Clinical efficacy of primary human papillomavirus (HPV) screening with partial genotyping for HPV-16 and HPV-18 subtypes in women from 25 years old

Introduction

Cervical screening programmes differ in the age of women recommended for primary human papillomavirus (HPV) testing. This study aims to determine the clinical efficacy and impact of 14-high-risk HPV DNA testing for women from 25 years old.

Method

This was a retrospective analysis of data collected prospectively from women 25 years or older who attended hospital-based gynaecology clinics for cervical screening. Women with history of cervical neoplasia or abnormal cytology were excluded. High-risk HPV DNA testing with partial genotyping for HPV-16 and HPV-18 were performed on cobas 4800 System (Roche Diagnostics International AG, Rotkreuz, Switzerland). Women tested positive for the 12 other high-risk HPV subtypes (HPV-12 other) had a reflex cytology test. Positive screening included positive for HPV-16 and/or HPV-18, HPV-12 other with cytology abnormalities equal to or greater than atypical squamous cells of undetermined significance, and repeated positive HPV at 12 months. HPV detection and colposcopy referral rates, and detection of high-grade neoplasia were determined.

Results

Of 10,967 women studied, 822 (7.50%) were HPV DNA positive. The overall discharge rate to routine screening according to screening protocol was 93.1%. Colposcopy referral rate was 4.4%. The screening detected 41 cervical intraepithelial neoplasia grade 2+ (CIN2+) (0.37%) and 31 (0.28%) CIN3+. The number of colposcopies needed per case of CIN2+ was 9.5, similar for women below and above 30 years old. The number of colposcopies needed per case of CIN3+ for HPV-16 positivity was 8.5, compared to 17.0 for other categories (P=0.040). Colposcopy efficacy was similar for HPV-18 and HPV-12 other positivity with abnormal cytology.

Conclusion

Taking CIN2+ detection and colposcopy referral rate as endpoints, HPV testing in Singapore can be extended to include women from 25 years old.

Cost-Effectiveness Analysis of HPV Extended versus Partial Genotyping for Cervical Cancer Screening in Singapore

Human papillomavirus (HPV) partial genotyping (PGT) identifies HPV16 and HPV18 individually, alongside 12 other high-risk HPV genotypes (hrHPV) collectively. HPV extended genotyping (XGT) identifies four additional hrHPV individually (HPV31, 45, 51, and 52), and reports the remaining eight in three groups (HPV33|58; 56|59|66; 35|39|68). Quality-adjusted life years (QALY), health care resource use, and costs of XGT were compared to PGT for cervical cancer screening in Singapore using DICE simulation. Women with one of the three hrHPV identified by XGT (HPV35|39|68; 56|59|66; 51), and atypical squamous cells of undetermined significance (ASCUS) on cytology, are recalled for a repeat screening in one year, instead of undergoing an immediate colposcopy with PGT. At the repeat screening, the colposcopy is performed only for persistent same-genotype infections in XGT, while with PGT, all the women with persistent HPV have a colposcopy. Screening 500,122 women, aged 30-69, with XGT, provided an incremental cost-effectiveness ratio (ICER) versus PGT of SGD 16,370/QALY, with 7130 (19.4%) fewer colposcopies, 6027 (7.0%) fewer cytology tests, 9787 (1.6%) fewer clinic consultations, yet 2446 (0.5%) more HPV tests. The XGT ICER remains well below SGD 100,000 in sensitivity analyses, (-SGD 17,736/QALY to SGD 50,474/QALY). XGT is cost-effective compared to PGT, utilizes fewer resources, and provides a risk-based approach as the primary cervical cancer screening method.

Cervical screening in foreign domestic workers in Singapore

INTRODUCTION

Globally, cervical cancer is the fourth most common cancer in women, with about 85% occurring in low-middle income countries (LMIC) and an age-standardised incidence rate of more than 15 per 100,000. It is largely preventable through HPV vaccination and cervical cancer screening. In Singapore, 18% of the foreign domestic workforce hail from Indonesia, the Philippines, Myanmar, and India. However, there is no data on preinvasive cervical disease and cervical cancer in foreign domestic workers (FDWs) and the aim of this pilot programme is to determine the baseline screen positive rate of high-grade intraepithelial in this population.

METHODS

A total of 322 FDWs were offered HPV screening through the Helping Our Helper (HOH) pilot programme. Data from this pilot programme were analysed and reported using simple descriptive statistics.

RESULTS

Out of the 322 FDWs who registered for HPV screening, 68.6% participated. There was a 22.2% screen-positive rate; 10% of those who screened positive for high-risk HPV had histologically confirmed high-grade cervical intraepithelial neoplasia. This result is similar to other data on cervical cancer screening in Singaporeans. This pilot project screened less than 1% of the eligible FDWs in Singapore.

DISCUSSION

The findings of this pilot programme suggest that there is public health value in providing cervical cancer screening to FDWs. Improving cervical cancer screening by increasing awareness and including routine cervical cancer screening as part of the employment medical examination should be studied.