Ethnic disparities in cancer mortality in the capital and northeast of the State of São Paulo, Brazil 2001-17

PURPOSE

There is a paucity of studies investigating cancer disparities in groups defined by ethnicity in transitioning economies. We examined the influence of ethnicity on mortality for the leading cancer types in São Paulo, Brazil, comparing patterns in the capital and the northeast of the state.

METHODS

Cancer deaths were obtained from a Brazilian public government database for the Barretos region (2003-2017) and the municipality of São Paulo (2001-2015). Age-standardized rates (ASR) per 100,000 persons-years, by cancer type and sex, for five self-declared racial classifications (white, black, eastern origin (Asian), mixed ethnicity (pardo), and indigenous Brazilians), were calculated using the world standard population.

RESULTS

Black Brazilians had higher mortality rates for most common cancer types in Barretos, whereas in São Paulo, white Brazilians had higher rates of mortality from breast, colorectal, and lung cancer. In both regions, lung cancer was the leading cause of cancer death among white, black, and pardo Brazilians, with colorectal cancer deaths leading among Asian Brazilians. Black and pardo Brazilians had higher cervical cancer mortality rates than white Brazilians.

CONCLUSION

There are substantial disparities in mortality from different cancers in São Paulo according to ethnicity, pointing to inequities in access to health care services.

Global epidemiologic patterns of oropharyngeal cancer incidence trends

BACKGROUND

The emergence of human papillomavirus (HPV)-positive oropharyngeal cancer and evolving tobacco use patterns have changed the landscape of head and neck cancer epidemiology internationally. We investigated updated trends in oropharyngeal cancer incidence worldwide.

METHODS

We analyzed cancer incidence data between 1993 and 2012 from 42 countries using the Cancer Incidence in Five Continents database volumes V through XI. Trends in oropharyngeal cancer incidence were compared with oral cavity cancers and lung squamous cell carcinomas using log-linear regression and age period-cohort modeling.

RESULTS

In total, 156 567 oropharyngeal cancer, 146 693 oral cavity cancer, and 621 947 lung squamous cell carcinoma patients were included. Oropharyngeal cancer incidence increased (P < .05) in 19 and 23 countries in men and women, respectively. In countries with increasing male oropharyngeal cancer incidence, all but 1 had statistically significant decreases in lung squamous cell carcinoma incidence, and all but 2 had decreasing or nonsignificant net drifts for oral cavity cancer. Increased oropharyngeal cancer incidence was observed both in middle-aged (40-59 years) and older (≥60 years) male cohorts, with strong nonlinear birth cohort effects. In 20 countries where oropharyngeal cancer incidence increased for women and age period-cohort analysis was possible, 13 had negative or nonsignificant lung squamous cell carcinoma net drifts, including 4 countries with higher oropharyngeal cancer net drifts vs both lung squamous cell carcinoma and oral cavity cancer (P < .05 for all comparisons).

CONCLUSIONS

Increasing oropharyngeal cancer incidence is seen among an expanding array of countries worldwide. In men, increased oropharyngeal cancer is extending to older age groups, likely driven by human papillomavirus-related birth cohort effects. In women, more diverse patterns were observed, suggesting a complex interplay of risks factors varying by country, including several countries where female oropharyngeal cancer increases may be driven by HPV.

Mortality among papillary thyroid cancer patients by detection route: a hospital-based retrospective cohort study

Background

Incidence rates of papillary thyroid cancer (PTC) have increased rapidly, with incidentally detected cancers contributing a large proportion. We aimed to explore the impact of incidental detection on thyroid cancer-specific and competing mortality among PTC patients.

Methods

We conducted a retrospective cohort study of PTC patients at a cancer center in Guangzhou. Baseline information on detection route and other covariates were collected between 2010 and 2018, and death outcome was followed up for each patient. Cumulative incidence functions were used to estimate the mortality risk of thyroid cancer and competing risk. Cause-specific hazard models were then utilized to explore the association between detection routes and PTC-specific and competing mortality.

Results

Of the 2874 patients included, 2011 (70.0%) were detected incidentally, and the proportion increased from 36.9% in 2011 to 82.3% in 2018. During a median follow-up of 5.6 years, 42 deaths occurred, with 60% of them due to competing causes. The probability of competing mortality at 5 years in the non-incidental group and incidental group was 1.4% and 0.4%, respectively, and PTC-specific mortality in the non-incidental group and incidental group was 1.0% and 0.1%, respectively. After adjusting for covariates, the HRs of incidental detection were 0.13 (95% CI: 0.04-0.46; P = 0.01) and 0.47 (95% CI: 0.20-1.10; P = 0.10) on PTC-specific mortality and competing mortality, respectively.

Conclusions

Incidental detection is associated with a lower risk of PTC-specific and competing mortality. Under the context of increasing magnitude of overdiagnosis, incorporation of detection route in clinical decision-making might be helpful to identify patients who might benefit from more extensive or conservative therapeutic strategies.

Global variations in lung cancer incidence by histological subtype in 2020: a population-based study

BACKGROUND

Lung cancer is the second most common cancer worldwide, yet the distribution by histological subtype remains unknown. We aimed to quantify the global, regional, and national burden of lung cancer incidence for the four main subtypes in 185 countries and territories.

METHODS

In this population-based study, we used data from Cancer Incidence in Five Continents Volume XI and the African Cancer Registry Network to assess the proportions of adenocarcinoma, squamous cell carcinoma, small-cell carcinoma, and large-cell carcinoma among all lung cancers by country, sex, and age group and subsequently applied these data to corresponding national (GLOBOCAN) estimates of lung cancer incidence in 2020. Unspecified morphologies were reallocated to specified subtypes. Age-standardised incidence rates were calculated using the world standard population to compare subtype risks worldwide, adjusted for differences in age composition between populations by country.

FINDINGS

In 2020, there were an estimated 2 206 771 new cases of lung cancer, with 1 435 943 in males and 770 828 in females worldwide. In males, 560 108 (39%) of all lung cancer cases were adenocarcinoma, 351 807 (25%) were squamous cell carcinoma, 163 862 (11%) were small-cell carcinoma, and 115 322 (8%) were large-cell carcinoma cases. In females, 440 510 (57%) of all lung cancer cases were adenocarcinoma, 91 070 (12%) were squamous cell carcinoma, 68 224 (9%) were small-cell carcinoma, and 49 246 (6%) were large-cell carcinoma cases. Age-standardised incidence rates for adenocarcinoma, squamous cell carcinoma, small-cell carcinoma, and large-cell carcinoma, respectively, were estimated to be 12·4, 7·7, 3·6, and 2·6 per 100 000 person-years in males and 8·3, 1·6, 1·3, and 0·9 per 100 000 person-years in females worldwide. The incidence rates of adenocarcinoma exceeded those of squamous cell carcinoma in 150 of 185 countries in males and in all 185 countries in females. The highest age-standardised incidence rates per 100 000 person-years for adenocarcinoma, squamous cell carcinoma, small-cell carcinoma, and large-cell carcinoma, respectively, for males occurred in eastern Asia (23·5), central and eastern Europe (17·5), western Asia (7·2), and south-eastern Asia (11·0); and for females occurred in eastern Asia (16·0), northern America (5·4), northern America (4·7), and south-eastern Asia (3·4). The incidence of each subtype showed a clear gradient according to the Human Development Index for male and female individuals, with increased rates in high and very high Human Development Index countries.

INTERPRETATION

Adenocarcinoma has become the most common subtype of lung cancer globally in 2020, with incidence rates in males exceeding those of squamous cell carcinoma in most countries, and in females in all countries. Our findings provide new insights into the nature of the global lung cancer burden and facilitates tailored national preventive actions within each world region.

FUNDING

None.

Thyroid Cancer Incidence and Mortality by Socioeconomic Level in the State of São Paulo, Brazil 2001-2017

OBJECTIVE

Thyroid cancer is rising largely due to greater detection of indolent or slow-growing tumors; we sought to compare the incidence and mortality profiles of thyroid cancer in the State of São Paulo by socioeconomic status (SES).

