Long-term effectiveness of human papillomavirus vaccines among adult women: A real-world scenario.

OBJECTIVE: This study aimed to determine the real-world effectiveness of bi- or quadrivalent human papillomavirus (HPV) vaccines in Thai adult women ≥5 years post-vaccination in reducing HPV 16/18-associated low-grade squamous intraepithelial lesions or worse (LSIL+), atypical squamous cells of undetermined significance or worse (ASC-US+), and HPV 16/18 positivity. METHODS: A retrospective cohort study was conducted among Thai women aged 20-45 years in Bangkok. The vaccinated and unvaccinated groups were matched according to baseline years. HPV/Pap test results were collected from the medical records and/or obtained by cervical sample collection at the study sites. Adjusted hazard ratios were measured using multivariable Cox regression analyses. RESULTS: A total of 993 participants (493 vaccinated and 500 unvaccinated) were enrolled from 2018 to 2019. The median ages at baseline of the vaccinated and unvaccinated groups were 33 years (interquartile range [IQR] 27-38) and 34 years (IQR 30-38), respectively. The median follow-up periods were 7.3 years (IQR 6.1-8.6) and 7.2 years (IQR 5.8-8.9) for the vaccinated group and the unvaccinated group, respectively. More women in the vaccinated group were single (29.2% vs. 13.2%, P < 0.001) and university graduates (83.2% vs. 75.4%, P = 0.009). The vaccinated and unvaccinated groups had similar personal monthly incomes (>20,000 THB/month, 63.9% vs. 62.4%, respectively, P = 0.685). There were no cases of HPV 16/18-associated LSIL+ in the vaccinated group, whereas there were four cases in the unvaccinated group. HPV vaccine effectiveness was 88.0% (95% CI 2.0-98.5) in the reduction of HPV 16/18-associated ASC-US+, and 84.6% (95% CI 43.5-95.8) in the reduction of HPV 16/18 positivity. CONCLUSIONS: HPV vaccine effectiveness was high in adult women in a real-world scenario in a developing country. Free HPV vaccination in adult women in this age group should be further explored when vaccine supplies are not limited. (HPV: human papillomavirus. LSIL+: low-grade squamous intraepithelial lesion or worse. ASC-US+: atypical squamous cells of undetermined significance or worse).

Experiences in the prevention and screening of cervical cancer within Thailand.

Cervical cancer is the third most common cancer among Thai women, after breast and colon cancer, with an age-standardized incidence rate (ASR) of 11.7/100 000 women each year, as of 2015. Over decades, comprehensive national cervical cancer screening programs, research, and the HPV vaccination policy have gradually helped decrease the incidence of cervical cancer in Thailand. In 2017, the Thai Ministry of Public Health signed a memorandum of understanding with the Royal Thai College of Obstetricians and Gynecologists to eliminate invasive cervical cancer from Thailand. This is a tremendous challenge for Thailand as a whole. The present paper reviews and discusses the experiences in the prevention and screening of cervical cancer in Thailand.

Cost-effectiveness analysis study of HPV testing as a primary cervical cancer screening in Thailand.

OBJECTIVES: The aim of this study is to compare the cost and benefit of four different cervical cancer screening strategies involving primary HPV 16/18 genotyping, hrHPV testing alone and cytology for detecting CIN2 +. METHODS: Economical analysis using Markov modeling approach to combine the epidemiological data from current population-based study of The National Cancer Institute of Thailand. A cohort of 100,000 hypothetical female population age 30-65 years was simulated in each strategy. The compared strategies are HPV 16/18 genotyping with reflexed cytology, hrHPV testing alone followed by colposcopy, Papanicolaou standard cytology and liquid based cytology followed by colposcopy. The interval of screening was 5 years' interval. The main outcomes were defined as a number of CIN2 + cases and cost per 100,000 women screening over 35 years. RESULTS: Model predictions indicated that, the most cost-effectiveness strategy is hrHPV testing alone by reducing cost and also increase CIN2 + detection rate. It identify an additional 130 cases and decrease cost by 46,950,840 THB (1,394,441 USD) per 100,000 women screened when compared to HPV 16/18 genotyping. Compared with cytology, hrHPV testing decrease cost by 51,279,781 THB (1,523,011 USD) and detected more 506 cases of CIN2 +. From sensitivity analysis, the cost of HPV testing, cost of colposcopy, incidence of HPV infection and sensitivity of cytology may affect the results. (1 USD = 33.67 Baht). CONCLUSION: The results of this cost-effectiveness analysis support the full scale implementation of HPV testing as a primary cervical cancer screening in Thailand.

Comparison of human papillomavirus (HPV) detection in urine and cervical swab samples using the HPV GenoArray Diagnostic assay.

Human papillomavirus (HPV) is the leading cause of cervical cancer. Urine-based HPV testing offers a simple and non-invasive method because of its increasing acceptance. A total of 164 pairs of cervical swab and urine samples from Thai women who underwent cervical cancer screening were used for HPV testing with HPV GenoArray Diagnostic Kits. The overall concordance percentage for HPV detection in the cervical swab and urine samples was 65.2%. The HPV genotypes most commonly detected were HPV16 and HPV18. An analysis of the urine samples and a second analysis of the cervical swab samples showed that the differences in the overall HPV detection rate between women with normal and abnormal cytology were not significant (p > 0.05). Urine samples processed with the GenoArray assay is an alternative for women who decline to undergo Pap smear even though it is not ideal as the first-line screening option.

