Age-specific Cancer Incidence Research Articles

No evidence that breast cancer occurs at higher rates among young Arab women

Background: Breast cancer is often thought to occur at a younger age among Arab women based on the mean or median age at diagnosis, or the proportion of women diagnosed with breast cancer at a young age. Objective: To compare age-specific breast cancer incidence rates among women from selected Arab countries with selected high- and middle-income countries. Methods: We examined population-based, age-specific, national or regional breast cancer incidence data for 2008–2012 and 2013–2017 from Australia, Brazil, Canada, Germany, Japan, United Kingdom, and United States of America, and compared them with data from Algeria, Bahrain, Jordan, Kuwait, Morocco, Qatar, and Saudi Arabia. Results: Breast cancer incidence among young women in the selected Arab countries was comparable to, or even lower than, the selected high- and middle-income countries. In contrast to the continued increase in rates observed in the high- and middle-income countries, the rates tended to plateau or decrease among older Arab women. Age-standardized incidence rates were lower than crude rates in the Arab countries. Conclusion: We found no evidence that Arab women are at higher risk of developing breast cancer at a younger age. The high number of cases among them was probably due to the younger population structure. These findings are important for refining breast cancer screening policies in the region.

Estimating the Proportion of Overdiagnosis among Prostate, Breast, and Thyroid Cancers in China: Findings from the Global Burden of Disease 2019.

The incidence of prostate, breast, and thyroid cancers has increased in China over the past few decades. Whether and how much these increases can be attributed to overdiagnosis are less understood. This study aimed to estimate the proportion of overdiagnosis among these three cancers in China during 2004-2019. The age-specific cancer incidence, cancer mortality, and all-cause mortality in China were extracted from the Global Burden of Diseases 2019. The lifetime risk of developing and that of dying from each cancer were calculated using the life table method. The proportion of overdiagnosis of a cancer was estimated as the difference between the lifetime risk of developing the cancer and that of suffering from the cancer (including death, metastasis, and symptoms caused by the cancer), further divided by the lifetime risk of developing the cancer. The highest possible values of these parameters were adopted in the estimation so as to obtain the lower bounds of the proportions of overdiagnosis. Sensitivity analyses assuming different lag periods between the diagnosis of a cancer and death from the cancer were performed. The results showed that the lifetime risk of developing prostate, breast, and thyroid cancer increased dramatically from 2004 to 2019 in China, while the increase in the lifetime risk of dying from these cancers was less pronounced. The proportions of overdiagnosis among prostate, breast, and thyroid cancers were estimated to be 7.88%, 18.99%, and 24.92%, respectively, in 2004, and increased to 18.20%, 26.25%, and 29.24%, respectively, in 2019. The increasing trends were statistically significant for all three cancers (all p < 0.001). In sensitivity analyses, the proportions of overdiagnosis decreased, but upward trends over time remained for all three cancers. In conclusion, the overdiagnosis of prostate, breast, and thyroid cancers in China increased from 2004 to 2019, with the highest proportion seen in thyroid cancer and the most rapid increase seen in prostate cancer. Multifaceted efforts by policy makers, guideline developers, and clinicians are needed to tackle this problem.

Age-specific colorectal cancer incidence trends in Canada, 1971–2021

IntroductionColorectal cancer (CRC) incidence among adults younger than 50 years has increased in recent decades, leading to some advocating for lowering the age to start CRC screening. Here, we estimate age-specific trends in CRC incidence in Canada and changes in risk by birth cohort. MethodsCRC incidence data from 1971 to 2021 by province, sex, and five-year age group (35−64) were obtained from the National Cancer Incidence Reporting System and the Canadian Cancer Registry. Annual percent changes in age-specific or age-adjusted incidence rates were analyzed with joinpoint regression. Birth cohort effect was estimated with age-period-cohort models and reported as cohort incidence rate ratios (IRRs) with respect to the 1947–51 cohort. ResultsCRC incidence has increased among all age groups under 50 years, with the largest relative increases occurring in the youngest age group (35–39 years). Males and females had similar incidence trends, though males under age 50 had larger increases than females. The birth cohort analysis showed that males born since 1966 have a significantly higher risk than those born at any other time. ConclusionsThese results up to 2021 confirm and update reports that CRC incidence is increasing among adults under age 50 in Canada and that the youngest birth cohorts carry the highest risk. Future studies should assess the effectiveness of CRC screening in younger populations.

