The Introduction of Low-Dose CT Imaging and Lung Cancer Overdiagnosis in Chinese Women

Understanding East-West differences in subsolid nodules: prevalence and overdiagnosis implications in lung cancer screening

BACKGROUND

Owing to the widespread opportunistic LDCT screening leading to increased overdiagnosis in Asian countries, such as South Korea, mainland China, and Taiwan, this study seeks to analyze the divergence in SSN prevalence between Eastern and Western nations, focusing on the influence of SSN on the growing overdiagnosis trend, notably among females.

METHODS

This retrospective study collected data from 4166 participants who underwent baseline LDCT in a hospital-based cohort between January 2014 and August 2021. Clinical parameters, including age, sex, lung imaging reporting and data system (Lung-RADS) categories, smoking history, pack-year dose, and SSN characteristics, were extracted from electronic medical records. Additionally, a narrative review and pooled analysis integrated relevant published studies on the prevalence of subsolid nodules and sex disparities.

RESULTS

The study encompassed 4166 participants, with females accounting for 49.3% and males for 50.7%, with a mean age of 53.38 ± 10.89. The prevalence of SSNs was significantly higher in females (20.1%) than in males (12.6%). Pooled analysis across seven studies revealed a significantly higher prevalence of SSN in Eastern countries (12.6%) compared to the prevalence in Western countries (3.6%) (test for subgroup differences: p < 0.01; I2 = 100%). Additionally, a notable sex difference was observed in the prevalence of SSNs (risk ratio = 0.489, 95% CI: 0.301-0.796, p < 0.01; reference group: male group).

CONCLUSIONS

Apart from differences in clinical management and health literacy regarding SSNs between Eastern and Western countries, the high prevalence of SSNs in Asian nations, particularly among females, significantly contributes to the issue of overdiagnosis in opportunistic lung cancer screening in Asian countries. Tailored sex-specific strategies and risk prediction models are essential for effective screening optimization.

Screening for Lung Cancer, Overdiagnosis, and Healthcare Utilization: A Nationwide Population-Based Study

INTRODUCTION

Guideline-discordant low-dose computed tomography (LDCT) screening may cause lung cancer (LC) overdiagnosis, but its extent and consequences are unclear. This study aimed to investigate the prevalence of self-initiated, non-reimbursed LDCT screening in a predominantly non-smoking population and its impact on LC epidemiology and healthcare utilization.

METHODS

This nationwide cohort study analyzed data from Korea's National Health Information Database and 11 academic hospital screening centers (1999-2022). The overall analysis encompassed the entire Korean population. For non-reimbursed LDCT screening prevalence, which the National Health Information Database does not capture, a separate analysis was conducted on a cohort of 1.7 million adults to extrapolate nationwide rates. Outcomes included trends in self-initiated, non-reimbursed LDCT screening, LC incidence, mortality, stage and age at diagnosis, 5-year survival, and LC-related healthcare utilization, including surgeries and biopsies. Joinpoint regression assessed trend changes.

RESULTS

Self-initiated, non-reimbursed LDCT screening during health check-ups increased from 29% to 60% in men and 7% to 46% in women, despite only 2.4% of men and 0.04% of women qualifying for risk-based screening. In women, localized-stage LC incidence nearly doubled (age-standardized incidence rate: from 7.6 to 13.7 per 100,000), whereas distant-stage incidence decreased (age-standardized incidence rate: from 16.1 to 15.0 per 100,000). LC mortality declined (age-standardized mortality rate: from 23.3 to 19.8 per 100,000), whereas 5-year survival rates improved substantially. LC diagnoses in women shifted towards earlier stages and younger ages. Lung surgeries for both malignant and benign lesions, frequently lacking nonsurgical biopsies, increased sharply in women.

CONCLUSIONS

Widespread guideline-discordant LDCT screening correlates with LC overdiagnosis and increased healthcare utilization, particularly in women. Randomized controlled trials are needed to assess the risks and benefits of screening in low-risk populations to determine its efficacy and consequences.

Prognostic factors of survival in patients with lung cancer after low-dose computed tomography screening: a multivariate analysis of a lung cancer screening cohort in China

OBJECTIVE

This study aimed to evaluate the prognostic factors influencing the survival of patients with lung cancer identified from a lung cancer screening cohort in the community.

METHODS

A total of 25,310 eligible participants were enrolled in this population-based prospective cohort study, derived from a community lung cancer screening program started from 2013 to 2017. Survival analyses were conducted using the Kaplan-Meier method and the log-rank test. Cox proportional hazards regression models were utilized to identify prognostic factors, including demographic characteristics, risk factors, low-dose CT (LDCT) screening, and treatment information.

RESULTS

The screening cohort identified a total of 429 patients with lung cancer (276 men, 153 women) during the study period. The 1-year, 3-year, and 5-year survival rates were 74.4%, 59.4% and 54.5%, respectively. The prognostic factors discovered by the multivariate analysis include gender (male vs. female, HR: 2.96, 95% CI: 1.88-4.64), age (HR: 1.02, 95% CI: 1.00-1.05), personal monthly income (2000-3999 CNY vs. < 2000 CNY, HR: 0.70, 95% CI: 0.52-0.95), pathological type (small cell carcinoma vs. adenocarcinoma, HR: 2.55, 95% CI: 1.39-4.66), stage (IV vs. 0-I, HR: 5.21, 95% CI: 2.78-9.75; III vs. 0-I, HR: 3.81, 95% CI: 1.88-7.74), surgery (yes vs. no, HR: 0.36, 95% CI: 0.23-0.57), and KPS (HR: 0.98, 95% CI: 0.98-0.99) among lung cancer patients identified by the basic model. Furthermore, solid nodule (non-solid nodule vs. solid nodule, HR: 0.47, 95% CI: 0.23-0.96) and larger-sized nodule (HR: 1.02, 95% CI: 1.00-1.03) were associated with a worse prognosis for lung cancer in the LDCT screening model.

