The report in 1981 of a cluster of cases of Kaposi sarcoma (KS) in homosexual men in New York and California was one of the earliest harbingers of the AIDS pandemic, and association of cancer with HIV/AIDS has been one of the key features of this disease since. Looking back at year 40, the development of anti-retroviral therapy markedly reduced the incidence of AIDS-related cancers that occur at low CD4 counts, and this has been one of the most impressive advances in cancer prevention over the past half-century. There have also been advances in prevention and treatment of various HIV-associated tumors. However, as AIDS patients are living longer, there has been an increase in other cancers. Cancer continues to be one of the most frequent causes of death in persons living with HIV, and further basic, translational, clinical, and epidemiologic research in this area is urgently needed.

In recent years, collaboration among researchers in the field of cancer epidemiology has been accelerating in various forms. Here, we review recent trends in international collaborative research activities in the cancer epidemiology field in Japan. These include not only support for other countries with less developed cancer statistics infrastructures, but also large-scale compilations and international comparisons through collaborative studies, as well as integration with analytical epidemiology and clinical research. Formation of international cohort consortia and estimates of cancer and risk factors in each country have contributed to raising the skill levels of cancer epidemiologists as well as to expanding research networks and activities among cancer epidemiologists. Molecular and genome epidemiological studies on cancer have progressed over decades and these continue to increase in size and dimension. Application of evidence from this area in prevention is still underway and needs further effort. Japanese epidemiologists have great potential to assume international leadership roles by taking advantage of the uniqueness, originality and characteristics of Japanese cohorts.

Frailty prevention is a cornerstone for the extension of healthy life expectancy. It is a multi-dimensional construct that includes physical, mental, and social aspects. Frailty is reversible and can be attenuated by intervention; therefore, its early detection is important in primary and community care. The mainstream of disability prevention in Japan, which comprises the Japanese and local governments as well as healthcare workers, was a high-risk approach until 2014. Given the revision on Japan's long-term care insurance law, current ageing health policies have shifted to more population centric approach. Implements group activities called "Kayoi-no-ba" has been valued in Japan as disability prevention initiative. The Kihon Checklist – a 25-item questionnaire – has been broadly used by health experts and researchers to assess frailty in Japan. However, a new 15-item questionnaire has been newly developed to identify frailty and other health-related problems in older people of 75 years and above. This will enable providing the necessary support to frail individuals at any healthcare facility in local communities. The increase in frailty prevalence in older people has been concern during the COVID-19 pandemic. Home-based physical exercise programs are expected to be effective for frailty prevention. Utilization of information and communication technologies, social network services, and video calls has attracted attention for being effective tools to facilitate communication for older people during the pandemic. Further, life course approaches are needed to clarify the midlife risk of frailty development in later life.

According to the statistics for 2018 in Japan, cardiovascular disease and cerebrovascular disease were the most common causes of death (cardiovascular disease with 208,210, cerebrovascular disease with 108,165), and these two diseases account for 23.2% of all deaths. Stroke, especially cerebral hemorrhage, was the main cause of death in Japan after World War II. Along with improved management of hypertension, the mortality rate from cerebral hemorrhage reached a high of 266.7 per 100,000 men in 1960 and 213.9 per 100,000 women in 1951, then decreased to 15.9 per 100,000 men and 6.9 per 100,000 women in 2013. However, mortality from lifestyle-related diseases such as metabolic syndrome and ischemic heart disease has been on the rise since 1990 due to the westernization of diet, urban lifestyles, and lack of exercise habits. Moreover, since aging is the greatest risk factor for heart failure, the number of patients with heart failure in Japan will inevitably increase in the future. A large amount of evidence has demonstrated that prevention and proper management of risk factors can reduce the future incidence of cardiovascular disease. Specific health checkups (metabolic syndrome checkups) have been carried out in Japan since 2008. Big data on physical examinations are valuable real-world data that can be utilized for clinical research. As the importance of preventive cardiology increases in the future, we should analyze the real-world data from health checkups in Japan in detail and disseminate these results to clinical practice, which will contribute to development of preventive cardiology and the promotion of public health.