METHODS

Data on thyroid cancer cases diagnosed from 2003 to 2017 in the Barretos Region and from 2001 to 2015 in the municipality of São Paulo were obtained from the respective cancer registries. Corresponding death data were obtained from a Brazilian public government database. Age-standardized rates were calculated and presented as thematic maps. The rates were also calculated by SES and spatial autocorrelation was assessed by global and local indices.

RESULTS

There were 419 cases of thyroid cancer and 21 deaths in Barretos, contrasting with the highly populated São Paulo, with 30 489 cases and 673 deaths. The overall incidence rates in São Paulo (15.9) were three times higher than in Barretos (5.7), while incidence rates in women were close to five times higher in Barretos and four times higher in São Paulo than in men. Mortality rates were, in relative terms, very low in both regions. A clear stepwise gradient of increasing thyroid cancer incidence with increasing SES was observed in São Paulo, with rates in very high SES districts four times those of low SES (31.6 vs 8.1). In contrast, the incidence rates in Barretos presented little variation across SES levels.

CONCLUSION

Thyroid cancer incidence varied markedly by SES in São Paulo, with incidence rates rising with increasing socioeconomic index. Overdiagnosis is likely to account for a large proportion of the thyroid cancer burden in the capital.

The Economic Cost of Thyroid Cancer in France and the Corresponding Share Associated With Treatment of Overdiagnosed Cases

OBJECTIVES

Thyroid cancer incidence in France has increased rapidly in recent decades. Most of this increase has been attributed to overdiagnosis, the major consequence of which is overtreatment. We aimed to estimate the cost of thyroid cancer management in France and the corresponding cost proportion attributable to the treatment of overdiagnosed cases.

METHODS

Multiple data sources were integrated: the mean cost per patient with thyroid cancer was estimated by using the Echantillon Généraliste des Bénéficiaires data set; thyroid cancer cases attributable to overdiagnosis were estimated for 21 departments using data from the French network of cancer registries and extrapolated to the whole country; medical records from 6 departments were used to refine the diagnosis and care pathway.

RESULTS

Between 2011 and 2015, 33 911 women and 10 846 men in France were estimated to be diagnosed of thyroid cancer, with mean cost per capita of €6248. Among those treated, 8114 to 14 925 women and 1465 to 3626 men were due to overdiagnosis. The total cost of thyroid cancer patient management was €203.5 million (€154.3 million for women and €49.3 million for men), of which between €59.9 million (or 29.4% of the total cost, lower bound) and €115.9 million (or 56.9% of the total cost, upper bound) attributable to treatment of overdiagnosed cases.

CONCLUSIONS

The management of thyroid cancer represents not only a relevant clinical and public health problem in France but also a potentially important economic burden. Overdiagnosis and corresponding associated treatments play an important role on the total costs of thyroid cancer management.

Cancer inequalities in incidence and mortality in the State of São Paulo, Brazil 2001-17

BACKGROUND

Cancer disparities exist between and within countries; we sought to compare cancer-specific incidence and mortality according to area-level socioeconomic status (SES) in the State of São Paulo, Brazil.

METHODS

Cancer cases diagnosed 2003-2017 in the Barretos region and 2001-2015 in the municipality of São Paulo were obtained from the respective cancer registries. Corresponding cancer deaths were obtained from a Brazilian public government database. Age-standardized rates for all cancer combined and the six most common cancers were calculated by SES quartiles.

RESULTS

There were 14,628 cancer cases and 7513 cancer deaths in Barretos, and 472,712 corresponding cases and 194,705 deaths in São Paulo. A clear SES-cancer gradient was seen in São Paulo, with rates varying from 188.4 to 333.1 in low to high SES areas, respectively. There was a lesser social gradient for mortality, with rates in low to high SES areas ranging from 86.4 to 98.0 in Barretos, and from 99.2 to 100.1 in São Paulo. The magnitude of the incidence rates rose markedly with increasing SES in São Paulo city for colorectal, lung, female breast, and prostate cancer. Conversely, both cervical cancer incidence and mortality rose with lower levels of SES in both regions.

CONCLUSIONS

A clear SES association was seen for cancers of the prostate, female breast, colorectum, and lung for São Paulo. This study offers a better understanding of the cancer incidence and mortality profile according to SES within a highly populated Brazilian state.

Trends in radioactive iodine treatment after total thyroidectomy in Italy, 2001-2018

Objective

A decrease in the use of radioactive iodine (RAI) treatment for thyroid cancer has been described in the last decade in the US following subsequent updates of the American Thyroid Association guidelines. By contrast, population-based data from European countries are lacking. The study aims to assess the frequency and long-term trends in the use of RAI in Italy.

Methods

From the Italian national hospital discharge database, the proportion of RAI treatment after total thyroidectomy with thyroid cancer diagnosis has been assessed by sex and age class during 2001-2018.

Results

Throughout the whole study period, RAI was performed after 58% of 149,419 total thyroidectomies. The use of RAI was higher for men and younger patients; it peaked in 2007 (64% in women and 68% in men) and declined thereafter (2018: 46% in women and 53% in men), with a similar pattern observed across all ages and areas.

Conclusion

National data show that in Italy trends in RAI treatment paraleled those observed in the US. Further monitoring of the use of RAI is warranted in Italy, as elsewhere, to assess the impact of international guidelines on real-life clinical management of thyroid cancer.

Socioeconomic inequalities in cancer mortality between and within countries in Europe: a population-based study

Background

Reducing socioeconomic inequalities in cancer is a priority for the public health agenda. A systematic assessment and benchmarking of socioeconomic inequalities in cancer across many countries and over time in Europe is not yet available.

Methods

Census-linked, whole-of-population cancer-specific mortality data by socioeconomic position, as measured by education level, and sex were collected, harmonized, analysed, and compared across 18 countries during 1990-2015, in adults aged 40-79. We computed absolute and relative educational inequalities; temporal trends using estimated-annual-percentage-changes; the share of cancer mortality linked to educational inequalities.

Findings

Everywhere in Europe, lower-educated individuals have higher mortality rates for nearly all cancer-types relative to their more highly-educated counterparts, particularly for tobacco/infection-related cancers [relative risk of lung cancer mortality for lower- versus higher-educated = 2.4 (95% confidence intervals: 2.1-2.8) among men; = 1.8 (95% confidence intervals: 1.5-2.1) among women]. However, the magnitude of inequalities varies greatly by country and over time, predominantly due to differences in cancer mortality among lower-educated groups, as for many cancer-types higher-educated have more similar (and lower) rates, irrespective of the country. Inequalities were generally greater in Baltic/Central/East-Europe and smaller in South-Europe, although among women large and rising inequalities were found in North-Europe (relative risk of all cancer mortality for lower- versus higher-educated ≥1.4 in Denmark, Norway, Sweden, Finland and the England/Wales). Among men, rate differences (per 100,000 person-years) in total-cancer mortality for lower-vs-higher-educated groups ranged from 110 (Sweden) to 559 (Czech Republic); among women from approximately null (Slovenia, Italy, Spain) to 176 (Denmark). Lung cancer was the largest contributor to inequalities in total-cancer mortality (between-country range: men, 29-61%; women, 10-56%). 32% of cancer deaths in men and 16% in women (but up to 46% and 24%, respectively in Baltic/Central/East-Europe) were associated with educational inequalities.

Interpretation

Cancer mortality in Europe is largely driven by levels and trends of cancer mortality rates in lower-education groups. Even Nordic-countries, with a long-established tradition of equitable welfare and social justice policies, witness increases in cancer inequalities among women. These results call for a systematic measurement, monitoring and action upon the remarkable socioeconomic inequalities in cancer existing in Europe.

Funding

This study was done as part of the LIFEPATH project, which has received financial support from the European Commission (Horizon 2020 grant number 633666), and the DEMETRIQ project, which received support from the European Commission (grant numbers FP7-CP-FP and 278511). SV and WN were supported by the French Institut National du Cancer (INCa) (Grant number 2018-116). PM was supported by the Academy of Finland (#308247, # 345219) and the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement No 101019329). The work by Mall Leinsalu was supported by the Estonian Research Council (grant PRG722).