CONCLUSION

Prognostic factors of patients with lung cancer detected by LDCT screening were identified, which could potentially guide clinicians in the decision-making process for lung cancer management and treatment. Further studies with larger sample sizes and more detailed follow-up data are warranted for prognostic prediction.

Early Lung Adenocarcinoma Manifesting as Irregular Subsolid Nodules: Clinical and CT Characteristics

RATIONALE AND OBJECTIVES

To explore the clinical and computed tomography (CT) characteristics of early-stage lung adenocarcinoma (LADC) that presents with an irregular shape.

MATERIALS AND METHODS

The CT data of 575 patients with stage IA LADC and 295 with persistent inflammatory lesion (PIL) manifesting as subsolid nodules (SSNs) were analyzed retrospectively. Among these patients, we selected 233 patients with LADC and 140 patients with PIL, who showed irregular SSNs, hereinafter referred to as irregular LADC (I-LADC) and irregular PIL (I-PIL), respectively. The incidence rates, clinical characteristics, and CT features of I-LADC and I-PIL were compared. Additionally, binary logistic regression analysis was performed to determine the independent factors for diagnosing I-LADC.

RESULTS

The incidence rates of I-LADC and I-PIL were 40.5% (233/575) and 47.5% (140/295), respectively, with no statistically significant difference observed between the two groups (P > 0.05). Univariate analysis revealed significant differences in three clinical characteristics and 13 radiological features between I-LADC and I-PIL (all P < 0.05). Binary logistic regression indicated that the alignment of the long axis of SSN with the bronchial vascular bundle, a well-defined boundary of ground-glass opacity, lobulation, arc concave sign, and absence of knife-like change were the independent predictors of I-LADC, yielding an area under the curve and accuracy of 0.979% and 93.5%, respectively.

CONCLUSION

Early LADC presenting as SSNs is associated with a high incidence of irregular shape. I-LADC and I-PIL exhibited different clinical and imaging characteristics. A good understanding of these differences may be helpful for the accurate diagnosis of I-LADC.

Prognosis of surgically resected clinical stage 1A non-small cell lung cancers manifesting as a subsolid nodule on computed tomography including pure ground glass nodules

OBJECTIVES

This is a protocol for a Cochrane Review (prognosis). The objectives are as follows: To quantify the risk of tumour relapse/recurrence after a surgical resection of stage 1A non-small cell lung cancer (NSCLC) as manifested on computed tomography (CT) imaging as a subsolid nodule.

Examining the relationship between incidence and mortality for commonly diagnosed cancers in the USA: an observational study using population-based SEER database

OBJECTIVE

Incidence and mortality are fundamental epidemiologic measures of cancer burden, yet few studies have examined individual cancers to determine how these measures correlate across place. We assessed the relationship between incidence and mortality for commonly diagnosed cancers in the USA.

DESIGN

Population-based observational study of US counties.

SETTING AND PARTICIPANTS

The Surveillance, Epidemiology and End Results (SEER) database was used to obtain incidence (2000-2016) and mortality (2002-2018) data for the 12 most commonly diagnosed non-haematologic cancers.

OUTCOME MEASURES

County-level correlation between cancer incidence and mortality. Cancers were grouped into terciles based on the population-weighted correlation coefficient (r). We also examined the 10 year risk of death, both from the diagnosed cancer and other causes.

RESULTS

County-level incidence and mortality were strongly correlated in some cancers, yet uncorrelated in others. Cancers in the high-correlation tercile (r range: 0.96 to 0.78) included lung, stomach, liver and pancreas. For patients with these cancers, the risk of death from the diagnosed cancer was >4-times the risk of death from other causes. The moderate-correlation tercile (r: 0.75 to 0.58) included cancers of the colon, bladder, kidney and uterus. There was little or no relationship between incidence and mortality for cancers in the low-correlation tercile (r: 0.33 to -0.10): melanoma, prostate, breast and thyroid. The risk of death from the diagnosed cancer for these patients was either lower or no different than their risk of death from other causes.

CONCLUSIONS

For some cancers in the USA, the fundamental epidemiologic measure of disease frequency-incidence-now has little relationship with cancer death (mortality). Low correlations are most likely explained by differences in diagnostic practice leading to variable amounts of cancer overdiagnosis between different US counties.

Overdiagnosis and overtreatment of ground-glass nodule-like lung cancer

Lung cancer has had one of the highest incidences and mortality in the world over the last few decades, which has aided in the promotion and popularization of screening for lung ground-glass nodules (GGNs). People have great psychological anxiety about GGN because of the chance that it will develop into lung cancer, which makes clinical treatment of GGN a generally excessive phenomenon. Overdiagnosis in screening has recently been mentioned in the literature. An important research emphasis of screening is how to reduce the incidence of overdiagnosis and overtreatment. This paper discusses from different aspects how to characterize the occurrence of overdiagnosis and overtreatment, how to reduce overdiagnosis and overtreatment, and future screening, follow-up, and treatment approaches.