Abstract B052: Ovarian cancer risk prediction: a systematic assessment of the state of the art and development of a new model

Abstract B052: Ovarian cancer risk prediction: a systematic assessment of the state of the art and development of a new model

Polygenic Risk Score, Environmental Tobacco Smoke, and Risk of Lung Adenocarcinoma in Never-Smoking Women in Taiwan

Estimating absolute risk of lung cancer for never-smoking individuals is important to inform lung cancer screening programs. To integrate data on environmental tobacco smoke (ETS), a known lung cancer risk factor, with a polygenic risk score (PRS) that captures overall genetic susceptibility, to estimate the absolute risk of lung adenocarcinoma (LUAD) among never-smokers in Taiwan. The analyses were conducted in never-smoking women in the Taiwan Genetic Epidemiology Study of Lung Adenocarcinoma, a case-control study. Participants were recruited between September 17, 2002, and March 30, 2011. Data analysis was performed from January 17 to July 15, 2022. A PRS was derived using 25 genetic variants that achieved genome-wide significance (P < 5 × 10-8) in a recent genome-wide association study, and ETS was defined as never exposed, exposed at home or at work, and exposed at home and at work. The Individualized Coherent Absolute Risk Estimator software was used to estimate the lifetime absolute risk of LUAD in never-smoking women aged 40 years over a projected 40-year span among the controls by using the relative risk estimates for the PRS and ETS exposures, as well as age-specific lung cancer incidence rates for never-smokers in Taiwan. Likelihood ratio tests were conducted to assess an additive interaction between the PRS and ETS exposure. Data were obtained on 1024 women with LUAD (mean [SD] age, 59.6 [11.4] years, 47.9% ever exposed to ETS at home, and 19.5% ever exposed to ETS at work) and 1024 controls (mean [SD] age, 58.9 [11.0] years, 37.0% ever exposed to ETS at home, and 14.3% ever exposed to ETS at work). The overall average lifetime 40-year absolute risk of LUAD estimated using PRS alone was 2.5% (range, 0.6%-10.3%) among women never exposed to ETS. When integrating both ETS and PRS data, the estimated absolute risk was 3.7% (range, 0.6%-14.5%) for women exposed to ETS at home or work and 5.3% (range, 1.2%-12.1%) for women exposed to ETS at home and work. A super-additive interaction between ETS and the PRS (P = 6.5 × 10-4 for interaction) was identified. This study found differences in absolute risk of LUAD attributed to genetic susceptibility according to levels of ETS exposure in never-smoking women. Future studies are warranted to integrate these findings in expanded risk models for LUAD.

Associations of increasing breast cancer incidence with the current drinking habits and the past smoking habits among Japanese women

Background We have reported that age-specific incidence rates of breast cancer among Japanese women increased from 2005 to 2015 in a bimodal distribution pattern, with two peaks in the pre- and postmenopausal age groups. Objectives The present study aimed to assess the associations of the increasing age-specific breast cancer incidence or mortality with the prevalence of obesity and drinking and smoking habits, compared with those in uterine body, female and male colon and lung cancers. Methods Linear correlations of annual rates from 2005 to 2015 of the 10-year age-specific cancer incidence and mortality with the prevalence of obesity (body mass index, 25 and over) and drinking (alcohol, 20 g and over 3 times or more a week) and smoking habits were assessed by Pearson’s correlation coefficients during the same 10-year period (from 2005 to 2015) or the 10-year period 10 years before the cancer incidence and mortality were noted (from 1995 to 2005). Results Positive correlations (r&gt;0.640) were found between the increasing breast cancer incidence and the drinking habit during the same period or the smoking habit during the period 10 years before. Similar but weaker correlations were found for the breast cancer mortality rate increasing with age. Positive correlations were found between the decreasing male lung cancer mortality rate and the smoking habit rate during the period 10 years before. Conclusions The present ecological study indicated that the breast cancer incidence was associated with the current drinking habits and the past smoking habits among Japanese women.

Modeling of senescent cell dynamics predicts a late-life decrease in cancer incidence.