Global estimates of incidence and mortality of cervical cancer in 2020: a baseline analysis of the WHO Global Cervical Cancer Elimination Initiative

BACKGROUND

Tracking progress and providing timely evidence is a fundamental step forward for countries to remain aligned with the targets set by WHO to eliminate cervical cancer as a public health problem (ie, to reduce the incidence of the disease below a threshold of 4 cases per 100 000 women-years). We aimed to assess the extent of global inequalities in cervical cancer incidence and mortality, based on The Global Cancer Observatory (GLOBOCAN) 2020 estimates, including geographical and socioeconomic development, and temporal aspects.

METHODS

For this analysis, we used the GLOBOCAN 2020 database to estimate the age-specific and age-standardised incidence and mortality rates of cervical cancer per 100 000 women-years for 185 countries or territories aggregated across the 20 UN-defined world regions, and by four-tier levels of the Human Development Index (HDI). Time trends (1988-2017) in incidence were extracted from the Cancer Incidence in Five Continents (CI5) plus database. Mortality estimates were obtained using the most recent national vital registration data from WHO.

FINDINGS

Globally in 2020, there were an estimated 604 127 cervical cancer cases and 341 831 deaths, with a corresponding age-standardised incidence of 13·3 cases per 100 000 women-years (95% CI 13·3-13·3) and mortality rate of 7·2 deaths per 100 000 women-years (95% CI 7·2-7·3). Cervical cancer incidence ranged from 2·2 (1·9-2·4) in Iraq to 84·6 (74·8-94·3) in Eswatini. Mortality rates ranged from 1·0 (0·8-1·2) in Switzerland to 55·7 (47·7-63·7) in Eswatini. Age-standardised incidence was highest in Malawi (67·9 [95% CI 65·7 -70·1]) and Zambia (65·5 [63·0-67·9]) in Africa, Bolivia (36·6 [35·0-38·2]) and Paraguay (34·1 [32·1-36·1]) in Latin America, Maldives (24·5 [17·0-32·0]) and Indonesia (24·4 [24·2-24·7]) in Asia, and Fiji (29·8 [24·7-35·0]) and Papua New Guinea (29·2 [27·3-31·0]) in Melanesia. A clear socioeconomic gradient exists in cervical cancer, with decreasing rates as HDI increased. Incidence was three times higher in countries with low HDI than countries with very high HDI, whereas mortality rates were six times higher in low HDI countries versus very high HDI countries. In 2020 estimates, a general decline in incidence was observed in most countries of the world with representative trend data, with incidence becoming stable at relatively low levels around 2005 in several high-income countries. By contrast, in the same period incidence increased in some countries in eastern Africa and eastern Europe. We observed different patterns of age-specific incidence between countries with well developed population-based screening and treatment services (eg, Sweden, Australia, and the UK) and countries with insufficient and opportunistic services (eg, Colombia, India, and Uganda).

INTERPRETATION

The burden of cervical cancer remains high in many parts of the world, and in most countries, the incidence and mortality of the disease remain much higher than the threshold set by the WHO initiative on cervical cancer elimination. We identified substantial geographical and socioeconomic inequalities in cervical cancer globally, with a clear gradient of increasing rates for countries with lower levels of human development. Our study provides timely evidence and impetus for future strategies that prioritise and accelerate progress towards the WHO elimination targets and, in so doing, address the marked variations in the global cervical cancer landscape today.

FUNDING

French Institut National du Cancer, Horizon 2020 Framework Programme for Research and Innovation of the European Commission; and EU4Health Programme.

Response to Toshihide Tsuda, Yumiko Miyano and Eiji Yamamoto [1]

BACKGROUND

Using a toolkit approach, Tsuda et al. critiqued work carried out by or in collaboration with the International Agency for Research on Cancer (IARC/WHO), including the IARC technical publication No. 46 on "Thyroid health monitoring after nuclear accidents" (TM-NUC), the project on nuclear emergency situations and improvement on medical and health surveillance (SHAMISEN), and the IARC-led work on global thyroid cancer incidence patterns as per IARC core mandate.

MAIN BODY

We respond on the criticism of the recommendations of the IARC technical publication No. 46, and of global thyroid cancer incidence evaluation.

CONCLUSION

After nuclear accidents, overdiagnosis can still happen and must be included in informed decision making when providing a system of optimal help for cases of radiation-induced thyroid cancer, to minimize harm to people by helping them avoid diagnostics and treatment they may not need.

Mediating Role of Lifestyle Behaviors in the Association between Education and Cancer: Results from the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Many studies have shown that socioeconomic position (SEP) is associated with the incidence of malignant tumors at different sites. This study aims to estimate the association between educational level (as proxy for SEP) and cancer incidence and to understand whether the observed associations might be partially explained by lifestyle behaviors.

METHODS

The analyses were performed on data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, globally and by sex. We used Cox proportional hazards models together with mediation analysis to disentangle the total effect (TE) of educational level [measured through the Relative Index of Inequality (RII)] on cancer incidence into pure direct (PDE) and total indirect (TIE) effect, unexplained and explained by mediators, respectively. PDE and TIE were then combined to compute the proportions mediated (PM).

RESULTS

After an average of 14 years of follow-up, 52,422 malignant tumors were ascertained. Low educated participants showed higher risk of developing stomach, lung, kidney (in women), and bladder (in men) cancers, and, conversely, lower risk of melanoma and breast cancer (in post-menopausal women), when compared with more educated participants. Mediation analyses showed that portions of the TE of RII on cancer could be explained by site-specific related lifestyle behaviors for stomach, lung, and breast (in women).

CONCLUSIONS

Cancer incidence in Europe is determined at least in part by a socioeconomically stratified distribution of risk factors.

IMPACT

These observational findings support policies to reduce cancer occurrence by altering mediators, such as lifestyle behaviors, particularly focusing on underprivileged strata of the population.

Global and regional estimates of orphans attributed to maternal cancer mortality in 2020

Despite women being disproportionally affected by cancer deaths at young ages, there are no global estimates of the resulting maternal orphans, who experience health and education disadvantages throughout their lives. We estimated the number of children who became maternal orphans in 2020 due to their mother dying from cancer in that year, for 185 countries worldwide and by cause of cancer-related death. Female cancer deaths-by country, cancer type and age (derived from GLOBOCAN estimates)-were multiplied by each woman's estimated number of children under the age of 18 years at the time of her death (fertility data were derived from United Nations World Population Prospects for birth cohort), accounting for child mortality and parity-cancer risk associations. Globally, there were 1,047,000 such orphans. Over half of these were orphans due to maternal deaths from breast (258,000, 25%), cervix (210,000, 20%) and upper-gastrointestinal cancers (136,000, 13%), and most occurred in Asia (48%: India 15%, China 10%, rest of Asia 23%) and Africa (35%). Globally, there were 40 new maternal orphans due to cancer per 100,000 children, with a declining trend with a higher Human Development Index (range: 121 in Malawi to 15 in Malta). An estimated 7 million children were prevalent maternal orphans due to cancer in mid-2020. Accelerating the implementation of the World Health Organization's cervical and breast cancer initiatives has the potential to avert not only millions of preventable female cancer deaths but also the associated, often-overlooked, intergenerational consequences of these deaths.

The Current Burden of Oropharyngeal Cancer: A Global Assessment Based on GLOBOCAN 2020

BACKGROUND

Oropharyngeal cancer (OPC) is a complex disease whose etiologies, either related to risk factors such as smoking or alcohol, or linked to HPV infection, are believed to be responsible for wide gender and geographical variability. This study depicts the current burden of OPC worldwide.

METHODS

Estimated OPC new cases, deaths, age-standardized rates (ASR) for both incidence and mortality in 2020 were obtained from the GLOBOCAN database for each country and across 20 UN-defined world regions by sex. The incidence-to-mortality ratio (IMR) was also estimated from ASR.

RESULTS

Worldwide, 98,400 new cases and 48,100 OPC deaths were estimated in 2020, with ASR of 1.1 and 0.51 per 100,000 for incidence and mortality, respectively. ASR for both incidence and mortality were approximately four times higher in men and varied greatly across geographical regions and countries within the same region. Higher incidence was estimated in Europe, North-America, Australia, and New Zealand. Mortality was the highest in Central-East Europe, Western Europe, Melanesia, South-Central Asia, and the Caribbean. South-Central Asia, most African areas, and Central America exhibited the lowest IMR values, whereas North-America, Australia, New Zealand, and North-Europe had the highest.

