Much higher risk of premalignant and malignant cervical diseases in younger women positive for HPV16 than in older women positive for HPV16

Genotype prevalence and age distribution of human papillomavirus from infection to cervical cancer in Japanese women: A systematic review and meta-analysis

BACKGROUND

National HPV vaccination coverage in Japan is less than one percent of the eligible population and cervical cancer incidence and mortality are increasing. This systematic review and meta-analysis aimed to provide a comprehensive estimate of HPV genotype prevalence for Japan.

METHODS

English and Japanese databases were searched to March 2021 for research reporting HPV genotypes in cytology and histology samples from Japanese women. Summary estimates were calculated by disease stage from cytology only assessment - Normal, ASCUS, LSIL, HSIL and from histological assessment - CIN1, CIN2, CIN3/AIS, ICC (ICC-SCC, and ICC-ADC), and other. A random-effects meta-analysis was used to calculate summary prevalence estimates of any-HPV, high-risk (HR) and low-risk (LR) vaccine types, and vaccine genotypes (bivalent, quadrivalent, or nonavalent). This study was registered with PROSPERO: CRD42018117596.

RESULTS

A total of 57759 women with normal cytology, 1766 ASCUS, 3764 LSIL, 2017 HSIL, 3130 CIN1, 1219 CIN2, 869 CIN3/AIS, and 4306 ICC (which included 1032 ICC-SCC, and 638 ICC-ADC) were tested for HPV. The summary estimate of any-HPV genotype in women with normal cytology was 15·6% (95% CI: 12·3-19·4) and in invasive cervical cancer (ICC) was 85·6% (80·7-89·8). The prevalence of HR-HPV was 86·0% (95% CI: 73·9-94·9) for cytological cases of HSIL, 76·9% (52·1-94·7) for histological cases of CIN3/AIS, and 75·7% (68·0-82·6) for ICC. In women with ICC, the summary prevalence of bivalent vaccine genotypes was 58·5% (95% CI: 52·1-64·9), for quadrivalent genotypes was 58·6% (52·2-64·9) and for nonavalent genotypes was 71·5% (64·9-77·6), and of ICC cases that were HPV positive over 90% of infections are nonavalent vaccine preventable. There was considerable heterogeneity in all HPV summary estimates and for ICC, this heterogeneity was not explained by variability in study design, sample type, HPV assay type, or HPV DNA detection method, although studies published in the 1990s had lower prevalence estimates of any-HPV and HR HPV genotypes.

INTERPRETATIONS

HPV prevalence is high among Japanese women. The nonavalent vaccine is likely to have the greatest impact on reducing cervical cancer incidence and mortality in Japan.

Uneven distribution of human papillomavirus 16 in cervical carcinoma in situ and squamous cell carcinoma in older females: A retrospective database study

Human papillomavirus (HPV) 16 is the dominant cofactor in cervical cancer development. The present report investigated the age-specific prevalence of HPV16 in cervical carcinoma in situ (CIS) in females attending organised cervical cancer screening. A retrospective observational study was performed based on individual data from two databases. A total of 162 females aged between 20 and 65 years from Uppsala County, Sweden with CIS and an HPV test conducted between 2010 and 2011, preceding or concomitant to CIS diagnosis, were included. Females with cervical squamous cell carcinoma (SCC; n=35) were used for comparison. In total, 96% (n=156) of females with CIS were positive for high-risk HPV; HPV16 was the most prevalent (44.5%), followed by HPV33/52/58 (19.5%), HPV31 (13.1%) and HPV18/45 (9.5%). HPV16 was most frequently detected in females with CIS aged between 20 and 29 years (73.6%) and least frequently detected in those aged between 50 and 65 years (33.3%), with a statistically significant age-specific difference (P=0.001). Among the HPV16-positive females, multiple infections were most frequent in the younger age groups. The prevalence of HPV16 in females with CIS decreased with age, whereas a high prevalence of HPV16 remained in females with SCC. These results may indicate that HPV16 has increased oncogenic potential in older females.

Human papilloma virus type 16 infection and the early onset of cervical cancer

Human papilloma viruses (HPV), particularly type 16, have been associated with cervical cancer. It has been noted that the average onset of cervical cancer is occurring in younger women coupled with a higher prevalence of cervical HPV infection. However, the correlation between HPV 16 infection and the early onset of cervical cancer is still unclear. We hypothesize that HPV infection is an indicator of early onset of cervical cancer. To test this hypothesis, cervical smears from 197 women were evaluated by the polymerase chain reaction for HPV 16. These data revealed that the HPV 16-positive women were significantly younger than the HPV 16-negative women. Moreover, the average age of HPV 16-positive women with CIN 3 or invasive cancer was significantly younger compared with the other groups. These data clearly suggest that HPV 16 infection is a significant risk factor for the progression for cervical cancer in a young population of women.

Adding HPV16 testing to abnormal cervical smear detection is useful for predicting CIN3: a prospective study

BACKGROUND

The aim of this prospective study was to estimate whether adding human papillomavirus 16 (HPV16) testing to abnormal cervical smears is useful in the prediction of cervical intraepithelial neoplasia 3 (CIN3).

METHODS

Between October 1994 and May 1996, a total of 207 patients at the Akita University Hospital had abnormal smears. Of these patients, 153 patients with CIN1,2 or atypical squamous cells of undetermined significance (ASCUS) were enrolled in this study and followed until June 2001. At the initial visit, a cervical swab was collected for cytology and for HPV16 testing using nested polymerase chain reaction (PCR). When the HPV16 test was positive, HPV16 testing was performed every 3 to 6 months. We compared the prevalence of progression to CIN3 between the HPV16-positive group (n = 16) and the HPV16-negative group (n = 137). We also investigated the risk of progression to CIN3 associated with persistent HPV16 infection.

RESULTS

At the end of the study period, four patients (25%) in the HPV16-positive group developed CIN3, and all of these patients were found to have persistent HPV16 infection during this period. Only three patients (2.2%) in the HPV16-negative group developed CIN3.

CONCLUSIONS

The prevalence of progression to CIN3 in the HPV16-positive group was significantly higher than that in the negative group (p = 0.0023). The odds ratio of progression to CIN3 was 14.9 [95% confidence interval (CI) 2.98-74.4]. In particular, the risk of progression to CIN3 increased with persistent HPV16 infection. Adding HPV16 testing when abnormal cervical smears are detected promises to be useful for predicting CIN3.