Current oncogenic theories state that tumors arise from cell lineages that sequentially accumulate (epi)mutations, progressively turning healthy cells into carcinogenic ones. While those models found some empirical support, they are little predictive of intraspecies age-specific cancer incidence and of interspecies cancer prevalence. Notably, in humans and lab rodents, a deceleration (and sometimes decline) of cancer incidence rate has been found at old ages. Additionally, dominant theoretical models of oncogenesis predict that cancer risk should increase in large and/or long-lived species, which is not supported by empirical data. Here, we explore the hypothesis that cellular senescence could explain those incongruent empirical patterns. More precisely, we hypothesize that there is a trade-off between dying of cancer and of (other) ageing-related causes. This trade-off between organismal mortality components would be mediated, at the cellular scale, by the accumulation of senescent cells. In this framework, damaged cells can either undergo apoptosis or enter senescence. Apoptotic cells lead to compensatory proliferation, associated with an excess risk of cancer, whereas senescent cell accumulation leads to ageing-related mortality. To test our framework, we build a deterministic model that first describes how cells get damaged, undergo apoptosis, or enter senescence. We then translate those cellular dynamics into a compound organismal survival metric also integrating life-history traits. We address four different questions linked to our framework: can cellular senescence be adaptive, do the predictions of our model reflect epidemiological patterns observed among mammal species, what is the effect of species sizes on those answers, and what happens when senescent cells are removed? Importantly, we find that cellular senescence can optimize lifetime reproductive success. Moreover, we find that life-history traits play an important role in shaping the cellular trade-offs. Overall, we demonstrate that integrating cellular biology knowledge with eco-evolutionary principles is crucial to solve parts of the cancer puzzle.

Risk prediction models for endometrial cancer: development and validation in an international consortium.

Endometrial cancer risk stratification may help target interventions, screening, or prophylactic hysterectomy to mitigate the rising burden of this cancer. However, existing prediction models have been developed in select cohorts and have not considered genetic factors. We developed endometrial cancer risk prediction models using data on postmenopausal White women aged 45-85 years from 19 case-control studies in the Epidemiology of Endometrial Cancer Consortium (E2C2). Relative risk estimates for predictors were combined with age-specific endometrial cancer incidence rates and estimates for the underlying risk factor distribution. We externally validated the models in 3 cohorts: Nurses' Health Study (NHS), NHS II, and the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Area under the receiver operating characteristic curves for the epidemiologic model ranged from 0.64 (95% confidence interval [CI] = 0.62 to 0.67) to 0.69 (95% CI = 0.66 to 0.72). Improvements in discrimination from the addition of genetic factors were modest (no change in area under the receiver operating characteristic curves in NHS; PLCO = 0.64 to 0.66). The epidemiologic model was well calibrated in NHS II (overall expected-to-observed ratio [E/O] = 1.09, 95% CI = 0.98 to 1.22) and PLCO (overall E/O = 1.04, 95% CI = 0.95 to 1.13) but poorly calibrated in NHS (overall E/O = 0.55, 95% CI = 0.51 to 0.59). Using data from the largest, most heterogeneous study population to date (to our knowledge), prediction models based on epidemiologic factors alone successfully identified women at high risk of endometrial cancer. Genetic factors offered limited improvements in discrimination. Further work is needed to refine this tool for clinical or public health practice and expand these models to multiethnic populations.

Mathematical modeling the gene mechanism of colorectal cancer and the effect of radiation exposure.

Cancer is the result of continuous accumulation of gene mutations in normal cells. The number of mutations is different in different types of cancer and even in different patients with the same type of cancer. Therefore, studying all possible numbers of gene mutations in malignant cells is of great value for the understanding of tumorigenesis and the treatment of cancer. To this end, we applied a stochastic mathematical model considering the clonal expansion of any premalignant cells with different mutations to analyze the number of gene mutations in colorectal cancer. The age-specific colorectal cancer incidence rates from the Surveillance, Epidemiology and End Results (SEER) registry in the United States and the Life Span Study (LSS) in Nagasaki and Hiroshima, Japan are chosen to test the reasonableness of the model. Our fitting results indicate that the transformation from normal cells to malignant cells may undergo two to five driver mutations for colorectal cancer patients without radiation-exposed environment, two to four driver mutations for colorectal cancer patients with low level radiation-exposure, and two to three driver mutations for colorectal cancer patients with high level radiation-exposure. Furthermore, the net growth rate of the mutated cells with radiation-exposure was is higher than that of the mutated cells without radiation-exposure for the models with two to five driver mutations. These results suggest that radiation environment may affect the clonal expansion of cells and significantly affect the development of tumors.

