Comparative study of HPV prevalence in Japanese and North-east Chinese oral carcinoma

Absence of high-risk HPV 16 and 18 in Chinese patients with oral squamous cell carcinoma and oral potentially malignant disorders

BACKGROUND

The critical role of human papillomavirus (HPV) in cancer has been recognized, but the involvement of HPV in oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD) is still controversial. The aim of this study was to identify and verify the prevalence of high-risk HPV infection (HPV16 and 18) in Chinese patients with OSCC or OPMD using real-time PCR and DNA sequencing.

METHODS

Paired tissue and serum DNA samples were extracted from 40 Chinese patients with OSCC and 59 with OPMD. A SYBR Green-based real-time PCR assay was developed to detect the E6 gene of HPV16 and HPV18. Suspicious positive samples were then sequenced to eliminate false positives.

RESULTS

We found that none of the tissue and serum samples of OSCCs and OPMDs were positive for HPV16 E6 or 18 E6, using both real-time PCR and DNA sequencing. Overall, 3 of 198 (1.52 %) and 7 of 198 (3.54 %) samples were false-positive for HPV16 E6 and HPV18 E6, respectively, using real-time PCR.

CONCLUSION

The lack of HPV16 and HPV18 detected in this study indicates that high-risk HPV 16 and 18 infections are uncommon in Chinese patients with OSCC and OPMD. Real-time PCR followed by DNA sequencing for HPV DNA detection is an effective strategy to rule out false positives.

High-risk human papilloma virus in archival tissues of oral pathosis and normal oral mucosa

Objectives:

Oral cancer ranks third among all cancers in the Indian population. Human papilloma virus (HPV) plays a significant role in oral carcinogenesis. Population-based subtype variations are present in the HPV prevalence. This study gives an emphasis on the parameters to be considered in formalin fixed paraffin embedded tissues for polymerase chain reaction (PCR)-based research work.

Materials and Methods:

Cross-sectional study on archival paraffin-embedded tissue samples of oral squamous cell carcinoma (OSCC), epithelial dysplasia, and normal oral mucosa surrounding impacted tooth was amplified by PCR for the E6 gene of HPV type 16 and E1 gene of HPV type 18.

Results:

HPV 18 was positive in three OSCC cases. There was no statistically significant association of the positivity of HPV with the age, gender or habit. The HPV positive patients had a tobacco habit and were of a younger age group.

Conclusion:

The presence of HPV in carcinomatous tissue highlights the possible role of HPV in carcinogenesis and archival paraffin embedded tissue specimen can be used for this analysis. Recent studies on genomic analyses have highlighted that the HPV positive tumors are a separate subgroup based on genomic sequencing. The results of a larger retrospective study will help further in our understanding of the role of HPV in carcinogenesis, this study could form the baseline for such follow-up studies.

The distribution of human papillomavirus in tissues from patients with head and neck squamous cell carcinoma

Several types of HPVs have been shown to be associated with the development of malignant cancers in various head and neck tumors. More information on the HPV prevalence in patients with head and neck squamous cell carcinomas (SCCs) need to be obtained. In this study, formalin-fixed and paraffin-embedded tissues of 93 pathologically diagnosed head and neck SCC patients were collected from Peking University Cancer Hospital. HPV DNA sequences in tumor tissues were screened by a commercial Luminex technique for HPVs and HPV-specific PCR assays. Presence of HPV16/18 oncoprotein in tumor tissues was assessed by immunohistochemistry (IHC) with HPV16/18 E6-specific antibodies. Of the 93 patients, 16 (17.2%) cases were found to be HPV DNA-positive, including 7 HPV18-positive, 8 HPV16-positive and 1 HPV52-positive. IHC assays demonstrated that 31.2% (29/93) tested sections showed positive signals in the tumor cells. The total positive rate of HPV genome and its encoding products in the tested samples was 44.1% (41/93). Further analyses revealed that HPV infections in head and neck SCCs were significantly related with the tumor anatomic sites, showing decreasing tendency from outside (lip cancer) to inside (laryngeal cancer), but had no correlation with pathological, clinical grades and age of the patients. In all, HPV infections are commonly identified in the tumor tissues of patients with head and neck SCCs, in which HPV16 and 18 are the most prevalent HPV genotypes. Direct detection of high-risk HPV oncoprotein by IHC may be a good tool for classifying a tumor as truly HPV-associated.

Epidemiology of human papillomavirus-related head and neck cancer

Human papillomavirus (HPV) is now recognized to cause a subset of head and neck squamous cell carcinomas (HNSCC). Although excessive tobacco and alcohol use continue to be important risk factors for HNSCC, epidemiologic studies suggest that more than 25% of HNSCC are now caused by HPV. The incidence of HPV-related HNSCC is increasing, highlighting the need to understand the oral HPV infections causing these cancers. This article reviews the evidence for a causal association between HPV and HNSCC, examines the changing epidemiologic trends of HNSCC, and discusses what is currently known about oral HPV infection, natural history, and transmission.

