Secular trends in incidence of lung cancer by histological type in Beijing, China, 20002016

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.

Secular-Trend Analysis of the Incidence Rate of Lung Squamous Cell Carcinoma in Taiwan

Lung cancer is the leading cause of cancer deaths worldwide, and squamous cell carcinoma (SQC) is Taiwan's second most common lung carcinoma histotype. This study aimed to investigate changes in the long-term trend of the SQC incidence rate in Taiwan. SQC cases between 1985 and 2019 were adopted from Taiwan's Cancer Registry System; the age-adjusted incidence rate was calculated using the World Standard Population in 2000. The long-term trends of the age, period, and birth cohort effect of SQC incidence rates were estimated using the SEER Age-Period-Cohort Web Tool. The results revealed that the incidence of lung carcinoma in Taiwan increased, while the incidence of SQC exhibited a slight decrease during this study period. The age rate ratio (ARR) of the incidence rate in men declined gradually, and the period effect changed more slowly for women than men. The cohort effect formed a bimodal curve. The annual percentage change results for women indicated that the ARR decreased from 1.652 (95% confidence interval (CI): 1.422, 1.9192) at 30 to 34 years to 0.559 (95% CI: 0.4988, 0.6265) at 75 to 79 years; the period effect decreased from 1.2204 (95% CI: 1.1148, 1.336) in 1995 to 1999 to 0.608 (95% CI: 0.5515, 0.6704) in 2015 to 2019, with a greater decline in the later period. The cohort effect was unimodal, with the SQC risk value peaking in the 1915 birth cohort and exhibiting a steady decline thereafter. The results of this study suggest that a decrease in the smoking rate may be the reason for the decline in the incidence of SQC, and we observed a similar trend between SQC and the smoking rate in men.

Cancer situation in China: what does the China cancer map indicate from the first national death survey to the latest cancer registration?

BACKGROUND

Over the past four decades, the Chinese government has conducted three surveys on the distribution of causes of death and built cancer registration. In order to shine a new light on better cancer prevention strategies in China, we evaluated the profile of cancer mortality over the forty years and analyzed the policies that have been implemented.

METHODS

We described spatial and temporal changes in both cancer mortality and the ranking of major cancer types in China based on the data collected from three national surveys during 1973-1975, 1990-1992, 2004-2005, and the latest cancer registration data published by National Central Cancer Registry of China. The mortality data were compared after conversion to age-standardized mortality rates based on the world standard population (Segi's population). The geographical distribution characteristics were explored by marking hot spots of different cancers on the map of China.

RESULTS

From 1973 to 2016, China witnessed an evident decrease in mortality rate of stomach, esophageal, and cervical cancer, while a gradual increase was recorded in lung, colorectal, and female breast cancer. A slight decrease of mortality rate has been observed in liver cancer since 2004. Lung and liver cancer, however, have become the top two leading causes of cancer death for the last twenty years. From the three national surveys, similar profiles of leading causes of cancer death were observed among both urban and rural areas. Lower mortality rates from esophageal and stomach cancer, however, have been demonstrated in urban than in rural areas. Rural areas had similar mortality rates of the five leading causes of cancer death with the small urban areas in 1973-1975. Additionally, rural areas in 2016 also had approximate mortality rates of the five leading causes with urban areas in 2004-2005. Moreover, stomach, esophageal, and liver cancer showed specific geographical distributions. Although mortality rates have decreased at most of the hotspots of these cancers, they were still higher than the national average levels during the same time periods.

CONCLUSIONS

Building up a strong primary public health system especially among rural areas may be one critical step to reduce cancer burden in China.

Community-based lung cancer screening by low-dose computed tomography in China: First round results and a meta-analysis

OBJECTIVE

To evaluate the efficiency of low-dose computed tomography (LDCT) screening for lung cancer in China by analyzing the baseline results of a community-based screening study accompanied with a meta-analysis.