Age-specific cancer incidence rates in children and adolescents in the world

Age-specific cancer incidence rates in children and adolescents in the world

The NCC mathematical modeling framework for decision-making of six major cancers

ObjectiveMathematical modeling and simulation is a useful research method to inform decision-making. This article aims to describe the National Cancer Center (NCC) modeling framework and how well it reproduces observed empirical data for six major cancers. MethodsWe developed the NCC modeling framework for six major cancers in China (lung, liver, stomach, colorectal, esophageal, and breast), which simulates the life-histories represented by states among normal, precancerous lesion, stage-specific invasive cancer, and death for six cancers separately. Each NCC simulation model could be illustrated as an integrated framework of 3 modules: a demography module, natural history module, and screening module. Combined with costs and health utilities data, the models could have many detailed outputs for informing decisions, including the harm of screening (e.g., false positives, complications, and overdiagnosis), healthcare costs, and benefits (quality-adjusted life years gained, cancer incidence and mortality, and investment returns). We calibrated the models to Chinese population-based observations on cancer incidence, mortality, and stage distribution. All models are validated by comparing model simulated results to data observed from nationwide cancer registration and a large prospective cohort study. ResultsThe simulated results from the calibrated models consistently match the epidemiological patterns in six major cancer incidence, mortality, and stage distributions in China. Model projected age-specific cancer incidence and mortality were close to the observed data in the national cancer registration. The NCC modeling framework reproduced the cumulative cancer cases and deaths observed in the prospective cohort study at 7.0 and 10.8 years of follow-up. Model estimated net survival rates also consistent with population-based statistics. ConclusionThe NCC modeling framework's ability to reproduce the observed population-level cancer statistics and the cancer cases in a prospective cohort study suggests its results are reliable to inform decision-making related to six major cancers in China.

Incidence of Cancer in Nepal: A Three-Year Trend Analysis

Background: Cancer is a major public health problem in the world. This study aims to present a three-year trend of cancer incidence in Nepal. &#x0D; Methods: This study used the three-year data of National Cancer Registry Program (NCRP) from January 2013 to December 2015. NCRP currently includes 12 major hospitals where diagnostic treatment facilities are available and represent the majority of the cases in Nepal. Descriptive analysis was used to present the demographic profile of the participants and the incidence of different topography of cancer. Age-specific and age-adjusted cancer incidence per 100,000 population were presented. &#x0D; Results: A total of 27,483 new cancer cases were included in the study. The age-adjusted incidence rates were 39.1, 39.8 and 41.8 per 100,000 population in the year 2013, 2014 and 2015 respectively. The most common cancer in Nepal was lung followed by cervical, breast, stomach and colorectal cancer. Among males, lung cancer was the most common followed by lip and oral cavity, stomach, colorectal cancer and leukemia and among females, cervical cancer followed by breast, lung, ovary and stomach. &#x0D; Conclusion: Cancer incidence is rising in Nepal and thus comprehensive policies targeting prevention, early detection, and treatment programs should be carried out.

ON RADIATION-INDUCED AGING: ACCELERATED OR PREMATURE AGING.

The concept of radiation-induced aging is revisited from the viewpoint of a mathematical model. The effect of radiation on carcinogenesis is treated based on the Armitage-Doll multi-stage theory. The formula obtained for cancer incidence rate indicates that radiation dose can be explained in terms of time. Radiation-induced aging for acute and chronic exposures is described using age-specific cancer incidence rates as a measure of aging. It shows that accelerated aging is related to the dose rate, whereas premature aging is related to the cumulative dose, providing a simple and natural interpretation of radiation-induced aging. The usefulness of this approach is demonstrated by applying the formula to cancer prevalence data from mice chronically exposed to low dose-rate radiation.