CONCLUSIONS

The marked geographical and gender variability in OPC incidence and mortality is likely to reflect the distribution of risk factors and the diverse prevalence of HPV-negative and HPV-positive cases.

IMPACT

Findings are likely to drive future research, support the development of targeted strategies to counteract disease burden, establish priorities for prevention and treatment programs, and address inequality in access to services.

The influence of postscreening follow-up time and participant characteristics on estimates of overdiagnosis from lung cancer screening trials

We aimed to explore the underlying reasons that estimates of overdiagnosis vary across and within low-dose computed tomography (LDCT) lung cancer screening trials. We conducted a systematic review to identify estimates of overdiagnosis from randomised controlled trials of LDCT screening. We then analysed the association of Ps (the excess incidence of lung cancer as a proportion of screen-detected cases) with postscreening follow-up time using a linear random effects meta-regression model. Separately, we analysed annual Ps estimates from the US National Lung Screening Trial (NLST) and German Lung Cancer Screening Intervention Trial (LUSI) using exponential decay models with asymptotes. We conducted stratified analyses to investigate participant characteristics associated with Ps using the extended follow-up data from NLST. Among 12 overdiagnosis estimates from 8 trials, the postscreening follow-up ranged from 3.8 to 9.3 years, and Ps ranged from -27.0% (ITALUNG, 8.3 years follow-up) to 67.2% (DLCST, 5.0 years follow-up). Across trials, 39.1% of the variation in Ps was explained by postscreening follow-up time. The annual changes in Ps were -3.5% and -3.9% in the NLST and LUSI trials, respectively. Ps was predicted to plateau at 2.2% for NLST and 9.2% for LUSI with hypothetical infinite follow-up. In NLST, Ps increased with age from -14.9% (55-59 years) to 21.7% (70-74 years), and time trends in Ps varied by histological type. The findings suggest that differences in postscreening follow-up time partially explain variation in overdiagnosis estimates across lung cancer screening trials. Estimates of overdiagnosis should be interpreted in the context of postscreening follow-up and population characteristics.

Global patterns of Hodgkin lymphoma incidence and mortality in 2020 and a prediction of the future burden in 2040

Our study examines global patterns of Hodgkin lymphoma (HL) in 2020 and predicts the future incidence and mortality burden in 2040 using IARC's GLOBOCAN estimates of the number of new cases and deaths of HL in 185 countries. A total of 83 000 new cases of HL and 23 000 deaths from HL were estimated in 2020. In general, incidence and mortality rates were consistently higher in males (50% more cases and deaths than females) across world regions and countries. Incidence rates varied markedly by world region, at least 10-fold in both sexes, with the highest incidence rates observed in Southern Europe. Mortality exhibited an inverse pattern compared to incidence, with rates elevated in Western Asia and Northern Africa. The number of HL incident cases is predicted to rise to around 107 000 cases (a 30% increase) by 2040 due to demographic changes, assuming global rates in 2020 remains unchanged. The findings provide a baseline and impetus for developing strategies that aim to reduce the burden of HL in future decades.

Global Burden of Cutaneous Melanoma in 2020 and Projections to 2040

Importance

Despite many cases being preventable, cutaneous melanoma remains the most serious skin cancer worldwide. Understanding the scale and profile of the disease is vital to concentrate and reinforce global prevention efforts.

Objective

To examine global patterns of cutaneous melanoma in 2020 and to provide projected estimates of cases and deaths by 2040.

Design, Setting, and Participants

This population-based study used the GLOBOCAN 2020 database for global epidemiological assessment of new cases and deaths due to invasive melanoma.

Main Outcomes and Measures

Age-standardized incidence and mortality rates were calculated per 100 000 person-years by country, world region, and 4-tier level of human development. Estimated numbers of cases and deaths were calculated for the year 2040.

Results

A worldwide total of 325 000 new melanoma cases (174 000 males, 151 000 females) and 57 000 deaths (32 000 males, 25 000 females) was estimated for 2020. Large geographic variations existed across countries and world regions, with the highest incidence rates among males (42 per 100 000 person-years) and females (31 per 100 000 person-years) observed in Australia/New Zealand, followed by Western Europe (19 per 100 000 person-years for males and females), North America (18 per 100 000 person-years for males, 14 per 100 000 person-years for females), and Northern Europe (17 per 100 000 person-years for males, 18 per 100 000 person-years for females). Melanoma continued to be rare in most African and Asian countries, with incidence rates commonly less than 1 per 100 000 person-years. Mortality rates peaked at 5 per 100 000 person-years in New Zealand, and geographic variations were less pronounced than for incidence. Melanoma was more frequent among males than females in most world regions. If 2020 rates continue, the burden from melanoma is estimated to increase to 510 000 new cases (a roughly 50% increase) and to 96 000 deaths (a 68% increase) by 2040.

Conclusions and Relevance

This epidemiological assessment suggests that melanoma remains an important challenge to cancer control and public health globally, especially in fair-skinned populations of European descent.

Socioeconomic status and risk of lung cancer by histological subtype in the Nordic countries

BACKGROUND

While the excess in lung cancer risk among lower socioeconomic status individuals has been widely described, the magnitude of this association across lung cancer subtypes, as well as histotype-related long-term incidence trends, are inconclusively reported.

AIMS

We explored the variation in the incidence of the three main lung cancer histotypes (i.e. squamous cell carcinoma, small cell carcinoma and adenocarcinoma) by socioeconomic status (SES, i.e. upper and lower white collar, upper and lower blue collar, and farming/forestry/fishing) in the adult population of four Nordic countries (i.e. Sweden, Norway, Finland and Denmark).

MATERIALS & METHODS

We have used data from the Nordic Occupational Cancer Study (NOCCA), computing age-standardized incidence rates per 100,000 person-years truncated at ages 50-69 years, by sex, histotype, country and SES, for the period 1971-2005. We estimated relative risks and the corresponding 95% confidence intervals through Poisson regression models, including terms for SES, age, sex and country, as indicated.

RESULTS

A clear socioeconomic gradient, with a progressive increase in lung cancer risk as SES level decreases, was observed in all subtypes and in both sexes. Favourable lung cancer incidence trends were seen among men for squamous cell and small cell carcinomas, although for adenocarcinomas rates were increasing everywhere except for Finland. Among women, upward temporal trends were seen in all SES groups and for all subtypes, although rates increased to a greater extent for low, compared to high, SES, especially in Denmark and Norway. Farmers showed comparatively lower risks compared to other SES categories.

DISCUSSION

This prospective cohort study shows that substantial socioeconomic inequalities in the incidence of the most important lung cancer histotypes exist in the Nordic Countries, and that these inequalities are on the rise, especially among women.

CONCLUSION

Smoking habits are likely to largely explain the observed social gradient for lung cancer histotypes in both sexes.

The epidemiological landscape of thyroid cancer worldwide: GLOBOCAN estimates for incidence and mortality rates in 2020

BACKGROUND

Thyroid cancer incidence rates have increased in many countries and settings; however, mortality rates have remained stable at lower rates. This epidemiological pattern has been largely attributed to an overdiagnosis effect. Timely evidence for the global epidemiological status is necessary to identify the magnitude of this problem and the areas mostly affected by it. We therefore aimed to provide an up-to-date assessment on the global distribution of thyroid cancer incidence and mortality rates in 2020.

METHODS

We extracted age-standardised incidence and mortality rates per 100 000 person-years of thyroid cancer as defined by the International Classification of Diseases for Oncology 10th Revision (code C73), for 185 countries or territories by sex and 18 age groups (ie, 0-4, 5-9, …, 80-84, and ≥85 years) from the GLOBOCAN database. Both incidence and mortality estimates were presented by country and aggregated across the 20 UN-defined world regions and according to the UN's four-tier Human Development Index (ie, low, medium, high, and very high) in 2020.

FINDINGS

Globally, in 2020, the age-standardised incidence rates of thyroid cancer were 10·1 per 100 000 women and 3·1 per 100 000 men, and age-standardised mortality rates were 0·5 per 100 000 women and 0·3 per 100 000 men. In both sexes, incidence rates were five times higher in high and very high Human Development Index countries than in low and medium Human Development Index countries, whereas mortality rates were relatively similar across different settings. Incidence rates in women differed by more than 15 times across world regions, with the highest incidence rates being in the Federated States of Micronesia and French Polynesia (18·5 per 100 000 women), North America (18·4 per 100 000), and east Asia (17·8 per 100 000, with South Korea reaching 45 per 100 000). Mortality rates were less than one per 100 000 in most countries and in both sexes. South Korea had the highest incidence-to-mortality rate ratio in both sexes, followed by Cyprus and Canada.