METHODS

A first round of community-based lung cancer screening with LDCT was conducted in Tianjin, China, and a systematic literature search was performed to identify LDCT screening and registry-based clinical studies for lung cancer in China. Baseline results in the community-based screening study were described by participant risk level and the lung cancer detection rate was compared with the pooled rate among the screening studies. The percentage of patients per stage was compared between the community-based study and screening and clinical studies.

RESULTS

In the community-based study, 5523 participants (43.6% men) underwent LDCT. The lung cancer detection rate was 0.5% (high-risk, 1.2%; low-risk, 0.4%), with stage I disease present in 70.0% (high-risk, 50.0%; low-risk, 83.3%), and the adenocarcinoma present in 84.4% (high-risk, 61.5%; low-risk, 100%). Among all screen-detected lung cancer, women accounted for 8.3% and 66.7% in the high- and low-risk group, respectively. In the screening studies from mainland China, the lung cancer detection rate 0.6% (95 %CI: 0.3%-0.9%) for high-risk populations. The proportions with carcinoma in situ and stage I disease in the screening and clinical studies were 76.4% (95 %CI: 66.3%-85.3%) and 15.2% (95 %CI: 11.8%-18.9%), respectively.

CONCLUSIONS

The stage shift of lung cancer due to screening suggests a potential effectiveness of LDCT screening in China. Nearly 70% of screen-detected lung cancers in low-risk populations are identified in women.

Spatial and Temporal Analysis of Lung Cancer in Shenzhen, 2008-2018

Lung cancer is the most commonly diagnosed cancer in China. The incidence trend and geographical distribution of lung cancer in southern China have not been reported. The present study explored the temporal trend and spatial distribution of lung cancer incidence in Shenzhen from 2008 to 2018. The lung cancer incidence data were obtained from the registered population in the Shenzhen Cancer Registry System between 2008 and 2018. The standardized incidence rates of lung cancer were analyzed by using the joinpoint regression model. The Moran's I method was used for spatial autocorrelation analysis and to further draw a spatial cluster map in Shenzhen. From 2008 to 2018, the average crude incidence rate of lung cancer was 27.1 (1/100,000), with an annual percentage change of 2.7% (p < 0.05). The largest average proportion of histological type of lung cancer was determined as adenocarcinoma (69.1%), and an increasing trend was observed in females, with an average annual percentage change of 14.7%. The spatial autocorrelation analysis indicated some sites in Shenzhen as a high incidence rate spatial clustering area. Understanding the incidence patterns of lung cancer is useful for monitoring and prevention.

Burden of lung cancer attributable to ambient fine particles and potential benefits from air quality improvements in Beijing, China: A population-based study

OBJECTIVE

We aimed to establish a representative exposure response function between PM_2.5 and lung cancer to evaluate the impact on lung cancer burden and the benefits gained in association with the environmental policy change in Beijing, China.

METHODS

Based on population-based cancer registration data during 2001-2016, using a spatiotemporal Poisson regression model, long-term concentrations of PM_2.5 were linked to sex-age adjusted incidence rates of total lung cancer and its pathological subtypes. We calculated the health and monetary benefits associated with air quality improvement using the cost of illness method.

RESULTS

In the constructed regression model, a 10 μg/m³ increment of PM_2.5 was associated with increases of 6.0% (95% confidence interval [95% CI]: 4.3%, 7.7%), 14.8% (10.3%, 19.4%), and 6.5% (3.3%, 9.8%) in the incidence of total lung cancer, squamous cell carcinoma, and adenocarcinoma, respectively. The estimated associations indicate that long-term exposure to PM_2.5 contributed 1947 to 3059 incident cases of lung cancer per year among the residents in Beijing during the study period. Clean air actions saved 4978 (95% CI: 2711, 7417) lung cancer cases, which brought a savings of 218 (118, 324) million RMB (~31 [17, 46] million US dollars) in direct inpatient medical expenditures. If air quality had met national standards of long-term PM_2.5 (35 μg/m³) in 2014-2016, 10,003 (95% CI: 9325, 10,650) lung cancer cases could have been prevented and direct inpatient medical expenditures of 438 (409, 466) million RMB (~63 [58, 67] million US dollars) could have been saved.

