Beneficial Effects of Human Papillomavirus Vaccine for Prevention of Cervical Abnormalities in Miyagi, Japan

Abstract

Prevention of cervical cancer has been unsuccessful in Japan because of low rates of cancer screening and vaccination. The Vaccine Adverse Review Committee of the Japanese Government investigated 2,475 adverse events and reported 617 (6.9/100,000) severe cases and 176 (2.0/100,000) cases with chronic pain. The proactive recommendation for human papillomavirus (HPV) vaccination has been suspended since June 2013. In this study, we examined vaccination rate and incidence of abnormal cervical cytology in women aged 20 to 24 years attending cancer screening in Miyagi. Among the 3,272 women who underwent a health check in the fiscal year 2014 (April 2014-March 2015), 332 (10.2%) received a HPV vaccination. The HPV vaccination rates were 42.3%, 10%, 17.5%, 3.8% and 4.0% in women aged 20, 21, 22, 23 and 24 years, respectively. The rates of atypical squamous cells of undetermined significance (ASC-US) or worse were 2.41% (8/332) in women with HPV vaccination and 5.03% (148/2,940) in those without HPV vaccination, indicating a significant decrease in vaccinated women (p = 0.03). ASC-US cases were referred to HPV DNA tests. In addition, the rates of high grade squamous intraepithelial lesion (HSIL) or worse were 0.30% (1/332) in women with HPV vaccination and 0.82% (24/2,940) in those without HPV vaccination, showing the marginal decrease in women who were vaccinated (p = 0.3). Thus, this study indicates that HPV vaccination is associated with a reduction in the incidence of cervical abnormalities, suggesting a need for scientific discussion of reinstatement of proactive recommendation for HPV vaccine in Japan.

Preventive effect of human papillomavirus vaccination on the development of uterine cervical lesions in young Japanese women

“…It is likely that the vaccination rate decreases with aging. These data, however, are very similar to those reported by Ozawa et al They reported that the vaccination rate in the same age groups of women who underwent cervical cancer screening was 42.3%, 10.0%, 17.5%, 3.8%, and 4.0%, respectively.…”

“…Approximately 4 years have passed since the public HPV vaccination program was initiated; thus, women aged 20–24 years who have possibly received the public HPV vaccine have since undergone cervical cancer screening. Nonetheless, limited studies have investigated the effect of HPV vaccination on cervical cytologic abnormalities . Therefore, aim of the present study was to compare the prevalence of abnormal cytology results during cervical cancer screening in women aged 20–24 years who have received HPV vaccination and those who have not in the Akita Prefecture between 2014 and 2016.…”

Lower Incidence of Cervical Intraepithelial Neoplasia among Young Women with Human Papillomavirus Vaccination in Miyagi, Japan

“…The rates in FY 2014 were recalculated from the data published in the earlier report (Ozawa et al 2016). In FY 2015, the overall vaccination rate was 25.41% for women aged 20 to 24 years old, and the rates of vaccination were 59.26%, 49.68%, 11.97%, 9.08%, and 4.58% in those aged 20, 21, 22, 23, and 24 years old, respectively, with the exclusion of the 538 women ( Table 1).…”

“…The rates of FY 2014 were recalculated from the data published in the earlier report (Ozawa et al 2016) and are presented for comparison. (Ozawa et al 2016). cination and 1.14% (56/4,922) in those without vaccination.…”

“…However, because of the limited number of the enrolled women, the effects of vaccine were not conclusive (Ozawa et al 2016). Therefore, we examined the effects of HPV vaccine in Miyagi by investigating the incidence of abnormal cytology and histology in FY 2014-2015.…”