Gender Disparities and Lung Cancer Screening Outcomes Among Individuals Who Have Never Smoked

Importance

Lung cancer in individuals who have never smoked (INS) is a growing global concern, with a rapidly increasing incidence and proportion among all lung cancer cases. Particularly in East Asia, opportunistic lung cancer screening (LCS) programs targeting INS have gained popularity. However, the sex-specific outcomes and drawbacks of screening INS remain unexplored, with data predominantly focused on women.

Objective

To compare LCS outcomes between Asian women and men with no smoking history.

Design, Setting, and Participants

This multicenter cohort study was conducted at health checkup centers in South Korea from 2009 to 2021. Participants included individuals aged 50 to 80 years with no smoking history who underwent low-dose computed tomography (LDCT) screening. Data were retrospectively analyzed from November 2023 to June 2024.

Exposures

Opportunistic LDCT screening for lung cancer.

Main Outcomes and Measures

Participants were followed up until December 2022 for the outcome of death. Lung cancer diagnosis, diagnostic characteristics, clinical course, and lung cancer-specific deaths (LCSD) were compared between women and men.

Results

A total of 21 062 participants (16 133 [76.6%] women and 4929 [23.4%] men) with a mean (SD) age of 59.8 (7.2) years were included. From baseline screening, 176 participants (139 women [0.9%] and 37 men [0.8%]) were diagnosed with lung cancer (screen-detected); 131 of 139 women (94.3%) and 33 of 37 men (89.2%) were diagnosed with stage 0 to I disease, with 133 of 139 women (95.7%) and 36 of 37 men (97.3%) having adenocarcinoma. There were no significant sex-based differences in stage or histologic type distribution. Among the 21 062 screened individuals, LCSD was reported in 8 women and 3 men during a mean (SD) follow-up of 83.8 (41.7) months. Multivariable analyses found no significant association between sex and cumulative hazards of lung cancer diagnosis (adjusted hazard ratio [aHR], 0.90 [95% CI, 0.64-1.26] for men vs women) or LCSD (aHR, 1.06 [95% CI, 0.28-4.00] for men vs women). The estimated 5-year lung cancer-specific survival rate was 97.7% for women and 100% for men with screen-detected lung cancer, showing no significant sex differences.

Conclusions and Relevance

In this cohort study of Asian individuals with no smoking history who underwent LDCT screening, no significant sex-based differences were detected in lung cancer diagnosis, stage distribution, or LCSD. These findings suggest that men and women who have never smoked would experience similar risks of overdiagnosis with little to no benefit when exposed to indiscriminate screening.

Burdens of Tracheal, Bronchus, and Lung Cancer From 1990 to 2021 in China Compared to the Global Projection of 2036: Findings From the 2021 Global Burden of Disease Study

BACKGROUND

Tracheal, bronchial, and lung cancers (TBL cancers) pose a significant global health challenge, with rising incidence and mortality rates, particularly in China. Studies from the Global Burden of Disease (GBD), 2021, can guide screening and prevention strategies for TBL cancer. This study aims to provide a comprehensive analysis of the burden of TBL cancers in China compared to global data.

METHODS

We conducted an analysis of incidence, prevalence, mortality, and disability-adjusted life years (DALYs) from 1990 to 2021. We also performed Joinpoint regression analysis and Bayesian age-period-cohort (BAPC) modeling to project future trends.

RESULTS

From 1990 to 2021, there was a substantial increase in TBL cancer indicators for all sexes in China, with the most significant rise observed in females. The female population showed alarming increases in age-standardized incidence rate (ASIR) and age-standardized prevalence rate (ASPR). While global efforts have managed to stabilize these rates, China's figures remain high, suggesting the impact of persistent risk factors such as smoking and air pollution, coupled with an aging population. Furthermore, we utilized the projection model in China to estimate that these indicators of TBL cancers in females will likely follow continuous and rapid upward trends, while the burden of TBL cancers among males is expected to have a steady trend.

CONCLUSION

Although global efforts have been effective in reducing the burden of TBL cancers over the past three decades, there still remains strong regional and gender heterogeneity. TBL cancers need more screening strategies and medical attention in China and in the female population.

A 16-year evaluation of opportunistic lung cancer screening with low-dose CT in China: comparative findings between non-smokers and smokers

BACKGROUND

Although low-dose computed tomography (LDCT) screening effectively reduces LC mortality in high-risk individuals with a history of smoking in China, the feasibility and efficacy of lung cancer screening (LCS) in individuals who never smoked versus individuals who smoked remains unclear.

METHODS

We conducted a retrospective analysis of prospective cohort studies at the National Cancer Center (NCC) in China from January 2006 to December 2022. A comprehensive LCS initiative was undertaken, involving 30,468 participants (54.5% male). Participants underwent LCS using LDCT. Potential malignancies were managed through joint consensus between patients and their physicians. Epidemiology, screening eligibility criteria, and LC detection rates and survival outcomes were compared between individuals who smoked and individuals who never smoked.

