Human papillomavirus in cervical cancers of Malaysians

High Prevalence of Human Papillomavirus Types 56 and 70 Identified in the Native Populations of Sabah, Malaysia

Background:

Cervical cancer is currently the third most common female cancer in Malaysia, with the human papillomavirus (HPV) considered as one of the important contributory factors. This study was conducted to determine HPV prevalence, its genotype distribution, and other potential risk factors among women in Kota Kinabalu, Sabah in order to evaluate the likely efficacy of current HPV vaccines in the local population.

Methods:

A total of 240 cervical samples were collected and subjected to DNA extraction, PCR amplification using the MY09/MY11 primer pair, and restriction fragment length polymorphism (RFLP) for HPV detection and genotyping. Sociodemographic, clinical, and behavioural data were also collected via questionnaires.

Results:

The prevalence of HPV infection was 9.6%. The most common HPVs among 13 genotypes were high-risk HPV-56 (16.7%) and probable high-risk HPV-70 (16.7%) followed by HPV-16, -58, -53, -61, -33, -59, and -66 (in decreasing order of prevalence) including the rare genotypes: HPV-62, -81, -82 and -84. Statistical analyses using logistic regression models showed that HPV infection was significantly associated with employment (OR 4.94; CI 1.58-15.40) and education at secondary/high school level (OR 0.13; CI 0.03-0.62).

Conclusion:

Distribution of HPV genotypes in Sabah indicated a high prevalence of HPV-56 and -70 which are among the rare HPV types in West Malaysia and merit consideration in future strategies for HPV vaccination specifically for local Sabahan women.

Esophageal squamous cell carcinomas in a Malaysian cohort show a lack of association with human papillomavirus

OBJECTIVE

With an age-standardized incidence rate of 2 per 100 000, esophageal cancer is not common among Malaysians, but they are nevertheless important due to its poor prognosis. The study is to clarify whether the human papillomavirus (HPV) is associated with esophageal cancer in Malaysians as there has been no report to date on this in Malaysians and other South East Asians.

METHODS

Altogether 67 esophageal squamous cell carcinomas histologically diagnosed between 1 January 2004 and 31 December 2014 at the Department of Pathology, University of Malaya Medical Center, Malaysia were considered for HPV analysis using two commercially available methods, polymerase chain reaction with flow-through hybridization (21 HPV GenoArray Diagnostic Kit) and multiplex real-time polymerase chain reaction (Anyplex II HPV28 Detection). The DNA amplifiability of the formalin-fixed, paraffin-embedded tumor was checked by amplification of a 268 bp segment of the human β-globin gene (GH20/PC04) prior to HPV detection.

RESULTS

HPV detection was finally carried out in 51 patients. HPV16 was detected in the moderately differentiated, stage IV lower esophageal tumor of a 32-year-old Malaysian-born Chinese woman by both methods. Except for a predilection for Indians, the clinical characteristics of esophageal squamous cell carcinomas in this Malaysian cohort were generally similar to those of other populations.

CONCLUSION

It appears that HPV is rare and an unlikely oncovirus in esophageal squamous cell carcinomas of Malaysians.

Prevalence and type distribution of human papillomavirus (HPV) in Malaysian women with and without cervical cancer: an updated estimate

Information on the prevalence and type distribution of human papillomavirus (HPV) among Malaysian women is currently limited. The present study therefore aimed to provide an updated estimate on the prevalence and type distribution of HPV among Malaysian women with and without cervical cancer. Total DNA was isolated from the cervical cell specimens of 185 histopathologically confirmed cervical cancer patients and 209 cancer-free healthy females who were tested negative in a recent Pap test. Viral-specific DNA was subsequently amplified with biotinylated primers and hybridized to HPV type-specific probes via a proprietary "flow-through hybridization" process for determination of HPV genotype. It was demonstrated that 83.2% of the cervical cancer patients and none (0.0%) of the cancer-free females were positive for HPV infection. Among HPV-positive subjects, 14 different viral genotypes were observed, namely HPV16, 18, 31, 33, 35, 45, 52, 53, 58, 66/68, 73, 81, 82, and 84/26. A total of 91.6% of the HPV-positive subjects had single-type HPV infections and the remaining 8.4% were simultaneously infected by two HPV genotypes. The most common HPV infections found were HPV16 (35.7%), HPV18 (26.0%), HPV58 (9.1%), and HPV33 (7.1%) single-type infections, followed by HPV16 + HPV18 co-infections (5.2%). The study has successfully provided an updated estimate on the prevalence and type distribution of HPV among Malaysian women with and without cervical cancer. These findings could contribute valuable information for appraisal of the impact and cost-effectiveness of prophylactic HPV vaccines in the Malaysian population.

