Recent Increasing Incidence of Early-Stage Cervical Cancers of the Squamous Cell Carcinoma Subtype among Young Women

Abstract

Few studies have reported on the increase in cervical cancer incidence in Japan. We aimed to determine the relevant trends in the metropolitan regions of Japan and to identify the population with the highest risk, based on histological subtype, cancer stage, and diagnostic processes. Using population-based data (2009–2013), we identified 2110 women, aged ≥20 years, with cervical cancer. We estimated the age-standardized and age-specific incidence rates of cervical cancer for the study period based on the 1985 national model population. The average annual percent change (AAPC) and 95% confidence interval (CI) were calculated using the joinpoint regression analysis. We stratified the analyses based on histological subtypes, stage, and diagnostic process via cancer screening. The increase in the overall age-standardized incidence was not significant. However, the increase was significant for women aged 30–39 years (AAPC 20.0%/year, 95% CI: 9.9–31.1), which was attributable to the increase in the incidence of the squamous cell carcinoma (SCC) subtype (AAPC 23.1%/year, 95% CI: 10.7–36.8). Among younger women, aged <50 years, further stratification showed an increase in the undiagnosed early-stage SCC subtype via cancer screening. In Japan, the incidence of HPV-related cervical cancer has been increasing in undiagnosed younger women.

Trends in cervical cancer incidence and mortality of young and middle adults in Japan

“…Although incidence data were not obtained from all prefectures, past reports have confirmed its validity in terms of secular trends 19 . In addition, the data used for past reports published on cervical cancer trends in Japan are mainly based on a single city or prefecture, which also makes our population‐based study more precise 28‐30,46 …”

“…19 In addition, the data used for past reports published on cervical cancer trends in Japan are mainly based on a single city or prefecture, which also makes our population-based study more precise. [28][29][30]46 Previous reports on the trends in Japanese cervical cancer mortality should be interpreted with caution because the vital statistics registry could have included the shift from cancer of the uterus, NOS. 14 However, the proportion of NOS had been stable since the late 1990s.…”

Characteristics of patients who received helicopter emergency medical services in Japan from 2012 to 2019: a retrospective analysis of data from Tochigi Prefecture

“…In this retrospective and descriptive study, we analyzed the data of all patients who utilized HEMS in Tochigi across a span of eight years (2012–2019). The details of Tochigi Prefecture have been outlined in previous studies [ 11 , 15 ]. Briefly, Tochigi Prefecture has 1.9 million people (1.5% of Japan's total population) with an area of 6408 km 2 , stretching across approximately 84 km east–west and 98 km north–south.…”

Characteristics of Emergency Neurological Patients Who Were Transported by Helicopter Emergency Medical Services in Tochigi, Japan

“…This is a retrospective, observational study that analyzed a dataset of patients with neurological emergencies who used Tochigi HEMS from 2010-2018. The details of the Tochigi Prefecture have been previously described (Noguchi et al 2020). Briefly, Tochigi Prefecture has a population of 2 million people (1.5% of the total population of Japan) with a total area of 6,408 km 2 and is located 100 km north of Tokyo.…”