The prognosis has improved remarkably in recent years with the development of cancer treatment. With the increase in the number of cancer survivors, complications of cardiovascular disease have become a problem. Therefore, the field of onco-cardiology has been attracting attention. The field of onco-cardiology covers a wide range of areas. In the past, cardiac dysfunction caused by cardiotoxic drug therapies such as doxorubicin (Adriamycin) was the most common cause of cardiac dysfunction, but nowadays, cardiovascular complications caused by aging cancer survivors, atherosclerotic disease in cardiovascular risk carriers, thromboembolism, and new drugs (e.g., myocarditis caused by immune checkpoint inhibitors and hypertension caused by angiogenesis) are becoming more common. In this review, we summarize the latest findings of cardiotoxicity of cancer therapy, appropriate treatment and prevention, and cardiovascular complications of novel chemotherapy, which will increase in demand in the near future.

Identifying patients resistant to cisplatin treatment is expected to improve cisplatin-based chemotherapy for various types of cancers. Excision repair cross-complementing group 1 (ERCC1) is involved in several repair processes of cisplatin-induced DNA crosslinks. ERCC1 overexpression is reported as a candidate prognostic factor and considered to cause cisplatin resistance in major solid cancers. However, anti-ERCC1 antibodies capable of evaluating expression levels of ERCC1 in clinical specimens were not fully optimized. A mouse monoclonal antibody against human ERCC1 was generated in this study. The developed antibody 9D11 specifically detected isoforms of 201, 202, 203 but not 204, which lacks the exon 3 coding region. To evaluate the diagnostic usefulness of this antibody, we have focused on gastric cancer because it is one of the major cancers in Japan. When ERCC1 expression was analyzed in seventeen kinds of human gastric cancer cell lines, all the cell lines were found to express either 201, 202, and/or 203 as major isoforms of ERCC1, but not 204 by Western blotting analysis. Immunohistochemical staining showed that ERCC1 protein was exclusively detected in nuclei of the cells and a moderate level of constant positivity was observed in nuclei of vascular endothelial cells. It showed a clear staining pattern in clinical specimens of gastric cancers. Antibody 9D11 may thus be useful for estimating expression levels of ERCC1 in clinical specimens.

We investigated possible sources of newly infected patients with coronavirus disease (COVID-19) after the fourth wave in order to explore unknown sources. Retrospective chart review on all the confirmed patients with COVID-19 admitted to the National Center for Global Health and Medicine (NCGM) in Tokyo, Japan was conducted from May 22 through June 29, 2021. Among the 22 participants, 14 (64%) had a history of known high-risk infection behaviors. Of those, 12 reported that their activities involved eating and drinking. In addition, there were 24 high-risk situations, of those, 21 (88%) were related to indoor dining, and masks were not worn in 22 situations (92%). New source of infection has not been identified. In situations with a high known risk of infection, many cases were related to eating and drinking, and insufficient use of masks was evident. Raising risk awareness on infection prevention and control of COVID-19 is urgently needed.

The Eastern and Western Association for Liver Tumors (EWALT) is an international association for clinical and basic scientists dedicated to worldwide study on hepatocellular carcinoma. A single topic conference of EWALT on "COVID-19 and Liver Surgery" was held online on April 23th, 2021. The presenters from France, Italy, Japan, and the United States, reported the current situation of COVID-19 in each country and the influence on the clinical practice and education in hepato-pancreato-biliary surgery. Here we would like to summarize the core of this single topic conference.

Civil Registration and Vital Statistics (CRVS) is an essential administrative system that provides legal identification to all individuals and accurate statistical data of vital events, such as birth and death rates within the population. Globally, CRVS has been considered a priority issue, especially for low- and middle-income countries where the coverage of this system is poor. This may be attributed to factors such as inefficiency of laws, poor inter-ministerial cooperation, and a lack of awareness among people. To address these issues and improve coverage of the CRVS, the health sector could play a key role by acting as an entry point, collecting accurate vital data, and utilizing information from CRVS. However, the function of the health sector in implementing CRVS has not been fully analyzed in most countries. Further investigation is necessary to develop effective measures to strengthen CRVS.

Thanks to technological advances in computers and communication, the Internet of Things (IoT) has been increasingly used in healthcare to foster digital health in several countries. In conjunction with this trend, cybersecurity has become a matter of paramount importance in terms of protecting healthcare services and health-related information from cyberattacks. With the spread of the COVID-19 pandemic, individuals are encountering false information on the Internet and social media. As a result, an infodemic, which involves people taking inappropriate actions that threaten their health, has occurred worldwide. Cyber public health is a concept that comprehensively encompasses the above issues from the viewpoint of health. This concept helps to prevent various attempts that adversely affect people’s health and it utilizes the advantages of cyber technology to promote public health. Cyber public health is also an important concept from the viewpoint of national security.