RESULTS

Among 30,468 participants, 339 LCs were pathologically confirmed in 289 patients. The LC detection rate was 0.9% (289/30,468) overall, 0.8% in individuals who smoked (71/9,042), and 1.0% in individuals who never smoked (218/21,426). In individuals who smoked, LC detection rates were 0.5% (21/4516) and 1.1% (50/4526) in the < 20 and ≥ 20 pack-year subgroups, respectively (P = 0.001). Early-stage LC (stage 0 or I) was detected in 73.8% of the individuals who smoked and in 78.8% of individuals who never smoked, while advanced LC (stage III-IV) was found 8.8% of individuals who smoked and 4.2% of individuals who never smoked, respectively. Significant differences in histologic types were found between individuals who smoked and individuals who never smoked (P = 0.01), although adenocarcinoma was the most prevalent in both groups, at 83.0% and 78.8%, respectively. The median nodule size was 9.9 mm (IQR, 8.0-13.8) in individuals who smoked and 9.2 mm (IQR, 6.8-13.6) in individuals who never smoked (P = 0.228). Individuals who never smoked tended to favour surgical treatment alone (88.0%) more than individuals who smoked (81.3%). The 10-year survival rate was higher in individuals who never smoked (92.6%) than in individuals who smoked (88.8%). Only 15.6% (45/289) of patients with LC met the United States Preventive Services Task Force (USPSTF) criteria for LDCT eligibility, while 29.0% (84/289) met the China guideline for the screening and early detection of lung cancer (CGSL) criteria. Median follow-up for those followed was 25.4 (IQR, 13.7-43.3) months.

CONCLUSIONS

LDCT screening improves early LC detection and treatment outcomes for both individuals who smoked and individuals who never smoked. Significant differences exist in epidemiology, histologic type, and survival between these groups. The USPSTF and CGSL criteria miss a significant number of LC cases, particularly among individuals who never smoked. Integrating individuals who never smoked into LCS programs is essential, yet it comes with its own challenges, such as managing radiation risks, allocating resources effectively, and considering financial aspects. Consequently, there is an urgent need for LCS programs in China to better identify the "high-risk" non-smoker population susceptible to LC and to ensure that potential risks associated with screening are reduced.

What's behind thoracic surgery explosion in young patients under the age of 40 in Wuhan after COVID-19 outbreak?

INTRODUCTION

The COVID-19 pandemic was associated with a dramatic increase of chest CT scanning in Wuhan. This was partly a COVID effect: some private and public employers required employees to have CT examinations to confirm they were healthy before going back to work. But it also likely reflects the growing enthusiasm for low-dose computed tomography (LDCT) screening. This investigation examines the resulting impact in the under 40 population.

METHODS

The relevant de-identified information of the patients under age 40 who had also received thoracic surgery from 2018 to 2022 was analyzed using the medical record information system of Tongji Hospital in Wuhan.

RESULTS

The volume of thoracic surgeries increased continuously in young patients under the age of 40, from 219 in 2018 to 732 in 2022. The number of surgeries for pulmonary nodules or masses in this group increased over 6-fold, from 91 to 576. The number of surgeries leading to a diagnosis of adenocarcinoma of the lung increased more than 15-fold, from 26 to 415. The median adenocarcinoma size fell in half (from 15 mm to 7 mm) and the most common stage changed from Stage I invasive (46 % of adenocarcinomas in 2018) to microinvasive (60 % of adenocarcinomas in 2022). 70 % of lung adenocarcinomas were found in females.

CONCLUSIONS

There had been an explosion of thoracic surgery for adenocarcinomas among the under-40 population in Wuhan. The decrease in tumor size and the increase in microinvasive and in situ lesions in this young age group suggest considerable overdiagnosis. We should be vigilant about the risk of overdiagnosis and overtreatment especially in young women.

Lung cancer screening in never smokers

PURPOSE OF REVIEW

Low-dose computed tomography (LDCT) lung cancer screening has been established in smokers, but its role in never smokers remains unclear. The differences in lung cancer biology between smokers and nonsmokers highlight the importance of a discriminated approach. This overview focuses on the emerging data and implementation challenges for LDCT screening in nonsmokers.

RECENT FINDINGS

The first LDCT screening study in nonsmokers enriched with risk factors demonstrated a lung cancer detection rate double that of the phase 3 trials in smokers. The relative risk of lung cancer detected by LDCT has also been found to be similar amongst female never smokers and male ever smokers in Asia. Majority of lung cancers detected through LDCT screening are stage 0/1, leading to concerns of overdiagnosis. Risk prediction models to enhance individual selection and nodule management could be useful to enhance the utility of LDCT screening in never smokers.

SUMMARY

With appropriate risk stratification, LDCT screening in never smokers may attain similar efficacy as compared to smokers. A global effort is needed to generate evidence surrounding optimal screening strategies, as well as health and economic benefits to determine the suitability of widespread implementation.

Lymphangioleiomyomatosis as a potent lung cancer risk factor: Insights from a Japanese large cohort study

BACKGROUND AND OBJECTIVE

Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease associated with the functional tumour suppressor genes TSC1 and TSC2 and causes structural destruction in the lungs, which could potentially increase the risk of lung cancer. However, this relationship remains unclear because of the rarity of the disease.

METHODS

We investigated the relative risk of developing lung cancer among patients diagnosed with LAM between 2001 and 2022 at a single high-volume centre in Japan, using data from the Japanese Cancer Registry as the reference population. Next-generation sequencing (NGS) was performed in cases where tumour samples were available.