CONCLUSIONS

This study enriches epidemiological study, confirming the association between exposure to PM_2.5 and lung cancer or its subtypes, and provides novel evidence for the notable reduction in lung cancer burden and medical expenditure savings that were achieved through air quality improvements in Beijing from 2014 to 2016.

Spectral CT imaging parameters and Ki-67 labeling index in lung adenocarcinoma

Objective

To explore the correlation between the spectral computed tomography (CT) imaging parameters and the Ki-67 labeling index in lung adenocarcinoma.

Methods

Spectral CT imaging parameters [iodine concentrations of lesions (ICLs) in the arterial phase (ICLa) and venous phase (ICLv), normalized IC in the aorta (NICa/NICv), slope of the spectral HU curve (λHUa/λHUv) and monochromatic CT number enhancement on 40 keV and 70 keV images (CT40keVa/v, CT70keVa/v)] in 34 lung adenocarcinomas were analyzed, and common molecular markers, including the Ki-67 labeling index, were detected with immunohistochemistry. Different Ki-67 labeling indexes were measured and grouped into four grades according to the number of positive-stained cells (grade 0, ≤1%; 1%<grade 1≤10%; 10%<grade 2≤30%; and grade 3, >30%). One-way analysis of variance (ANOVA) was used to compare the four different grades, and the Bonferroni method was used to correct the P value for multiple comparisons. A Spearman correlation analysis was performed to further research a quantitative correlation between the Ki-67 labeling index and spectral CT imaging parameters.

Results

CT40keVa, CT40keVv, CT70keVa and CT70keVv increased as the grade increased, and CT70keVa and CT70keVv were statistically significant (P<0.05). These four parameters and the Ki-67 labeling index showed a moderate positive correlation with lung adenocarcinoma nodules. ICL, NIC and λHU in the arterial and venous phases were not significantly different among the four grades.

Conclusions

The spectral CT imaging parameters CT40keVa, CT40keVv, CT70keVa and CT70keVv gradually increased with Ki-67 expression and showed a moderate positive correlation with lung adenocarcinomas. Therefore, spectral CT imaging parameter-enhanced monochromatic CT numbers at 70 keV may indicate the extent of proliferation of lung adenocarcinomas.

Effects of insurance status on long-term survival among non-small cell lung cancer (NSCLC) patients in Beijing, China: A population-based study

Objective

To evaluate the effects of health insurance status on long-term cancer-specific survival of non-small cell lung cancer (NSCLC) in Beijing, China, using a population-based cancer registry data.

Methods

Information on NSCLC patients diagnosed in 2008 was derived from the Beijing Cancer Registry. The medical records of 1,134 cases were sampled and re-surveyed to obtain information on potential risk factors. Poorly-insured status was defined as Uninsured and New Rural Cooperative Medical Insurance Scheme (NRCMS), while well-insured included Urban Employees Basic Medical Insurance (UEBMI) and Free Medical Care (FMC). To estimate survival outcomes, individuals were followed-up until December 31, 2018. Cancer-specific survival probabilities at 5 and 10 years after diagnosis were estimated using the Kaplan-Meier method. Log-rank test was used to compare long-term survival with different characteristics. Multivariable Cox proportional hazard regression model was used to examine the relative effect of insurance status on cancer-specific mortality.

Results

Well-insured NSCLC patients have longer cancer-specific survival than poorly-insured individuals [hazard ratio (HR)=0.81; 95% confidence interval (95% CI): 0.67−0.97), even after adjusting for age, gender, cancer stage, smoking status, family history and residential area. Older age and rural residence were associated with a higher risk of cancer-specific mortality (HR=1.03; 95% CI: 1.02−1.03 and HR=1.25; 95% CI: 1.07−1.46, respectively). Smoking individuals had a 41% higher long-term cancer-specific mortality risk than non-smoking ones (HR=1.41; 95% CI: 1.20−1.66).

Conclusions

NSCLC patients with good insurance status had better survival rates than those with poor insurance. An association was significant even after 10 years. Large population-based studies are needed to validate that high reimbursement insurance status can lead to the improvement of long-term cancer prognosis in China.