Comparative accuracy of Pap smear and HPV screening in Ubon Ratchathani in Thailand.

We evaluate the potential for using high-risk human papillomavirus (hr-HPV) testing-based screening for cervical intraepithelial neoplasia (CIN) in routine health services in Thailand; its accuracy in comparison to that of conventional cytology (CC); and the utility of HPV16/18 positive results and liquid-based cytology (LBC) triage for HPV-positive women in the detection of high-grade CIN. Women aged 30-60 years in Ubon Ratchathani province, Thailand were screened with CC and hr-HPV testing and those abnormal on either tests were referred for colposcopy and/or directed biopsies. The final diagnosis using COBAS was based on histology or colposcopy when histology was not available. Estimation of test accuracy parameters was done using latent class analysis using Bayesian models. Of the 5004 women were enrolled, 20 (0.4%) had abnormal CC and 174 (3.5%) women were HPV-positive. Among 185 women abnormal on CC or HPV-positive, 176 (95.1%) underwent colposcopy, of whom 101 (57.4%) had abnormal colposcopy findings. Ninety-seven women with abnormal and 69 with normal colposcopy had biopsies performed. All 21 women with histological CIN2 or worse had hr-HPV and none were abnormal on CC. The estimated sensitivity, specificity and positive predictive value were respectively 71.8%, 97.0% and 13.0% of HPV testing; 53%, 98.7% and 20.3% for triage of HPV-positive women with LBC; and 70.4%, 98.2% and 16.9% when test positivity was taken as HPV16/18 irrespective of LBC result or positive for hr-HPV non 16/18 types and LBC triage. Our study findings indicate poor performance of cytology screening and demonstrate the potential and utility of using HPV testing in public health services in Thailand as well as the utility of primary HPV testing and LBC triage in screening for cervical neoplasia.

Prevalence of high risk human papillomavirus infection with different cervical cytological features among women undergoing health examination at the National Cancer Institute, Thailand.

High-risk (HR) human papillomavirus (HPV) testing is important in cervical cancer screening for triage colposcopy. The objective of the study was to evaluate the prevalence of HR HPV infection with different cervical cytological features among women undergoing health examination. A total of 2,897 women were retrospectively evaluated between May 2011 to December 2011. DNA was extracted from residual specimens collected during routine liquid-based cytology tests at the National Cancer Institute. Overall, HR HPV prevalence was 9.3% including 1.6% of HPV-16 and 0.4% of HPV-18. Of all 270 HPV positive samples, 211 (78.1% were HR-HPV non 16/18; 47 (17.4%) were HPV-16 and 12 (4.4%) were HPV-18. The prevalence of HPV infection was similar in all age groups, although a higher rate was observed in women age 31-40 years. Among women with normal cytology, HR HPV positive were found in 6.7%. In abnormal cytology, HR HPV were found 46.7% in atypical squamous cells (ASC), 54.8% in low-grade squamous intraepithelial lesions (LSIL) and 80.0% in high-grade squamous intraepithelial lesions (HSIL). HPV-16 was detected in 8.6%, 6.4% and 12.0% of ASC, LSIL and HSIL, respectively. The results of this study provide baseline information on the HPV type distribution, which may be useful for clinicians to decide who should be monitored or treated more aggressively.

Detection of human papillomavirus in male and female urine by electrochemical DNA chip and PCR sequencing.

BACKGROUND: Cervical cancer is the second most common cancer in Thai women after breast cancer. Currently, the Papanicolaou (Pap) smear is the recommended procedure for cervical cancer screening in Thailand, but only a relatively small percentage of women follow this screening program. An alternative method to detect HPV genotypes associated with cervical cancer is self-sampling of urine, which is a more widely accepted method. Our study aimed to evaluate the prevalence of HPV in Thai women using urine and cervical swabs and prevalence of HPV in Thai men using urine samples. MATERIALS AND METHODS: Tumorigenic HPV detection was accomplished by electrochemical DNA chip and PCR/direct sequencing. In addition to HPV prevalence, we report the concordance between different methods and sample types. One-hundred and sixteen women and 100 men were recruited. Histological examination revealed normal cytology in 52 women, atypical squamous cells of undetermined significance (ASCUS) in 9, low-grade squamous intraepithelial lesions (LSIL) in 24, and high-grade squamous intraepithelial lesions (HSIL) in 31. One-hundred men were classified as heterosexuals (n=45) and homosexuals (n=55). RESULTS: The most prevalent HPV genotype in our study was HPV16. The HPV detection rate was generally lower in urine samples compared with cervical samples. Overall, there was good agreement for the detection of carcinogenic HPV from female cervical samples between the DNA chip and PCR/ sequencing, with 88.8% total agreement and a kappa value of 0.76. In male urine samples, the level of agreement was higher in heterosexuals compared with homosexuals. CONCLUSIONS: Further improvement is required to increase an overall yield of HPV DNA detection in urine samples before clinical application of a urine-based HPV screening program. The electrochemical DNA chip test is a promising technique for carcinogenic HPV detection.