RESULTS

Among 642 patients diagnosed with LAM (sporadic LAM, n = 557; tuberous sclerosis complex-LAM, n = 80; unclassified, n = 5), 13 (2.2%) were diagnosed with lung cancer during a median follow-up period of 5.13 years. All patients were female, 61.5% were never smokers, and the median age at lung cancer diagnosis was 53 years. Eight patients developed lung cancer after LAM diagnosis. The estimated incidence of lung cancer was 301.4 cases per 100,000 person-years, and the standardized incidence ratio was 13.6 (95% confidence interval, 6.2-21.0; p = 0.0008). Actionable genetic alterations were identified in 38.5% of the patients (EGFR: 3, ALK: 1 and ERBB2: 1). No findings suggested loss of TSC gene function in the two patients analysed by NGS.

CONCLUSION

Our study revealed that patients diagnosed with LAM had a significantly increased risk of lung cancer. Further research is warranted to clarify the carcinogenesis of lung cancer in patients with LAM.

Screening Low-Risk Individuals for Lung Cancer: The Need May Be Present, but the Evidence of Benefit Is Not

Worldwide, lung cancer is the most common killer among cancers, advanced disease has worse outcomes, earlier stage detection leads to better outcomes, and high-quality screening has a favorable net benefit. With the mortality reduction recognized from annual low-radiation dose computed tomography by screening those at high risk, there has been consideration that this benefit could translate to those who have never smoked. There have been several large-scale, single-arm, observational trials in Asia in persons with light to no smoking histories, with or without a family history of lung cancer, which have revealed high or higher lung cancer detection rates than previously reported in high-risk persons who currently or formerly smoked. The Early Detection Program for Lung Cancer in Taiwan, of nearly 50,000 persons, revealed that the cancer detection rate for those screened with low-radiation dose computed tomography was more than twofold higher in light- or never-smokers with a family history of lung cancer compared with high-risk persons with more than 30 or more pack-years exposure and meeting U.S. Preventative Services Task Force criteria for screening. In addition, more than 90% of the cancers detected in those with a family history were in early stage. On the basis of those findings, the researchers concluded that screening first-degree relatives of those with a family history of lung cancer, irrespective of smoking history, would lead to a decrease in lung cancer mortality. We believe that the findings in this cohort and others like it represent substantial overdiagnosis and that the harms associated with screening a population that has a low likelihood of developing lethal cancers have not been thoroughly considered. Here, we provide our perspective and consider the potential benefits and harms of screening populations outside those currently eligible using the U.S. Preventative Services Task Force criteria.

Impact of annual trend volume of low-dose computed tomography for lung cancer screening on overdiagnosis, overmanagement, and gender disparities

BACKGROUND

With the increasing prevalence of nonsmoking-related lung cancer in Asia, Asian countries have increasingly adopted low-dose computed tomography (LDCT) for lung cancer screening, particularly in private screening programs. This study examined how annual LDCT volume affects lung cancer stage distribution, overdiagnosis, and gender disparities using a hospital-based lung cancer database.

METHODS

This study analyzed the annual utilized LDCT volume, clinical characteristics of lung cancer, stage shift distribution, and potential overdiagnosis. At the individual level, this study also investigated the relationship between stage 0 lung cancer (potential strict definition regarding overdiagnosis) and the clinical characteristics of lung cancer.

RESULTS

This study reviewed the annual trend of 4971 confirmed lung cancer cases from 2008 to 2021 and conducted a link analysis with an LDCT imaging examination database over these years. As the volume of lung cancer screenings has increased over the years, the number and proportion of stage 0 lung cancers have increased proportionally. Our study revealed that the incidence of stage 0 lung cancer increased with increasing LDCT scan volume, particularly during the peak growth period from 2017 to 2020. Conversely, stage 4 lung cancer cases remained consistent across different time intervals. Furthermore, the increase in the lung cancer screening volume had a more pronounced effect on the increase in stage 0 lung cancer cases among females than it had among males. The estimated potential for overdiagnosis brought about by the screening process, compared to non-participating individuals, ranged from an odds ratio of 7.617 to one of 17.114. Both strict and lenient definitions of overdiagnosis (evaluating cases of stage 0 lung cancer and stages 0 to 1 lung cancer) were employed.

CONCLUSIONS

These results provide population-level evidence of potential lung cancer overdiagnosis in the Taiwanese population due to the growing use of LDCT screening, particularly concerning the strict definition of stage 0 lung cancer. The impact was greater in the female population than in the male population, especially among females younger than 40 years. To improve lung cancer screening in Asian populations, creating risk-based prediction models for smokers and nonsmokers, along with gender-specific strategies, is vital for ensuring survival benefits and minimizing overdiagnosis.

A comprehensive approach for osteoporosis detection through chest CT analysis and bone turnover markers: harnessing radiomics and deep learning techniques

Purpose

The main objective of this study is to assess the possibility of using radiomics, deep learning, and transfer learning methods for the analysis of chest CT scans. An additional aim is to combine these techniques with bone turnover markers to identify and screen for osteoporosis in patients.

Method

A total of 488 patients who had undergone chest CT and bone turnover marker testing, and had known bone mineral density, were included in this study. ITK-SNAP software was used to delineate regions of interest, while radiomics features were extracted using Python. Multiple 2D and 3D deep learning models were trained to identify these regions of interest. The effectiveness of these techniques in screening for osteoporosis in patients was compared.

