 proteins. The differences in tobacco use by HPV serology were evaluated by ANOVA; and the reported odds ratios and 95% confidence intervals were determined by using unconditional logistic regression.

Results

We found no overall association of HPV16 serological markers with smoking. However, when the data were stratified by median age, smoking was positively associated with seropositivity for the HPV16 L1 capsid antigen in the younger controls while the older controls were less likely to be HPV16 L1 positive if they smoked (p_interaction < 0.002). There was no similar association of smoking and age with serological response to the early proteins (i.e E6, E7).

Conclusions

Exposure to HPV16 capsid protein (L1) is increased among relatively younger adults who smoke and diminished among older smokers. However, this pattern is not accompanied by a differential susceptibility for active infection (as determined by the early gene proteins such as E6 and E7) among young and older smokers.

Antibodies against high-risk human papillomavirus proteins as markers for invasive cervical cancer

Different human papillomavirus (HPV) genes are expressed during the various phases of the HPV life cycle and may elicit immune responses in the process towards malignancy. To evaluate their association with cervical cancer, antibodies against proteins from HPV16 (L1, E1, E2, E4, E6 and E7) and HPV18/31/33/35/45/52/58 (L1, E6 and E7) were measured in serum of 307 invasive cervical cancer cases and 327 controls from Algeria and India. Antibody response was evaluated using a glutathione S-transferase-based multiplex serology assay and HPV DNA detected from exfoliated cervical cells using a GP5+/6+-mediated PCR assay. Among HPV16 DNA-positive cases, seroprevalence of HPV16 antibodies ranged from 16% for HPV16 E1 to 50% for HPV16 E6 and all were significantly higher than controls. Seroprevalence of E6, E7 and L1 antibodies for HPV18 and for at least one of HPV31/33/35/45/52/58 were also higher in cases positive for DNA of the corresponding type (50% and 30% for E6 of HPV18 and HPV31/33/35/45/52/58 combined, respectively). E6 and E7 antibodies were rarely found in controls, but cross-reactivity was evident among cancer cases positive for DNA of closely phylogenetically-related HPV types. E6 or E7 antibodies against any of the eight HPV types were detected in 66.1% of all cervical cancer cases, as compared to 10.1% of controls. E6, and to a lesser extent E7, antibodies appear to be specific markers of HPV-related malignancy. However, even among cases positive for the same type of HPV DNA, approximately one-third of cervical cancer cases show no detectable immune response to either E6 or E7.

Prospective seroepidemiologic study on the role of Human Papillomavirus and other infections in cervical carcinogenesis: evidence from the EPIC cohort

To evaluate prospectively the association between serological markers of selected infections, including HPV, and risk of developing cervical cancer (CC) and precancer, we performed a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) study that included 184 cases of invasive CC (ICC), 425 cases of cervical intraepithelial neoplasia (CIN) grade 3 or carcinoma in situ (CIS), and 1,218 matched control women. At enrollment participants completed lifestyle questionnaires and provided sera. Subjects were followed-up for a median of 9 years. Immunoassays were used to detect serum antibodies to Human Herpes Virus 2 (HHV-2), Chlamydia trachomatis (CT), Chlamydia pneumoniae, L1 proteins of mucosal and cutaneous HPV types, E6/E7 proteins of HPV16/18, as well as to four polyomaviruses. Adjusted odds ratios (OR) [and 95% confidence intervals (CI)] for CIN3/CIS and ICC risk were respectively: 1.6 (1.2-2.0) and 1.8 (1.1-2.7) for L1 seropositivity to any mucosal HPV type, 1.0 (0.4-2.4) and 7.4 (2.8-19.7) for E6 seropositivity to HPV16/18, 1.3 (0.9-1.9) and 2.3 (1.3-4.1) for CT seropositivity, and 1.4 (1.0-2.0) and 1.5 (0.9-2.6) for HHV-2 seropositivity. The highest OR for ICC was observed for HPV16 E6 seropositivity [OR = 10.2 (3.3-31.1)]. Increasing number of sexually transmitted infections (STIs) was associated with increasing risk. Non-STIs were not associated with CC risk. In conclusion, this large prospective study confirms the important role of HPV and a possible contribution of CT and HHV-2 in cervical carcinogenesis. It further identifies HPV16 E6 seropositivity as the strongest marker to predict ICC well before disease development.