INTERPRETATION

The current thyroid cancer epidemiological landscape is strongly suggestive of a large effect of overdiagnosis in many countries and settings worldwide, confirming the relevance of thyroid cancer overdiagnosis as a global public health problem.

FUNDING

None.

Thyroidectomies in Italy: A Population-Based National Analysis from 2001 to 2018

Background: The incidence of thyroid disease is generally increasing, and it is subject to major geographic variability, between and within countries. Moreover, the incidence rates and the proportion of overdiagnosis for thyroid cancer in Italy are among the highest worldwide. This study aimed to estimate population-based frequency and trends of thyroidectomies in Italy by type of surgical procedure (total/partial), indication (tumors/other conditions), sex, age, and geographical region. Materials and Methods: Age-standardized rates (ASRs) of thyroidectomies were estimated from 2001 to 2018 using the national hospital discharges database. Results: In Italy, ASRs of thyroidectomies were nearly 100 per 100,000 women in 2002-2004 and decreased to 71 per 100,000 women in 2018. No corresponding variation was shown in men (ASR 27 per 100,000 men) in the overall period. A more than twofold difference between Italian regions emerged in both sexes. The proportion of total thyroidectomies (on the sum of total and partial thyroidectomies) in the examined period increased from 78% to 86% in women and from 72% to 81% in men. Thyroidectomies for goiter and nonmalignant conditions decreased consistently throughout the period (from 81 per 100,000 women in 2002 to 49 in 2018 and from 22 to 16 per 100,000 men), while thyroidectomies for tumors increased until 2013-2014 up to 24 per 100,000 women (9 per 100,000 men) and remained essentially stable thereafter. Conclusions: The decrease in thyroidectomies for nonmalignant diseases since early 2000s in Italy may derive from the decrease of goiter prevalence, possibly as a consequence of the reduction of iodine deficiency and the adoption of conservative treatments. In a context of overdiagnosis of thyroid cancer, recent trends have suggested a decline in the diagnostic pressure with a decrease in geographic difference. Our results showed the need and also the possibility to implement more conservative surgical approaches to thyroid diseases, as recommended by international guidelines.

A modeling analysis to compare eligibility strategies for lung cancer screening in Brazil

BACKGROUND

Country-specific evidence is needed to guide decisions regarding whether and how to implement lung cancer screening in different settings. For this study, we estimated the potential numbers of individuals screened and lung cancer deaths prevented in Brazil after applying different strategies to define screening eligibility.

METHODS

We applied the Lung Cancer Death Risk Assessment Tool (LCDRAT) to survey data on current and former smokers (ever-smokers) in 15 Brazilian state capital cities that comprise 18% of the Brazilian population. We evaluated three strategies to define eligibility for screening: (1) pack-years and cessation time (≥30 pack-years and <15 years since cessation); (2) the LCDRAT risk model with a fixed risk threshold; and (3) LCDRAT with age-specific risk thresholds.

FINDINGS

Among 2.3 million Brazilian ever-smokers aged 55-79 years, 21,459 (95%CI 20,532-22,387) lung cancer deaths were predicted over 5 years without screening. Applying the fixed risk-based eligibility definition would prevent more lung cancer deaths than the pack-years definition [2,939 (95%CI 2751-3127) vs. 2,500 (95%CI 2318-2681) lung cancer deaths], and with higher screening efficiency [NNS=177 (95%CI 170-183) vs. 205 (95%CI 194-216)], but would tend to screen older individuals [mean age 67.8 (95%CI 67.5-68.2) vs. 63.4 (95%CI 63.0-63.9) years]. Applying age-specific risk thresholds would allow younger ever-smokers to be screened, although these individuals would be at lower risk. The age-specific thresholds strategy would avert three-fifths (60.1%) of preventable lung cancer deaths [N = 2629 (95%CI 2448-2810)] by screening 21.9% of ever-smokers.

INTERPRETATION

The definition of eligibility impacts the efficiency of lung cancer screening and the mean age of the eligible population. As implementation of lung screening proceeds in different countries, our analytical framework can be used to guide similar analyses in other contexts. Due to limitations of our models, more research would be needed.

Temporal and geographical variations of thyroid cancer incidence and mortality in France during 1986-2015: The impact of overdiagnosis

BACKGROUND

France is among the countries showing fastest growth of thyroid cancer (TC) incidence and highest incidence rates in Europe. This study aimed to clarify the temporal and geographical variations of TC in France and to quantify the impact of overdiagnosis.

METHODS

We obtained TC incidence data in 1986-2015, and mortality data in 1976-2015, for eight French departments covering 8% of the national population, and calculated the age-standardised rates (ASR). We estimated the average annual percent changes (AAPC) of TC incidence, overall and by department and histological subtype. Numbers and proportions of TC cases attributable to overdiagnosis were estimated by department and period, based on the comparison between the shape of the age-specific curves with that observed prior to changes in diagnostic practice.

RESULTS

During 1986-2015, there were 13,557 TC cases aged 15-84 years. Large variations of TC incidence were observed across departments, with the highest ASR and the fastest increase in Isère. Papillary subtype accounted for 82.8% of the cases, and presented an AAPC of 7.0% and 7.6% in women and men, respectively. Anaplastic TC incidence decreased annually 3.0% in women and 0.8% in men. Mortality rates declined consistently for all departments. The absolute number (and proportion) of TC cases attributable to overdiagnosis grew from 1074 (66%) in 1986-1995 to 3830 (72%) in 2006-2015 in women, and varied substantially across departments.

CONCLUSIONS

Overdiagnosis plays an important role in the temporal and regional variations of TC incidence in France. Monitoring the time trends and regulating the regional healthcare practice are needed to reduce its impact.

Incidence of Clinically Relevant Thyroid Cancers Remains Stable for Almost a Century: A Population-Based Study

OBJECTIVE

To examine the trends in incidence of clinically relevant thyroid cancers within the overall rising incidence of thyroid cancers.

PATIENTS AND METHODS

This is a population-based cohort study conducted using the Rochester Epidemiology Project database to identify all new cases of thyroid cancer in Olmsted County, Minnesota, between January 1, 1935, and December 31, 2018. We extracted information about demographics and tumor pathologic type, size, and invasiveness. Clinically relevant cancers included aggressive histology or presence of metastatic disease, size larger than 4 cm, and gross extrathyroidal tumor invasion.

RESULTS

Between 1935 and 2018, 596 thyroid cancer cases were diagnosed (mean age, 46.4 years; 72% female; 87% papillary cancers; and median tumor size, 1.5 cm). The sex- and age-adjusted incidence of thyroid cancer increased from 1.3 per 100,000 person-years (p-y) from 1935-1949 to 12.0 per 100,000 p-y in 2010-2018, corresponding to an absolute change per decade of 1.4 (95% CI, 0.7 to 2.2). There was a nonsignificant period absolute change for patients with tumor greater than 4 cm (0.03; 95% CI, -0.2 to 0.3), with evidence of tumor invasion (0.1; 95% CI, -0.1 to 0.4), and with aggressive histology or presence of metastatic disease (0.2; 95% CI, -0.1 to 0.6). Thyroid cancer mortality was unchanged over the observation period.

CONCLUSION

Incidence rates of clinically relevant thyroid cancers, as defined by histology, size, and invasiveness, have not changed significantly in 80 years. The rising thyroid cancer incidence is driven by indolent thyroid cancers.

Risk of thyroid as a first or second primary cancer. A population-based study in Italy, 1998-2012

BACKGROUND

The number of patients living after a cancer diagnosis is increasing, especially after thyroid cancer (TC). This study aims at evaluating both the risk of a second primary cancer (SPC) in TC patients and the risk of TC as a SPC.

METHODS

We analyzed two population-based cohorts of individuals with TC or other neoplasms diagnosed between 1998 and 2012, in 28 Italian areas covered by population-based cancer registries. Standardized incidence ratios (SIRs) of SPC were stratified by sex, age, and time since first cancer.

