Time trend analysis of rare cancer incidence 2011-2018: Nationwide population-based cancer registries in Japan.

Rare cancers collectively account for a significant proportion of the overall cancer burden in Japan. We aimed to describe and examine the incidence of each rare cancer and the temporal changes using the internationally agreed rare cancer classification. Cancer cases registered in regional population-based cancer registries from 2011 to 2015 and the National Cancer Registry (NCR) from 2016 to 2018 were classified into 18 families, 68 Tier-1 cancer groupings, and 216 single cancer entities based on the RARECAREnet list. Crude incidence rates and age-standardized incidence rates (ASR) were calculated for Tier-1 and Tier-2 cancers. The annual percent change and the 95% and 99% confidence limits for annual ASR for each of the 68 Tier-1 cancers were estimated using the log-linear regression of the weighted least squares method. The differences in ASRs between 2011 and 2018 were evaluated as an absolute change. A total of 5,640,879 cases were classified into Tier-1 and Tier-2 cancers. The ASRs of 18 out of 52 Tier-1 cancers in the rare cancer families increased, whereas the ASR for epithelial tumors of gallbladder decreased. The ASRs of 6 out of the 16 Tier-1 cancers in the common cancer families increased, whereas those of epithelial tumors of stomach and liver decreased. There was no significant change in the incidence of the other 40 Tier-1 cancers. The incidence of several cancers increased due to the dissemination of diagnostic concepts, improved diagnostic techniques, changes in coding practice, and the initiation of the NCR.

[Defining sensitivity and specificity for quality control of organized cancer screening using Prefectural Cancer Registry data in Japan].

Objective　To decrease cancer mortality by implementing cancer screening programs, rigorous quality control measures that utilize standardized indicators are imperative. In Japan, although each municipality performing cancer screening programs implements quality control for their programs using the checklist authorized by the Ministry of Health, Labour and Welfare, compliance with all the items listed is not possible because calculating sensitivity and specificity using cancer registry data is difficult under these circumstances. This report elucidates the methodology for calculating indicators, including sensitivity and specificity, by delineating the parameters of false-negative cases within population-based cancer screening programs in Japan. Furthermore, the inherent challenges associated with ensuring the quality control of cancer screening procedures are expounded upon in this report.Method　Data from the Prefectural Cancer Registry of Japan and cancer screening records compiled by municipalities were used to differentiate true-positive, true-negative, false-positive, and false-negative cases based on the combination of screening test outcomes and subsequent cancer incidence.Results　A false-negative case was defined as an examinee who received a cancer diagnosis within one year after undergoing the screening test, notwithstanding the negative judgment of the cancer screening decision. The duration for judgment of true-positive, true-negative, and false-negative cases was also extended to one year. Cancer identification after cancer screening was ascertained using data from the Prefectural Cancer Registry, ensuring uniform categorization of the four cases. Subsequently, sensitivity and specificity values were calculated for municipalities conducting cancer screening programs.Conclusion　Sensitivity and specificity are indispensable metrics for the inherent quality control of cancer screening because these parameters directly assess the efficacy of screening tests. The anticipated increase in the number of municipalities engaged in comprehensive quality control of cancer screening in Japan is poised to enhance the efficiency of cancer control policies. This augmentation will be accomplished through the meticulous utilization of the sensitivity and specificity values elucidated in the present report. The forthcoming challenges involve the proliferation of medical institutes reporting their adherence to the checklist stipulated by the National Cancer Center of Japan and the widespread dissemination of fundamental knowledge pertaining to cancer screening.

Status of cervical cancer screening among adolescents and young adults (AYA) in Japan.

Cervical cancer ranks high among the cancers that affect people in their 20s and 30s. Cervical cancer is characterized by the presence of precancerous lesions, which can be detected by cancer screenings; some precancerous lesions are amenable to treatment, which can halt the progression to invasive cancer. As a result, cervical cancer screening has been shown to reduce the incidence of invasive cancer and its mortality. On the other hand, many precancerous lesions do not progress to invasive cancer, but stagnate or disappear spontaneously. In Japan, there is a nationwide cytological screening program for residents, and the screening is performed every two years after the age of 20. There are also screening programs provided by the workplaces in Japan. According to the National Health Survey 2019, the checkup rates of any type of cervical cancer screenings are low: 15.1% for those aged 20-24, 36.6% for those aged 25-29, and 49.4% for those aged 30-34. Statistics are reported every year for the nationwide screening, and according to them, the positive screening rate is 2.1% for all ages, but 4.5% and 3.2% for those in their 20s and 30s, respectively. On the other hand, the percentage of people with positive test results who undergo follow-up examinations or confirmatory tests should be at least 90%, but it is 72.1% for all ages, 72.0% for those in their 30s, and even lower for those in their 20s, at 67.1%. Improving the rate of people getting screenings and subsequent examinations is a challenge even among the young.