Prognostic significance of spontaneous antibody responses against tumor-associated antigens in malignant melanoma patients

Distribution, patterns and prognostic impact of spontaneous antibody responses against different tumor-associated antigens (TAAs) in malignant melanoma patients are unknown so far and were investigated in this study for the first time in a large cohort at different stages of the disease, identifying new prognostic biomarkers for malignant melanoma. Serum samples from 365 melanoma patients (97 Stage I melanoma patients, 87 Stage II, 92 Stage III and 89 Stage IV) and 100 age and gender matched healthy control donors were analyzed. Samples were drawn at the time of diagnosis (Stages I-III) or at time of diagnosis of distant metastasis (Stage IV). Applying a novel multiplex assay, humoral immune responses against 29 TAAs were determined and the association between response and patient survival was investigated. Antibody responses were mainly found in melanoma patients and all tested antigens elicited immune responses in all disease stages. Antibody responses against single antigens were either associated with poor prognosis and/or shorter progression-free survival (PFS) or had no influence. While in Stages I-III significant associations were observed between an antibody response and overall survival or PFS, among Stage IV patients, no significant association was found. Multivariate analyses identified specific humoral immune responses as prognostic factors independently of age, chemotherapy and immunotherapy. Antibody responses against specific TAA in Stage I-III melanoma patients correlate with poor prognosis and/or shorter PFS. These results may help to design clinical studies in order to evaluate the potential of these responses as prognostic serological biomarkers.

Leukocyte-adjusted epigenome-wide association studies of blood from solid tumor patients

Epigenome-wide studies of DNA methylation using blood-derived DNA from cancer patients are complicated by the heterogeneity of cell types within blood and the associated cell lineage specification of DNA methylation signatures. Here, we applied a novel set of analytic approaches to assess the association between cancer case-status and DNA methylation adjusted for leukocyte variation using blood specimens from three case-control cancer studies (bladder: 223 cases, 205 controls; head and neck: 92 cases, 92 controls; and ovarian: 131 cases, 274 controls). Using previously published data on leukocyte-specific CpG loci and a recently described approach to deconvolute subject-specific blood composition, we performed an epigenome-wide analysis to examine the association between blood-based DNA methylation patterns and each of the three aforementioned solid tumor types adjusted for cellular heterogeneity in blood. After adjusting for leukocyte profile in our epigenome-wide analysis, the omnibus association between case-status and methylation was significant for all three studies (bladder cancer: P = 0.047; HNSCC: P = 0.013; ovarian cancer: P = 0.0002). Subsequent analyses revealed that CpG sites associated with cancer were enriched for transcription factor binding motifs involved with cancer-associated pathways. These results support the existence of cancer-associated DNA methylation profiles in the blood of solid tumor patients that are independent of alterations in normal leukocyte distributions. Adoption of the methods developed here will make it feasible to rigorously assess the influence of variability of normal leukocyte profiles when investigating cancer related changes in blood-based epigenome-wide association studies.

High-risk HPV types and head and neck cancer

Although HPV16 has been strongly implicated in oropharyngeal carcinogenesis, the role of other high-risk HPV types in the etiology of head and neck cancer remains unclear. To date, few data exist addressing the nature of the association between antibodies to oncogenic proteins of non-HPV16 HPVs in relation to head and neck cancer. We examined the relationship between multiple HPV types (HPV6, 11, 16, 18, 31, 33, 45, 52, 58) and head and neck squamous cell carcinoma (HNSCC) in a large population-based case-control study (1069 cases and 1107 controls). Serological measures for HPV types included antibodies to L1, E6 and/or E7. In a secondary analysis, we excluded HPV16 seropositive subjects to examine independent associations with other high-risk HPVs. All analyses were adjusted for age, race, sex, education, smoking and alcohol consumption. Statistically significant associations were observed for HPV16, 18, 33 and 52 and risk of HNSCC after mutually adjusting for HPV types. Among HPV16 seronegative subjects, elevated risks of HNSCC were observed for HPV18 E6 (OR = 4.19, 95% CI = 1.26-14.0), HPV33 E6 (OR = 7.96, 95% CI = 1.56-40.5) and HPV52 E7 (OR = 3.40, 95% CI = 1.16-9.99). When examined by tumor type, associations with HPV18 and HPV33 remained statistically significant for oropharyngeal cancer, and HPV52 was associated with oral cancer. In addition, magnitude of associations for HNSCC increased markedly with increasing number of seropositive high-risk HPV infections. High-risk HPV types, other than HPV16, are likely to be involved in the etiology of HNSCC.