Biopsy vs. brushing: comparison of two sampling methods for the detection of HPV-DNA in squamous cell carcinoma of the oral cavity

BACKGROUND

HR HPV infection was proposed as aetiological factor of oral squamous cell carcinomas (OSCC). HPV frequency in OSCC is highly variable, due to the discrepancy in oral sampling procedures, HPV testing methods and inclusion criteria regarding tumour site (strictly oral cavity vs. nearby structures). Our aim was to compare HPV DNA frequency and type-specific distribution in paired cytological and histological samples of SCC strictly located in oral cavity. The correlation between HPV detection rate by each method of sampling and demographical, behavioural and clinical-pathological variables was also examined.

PATIENTS AND METHODS

HPV DNA was detected in brushed cells and formalin-fixed paraffin-embedded biopsies obtained from 83 consecutive unselected immunocompetent adults with OSCC. HPV DNA detection was performed in all samples by nPCR followed by direct DNA sequencing and the assay INNO-LiPA HPV Genotyping. Univariate and multivariate statistics were used, including Cohen κ index to evaluate agreement between two methods and association between HPV infection and demographical, behavioural and clinical-pathological variables for each method of sampling (p<0.05 statistically significant).

RESULTS

HPV DNA was detected in 15.7% (13/83) of brushings and 12.1% (10/83) of biopsies (p>0.05). High risk HPV 51, 16 and 39 were genotypes more frequently detected, especially among biopsies; no concordance between two methods was found (Cohen κ index=0.04, p=0.34).

CONCLUSION

A fraction of OSCC could be linked to HR HPV infection in the Mediterranean area. Although without a statistical significance, biopsy specimen demonstrated more accurate for HR HPV detection than brushing in OSCC.

Oral squamous cell carcinoma incidence by subsite among diverse racial and ethnic populations in California

OBJECTIVE

The aim of this report was to examine the oral cancer incidence by sex, race/ethnicity, and anatomical subsite.

STUDY DESIGN

Data from the California Cancer Registry (CCR) were used to calculate the age-adjusted incidence rates of invasive oral squamous cell carcinoma (OSCC) by sex, race/ethnicity, and anatomical subsite among residents in California during 1988 to 2001.

RESULTS

Although non-Hispanic (NH) black men have the highest overall incidence rate for OSCC, NH whites and NH blacks have similar incidence patterns by subsite, but the male-to-female (M:F) rate ratio is higher among NH blacks. The OSCC incidence rates for Hispanics are much lower than those for NH whites and NH blacks and similar to those of Asians. The Asian ethnic groups display dramatic variations in terms of the subsite-specific incidence rates and M:F rate ratios.

CONCLUSION

The findings illustrate the heterogeneity and complexity of oral cancer by anatomical location and the importance of cultural habits and behavioral factors in the development of oral cancer.

HPV infection in relation to OSCC histological grading and TNM stage. Evaluation by traditional statistics and fuzzy logic model

We aimed to evaluate if in oral squamous cell carcinoma (OSCC) there is a relationship between histological grading (HG), TNM clinical stage and HPV infection; and to study the performance of fuzzy logic compared to traditional statistics, in the analysis of HPV status and correlates of OSCC. In cross-sectional analysis, the study group comprised 63 patients (mean age 68.89 years (SD +/-11.78), range (32-93); males 28 (44.4%), females 35 (55.6%)) with OSCC histologically diagnosed. HPV-DNA was studied in exfoliated oral epithelial cells by nested PCR (MY09/MY11 and GP5+/GP6+ primers). Data were analysed in parallel by traditional statistics with multivariate analysis and a fuzzy logic (FL) technique (membership functions as input, the ANFIS methodology, and the Sugeno's model of first order). HPV infection was detected in 24/63 (38.1%) of OSCC, as being HPV+ve 14/36 (38.9%) in G1, 7/18 (38.9%) in G2, and 3/9 (33.3%) in G3; HPV+ve 8/33 (24.2%) in Stage I, 9/12 (75.0%) in Stage II, 6/11(54.5%) in Stage III, and 1/7 (14.3%) in Stage IV. In both methods of analysis, no significantly increased risk of HPV infection was found for any HG score; whereas, TNM stage II was significantly associated to HPV infection (p=0.004; OR=9.375 (95% CI=2.030:43.30); OR'=11.148 (95% CI=1.951:43.30)), and, in particular, to primary tumour size T2 (p=0.0036; OR=7.812 (95% CI=1.914:31.890); OR'=9.414 (95% CI=1.846:48.013)); FL (% of prevision: 79.8; Root Mean-Square Error (RMSE): 0.29). No association was found between HPV infection and any demographical variable. Our findings show an association between HPV infection with TNM (stage II-T2), but not with histological grading of OSCC. Also, FL seems to be an additional effective tool in analysing the relationship of HPV infection with correlates of OSCC.