Result

Clinical models based on gender, age, and β-cross achieved an accuracy of 0.698 and an AUC of 0.665. Radiomics models, which utilized 14 selected radiomics features, achieved a maximum accuracy of 0.750 and an AUC of 0.739. The test group yielded promising results: the 2D Deep Learning model achieved an accuracy of 0.812 and an AUC of 0.855, while the 3D Deep Learning model performed even better with an accuracy of 0.854 and an AUC of 0.906. Similarly, the 2D Transfer Learning model achieved an accuracy of 0.854 and an AUC of 0.880, whereas the 3D Transfer Learning model exhibited an accuracy of 0.740 and an AUC of 0.737. Overall, the application of 3D deep learning and 2D transfer learning techniques on chest CT scans showed excellent screening performance in the context of osteoporosis.

Conclusion

Bone turnover markers may not be necessary for osteoporosis screening, as 3D deep learning and 2D transfer learning techniques utilizing chest CT scans proved to be equally effective alternatives.

Evaluating Efficiency and Adherence in Asian Lung Cancer Screening: Comparing Self-paid and Clinical Study Approaches in Taiwan

RATIONALE AND OBJECTIVES

This study aimed to assess how different screening methods, specifically self-paid screening versus participation in clinical studies, affect screening efficiency and adherence in a real-world Asian lung cancer screening population.

MATERIALS AND METHODS

This study collected 4166 participants from our hospital imaging database who underwent baseline low-dose computed tomography (LDCT) between January 2014 and August 2021. Adherence status was determined by counting CT scans, with one check indicating non-adherence and two or more checks indicating adherence. The primary objective was to investigate adherence to LDCT follow-up schedules among individuals with baseline pure ground-glass nodules (GGNs) based on different screening settings and to evaluate adherence status and CT follow-up clinical profiles.

RESULTS

Of the 4166 participants in the study, 3619 in the self-paid group and 547 in the clinical study group were men, with an average follow-up period of 4.5 years. Significant differences were observed in the proportions of Lung-RADS 4 lesions, subsolid nodules, and pure GGN lesions between the self-paid and clinical trial groups. A significant difference was found in adherence rates between the self-paid screening group (60.5%) and the clinical study group (84.8%) (p < 0.001). Adherence status rates significantly increased with larger GGN sizes across categories (p < 0.001). Multivariate logistic regression revealed that age (odds ratio [OR], 1.025; p = 0.012), smoking habits (OR, 1.744; p = 0.036), and clinical study screening type (OR, 3.097; p < 0.001) significantly influenced the adherence status.

CONCLUSION

The disparities in Asian lung cancer screening emphasize the need for increased efficacy, public awareness, and culturally sensitive approaches to mitigate overdiagnosis and enhance adherence among self-paying groups.

Possible overdiagnosis of early-stage lung adenocarcinoma among never-smokers in Taiwan

10-year survival for never-smokers with >1 cm but ≤3 cm AIS/BAC/MIA was not inferior to that of the matched referents, pointing to possible overdiagnosis. Clinicians might consider adhering to Lung-RADS and watchful waiting for these non-solid nodules. https://bit.ly/41U6kxs.

Lung Cancer Risk Prediction Models for Asian Ever-Smokers

INTRODUCTION

Although lung cancer prediction models are widely used to support risk-based screening, their performance outside Western populations remains uncertain. This study aims to evaluate the performance of 11 existing risk prediction models in multiple Asian populations and to refit prediction models for Asians.

METHODS

In a pooled analysis of 186,458 Asian ever-smokers from 19 prospective cohorts, we assessed calibration (expected-to-observed ratio) and discrimination (area under the receiver operating characteristic curve [AUC]) for each model. In addition, we developed the "Shanghai models" to better refine risk models for Asians on the basis of two well-characterized population-based prospective cohorts and externally validated them in other Asian cohorts.

RESULTS

Among the 11 models, the Lung Cancer Death Risk Assessment Tool yielded the highest AUC (AUC [95% confidence interval (CI)] = 0.71 [0.67-0.74] for lung cancer death and 0.69 [0.67-0.72] for lung cancer incidence) and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial Model had good calibration overall (expected-to-observed ratio [95% CI] = 1.06 [0.90-1.25]). Nevertheless, these models substantially underestimated lung cancer risk among Asians who reported less than 10 smoking pack-years or stopped smoking more than or equal to 20 years ago. The Shanghai models were found to have marginal improvement overall in discrimination (AUC [95% CI] = 0.72 [0.69-0.74] for lung cancer death and 0.70 [0.67-0.72] for lung cancer incidence) but consistently outperformed the selected Western models among low-intensity smokers and long-term quitters.

CONCLUSIONS

The Shanghai models had comparable performance overall to the best existing models, but they improved much in predicting the lung cancer risk of low-intensity smokers and long-term quitters in Asia.

Low-dose CT screening among never-smokers with or without a family history of lung cancer in Taiwan: a prospective cohort study

BACKGROUND

In Taiwan, lung cancers occur predominantly in never-smokers, of whom nearly 60% have stage IV disease at diagnosis. We aimed to assess the efficacy of low-dose CT (LDCT) screening among never-smokers, who had other risk factors for lung cancer.