HPV infection in esophageal squamous cell carcinoma and its relationship to the prognosis of patients in northern China

Purpose. Human papillomavirus (HPV) as a risk factor for esophageal squamous cell carcinoma (ESCC) has previously been studied, but importance of HPV status in ESCC for prognosis is less clear. Methods. A total of 105 specimens with ESCC were tested by in situ hybridization for HPV 16/18 and immunohistochemistry for p16 expression. The 5-year overall survival (OS) and progression-free survival were calculated in relation to these markers and the Cox proportional hazards model was used to determine the hazard ratio (HR) of variables in univariate and multivariate analysis. Results. HPV was detected in 27.6% (29) of the 105 patients with ESCC, and all positive cases were HPV-16. Twenty-five (86.2%) of the 29 HPV-positive tumors were stained positive for p16. HPV infected patients had better 5-year rates of OS (65.9% versus 43.4% among patients with HPV-negative tumors; P = 0.002 by the log-rank test) and had a 63% reduction in the risk of death (adjusted HR = 0.37, 95% CI = 0.16 to 0.82, and P = 0.01). Conclusions. HPV infection may be one of many factors contributing to the development of ESCC and tumor HPV status is an independent prognostic factor for survival among patients with ESCC.

Evidences suggesting involvement of viruses in oral squamous cell carcinoma

Oral cancer is one of the most common cancers and it constitutes a major health problem particularly in developing countries. Oral squamous cell carcinoma (OSCC) represents the most frequent of all oral neoplasms. Several risk factors have been well characterized to be associated with OSCC with substantial evidences. The etiology of OSCC is complex and involves many factors. The most clearly defined potential factors are smoking and alcohol, which substantially increase the risk of OSCC. However, despite this clear association, a substantial proportion of patients develop OSCC without exposure to them, emphasizing the role of other risk factors such as genetic susceptibility and oncogenic viruses. Some viruses are strongly associated with OSCC while the association of others is less frequent and may depend on cofactors for their carcinogenic effects. Therefore, the exact role of viruses must be evaluated with care in order to improve the diagnosis and treatment of OSCC. Although a viral association within a subset of OSCC has been shown, the molecular and histopathological characteristics of these tumors have yet to be clearly defined.

Evidence of the causal role of human papillomavirus type 58 in an oropharyngeal carcinoma

Persistent human papillomavirus infection (HPV) is recognized as an important etiologic factor for a subset of head and neck squamous cell carcinomas (SCC), especially those arising from the oropharynx. Whereas HPV16 accounts for the majority of HPV DNA-positive oropharyngeal SCC, infections with other mucosal high-risk HPV types are quite rare and biological data demonstrating their causal involvement are insufficient. Here we present the first case of an oropharyngeal SCC driven by HPV type 58. A 69-year-old Caucasian woman presented with an enlarged and firm left tonsil. A computed tomography scan showed a left tonsillar mass, extending to the soft palate and the glossotonsillar sulcus. The patient underwent extended radical tonsillectomy and ipsilateral selective neck dissection. Pathology confirmed an infiltrating, poorly differentiated SCC of the left tonsil with node metastasis (pT2N1). Adjuvant external beam radiation therapy (60 Grays (Gy)) was administered. After 1 year of follow-up, the patient is well with no evidence of cancer recurrence. HPV analyses of the tumor tissue by BSGP5+/6+ -PCR/MPG, targeting 51 mucosal HPV types, showed single positivity for HPV type 58. Presence of HPV58 E6*I RNA demonstrated biological activity of the virus in the tumor tissue, and presence of serum antibodies to HPV58 oncoproteins E6 and E7 indicated presence of an HPV58-driven cancer. Overexpression of cellular protein p16INK4a and reduced expression of pRb, two cellular markers for HPV-induced cell transformation, were observed. Exons 4-10 of TP53 showed no mutations or polymorphisms. The presence of HPV58 as single HPV infection in combination with a broad variety of direct and indirect markers of HPV transformation provides comprehensive evidence that this oropharyngeal SCC was driven by HPV58.