RESULTS

A total of 38,535 TC patients and 1,329,624 patients with other primary cancers were included. The overall SIR was 1.16 (95% CI: 1.12-1.21) for SPC in TC patients, though no increase was shown for people with follicular (1.06) and medullary (0.95) TC. SPC with significantly increased SIRs was bone/soft tissue (2.0), breast (1.2), prostate (1.4), kidney (2.2), and hemolymphopoietic (1.4) cancers. The overall SIR for TC as a SPC was 1.49 (95% CI: 1.42-1.55), similar for all TC subtypes, and it was significantly increased for people diagnosed with head and neck (2.1), colon-rectum (1.4), lung (1.8), melanoma (2.0), bone/soft tissue (2.8), breast (1.3), corpus uteri (1.4), prostate (1.5), kidney (3.2), central nervous system (2.3), and hemolymphopoietic (1.8) cancers.

CONCLUSIONS

The increased risk of TC after many other neoplasms and of few SPC after TC questions the best way to follow-up cancer patients, avoiding overdiagnosis and overtreatment for TC and, possibly, for other malignancies.

Trends in thyroid function testing, neck ultrasound, thyroid fine needle aspiration, and thyroidectomies in North-eastern Italy

PURPOSE

Evidence of an increased diagnostic pressure on thyroid has emerged over the past decades. This study aimed to provide estimates of a wide spectrum of surveillance indicators for thyroid dysfunctions and diseases in Italy.

METHODS

A population-based study was conducted in North-eastern Italy, including 11.7 million residents (20% of the total Italian population). Prescriptions for TSH testing, neck ultrasound or thyroid fine needle aspiration (FNA), surgical procedures, and drugs for hypo- or hyperthyroidism were extracted from regional health databases. Proportions and rates of selected examinations were calculated from 2010 to 2017, overall and by sex, calendar years, age, and region.

RESULTS

Between 2010 and 2017 in North-eastern Italy, 24.5% of women and 9.8% of men received at least one TSH test yearly. In 2017, 7.1% of women and 1.5% of men were prescribed drugs for thyroid dysfunction, 94.6% of whom for hypothyroidism. Neck ultrasound examinations were performed yearly in 6.9% of women and 4.6% of men, with a nearly two-fold variation between areas. Thyroid FNA and thyroidectomies were three-fold more frequent in women (394 and 85 per 100,000) than in men (128 and 29 per 100,000) with a marked variation between areas. Both procedures decreased consistently after 2013.

CONCLUSIONS

The results of this population-based study describe recent variations over time and between surrounding areas of indicators of 'diagnostic pressure' on thyroid in North-eastern Italy. These results emphasize the need to harmonize practices and to reduce some procedures (e.g., neck ultrasound and total thyroidectomies) in certain areas.

Thyroid cancer incidence trends by histology in 25 countries: a population-based study

BACKGROUND

The incidence of thyroid cancer has increased in different populations worldwide in the past 30 years. We present here an overview of international trends of thyroid cancer incidence by major histological subtypes.

METHODS

We did a population-based study with data for thyroid cancer incidence collected by the International Agency for Research on Cancer (IARC) for the period 1998-2012. Data were extracted from the Cancer Incidence in Five Continents plus compendium. We selected data for 25 countries that had a population of more than 2 million individuals covered by cancer registration (87 registries in total). Further criteria were that the selected registration areas had to have a proportion of unspecified thyroid cancer of less than 10% and analyses were restricted to individuals aged 20-84 years. We calculated age-specific incidence rates and age-standardised rates per 100 000 person-years for individuals aged 20 to 84 years, and assessed trends by country, sex, and major histological subtype (papillary, follicular, medullary, or anaplastic) based on absolute changes in age-standardised incidence rates between 1998-2002 and 2008-12.

FINDINGS

Papillary thyroid cancer was the main contributor to overall thyroid cancer in all the studied countries, and was the only histological subtype that increased systematically in all countries, although with large variability between countries. In women, the age-standardised incidence rate of papillary thyroid cancer during 2008-12 ranged from 4·3-5·3 cases per 100 000 person-years in the Netherlands, the UK, and Denmark, to 143·3 cases per 100 000 women in South Korea. For men during the same period, the age-standardised incidence rates of papillary thyroid cancer per 100 000 person-years ranged from 1·2 cases per 100 000 in Thailand to 30·7 cases per 100 000 in South Korea. In many countries in Asia, the increase in papillary thyroid cancer rates in women was particularly pronounced after the year 2000; rates stabilised since around 2009 in the USA, Austria, Croatia, Germany, Slovenia, Spain, Lithuania, and Bulgaria. Temporal trends for follicular and medullary thyroid cancer did not show consistent patterns across countries, but slight decreases were seen for anaplastic thyroid cancer in 21 of 25 countries between 1998-2002, and 2008-12. In 2008-12, age-standardised rates for the follicular subtype ranged between 0·5 and 2·5 cases per 100 000 women (and between 0·3 and 1·5 per 100 000 men), while those for the medullary subtype were always less than 1 case per 100 000 women or men, and for anaplastic thyroid cancer less than 0·2 cases per 100 000 women or men.

INTERPRETATION

In the period from 1998 to 2012, the rapid increases in thyroid cancer incidence were observed only for papillary thyroid cancer, the subtype more likely to be found in a subclinical form and therefore detected by intense scrutiny of the thyroid gland.

FUNDING

French Institut National du Cancer, Italian Association for Cancer Research, Italian Ministry of Health.

Global patterns and trends in incidence and mortality of thyroid cancer in children and adolescents: a population-based study

BACKGROUND

There has been a considerable increase in thyroid cancer incidence among adults in several countries in the past three decades, attributed primarily to overdiagnosis. We aimed to assess global patterns and trends in incidence and mortality of thyroid cancer in children and adolescents, in view of the increased incidence among adults.

METHODS

We did a population-based study of the observed incidence (in 49 countries and territories) and mortality (in 27 countries) of thyroid cancer in children and adolescents aged 0-19 years using data from the International Incidence of Childhood Cancer Volume 3 study database, the WHO mortality database, and the cancer incidence in five continents database (CI5plus; for adult data [age 20-74 years]). We analysed temporal trends in incidence rates, including absolute changes in rates, and the strength of the correlation between incidence rates in children and adolescents and in adults. We calculated the average annual number of thyroid cancer deaths and the age-standardised mortality rates for children and adolescents.

FINDINGS

Age-standardised incidence rates of thyroid cancer among children and adolescents aged 0-19 years ranged from 0·4 (in Uganda and Kenya) to 13·4 (in Belarus) cancers per 1 million person-years in 2008-12. The variability in the incidence rates was mostly accounted for by the papillary tumour subtype. Incidence rates were almost always higher in girls than in boys and increased with age in both sexes. Rapid increases in incidence between 1998-2002 and 2008-12 were observed in almost all countries. Country-specific incidence rates in children and adolescents were strongly correlated (r>0·8) with rates in adults, as were the temporal changes in the respective incidence rates (r>0·6). Thyroid cancer deaths in those aged younger than 20 years were less than 0·1 per 10 million person-years in each country.

INTERPRETATION

The pattern of thyroid cancer incidence in children and adolescents mirrors the pattern seen in adults, suggesting a major role for overdiagnosis, which, in turn, can lead to overtreatment, lifelong medical care, and side effects that can negatively affect quality of life. We suggest that the existing recommendation against screening for thyroid cancer in the asymptomatic adult population who are free from specific risk factors should be extended to explicitly recommend against screening for thyroid cancer in similar populations of children and adolescents.

FUNDING

International Agency for Research on Cancer and the Union for International Cancer Control; French Institut National du Cancer; Italian Association of Cancer Research; and Italian Ministry of Health.