METHODS

The Taiwan Lung Cancer Screening in Never-Smoker Trial (TALENT) was a nationwide, multicentre, prospective cohort study done at 17 tertiary medical centres in Taiwan. Eligible individuals had negative chest radiography, were aged 55-75 years, had never smoked or had smoked fewer than 10 pack-years and stopped smoking for more than 15 years (self-report), and had one of the following risk factors: a family history of lung cancer; passive smoke exposure; a history of pulmonary tuberculosis or chronic obstructive pulmonary disorders; a cooking index of 110 or higher; or cooking without using ventilation. Eligible participants underwent LDCT at baseline, then annually for 2 years, and then every 2 years up to 6 years thereafter, with follow-up assessments at each LDCT scan (ie, total follow-up of 8 years). A positive scan was defined as a solid or part-solid nodule larger than 6 mm in mean diameter or a pure ground-glass nodule larger than 5 mm in mean diameter. Lung cancer was diagnosed through invasive procedures, such as image-guided aspiration or biopsy or surgery. Here, we report the results of 1-year follow-up after LDCT screening at baseline. The primary outcome was lung cancer detection rate. The p value for detection rates was estimated by the χ2 test. Univariate and multivariable logistic regression analyses were used to assess the association between lung cancer incidence and each risk factor. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of LDCT screening were also assessed. This study is registered with ClinicalTrials.gov, NCT02611570, and is ongoing.

FINDINGS

Between Dec 1, 2015, and July 31, 2019, 12 011 participants (8868 females) were enrolled, of whom 6009 had a family history of lung cancer. Among 12 011 LDCT scans done at baseline, 2094 (17·4%) were positive. Lung cancer was diagnosed in 318 (2·6%) of 12 011 participants (257 [2·1%] participants had invasive lung cancer and 61 [0·5%] had adenocarcinomas in situ). 317 of 318 participants had adenocarcinoma and 246 (77·4%) of 318 had stage I disease. The prevalence of invasive lung cancer was higher among participants with a family history of lung cancer (161 [2·7%] of 6009 participants) than in those without (96 [1·6%] of 6002 participants). In participants with a family history of lung cancer, the detection rate of invasive lung cancer increased significantly with age, whereas the detection rate of adenocarcinoma in situ remained stable. In multivariable analysis, female sex, a family history of lung cancer, and age older than 60 years were associated with an increased risk of lung cancer and invasive lung cancer; passive smoke exposure, cumulative exposure to cooking, cooking without ventilation, and a previous history of chronic lung diseases were not associated with lung cancer, even after stratification by family history of lung cancer. In participants with a family history of lung cancer, the higher the number of first-degree relatives affected, the higher the risk of lung cancer; participants whose mother or sibling had lung cancer were also at an increased risk. A positive LDCT scan had 92·1% sensitivity, 84·6% specificity, a PPV of 14·0%, and a NPV of 99·7% for lung cancer diagnosis.

INTERPRETATION

TALENT had a high invasive lung cancer detection rate at 1 year after baseline LDCT scan. Overdiagnosis could have occurred, especially in participants diagnosed with adenocarcinoma in situ. In individuals who do not smoke, our findings suggest that a family history of lung cancer among first-degree relatives significantly increases the risk of lung cancer as well as the rate of invasive lung cancer with increasing age. Further research on risk factors for lung cancer in this population is needed, particularly for those without a family history of lung cancer.

FUNDING

Ministry of Health and Welfare of Taiwan.

Long-term trends of lung cancer incidence and survival in southeastern China, 2011-2020: a population-based study

BACKGROUND

Lung cancer is the primary cause of cancer-related deaths in China. This study analysed the incidence and survival trends of lung cancer from 2011 to 2020 in Fujian Province, southeast of China, and provided basis for formulating prevention and treatment strategies.

METHODS

The population-based cancer data was used to analyse the incidence of lung cancer between 2011 and 2020, which were stratified by sex, age and histology. The change of incidence trend was analysed using Joinpoint regression. The relative survival of lung cancer with onset in 2011-2014, 2015-2017 and 2018-2020 were calculated using the cohort, complete and period methods, respectively.

RESULTS

There were 23,043 patients diagnosed with lung cancer in seven registries between 2011 and 2020, with an age-standardized incidence rate (ASIR) of 37.7/100,000. The males ASIR increased from 51.1/100,000 to 60.5/100,000 with an annual percentage change (APC) of 1.5%. However, females ASIR increased faster than males, with an APC of 5.7% in 2011-2017 and 21.0% in 2017-2020. Compared with 2011, the average onset age of males and females in 2020 was 1.5 years and 5.9 years earlier, respectively. Moreover, the proportion of adenocarcinoma has increased, while squamous cell carcinoma and small cell carcinoma have decreased over the past decade. The 5-year relative survival of lung cancer increased from 13.8 to 23.7%, with a greater average increase in females than males (8.7% and 2.6%). The 5-year relative survival of adenocarcinoma, squamous cell carcinoma and small cell carcinoma reached 47.1%, 18.3% and 6.9% in 2018-2020, respectively.

CONCLUSIONS

The incidence of lung cancer in Fujian Province is on the rise, with a significant rise in adenocarcinoma, a younger age of onset and the possibility of overdiagnosis. Thus, Fujian Province should strengthen the prevention and control of lung cancer, giving more attention to the prevention and treatment of lung cancer in females and young populations.