Abstract 2254: Risk models for lung cancer in never-smoking women in Shanghai with implications for screening

Abstract Background: The majority of female lung cancer cases in Asia are never-smokers with distinct risk factor profiles. Given the high burden of disease in this population, there is an increasing need to improve the understanding of lung cancer. Current risk models for lung cancer focus on active smokers and individuals of European ancestry. Therefore, we developed statistical models by integrating genetic and environmental risk factors to estimate absolute and population attribute risk of lung cancer among never-smoking women in Asia. Methods: We built absolute risk models for lung cancer among never-smoking women using data from 71,300 women (760 incident cases) in the Shanghai Women’s Health Study (SWHS), a population-based prospective cohort study. Relative risks were estimated using a multivariable Cox regression model with questionnaire-based risk factors. To account for missing genetic data for some subjects, we simulated genotypes for 10 common single nucleotide polymorphisms (SNP) using information on minor allele frequencies (MAF) and odds ratio estimates from previous genome-wide association studies (GWAS), conditional on family history of lung cancer. We used the iCARE tool to build two models for predicting lifetime (40 years) and 6-year absolute risk of lung cancer using age-specific lung cancer incidence rates, age-specific competing mortality rates, and risk factor distribution with: 1) questionnaire-based risk factors only and 2) questionnaire and genetic data. We then used the full absolute risk model to estimate the population attributable risk (PAR) due to modifiable risk factors, namely coal use and exposure to environmental tobacco smoke (ETS). Results: The questionnaire-based only model included family history of lung cancer, coal use, exposure to ETS, and body mass index (BMI). The full model also included data on 10 lung cancer related SNPs from our previous GWAS and had a wider spread in distribution of absolute lifetime risk (median=2.41%; range=0.43-12.36) compared to the questionnaire-based only model (median=2.72%; range=1.93-4.87). We used the full model to estimate the PAR and found that 1.74% and 6.33% of lung cancer cases could be prevented if never-smoking women in Shanghai did not use coal and were not exposed to ETS, respectively. Furthermore, we found that the full model estimated that 2.5% of the study population had a 6-year absolute risk of lung cancer higher than 1.51%, which is the suggested risk threshold for screening by existing risk models. Conclusion: We built risk models for never-smoking Asian women and estimated the contribution of coal use and ETS to the burden of lung cancer in Shanghai. This initial work shows promise for expanding and validating risk models in this population with potential translational implications, such as providing insight to identifying high risk individuals that may be eligible for lung cancer screening and primary prevention efforts. Citation Format: Batel Blechter, Parichoy Pal Choudhury, Xiao-ou Shu, Wei Zheng, Qiuyin Cai, Gong Yang, Jason Y.Y. Wong, Bu-Tian Ji, Wei Hu, Anne Rositch, Nilanjan Chatterjee, Nathaniel Rothman, Qing Lan. Risk models for lung cancer in never-smoking women in Shanghai with implications for screening [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2254.

Abstract 2740: Stochastic modeling uncovers the interplay between early cancer progression and adaptive immune-specific cancer escape

Abstract The lack of durable therapeutic interventions continues to limit cancer treatment efficacy. While breakthroughs in immunotherapy have improved patient survival for some disease subtypes, immune escape is an unfortunate and common hallmark of cancer evasion. Understanding the dynamic interplay between an evolving and heterogeneous malignant population and the adaptive immune system, consisting of millions of unique T cells, is therefore required for designing optimized treatment strategies. We begin by describing the implications of cancer escape via durable evasion events, such as major histocompatibility antigen presentation down-regulation. Durable escape is then applied to relate observed cancer age-specific incidence to physiologic impairments in T cell turnover and diversity. We then discuss a more generalized stochastic process that enables transient escape and recurrent recognition via distinct T cell subclones. This co-evolutionary model predicts repeated immune recognition and cancer evasion prior to disease manifestation. Using this model, we find that T cell turnover and cancer mutation rates explain differences in early age incidence data across nearly all cancer types. Lastly, we introduce a modeling approach for understanding the extent of optimality occurring in cancer evasion via tumor-associated antigen downregulation, emphasizing the utility of foundational modeling frameworks for optimizing cancer T cell immunotherapy. Citation Format: Jason T. George. Stochastic modeling uncovers the interplay between early cancer progression and adaptive immune-specific cancer escape [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2740.