Occupational asbestos exposure is associated with pharyngeal squamous cell carcinoma in men from the greater Boston area

OBJECTIVES

Asbestos is the name given to a group of naturally occurring silicate mineral fibres that were widely used in industry during the 20th century due to their desirable physical properties. Although use in the USA has fallen over the last three decades, significant exposure in the developing world continues and the burden of disease is considerable. Asbestos is a known risk factor for several malignant diseases, including lung cancer and mesothelioma, and has more recently been implicated in pharyngeal and laryngeal cancer. However, studies of asbestos and cancers of the larynx or pharynx with adequate sample size that control for major head and neck squamous cell carcinoma (HNSCC) risk factors remain relatively sparse.

METHODS

We report findings from a case-control study of 674 incident male HNSCC cases from the greater Boston region and 857 population-based male controls, matched on age (±3 years), sex, and town or neighbourhood of residence. Multivariable logistic regression was used to assess the association between occupational asbestos exposure and HNSCC by primary tumour site.

RESULTS

190 cases (28.2%) and 203 controls (23.7%) reported occupational exposure to asbestos. Occupational asbestos exposure was associated with elevated risk of pharyngeal carcinoma in men (OR 1.41, 95% CI 1.01 to 1.97), adjusted for age, race, smoking, alcohol consumption, education, income and HPV16 serology, with borderline increasing risk for each decade in the exposed occupation (OR 1.10, 95% CI 0.99 to 1.23).

CONCLUSIONS

These observations are consistent with mounting evidence that asbestos is a risk factor for pharyngeal cancer.

Risk factors for anal cancer in persons infected with HIV: a nested case-control study in the Swiss HIV Cohort Study

Although persons infected with human immunodeficiency virus (HIV), particularly men who have sex with men, are at excess risk for anal cancer, it has been difficult to disentangle the influences of anal exposure to human papillomavirus (HPV) infection, immunodeficiency, and combined antiretroviral therapy. A case-control study that included 59 anal cancer cases and 295 individually matched controls was nested in the Swiss HIV Cohort Study (1988-2011). In a subset of 41 cases and 114 controls, HPV antibodies were tested. A majority of anal cancer cases (73%) were men who have sex with men. Current smoking was significantly associated with anal cancer (odds ratio (OR) = 2.59, 95% confidence interval (CI): 1.25, 5.34), as were antibodies against L1 (OR = 4.52, 95% CI: 2.00, 10.20) and E6 (OR = ∞, 95% CI: 4.64, ∞) of HPV16, as well as low CD4+ cell counts, whether measured at nadir (OR per 100-cell/μL decrease = 1.53, 95% CI: 1.18, 2.00) or at cancer diagnosis (OR per 100-cell/μL decrease = 1.24, 95% CI: 1.08, 1.42). However, the influence of CD4+ cell counts appeared to be strongest 6-7 years prior to anal cancer diagnosis (OR for <200 vs. ≥500 cells/μL = 14.0, 95% CI: 3.85, 50.9). Smoking cessation and avoidance of even moderate levels of immunosuppression appear to be important in reducing long-term anal cancer risks.

Evaluation of human papillomavirus antibodies and risk of subsequent head and neck cancer

PURPOSE

Human papillomavirus type 16 (HPV16) infection is causing an increasing number of oropharyngeal cancers in the United States and Europe. The aim of our study was to investigate whether HPV antibodies are associated with head and neck cancer risk when measured in prediagnostic sera.

METHODS

We identified 638 participants with incident head and neck cancers (patients; 180 oral cancers, 135 oropharynx cancers, and 247 hypopharynx/larynx cancers) and 300 patients with esophageal cancers as well as 1,599 comparable controls from within the European Prospective Investigation Into Cancer and Nutrition cohort. Prediagnostic plasma samples from patients (collected, on average, 6 years before diagnosis) and control participants were analyzed for antibodies against multiple proteins of HPV16 as well as HPV6, HPV11, HPV18, HPV31, HPV33, HPV45, and HPV52. Odds ratios (ORs) of cancer and 95% CIs were calculated, adjusting for potential confounders. All-cause mortality was evaluated among patients using Cox proportional hazards regression.