Cancer Screening, Incidental Detection, and Overdiagnosis

BACKGROUND

In the past, patients were only diagnosed with cancer because they had symptoms. Now, because of screening and incidental detection, some patients are diagnosed with cancer when they are asymptomatic. While this shift is typically viewed as desirable, it has produced an unfortunate side-effect: it is now possible to be diagnosed with a cancer not destined to cause symptoms or death-a phenomenon labeled as overdiagnosis.

CONTENT

We begin with a brief introduction to the heterogeneity of cancer progression: at one extreme, some cancers are already systemic by the time they are detectable; at the other, some grow extremely slowly or even regress. The ensuing sections describe the evidence that the pursuit of earlier detection has led to overdiagnosis. Although rarely confirmed in an individual, overdiagnosis is readily identifiable in a long-term follow-up of a randomized trial of screening. Furthermore, 2 population signatures for overdiagnosis exist: (a) rising incidence coupled with stable mortality and (b) rising early-stage incidence coupled with stable late-stage incidence. Finally, we review the misleading feedback produced by overdiagnosis-such as rising 5-year survival rates and more cancer survivors. This feedback is erroneously interpreted as reinforcing the value of early detection, encourages more screening/incidental detection and, ironically, promotes more overdiagnosis.

SUMMARY

Overdiagnosis is an unintended consequence of the desire to detect cancer early. Given the evolving understanding that tumor biology and host response are more relevant to prognosis than early vs late diagnosis, it is time to challenge the assertion that early diagnosis is always the best approach to curing cancer.

Incidence of Lung Adenocarcinoma by Age, Sex, and Smoking Status in Taiwan

Importance

Knowing whether the effects of smoking and other risk factors with lung adenocarcinoma (ADC) incidence varies by sex would provide information on lung cancer prevention strategies.

Objective

To evaluate whether women in Taiwan have higher age- and tumor stage-specific lung ADC incidence rates than men irrespective of smoking status (ie, ever smoker or never smoker).

Design, Setting, and Participants

This population-based cohort study used data sets synthesized from the Taiwan Cancer Registry (TCR) from 1979 to 2019; the TCR Long Form (TCRLF) from 2011 to 2019, which provides individual-level smoking and tumor stage information; the Taiwan Cause of Death Database (TCOD) from 1985 to 2019; the National Health Insurance Research Database (NHIRD) from 2000 to 2020; the Monthly Bulletin of Interior Statistics (MBIS) from 2011 to 2019; the National Health Interview Survey from 2001, 2005, 2009, 2013, and 2017; and Taiwan Biobank data from 2008 to 2021. Included patients were aged 40 to 84 years and had any invasive lung cancer from January 1, 2011, to December 31, 2019.

Exposure

Smoking status.

Main Outcomes and Measures

The main outcomes were age-specific female-to-male incidence rate ratios (IRRs) of lung ADC by smoking status and tumor stage. Linked data from the TCR, TCOD, NHIRD, Taiwan National Health Interview Survey, and MBIS were used to estimate the age- and sex-specific numbers of cancer-free individuals at midyears from 2011 to 2019 by smoking status. Using the TCR and TCRLF, age-, sex-, tumor stage-, and diagnosis year-specific numbers of patients with lung ADC from 2011 to 2019 by smoking status were estimated.

Results

A total of 61 285 patients (32 599 women [53.2%]) aged 40 to 84 years (mean [SD] age, 64.66 [10.79] years) in the Taiwanese population of approximately 23 million were diagnosed with invasive lung ADC as their first lifetime cancer between 2011 and 2019. Among smokers, men had higher tobacco use by almost all examined metrics, including nearly twice the mean (SD) number of pack-years smoked (eg, 7.87 [8.30] for men aged 30-34 years vs 4.38 [5.27] for women aged 30-34 years). For 5-year age bands between 40 and 84 years, incidence of lung ADC was significantly higher among females than males for nearly all age groups irrespective of tumor stage and smoking status (eg, for the age group 70-74 years, the female-to-male IRR for late-stage lung ADC among never smokers was 1.38 [95% CI, 1.30-1.50]).

Conclusions and Relevance

In this cohort study, women had higher age- and stage-specific lung ADC incidence rates than men in Taiwan for both never and ever smokers, suggesting the possibility of differential exposures between sexes to risk factors other than smoking and the potential modification of ADC risk factors by sex. Further work is needed to determine whether this pattern replicates in other populations, discover the causes of lung ADC, and put preventive measures in place.

Managing Persistent Subsolid Nodules in Lung Cancer: Education, Decision Making, and Impact of Interval Growth Patterns

With the popularization of lung cancer screening, many persistent subsolid nodules (SSNs) have been identified clinically, especially in Asian non-smokers. However, many studies have found that SSNs exhibit heterogeneous growth trends during long-term follow ups. This article adopted a narrative approach to extensively review the available literature on the topic to explore the definitions, rationale, and clinical application of different interval growths of subsolid pulmonary nodule management and follow-up strategies. The development of SSN growth thresholds with different growth patterns could support clinical decision making with follow-up guidelines to reduce over- and delayed diagnoses. In conclusion, using different SSN growth thresholds could optimize the follow-up management and clinical decision making of SSNs in lung cancer screening programs. This could further reduce the lung cancer mortality rate and potential harm from overdiagnosis and over management.