Recent Increase in the Breast Cancer Incidence Among Japanese Women Seems to Correlate With the Prevalence of Drinking and Smoking Habits, but Not Obesity, as a Modern Lifestyle

ObjectivesWe have recently reported that age-specific incidence rates of breast cancer among Japanese women clearly increased from 2000 to 2015 in a bimodal distribution pattern with two peaks at the age groups of 45 to 49 and 60 to 64 years. The present study aimed to assess the association of age-specific breast cancer incidence rates with the prevalence of obesity and drinking and smoking habits among Japanese women, compared with those of uterine body, colon and lung cancers. MethodsAge-specific cancer incidence and mortality rates and the prevalence of obesity and drinking and smoking habits were obtained from national data published by Cancer Information Services or National Institute of Health and Nutrition of Japan. Linear correlations of annual rates from 2005 to 2015 of the 10-year age-specific cancer incidence and mortality with the prevalence of obesity (body mass index, 25 and over) and drinking (alcohol, 20g and over 3 times or more a week) and smoking habits during the same 10-year period or the 10-year period 10 years before the cancer incidence and mortality were assessed by Pearson’s correlation coefficients. ResultsSignificant (p < 0.05) and positive correlations were found between breast cancer incidence and drinking habits during the same period at the age of 50–59 (r = 0.901), 60–69 (r = 0.808) and 70–79 years (r = 0.643) and during the 10-year-before period at 50–59 (r = 0.676); between the incidence and smoking habits during the 10-year-before period at 40–49 (r = 0.897), 50–59 (r = 0.731) and 60–69 (r = 0.696); between the mortality and drinking habits during the same period at 30–39 (r = 0.739), 60–69 (r = 0.817) and 70–79 (r = 712); and between the mortality and smoking habits during the same period at 30–39 (r = 0.733) and during the 10-year-before period at 60–69 (r = 0.663). Similar but less positive correlations for uterine body cancer or more positive correlations for male lung cancer were found. The prevalence of male drinking and smoking habits was decreasing during the 20 years. No positive correlations were found between the breast cancer incidence or mortality and the prevalence of obesity. ConclusionsThe present ecological study demonstrated that the prevalence of drinking and smoking habits, but not obesity, as a modern lifestyle correlated with the recent increase in the age-specific breast cancer incidence among Japanese women. Funding SourcesNone.

Incidence and mortality of cervical cancer in China in 2015

ObjectiveTo estimate the incidence and mortality of cervical cancer in China based on the cancer registration data in 2015, collected by the National Central Cancer Registry (NCCR). MethodsThere were 501 cancer registries that submitted data to the NCCR, whose data were the basis for estimating the incidence and mortality of cervical cancer in China in 2015. After evaluating the data quality, 368 registries’ data were accepted for the analysis and stratified by area (urban/rural) and age group. Combined with data on the national population in 2015, the nationwide incidence and mortality of cervical cancer were estimated. Cervical Cancer cases of 22 cancer registries were applied for temporal trends from 2000 to 2015. The Chinese population census in 2000 and Segi's population were used to calculate age-standardized incidence and mortality rates. ResultsAn estimated 111,000 new cases were attributed to cervical cancer in China in 2015, accounting for 6.24% of all female new cancer cases in that year in China. The crude rate (CR) of incidence and age-standardized incidence rates by the China standard population (ASIRC) and by Segi's world standard population (ASIRW) of cervical cancer were 16.56/100,000, 11.78/100,000, and 10.86/100,000, respectively. The cumulative incidence rate from birth to 74 years old was 1.15%, whereas the calculation of incidence rates over the truncated age range of 35-64 years by Segi's world standard population (T-ASIRW) was 27.66/100,000. The estimates of cervical cancer deaths were about 33,800 and 3.94% of all female cancer-related deaths in China in 2015, with a crude mortality rate of 5.04/100,000. The age-standardized mortality rates adjusted by the Chinese standard population (ASMRC) and by world Segi's population (ASMRW) were 3.29/100,000 and 3.15/100,000, respectively, with a cumulative mortality rate (0-74 years old) of 0.35%. Both the incidence and mortality were higher in rural than in urban areas. The age-specific cervical cancer incidence significantly increased with age, particularly after age 25 years, and peaked at 50–54 years old, whereas age-specific mortality increased rapidly after 35 years old, peaking at 80–84 years old. The age-standardized incidence rates increased by about 8.6 (95% CI: 6.9, 10.3) per year during the period of 2000−2015. The age at diagnosis of patients with cervical cancer tended to be younger. In rural areas, the mean age at diagnosis decreased about 3.22 years from 2000 to 2015 (β = –0.33, P < 0.001). ConclusionsChina has a high burden of cervical cancer and important disparities among different regions. Especially in the middle and western areas and rural areas, cervical cancer is a serious issue in women's health, and prevention strategies need to be enhanced. Prevention and control strategies need to be enhanced and implemented with reference to local status, such as human papillomavirus (HPV) vaccination and screening programs.