RESULTS

HPV16 E6 seropositivity was present in prediagnostic samples for 34.8% of patients with oropharyngeal cancer and 0.6% of controls (OR, 274; 95% CI, 110 to 681) but was not associated with other cancer sites. The increased risk of oropharyngeal cancer among HPV16 E6 seropositive participants was independent of time between blood collection and diagnosis and was observed more than 10 years before diagnosis. The all-cause mortality ratio among patients with oropharyngeal cancer was 0.30 (95% CI, 0.13 to 0.67), for patients who were HPV16 E6 seropositive compared with seronegative.

CONCLUSION

HPV16 E6 seropositivity was present more than 10 years before diagnosis of oropharyngeal cancers.

A history of allergies is associated with reduced risk of oral squamous cell carcinoma

PURPOSE

A history of allergies is associated with a decreased risk of several types of cancers. Potential mechanisms include enhanced immune surveillance against tumor cells early in disease development and/or carcinogenic infectious agents. We tested whether allergies are inversely associated with oral squamous cell carcinoma (OSCC), accounting for factors that may modify the association, such as tumor site, stage, and HPV infection.

METHODS

We estimated odds ratios (OR) and 95 % confidence intervals (CI) for the association between allergy history (including different types of allergies) and OSCC, adjusted for potential confounders, among 400 cases and 613 controls. Analyses were also stratified by site, stage, and measures of HPV infection.

RESULTS

We observed a weak inverse association between history of any allergy and OSCC (OR = 0.81, 95 % CI 0.61-1.08). This association was present only for allergies to airborne allergens (dust/pollen/mold) (OR = 0.67; 95 % CI 0.48-0.93). The inverse associations with airborne allergies were slightly stronger for oropharyngeal SCC (OR = 0.56; 95 % CI 0.35-0.90) than for oral cavity SCC (OR = 0.71; 95 % CI 0.49-1.05) and present only for later-stage cancers (OR = 0.42; 95 % CI 0.26-0.66) as opposed to earlier-stage cancers (OR = 0.98; 95 % CI 0.66-1.46). Inverse associations were not particularly present or stronger among HPV-16-seropositive individuals or for HPV DNA-positive OSCC.

CONCLUSION

There is an inverse association between history of allergies to dust, pollen, or mold and OSCC. Whether the inverse association involves heightened immune surveillance, increased immune response to HPV or other antigen, or other carcinogenic mechanism remains to be determined in more definitive studies.

Serological proteome analysis to identify systemic candidiasis patients in the intensive care unit: Analytical, diagnostic and prognostic validation of anti-Candida enolase antibodies on quantitative clinical platforms

Systemic candidiasis (SC) is associated with high morbidity and mortality, because it generally affects patients with severe underlying diseases and its diagnosis is difficult and often delayed, resulting in delayed therapy. We used serological proteome analysis to screen serum anti-Candida IgG antibody-reactivity profiles in 24 patients under intensive care, 12 of which had confirmed SC (fungal cultures), and in 12 healthy subjects. A total of 15 immunogenic proteins from Candida albicans protoplast lysates were differentially immunorecognized by serum IgG antibodies from SC patients compared to controls. Two-way hierarchical clustering and principal-component analyses of these antibody-reactivity patterns accurately differentiated SC patients from controls. Anti-Eno1p IgG antibodies were found to be present at high abundance in SC patients and be an important molecular fingerprint in serum for SC diagnosis. Differential anti-Eno1p IgG antibody reactivity was further validated by a tag capture ELISA and a Western blot assay in 45 SC patients and 118 non-SC subjects. Both quantitative assays provided comparable analytical, diagnostic and prognostic performances, and verified initial proteomic-profiling results. If confirmed in prospective cohort studies, these anti-Eno1p IgG antibodies might be useful for SC diagnosis. However, these, at least as measured by these clinical platforms, appear to have limited prognostic value in SC patients.