Human papillomavirus type distribution in invasive cervical cancer and high-grade cervical intraepithelial neoplasia across 5 countries in Asia

OBJECTIVE

Independent, prospective, multicenter, hospital-based cross-sectional studies were conducted across 5 countries in Asia, namely, Malaysia, Vietnam, Singapore, South Korea, and the Philippines. The objectives of these studies were to evaluate the prevalence of human papillomavirus (HPV) types (high risk and others including coinfections) in women with invasive cervical cancer (ICC) and high-grade precancerous lesions.

METHODS

Women older than 21 years with a histologic diagnosis of ICC and cervical intraepithelial neoplasia [CIN 2 or 3 and adenocarcinoma in situ (AIS)] were enrolled. Cervical specimens were reviewed by histopathologists to confirm the presence of ICC or CIN 2/3/AIS lesion and tested with short PCR fragment 10-DNA enzyme immunoassay-line probe assay for 14 oncogenic HPV types and 11 non-oncogenic HPV types. The prevalence of HPV 16, HPV 18, and other high-risk HPV types in ICC [including squamous cell carcinoma (SCC) and adenocarcinoma/adenosquamous carcinoma (ADC/ASC)] and CIN 2/3/AIS was estimated.

RESULTS

In the 5 Asian countries, diagnosis of ICC was confirmed in 500 women [SCC (n = 392) and ADC/ASC (n = 108)], and CIN 2/3/AIS, in 411 women. Human papillomavirus DNA was detected in 93.8% to 97.0% (84.5% for the Philippines) of confirmed ICC cases [94.0%-98.7% of SCC; 87.0%-94.3% (50.0% for the Philippines) of ADC/ASC] and in 93.7% to 100.0% of CIN 2/3/AIS. The most common types observed among ICC cases were HPV 16 (36.8%-61.3%), HPV 18 (12.9%-35.4%), HPV 52 (5.4%-10.3%), and HPV 45 (1.5%-17.2%), whereas among CIN 2/3/AIS cases, HPV 16 (29.7%-46.6%) was the most commonly observed type followed by HPV 52 (17.0%-66.7%) and HPV 58 (8.6%-16.0%).

CONCLUSIONS

This article presents the data on the HPV prevalence, HPV type distribution, and their role in cervical carcinogenesis in 5 Asian countries. These data are of relevance to public health authorities for evaluating the existing and future cervical cancer prevention strategies including HPV-DNA testing-based screening and HPV vaccination in these Asian populations.

Knowledge, attitude and practice of malaysian medical and pharmacy students towards human papillomavirus vaccination

Human Papillomavirus (HPV) infection is one of the most common sexually transmitted infections and oncogenic HPV is the main cause of cervical cancer. However, HPV vaccination is already available as the primary preventive method against cervical cancer. The objective of this study was to determine the level of knowledge, attitude and practice of HPV vaccination among Universiti Kebangsaan Malaysia (UKM) and Universiti Malaya (UM) students. This study was conducted from March until August 2009. Pre-tested and validated questionnaires were filled by the third year UKM (n=156) and UM (n=149) students from medical, dentistry and pharmacy faculties. The results showed that the overall level of knowledge on HPV infection, cervical cancer and its prevention among respondents was high and the majority of them had positive attitude towards HPV vaccination. Medical students had the highest level of knowledge (p<0.05). Very few students (3.6%) had already taken the vaccine with no significant difference between the two Universities (p=0.399). In conclusion, the knowledge and attitude of the respondents were high and positive, respectively. Only few students took HPV vaccination. Thus, more awareness campaigns and HPV vaccination services should be provided at universities' campuses with the price of the HPV vaccine reduced for the students.

p16(INK4a) is a useful marker of human papillomavirus integration allowing risk stratification for cervical malignancies

The present study was conducted to assess utility of p16(INK4a) immunopositivity as a surrogate marker for genomic integration of high-risk human papillomavirus infection (hrHPV). A total of 29 formalin-fixed, paraffin-embedded cervical low-grade squamous intraepithelial lesions (LSILs), 27 high-grade squamous intraepithelial lesions (HSILs) and 53 invasive squamous cell carcinomas (SCCs), histologically-diagnosed between 1st January 2006 to 31st December 2008 at the University of Malaya Medical Centre were stained for p16(INK4a) (CINtec Histology Kit (REF 9511, mtm laboratories AG, Heidelberg, Germany). Immunopositvity was defined as diffuse staining of the squamous cell cytoplasm and or nucleus (involving > 75% of the intraepithelial lesions or SCCs). Staining of basal and parabasal layers of intraepithelial lesions was pre-requisite. One (3.4%) LSIL, 24 (88.9%) HSIL and 46 (86.8%) SCC were p16(INK4a) immunopositive. All normal squamous epithelium did not express p16(INK4). p16(INK4a) expression was significantly lower (p<0.05) in LSIL compared with HSIL and SCC with no difference in expression between HSIL and SCC.The increased p16(INK4a) immunopositivity in HSIL and SCC appears in line with the integrated existence of the hrHPV and may provide more insightful information on risk of malignant transformation of cervical squamous intraepithelial lesions than mere hrHPV detection.