Profiling global cancer incidence and mortality by socioeconomic development

Economic and living conditions have improved over time in most countries, although often in association with detrimental lifestyle and environmental changes that are major determinants of cancer. In this ecological study, we assess the association between national socioeconomic levels and incidence and mortality rates for all cancers combined and 27 cancer types, in 175 countries. We obtained national level cancer incidence and mortality estimates for 2018 from GLOBOCAN and computed an index of socioeconomic development based on national education and income levels extracted from the United Nations Development Programme. Cancer incidence rates are strongly positively associated with the national socioeconomic level for all cancers combined and for a large number of cancer types, in both sexes. Conversely, the association between socioeconomic development and cancer mortality rates is less clear. The most common pattern for type-specific cancers is an increasing incidence rate with a relatively stable mortality rate as socioeconomic development increases. Despite the high incidence rates for many cancer types, mortality rates are relatively low in high-income countries, partly due to the availability of early detection and effective treatments. As socioeconomic development continues to rise, countries with currently low- and medium-development levels may experience large increases in the incidence of several cancers. Given the limited resources and lack of infrastructure, increases in incidence rates in low-income countries will likely be paralleled by increases in mortality rates. Efforts to plan, implement and evaluate prevention programs must therefore be considered as greater priorities in Low- and Middle-income countries.

Time trends and other sources of variation in Helicobacter pylori infection in mainland China: A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (H pylori) is a carcinogen that causes a huge burden of gastric cancer in China. We aimed to evaluate the temporal trends and other sources of variation of H pylori infection in adults from mainland China.

MATERIALS AND METHODS

For this systematic review and meta-analysis, we searched PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases for articles published from January 1983 to June 2020. We included studies reporting H pylori prevalence in adults and then applied random effect meta-analyses to obtain pooled prevalence estimates for all studies and subgroups. Sources of heterogeneity were investigated by moderator analysis, and time trends were assessed through random effect meta-regression.

RESULTS

Of the 2121 studies identified, 98 were eligible for inclusion. The pooled estimate of 670 572 participants from 26 provinces during 1983-2018 was 49.6% (95% CI: 46.9%, 52.4%). H pylori prevalence varied considerably, ranging from 20.6% to 81.8%. Periods, urban/rural status, detection method, and study design explained 18.8%, 24.0%, 17.8%, and 30.4% of the heterogeneity, respectively. Overall, H pylori prevalence declined by -0.9% (95% CI: -1.1%, -0.6%) annually. Consistent declines in prevalence were observed by sex, age, and study characteristics.

CONCLUSIONS

Helicobacter pylori prevalence is slowly decreasing over time in mainland China, but the low declining speed is not enough to have a major impact on gastric cancer incidence for many years. The time trends and the large heterogeneity should be taken into account when conducting regional comparisons, disease burden estimations, and customized strategy making.

Thyroid Cancer Incidence in India Between 2006 and 2014 and Impact of Overdiagnosis

CONTEXT/OBJECTIVE

Increases of thyroid cancer (TC) incidence emerged in the past several decades in several countries. This study aimed to estimate time trends of TC incidence in India and the proportion of TC cases potentially attributable to overdiagnosis by sex, age, and area.

DESIGN

TC cases aged 0 to 74 years reported to Indian cancer registries during 2006 through 2014 were included. Age-standardized incidence rates (ASR) and TC overdiagnosis were estimated by sex, period, age, and area.

RESULTS

Between 2006 to 2008 and 2012 to 2014, the ASRs for TC in India increased from 2.5 to 3.5/100,000 women (+37%) and from 1.0 to 1.3/100,000 men (+27%). However, up to a 10-fold difference was found among regions in both sexes. Highest ASRs emerged in Thiruvananthapuram (14.6/100,000 women and 4.1/100,000 men in 2012-2014), with 93% increase in women and 64% in men compared with 2006 to 2008. No evidence of overdiagnosis was found in Indian men. Conversely, overdiagnosis accounted for 51% of TC in Indian women: 74% in those aged < 35 years, 50% at ages 35 to 54 years, and 30% at ages 55 to 64 years. In particular, 80% of TC overdiagnosis in women emerged in Thiruvananthapuram, whereas none or limited evidence of overdiagnosis emerged in Kamrup, Dibrugarh, Bhopal, or Sikkim.

CONCLUSIONS

Relatively high and increasing TC ASRs emerged in Indian regions where better access to health care was reported. In India, as elsewhere, new strategies are needed to discourage opportunistic screening practice, particularly in young women, and to avoid unnecessary and expensive treatments. Present results may serve as a warning also for other transitioning countries.

Long-Term Declines of Thyroid Cancer Mortality: An International Age-Period-Cohort Analysis

Background: Thyroid cancer (TC) incidence rates have been increasing in many countries, predominantly due to overdiagnosis. It is, however, not yet clear whether a true increase in exposure to risk factors might have also contributed to the TC epidemic. We assessed the TC mortality trends, which should not be affected by overdiagnosis, to disentangle the specific contribution of period and cohort effects. Methods: We analyzed long-term mortality data in 24 countries from 5 continents using age-period-cohort (APC) models. Nonidentifiability of the APC models was circumvented by integrating evidence of a consistent relationship between age and TC mortality, allowing to estimate period and cohort linear effects. Results: Substantial heterogeneity existed in the historical TC mortality rates across countries, but long-term rates declined over time in most of the countries, converging around a value of 0.5/100,000. The shape of the age-specific curves was consistently similar across countries and periods, resembling straight lines on the log-log scale, with the slopes ranging between 4.0 and 6.0. Both period and cohort effects showed long-term declines in most countries for both genders. In some countries, such as the United States, Canada, and Australia, substantial long-term declines by period were visible until the 1980s and 1990s, but then stabilized or increased slightly. Declining cohort effects were also seen in almost all countries, and were particularly pronounced in women from Switzerland, whereas stable cohort effects were recorded in South Africa. Although there were some indications of possible increasing risks of deaths among the youngest generations in some countries for both men and women, changes are too recent to be treated as unequivocal and estimates suffered from large statistical variability due to small numbers of deaths. Conclusions: Global long-term declines in TC mortality have been accompanied by downward trends in both period and cohort effects. Our results suggest lack of evidence of a possible major contribution of "real" risk factors in TC mortality, and indirectly confirm the main role of overdiagnosis in the epidemic of TC incidence.

Thyroid cancer incidence in India between 2006 and 2014 and impact of overdiagnosis

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Background: Increases of thyroid cancer (TC) incidence emerged in the last decades in several countries. This study aimed to estimate time trends of TC incidence in India and the proportion of TC cases potentially attributable to overdiagnosis by sex, age, and area. Methods: TC cases aged 0-74 years reported to Indian cancer registries during 2006- 2014 were included. Age-standardized incidence rates (ASR) and TC overdiagnosis were estimated by sex, period, age, and area. Results: Between 2006-2008 and 2012-2014, the ASRs for TC in India increased from 2.5 to 3.5/100,000 women (+37%) and from 1.0 to 1.3/100.000 men (+27%). However, up to a 10-fold difference was found among regions in both sexes. Highest ASRs emerged in Thiruvananthapuram (14.6/100,000 women and 4.1/100,000 men in 2012- 2014), with 93% increase in women and 64% in men compared to 2006-2008. No evidence of overdiagnosis was found in Indian men. Conversely, overdiagnosis accounted for 51% of TC in Indian women: 74% in those aged < 35 years, 50% at ages 35-54 years, and 30% at ages 55-64 years. In particular, 80% of TC overdiagnosis in women emerged in Thiruvananthapuram, while none or limited evidence of overdiagnosis emerged in Kamrup, Dibrugarh, Bhopal, and Sikkim. Conclusions: Relatively high and increasing TC ASRs emerged in Indian regions where better access to healthcare was reported. In India, as elsewhere, new strategies are needed to discourage opportunistic screening practice, particularly in young women, and to avoid unnecessary and expensive treatments. Present results may serve as a warning also for other transitioning countries.

Are U.S. trends a barometer of future cancer transitions in emerging economies?

The currently high cancer incidence rates in the U.S. and other high-income countries have been strongly affected by the acquisition of environmental and lifestyle risk factors that accompanied socioeconomic growth in the second half of the last century. The very same factors are now operating in many low- and middle-income countries (LMIC) undergoing rapid socioeconomic transition. A parallel is drawn between the past cancer trends in the U.S. and those anticipated in LMIC transitioning towards higher levels of socioeconomic development. We expect to see a major upsurge in the (still low to intermediate) cancer incidence and mortality rates in LMIC over the next decades, which coupled with population aging and growth, would translate to a scale of individuals diagnosed with, living and dying from cancer unparalleled in history. On account of resource constraints and organizational limitations, prevention strategies need to be prioritized in LMIC.