Role of human papillomavirus in the pathogenesis of oral squamous cell carcinoma

Oral cancer is one of the most common cancers and it constitutes a major health problem particularly in developing countries. Oral squamous cell carcinoma (OSCC) represents the most frequent of all oral neoplasms. Several risk factors have been well characterized to be associated with OSCC with substantial evidences. While tobacco and alcohol are the primary risk factors for OSCC development, many epidemiological studies report a strong association with human papillomavirus (HPV) in a subset of OSCC. This article presents our current knowledge on the relationship between HPV and development of OSCC. HPVs are DNA viruses that specifically target the basal cells of the epithelial mucosa. Most experimental data are consistent with the hypothesis that HPV plays a causal role in oral carcinogenesis. Genotypes, such as HPV1 infect epidermal cells, whereas HPV6, 11, 16 and 18 infect epithelial cells of the oral cavity and other mucosal surfaces. Several studies have shown that there is an increased risk of head and neck cancer in the two major HPV 16 oncogenes E6 and E7 -positive patients. The presence of antibodies to HPV E6 and E7 proteins was found to be more associated with tumors of the oro-pharynx than of the oral cavity. However, HPV alone appears to be insufficient as the cause of OSCC but requires other co-factors. Although a viral association within a subset of OSCC has been shown, the molecular and histopathological characteristics of these tumors have yet to be clearly defined.

Peripheral blood DNA methylation profiles are indicative of head and neck squamous cell carcinoma: an epigenome-wide association study

Head and neck cancer accounts for an estimated 47,560 new cases and 11,480 deaths annually in the United States, the majority of which are squamous cell carcinomas (HNSCC). The overall 5 year survival is approximately 60% and declines with increasing stage at diagnosis, indicating a need for non-invasive tests that facilitate the detection of early disease. DNA methylation is a stable epigenetic modification that is amenable to measurement and readily available in peripheral blood. We used a semi-supervised recursively partitioned mixture model (SS-RPMM) approach to identify novel blood DNA methylation markers of HNSCC using genome-wide methylation array data for peripheral blood samples from 92 HNSCC cases and 92 cancer-free control subjects. To assess the performance of the resultant markers, we constructed receiver operating characteristic (ROC) curves and calculated the corresponding area under the curve (AUC). Cases and controls were best differentiated by a methylation profile of six CpG loci (associated with FGD4, SERPINF1, WDR39, IL27, HYAL2 and PLEKHA6), with an AUC of 0.73 (95% CI: 0.62-0.82). After adjustment for subject age, gender, smoking, alcohol consumption and HPV16 serostatus, the AUC increased to 0.85 (95% CI: 0.76-0.92). We have identified a novel blood-based methylation profile that is indicative of HNSCC with a high degree of accuracy. This profile demonstrates the potential of DNA methylation measured in blood for development of non-invasive applications for detection of head and neck cancer.

Direct human papillomavirus E6 whole-cell enzyme-linked immunosorbent assay for objective measurement of E6 oncoproteins in cytology samples

A novel, whole-cell enzyme-linked immunosorbent assay (ELISA) based on a non-type-specific anti-human papillomavirus (HPV) E6 antibody was tested on 182 residual cytological specimens. For samples with a designation of more severe than cervical intraepithelial neoplasia grade 3 (CIN3+), 83% tested positive for E6; in a subset with paired testing for E6 ELISA and HPV DNA, 72% tested E6 positive and 92% tested high-risk (HR)-HPV DNA positive (P = 0.2). Among the women with a less than CIN3 diagnosis, 31% and 47% tested positive for E6 and HR-HPV DNA, respectively (P = 0.0006).

InterSCOPE study: Associations between esophageal squamous cell carcinoma and human papillomavirus serological markers

BACKGROUND

The role of human papillomavirus (HPV) in the causation of esophageal squamous cell carcinoma is unclear. We examined the associations between esophageal squamous cell carcinoma and 28 centrally measured HPV serological markers in serum from six existing case-control studies conducted in regions with differing background risks of esophageal cancer.

METHODS

We used centralized multiplex serology to test serum samples from 1561 case subjects and 2502 control subjects from six case-control studies for antibodies to the major HPV capsid protein (L1) and/or the early proteins E6 and/or E7 of eight high-risk, two low-risk, and four cutaneous HPV types. Study-specific odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using conditional logistic regression with adjustment for smoking, alcohol consumption, and other potential confounders. Pooled odds ratios and 95% confidence intervals were calculated using either a linear mixed-effects approach or a joint fixed-effects approach. All statistical tests were two-sided.