Fractions and trends of cancer burden attributable to population ageing in China

Objective: To analyse the fractions and trends of cancer burden attributable to population ageing, adult population size, age-specific incidence and case fatality rate in China between 1990 and 2019. Methods: We extracted data from the database of Global Disease Burden Study, including the number of cancer cases, deaths and corresponding population of 29 cancer types for Chinese adults aged 25 years and older from 1990 to 2019. Using the cancer deaths in 1990 as a reference, we employed a decomposition method to express cancer deaths as the product of four factors among men and women from 1991 to 2019. The fractions attributable to cancer deaths among total cancer deaths in that year were calculated and its time trends were assessed. Results: In 2019, we estimated that there were 2 690 000 cancer deaths among adults aged 25 and older in China. Of which, cancer deaths attributable to population ageing, adult population size, age-specific cancer incidence and case fatality rate were 740 000 (27.5% of total cancer deaths in 2019), 1 091 000 (40.6%), 198 000 (7.3%) and -728 000 (-27.1%), respectively. In 2019, lung cancer, stomach cancer, esophageal cancer, liver cancer and colorectal cancer ranked the top five cancers among population ageing attributable to cancer deaths. For 29 cancer types, the fractions of population ageing attributable to cancer deaths among total deaths of that cancer were ranged from 9.3% to 40.5%. The ageing attributable to cancer deaths and its fractions were increased rapidly since 1997, while those estimates were negative before 1997. Conclusions: The population ageing process in China was one of the major contributors to the increase in cancer burden in recent years, which has caused more cancer deaths than that by age-specific cancer incidence. Accordingly, activities toward healthy ageing would be the key to cancer prevention and control.

Age-specific lip, oral cavity and pharynx cancer incidence rate in the world

Age-specific lip, oral cavity and pharynx cancer incidence rate in the world

Global, Regional, and National Lifetime Probabilities of Developing Cancer in 2020

Background: The lifetime risk of cancer is a measure of the cumulative impact of cancer across a defined age span, and has obvious intuitive appeal. There are however few examples of its systematic use in comparative assessments of cancer-specific risk across populations. We therefore sought to estimate and interpret the lifetime and age-conditional probabilities of developing cancer at the country, world region and global level in 2020. Methods: We obtained estimates of sex- and age-specific cancer incidence rates from GLOBOCAN for 185 countries for the year 2020, alongside all-cause mortality and population data from the United Nations. Countries were categorized into quartiles of the Human Development Index (HDI) as developed by the United Nations Development Programme. The lifetime risk of cancer was estimated using the adjusted for multiple primaries (AMP) method, taking into account competing risks of death from causes other than cancer as well as average life expectancy. Findings: In 2020, the estimated global lifetime risk of cancer from birth to death was 25.1% (26.3% in men and 24.0% in women) . There were marked differences in risks between countries within world regions and by level of human development. In very high HDI, high HDI, medium HDI and low HDI countries, the lifetime risk of cancer was 38.5%, 25.4%, 11.4%, and 10.3%, respectively, with cancer risks highest in Ireland (49.7%) and lowest in Central African Republic (6.6%). There was similar heterogeneity according to cancer type by sex. Worldwide, prostate cancer and breast cancer were associated with the greatest lifetime risks among men and women, of 4.6% and 5.9% respectively. The lifetime risk of cancer decreased by age, with a remaining risk of 12.6% from the age 70 years. Interpretation: In 2020, the global lifetime risk of cancer from birth to death translates approximately 1 in 4 persons developing cancer, with men and women having similar levels of lifetime risk. The identified age-specific variations in cancer risk at the population level can provide important information to support the targeted cancer prevention and health systems planning. Funding: National Key R&D Program of China, National Natural Science Foundation of China, and Beijing Nova Program Declaration of Interest: All authors declare no competing interests.