Thyroid cancer in Friuli Venezia Giulia, northeastern Italy: incidence, overdiagnosis, and impact of type of surgery on survival

BACKGROUND

Incidence rates of thyroid cancer (TC) increased in the last decades worldwide. This study aimed to describe TC incidence in the Friuli Venezia Giulia (FVG) region, to estimate the quota of overdiagnosis, and to investigate the impact of surgery on long-term survival after TC diagnosis.

METHODS

TC cases reported to the FVG population-based cancer registry during 2002-2013, aged <85 years, were included. Age standardized rates (ASR) on the European population were computed, while proportion of TC overdiagnosis was estimated in comparison with expected age-specific incidence rates from published time series. Adjusted hazard ratios of death, with 95% confidence intervals, were also estimated.

RESULTS

During 2002-2013, 1701 TC cases were reported to the FVG cancer registry, with papillary TC (78.2%) as the most frequent histologic type. ASR increased from 12.4 to 16.5 in women and from 4.3 to 6.2 in men (+33.1% and +44.2%, respectively). Overdiagnosis was estimated as 79% of TC cases in women and 64% in men. Almost all TC cases (97.1%) underwent surgery, including 84.6% of women and 78.9% of men who underwent total thyroidectomy. Up to 10 years after TC diagnosis, the type of surgery did not appear to influence survival.

CONCLUSIONS

This study documented an increase in TC incidence in FVG in the last decade, with overdiagnosis accounting for a large proportion of TC diagnoses and total thyroidectomy in more than 80% of cases. These findings suggest reconsidering thyroid screening practice and aggressive therapeutic strategies, as recommended by new TC guidelines.

Thyroid cancer "epidemic" also occurs in low- and middle-income countries

Thyroid cancer incidence varies greatly between and within high-income countries (HICs), and overdiagnosis likely plays a major role in these differences. Yet, little is known about the situation in low- and middle-income countries (LMICs). We compare up-to-date thyroid cancer incidence and mortality at national and subnational levels. 599,851 thyroid cancer cases in subjects aged 20-74 reported in Cancer Incidence in Five Continents volume XI from 55 countries with at least 0.5 million population, aged 20-74 years, covered by population-based cancer registration, and 22,179 deaths from the WHO Mortality Database for 36 of the selected countries, over 2008-2012, were included. Age-standardized rates were computed. National incidence rates varied 50-fold. Rates were 4 times higher among women than men, with similar patterns between countries. The highest rates (>25 cases per 100,000 women) were observed in the Republic of Korea, Israel, Canada, the United States, Italy, France, and LMICs such as Turkey, Costa Rica, Brazil, and Ecuador. Incidence rates were low (<8) in a few HICs (the Netherlands, the United Kingdom, and Denmark) and lowest (3-4) in some LMICs (such as Uganda and India). Within-country incidence rates varied up to 45-fold, with the largest differences recorded between rural and urban areas in Canada (HIC) and Brazil, India, and China (LMICs). National mortality rates were very low (<2) in all countries and in both sexes, and highest in LMICs. The very high thyroid cancer incidence and low mortality rates in some LMICs also strongly suggest a major role of overdiagnosis in these countries.

Hepatitis B Virus Blocks the CRE/CREB Complex and Prevents TLR9 Transcription and Function in Human B Cells

Effective B cell responses such as cytokine secretion, proliferation, and Ab-specific responses are essential to clear hepatitis B virus (HBV) infection. However, HBV alters numerous immune pathways to persist in the host. B cell activity depends on activation of the innate sensor TLR9 by viral or bacterial DNA motifs. How HBV can deregulate B cell functions remains unknown. In this study, we show that HBV can enter and decrease TLR9 expression in human primary B cells. Using PBMCs from human blood donors, we show that TLR9 expression was reduced in all peripheral B cells subsets exposed to HBV. B cell function mediated by TLR9, but not TLR7, such as proliferation and proinflammatory cytokines secretion, were abrogated in the presence of HBV; however, global Ig secretion was not downregulated. Mechanistically, we show, using human myeloma B cell line RPMI 8226, that the surface Ag hepatitis B surface Ag was responsible for TLR9 dysfunction. hepatitis B surface Ag suppressed the phosphorylation and thus the activation of the transcription factor CREB, preventing TLR9 promoter activity. Finally, we corroborated our in vitro findings in a cohort of chronic HBV carriers and found that TLR9 expression and function were significantly suppressed. The effect of HBV on TLR9 activity in B cells gives insights into oncoviral immune escape strategies, providing knowledge to develop novel immunotherapeutic approaches in chronic HBV-carrier patients.

The impact of overdiagnosis on thyroid cancer epidemic in Italy,1998-2012

AIMS

In Italy, incidence rates of thyroid cancer (TC) are among the highest worldwide with substantial intracountry heterogeneity. The aim of the study was to examine time trends of TC incidence in Italy and to estimate the proportion of TC cases potentially attributable to overdiagnosis.

METHODS

Data on TC cases reported to Italian cancer registries during 1998-2012 aged <85 years were included. Age-standardised incidence rates (ASR) were computed by sex, period, and histology. TC overdiagnosis was estimated by sex, period, age, and Italian region.

RESULTS

In Italy between 1998-2002 and 2008-2012, TC ASR increased of 74% in women (from 16.2 to 28.2/100,000) and of 90% in men (from 5.3 to 10.1/100,000). ASR increases were nearly exclusively due to papillary TC (+91% in women, +120% in men). In both sexes, more than three-fold differences emerged between regions with highest and lowest ASR. Among TC cases diagnosed in 1998-2012 in Italy, we estimated that overdiagnosis accounted for 75% of cases in women and 63% in men and increased over the study period leading to overdiagnosis of 79% in women and 67% in men in 2008-2012. Notably, overdiagnosis was over 80% among women aged <55 years, and substantial variations were documented across Italian regions, in both genders.

CONCLUSION(S)

Incidence rates of TC are steadily increasing in Italy and largely due to overdiagnosis. These findings call for an update of thyroid gland examination practices in the asymptomatic general population, at national and regional levels.

Cervical cancer in Africa, Latin America and the Caribbean and Asia: Regional inequalities and changing trends

The vast majority (86% or 453,000 cases) of the global burden of cervical cancer occurs in Africa, Latin America and the Caribbean and Asia, where one in nine new cancer cases are of the cervix. Although the disease has become rare in high-resource settings (e.g., in North America, parts of Europe, Japan) that have historically invested in effective screening programs, the patterns and trends are variable elsewhere. While favourable incidence trends have been recorded in many populations in Asia and Latin America and the Caribbean in the past decades, rising rates have been observed in sub-Saharan African countries, where high quality incidence series are available. The challenge for countries heavily affected by the disease in these regions is to ensure resource-dependent programmes of screening and vaccination are implemented to transform the situation, so that accelerated declines in cervical cancer are not the preserve of high-income countries, but become the norm in all populations worldwide.

Assessing global transitions in human development and colorectal cancer incidence

Colorectal cancer incidence has paralleled increases in human development across most countries. Yet, marked decreases in incidence are now observed in countries that have attained very high human development. Thus, in this study, we explored the relationship between human development and colorectal cancer incidence, and in particular assessed whether national transitions to very high human development are linked to temporal patterns in colorectal cancer incidence. For these analyses, we utilized the Human Development Index (HDI) and annual incidence data from regional and national cancer registries. Truncated (30-74 years) age-standardized incidence rates were calculated. Yearly incidence rate ratios and HDI ratios, before and after transitioning to very high human development, were also estimated. Among the 29 countries investigated, colorectal cancer incidence was observed to decrease after reaching the very high human development threshold for 12 countries; decreases were also observed in a further five countries, but the age-standardized incidence rates remained higher than that observed at the threshold. Such declines or stabilizations are likely due to colorectal cancer screening in some populations, as well as varying levels of exposure to protective factors. In summary, it appears that there is a threshold at which human development predicts a stabilization or decline in colorectal cancer incidence, though this pattern was not observed for all countries assessed. Future cancer planning must consider the increasing colorectal cancer burden expected in countries transitioning towards higher levels of human development, as well as possible declines in incidence among countries reaching the highest development level.