RESULTS

We found statistically significant associations between esophageal squamous cell carcinoma and antibodies to E6 for HPV16 (OR = 1.89, 95% CI = 1.09 to 3.29, P = .023) and HPV6 (OR = 2.53, 95% CI = 1.51 to 4.25, P < .001) but not for other tested HPV types. There were no statistically significant associations between esophageal squamous cell carcinoma and antibodies to E7 for any of the tested HPV types. Simultaneous seropositivity for HPV16 E6 and E7 was rare (four case subjects, two control subjects; OR = 5.57, 95% CI = 0.90 to 34.35; P = .064). We also found statistically significant associations between esophageal squamous cell carcinoma and capsid antibodies for the high-risk mucosal type HPV33 L1 (OR = 1.30, 95% CI = 1.00 to 1.69; P = .047) and the low-risk mucosal types HPV6 (OR = 1.22, 95% CI = 1.05 to 1.42; P = .010) and HPV11 (OR = 1.30, 95% CI = 1.09 to 1.56, P = .0036).

CONCLUSIONS

We found limited serological evidence of an association between esophageal squamous cell carcinoma and HPV in the populations studied. Although HPV does not appear to be an important risk factor for esophageal squamous cell carcinoma, we cannot exclude the possibility that certain HPV types may be involved in a small subset of cancers.

Human papillomavirus serologic follow-up response and relationship to survival in head and neck cancer: a case-comparison study

Background

Human papillomavirus high risk (HPV-HR) type 16 is a significant risk factor for head and neck cancers (HNC) independent of tobacco and alcohol. The purpose of this study was to determine whether antibody levels to the HPV-16 oncoproteins E6 and E7 measured in sera collected at baseline (BL) prior to treatment and at two post-treatment follow-up (FU) visits were associated with HNC risk factors or prognosis.

Methods

Presence of antibodies to HPV-16 E6 and E7 was evaluated in 109 newly diagnosed HNC cases with BL and FU blood samples, using the enzyme-linked immunosorbent assay (ELISA).

Results

HPV-16 E6 and/or E7 seropositive HNC cases were associated with higher risk in younger patients (≤ 55 years), more sexual partners (≥ 10), oropharyngeal cancer, worse stage at diagnosis, poorer grade, and nodal involvement. Between BL and FU (median = 8.3 months), there were decreased antibody levels for seropositive E6 (73% vs. 27%, p = 0.02) and seropositive E7 patients (65% vs. 35%, p = 0.09) with 5% of BL E6 and 35% of BL E7 seropositive patients converting to negative status at FU. Overall mortality (OM) was significantly worse among BL E6 seronegative patients than among BL seropositive patients (40.2% vs.13.6%, p = 0.01). There were no disease specific (DS) deaths among BL E6 seropositive vs. 24% in BL E6 seronegative patients (p = 0.01). BL E7 seronegative patients also had higher mortality than BL seropositive patients (OM: 38.2% vs. 20.0%, p = 0.04; DS: 22.5% vs. 5.6%, p = 0.07).

Conclusion

These findings are the first to follow post-treatment OD levels of HPV-16 E6 and E7 in HNC and suggest that these HPV antibodies may be potential prognostic markers of survival in HNC patients.

A novel HPV 16 L1-based chimeric virus-like particle containing E6 and E7 seroreactive epitopes permits highly specific detection of antibodies in patients with CIN 1 and HPV-16 infection

Background

The presence of IgG antibodies to HPV-16 L1-virus like particles (VLPs) in serum has been reported as a result of persistent exposure to the virus and as a marker of disease progression. However, detection of VLP-specific antibodies in sera does not always indicate a malignant lesion as positive results may also be due to a nonmalignant viral infection. Furthermore, malignant lesions are associated with an increased antibody titer for E6 and E7 proteins. The aim of this study was to develop an ELISA using a novel chimeric virus-like particle (cVLP) encoding an L1 protein fused with a string of HPV-16 E6 and E7 seroreactive epitopes to its C-terminus to be used for detection of HPV-16 specific antibodies in patients with cervical intraepithelial lesion grade 1 (CIN 1).

