Objective: The incidence of breast cancer has progressively increased, making it the leading cause of cancer deaths in Japan. Breast cancer accounts for 20.4% of all new cancers with a reported agestandardized rate of 63.6 per 100 000 women. Methods: The Japanese Guidelines for Breast Cancer Screening were developed based on a previously established method. The efficacies of mammography with and without clinical breast examination, clinical breast examination and ultrasonography with and without mammography were evaluated. Based on the balance of the benefits and harms, recommendations for populationbased and opportunistic screenings were formulated. Results: Five randomized controlled trials of mammographic screening without clinical breast examination were identified for mortality reduction from breast cancer. The overall relative risk for women aged 40-74 years was 0.75 (95% CI: 0.67-0.83). Three randomized controlled trials of mammographic screening with clinical breast examination served as eligible evidence for mortality reduction from breast cancer. The overall relative risk for women aged 40-64 years was 0.87 (95% confidence interval: 0.77-0.98). The major harms of mammographic screening were radiation exposure, false-positive cases and overdiagnosis. Although two case-control studies evaluating mortality reduction from breast cancer were found for clinical breast examination, there was no study assessing the effectiveness of ultrasonography for breast cancer screening. Conclusions: Mammographic screening without clinical breast examination for women aged 40-74 years and with clinical breast examination for women aged 40-64 years is recommended for population-based and opportunistic screenings. Clinical breast examination and ultrasonography are not recommended for population-based screening because of insufficient evidence regarding their effectiveness.

The ATEC category of NTEMC system works well in a practical setting and resembles the Bethesda reporting system ASC (atypical squamous cells) category for cervical cytology.

To compare all available accuracy data on screening strategies for identifying cervical intraepithelial neoplasia grade ≥ 2 in healthy asymptomatic women, we performed a systematic review and network meta-analysis. MEDLINE and EMBASE were searched up to October 2020 for paired-design studies of cytology and testing for high-risk genotypes of human papillomavirus (hrHPV). The methods used included a duplicate assessment of eligibility, double extraction of quantitative data, validity assessment, random-effects network meta-analysis of test accuracy, and GRADE rating. Twenty-seven prospective studies (185,269 subjects) were included. The combination of cytology (atypical squamous cells of undetermined significance or higher grades) and hrHPV testing (excepting genotyping for HPV 16 or 18 [HPV16/18]) with the either-positive criterion (OR rule) was the most sensitive/least specific, whereas the same combination with the both-positive criterion (AND rule) was the most specific/least sensitive. Compared with standalone cytology, non-HPV16/18 hrHPV assays were more sensitive/less specific. Two algorithms proposed for primary cytological testing or primary hrHPV testing were ranked in the middle as more sensitive/less specific than standalone cytology and the AND rule combinations but more specific/less sensitive than standalone hrHPV testing and the OR rule combination. Further research is needed to assess these results in population-relevant outcomes at the program level.

The Bethesda system (TBS) has been used for cervical cytological diagnosis in Japan since 2008. Evaluation of specimen adequacy is the most important aspect of quality assurance and for precise diagnosis in TBS. A systematic review and meta‐analysis were carried out to assess the unsatisfactory specimen rate in the primary cervical cancer screening setting in Japan. Ovid Medline and Ichushi‐Web databases were searched from inception through to May 2017. Prospective and retrospective studies that reported the proportion of unsatisfactory specimens in healthy asymptomatic Japanese women in a cervical cancer screening program were eligible for inclusion; 17 studies were included in the meta‐analysis. The random‐effects model meta‐analysis calculated summary estimates of the unsatisfactory rate of 0.60% (95% confidence interval [CI], 0.18‐1.96%; I 2 = 99%) for conventional cytology and 0.04% (95% CI, 0.00‐0.35%; I 2 = 99%) for liquid‐based cytology (LBC). However, comparative results between conventional and liquid‐based cytology, based on four direct and nine comparative studies, showed no significant difference (summary odds ratio = 3.5 × 10−2 favoring LBC [95% CI, 6.9 × 10−4‐1.7]; I 2 = 98%). In the subgroup analyses and meta‐regressions, use of non‐cotton devices for conventional cytology and use of a particular platform for LBC were associated with lower unsatisfactory rates. Meta‐regression also suggested chronological improvement in unsatisfactory rates for both tests. In Japanese cervical cancer screening programs, conventional cytology remains prevalent. Future research needs to focus on evaluating the impact of screening programs using LBC by comparing the accuracy, performance, and cost‐effectiveness with conventional cytology in the Japanese population.

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