Death by suicide, other externally caused injuries and cardiovascular diseases within 6 months of cancer diagnosis (J-SUPPORT 1902).

OBJECTIVE: To conduct the first national population-based study in Japan to characterize risks of death by suicide, other externally caused injuries and cardiovascular diseases within 6 months of cancer diagnosis. METHODS: Cancer patients diagnosed between 1 January and 30 June 2016 and registered in the National Cancer Registry in Japan were followed up until death or 6 months after diagnosis. We calculated standardized mortality ratios and excess absolute risks per 10 000 person-years for death by suicide, other externally caused injuries and cardiovascular diseases compared with the Japanese general population. RESULTS: Of 546 148 patients with cancer (249 116 person-years at risk), we observed 145 suicides, 298 deaths due to other externally caused injuries and 2366 cardiovascular deaths during the follow-up period. Standardized mortality ratios within 6 months were 2.68 for suicide (95% confidence interval, 2.26-3.16; excess absolute risk, 3.65), 1.49 for other externally caused injuries (95% confidence interval, 1.32-1.67; excess absolute risk, 3.92) and 1.38 for cardiovascular diseases (95% confidence interval, 1.33-1.44; excess absolute risk, 26.85). Risks were highest during the first month after cancer diagnosis (standardized mortality ratios: suicide, 4.06 [95% confidence interval, 2.90-5.53]; other externally caused injuries, 2.66 [95% confidence interval, 2.17-3.12] and cardiovascular diseases, 2.34 [95% confidence interval, 2.18-2.51]). CONCLUSIONS: The first 6 months, and especially the first month, after cancer diagnosis were found to be a critical period for risks of death by suicide, other externally caused injuries and cardiovascular diseases. Our findings suggest that oncologists need to evaluate suicidal and cardiovascular risks of patients immediately after cancer diagnosis and provide preventive interventions.

Trends in the quality assurance process indicators for Japanese colorectal cancer screening during 2003-13.

BACKGROUND: Recently, the importance of quality assurance (QA) for cancer screening has gained increasing attention in Japan. This study aimed to evaluate QA process indicators for population-based colorectal cancer screening during 2003-13. METHODS: A national cancer screening database was used to evaluate the following process indicators: the positivity rate, diagnostic follow-up rate, unidentified results rate, non-compliance with diagnostic follow-up rate, cancer detection rate and positive predictive value (PPV). RESULTS: The positivity rate remained constant at 6.5% until 2011, and then increased slightly thereafter. During 2003-13, the cancer detection rate increased from 0.15% to 0.21%, and the PPV increased from 2.2% to 3.1%. Although the diagnostic follow-up rate increased from 58% to 67%, the non-compliance with diagnostic follow-up rate decreased from 24% to 16% and the unidentified results rate decreased from 18% to 17%. CONCLUSIONS: During the study period, the QA process indicators for colorectal cancer screening in Japan generally improved. However, the recent increase in the positivity rate requires careful observation. Innovative solutions are needed to increase the diagnostic follow-up rate.

Population-based cohort study assessing the efficacy of cervical cytology (Pap smear) and human papillomavirus (HPV) testing as modalities for cervical cancer screening.

In cervical cancer screening, several trials have shown that human papillomavirus (HPV) testing or combined HPV testing and cytology leads to earlier detection of cervical intraepithelial neoplasia Grade 3 or worse (CIN3+) compared with cytology alone. However, the availability of similar evidence in our country remains limited. In 2013, 34 local governments were selected to administer a cervical cancer screening program utilizing either cytology alone or in combination with HPV testing. We planned a cohort study to assess the effectiveness of HPV testing as a modality for cervical cancer screening. The primary outcome of this study was the incidence of CIN3+ in each group, as well as to assess the risks and benefits of receiving screening for women in both groups. These results will contribute to elucidating the details of the positive and negative impacts of introducing HPV testing into a population-based cervical cancer screening program in Japan.