Results

The sera of 30 patients with CIN 1 who also tested positive for HPV-16 DNA and of 30 age-matched normal donors negative for HPV infection were tested for the presence of IgG antibodies specific for either VLP-L1 (HPV-16 L1), gVLP (derived from Gardasil), or cVLP by ELISA. The cVLP-reactive sera yielded two distinct groups of results: (H) reactivity levels that presented very strong cVLP-specific titers, and (L) reactivity levels with significantly lower titers similar to those obtained with VLP-L1 and gVLP antigens. Additionally, the sera that presented the higher cVLP titers closely matched those that had significantly stronger reactivity to E6 and E7 epitopes. Interestingly, the samples with the highest titers corresponded to patients with the higher numbers of sexual partners and pregnancies. On the other hand only 4 out of the 12 sera that harbored antibodies with VLP neutralizing ability corresponded to the group with high cVLP antibody titers.

Conclusion

We report for the first time that chimeric particles containing HPV-16 L1 protein fused with E6 and E7 seroreactive epitopes enable much better detection of IgG antibodies in the sera of CIN 1 patients positive for HPV-16 infection than those obtained with VLPs containing only the HPV-16 L1 protein. We also found that the sera with higher cVLP antibody titers corresponded to patients with more sexual partners and pregnancies, and not always with to those with a high neutralizing activity. This novel assay could help in the development of a tool to evaluate cervical cancer risk.

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 SPF(10) L1 primers. In HPV-positive cases, we evaluated p16(INK4a) overexpression and HPV E6/E7 seropositivity as evidence of carcinogenic HPV activity. beta-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 SPF(10). By PGMY, 1 case tested weakly positive for HPV89, a noncancer causing HPV type. By SPF(10), 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.

High-throughput profiling of the humoral immune responses against thirteen human papillomavirus types by proteome microarrays

We have developed microarrays with all eight proteins encoded by 13 different human papillomavirus types associated with anogenital cancer (HPV-16, -18, -31, -33, -35, -45, and -53), genital warts (HPV-6 and -11), or skin lesions (HPV-1, -2, -4, and -5). We analyzed the seroprevalence of antibodies in 546 patients, which had either cervical carcinomas, or precursor lesions, or which were asymptomatic. All patient groups contained sera ranging from high reactivity against multiple HPV proteins to low or no reactivity. Computational analyses showed the E7 proteins of carcinogenic HPV types as significantly more reactive in cancer patients compared to asymptomatic individuals and discriminating between cancer and HSIL or LSIL patients. Antibodies against E4 and E5 had the highest seroprevalence but did not exhibit differential reactivity relative to pathology. Our study introduces a new approach to future evaluation of the overall antigenicity of HPV proteins and cross-reaction between homologous proteins.

Fowlpox virus recombinants expressing HPV-16 E6 and E7 oncogenes for the therapy of cervical carcinoma elicit humoral and cell-mediated responses in rabbits

Background

Around half million new cases of cervical cancer arise each year, making the development of an effective therapeutic vaccine against HPV a high priority. As the E6 and E7 oncoproteins are expressed in all HPV-16 tumour cells, vaccines expressing these proteins might clear an already established tumour and support the treatment of HPV-related precancerous lesions.

Methods

Three different immunisation regimens were tested in a pre-clinical trial in rabbits to evaluate the humoral and cell-mediated responses of a putative HPV-16 vaccine. Fowlpoxvirus (FP) recombinants separately expressing the HPV-16 E6 (FP_E6) and E7 (FP_E7) transgenes were used for priming, followed by E7 protein boosting.

Results

All of the protocols were effective in eliciting a high antibody response. This was also confirmed by interleukin-4 production, which increased after simultaneous priming with both FP_E6 and FP_E7 and after E7 protein boost. A cell-mediated immune response was also detected in most of the animals.

Conclusion

These results establish a preliminary profile for the therapy with the combined use of avipox recombinants, which may represent safer immunogens than vaccinia-based vectors in immuno-compromised individuals, as they express the transgenes in most mammalian cells in the absence of a productive replication.