Lung Cancer Epidemiology in Korea

Observed and relative survival trends of lung cancer: A systematic review of population-based cancer registration data

BACKGROUND

Using the published survival statistics from cancer registration or population-based studies, we aimed to describe the global pattern and trend of lung cancer survival.

METHODS

By searching SinoMed, PubMed, Web of Science, EMBASE, and SEER, all survival analyses from cancer registration or population-based studies of lung cancer were collected by the end of November 2022. The survival rates were extracted by sex, period, and country. The observed, relative, and net survival rates of lung cancer were applied to describe the pattern and time changes from the late 1990s to the early 21st century.

RESULTS

Age-standardized 5-year relative/net survival rate of lung cancer was typically low, with 10%-20% for most regions. The highest age-standardized relative/net survival rate was observed in Japan (32.9%, 2010-2014), and the lowest was in India (3.7%, 2010-2014). In most countries, the five-year age-standardized relative/net survival rates of lung cancer were higher in females and younger people. The patients with adenocarcinoma had a better prognosis than other groups. In China, the highest 5-year overall relative/net survival rates were 27.90% and 31.62% in men and women in Jiangyin (2012-2013).

CONCLUSION

Over the past decades, the prognosis of lung cancer has gradually improved, but significant variations were also observed globally. Worldwide, a better prognosis of lung cancer can be observed in females and younger patients. It is essential to compare and evaluate the histological or stage-specific survival rates of lung cancer between different regions in the future.

Clinical implication of the 2020 International Association for the Study of Lung Cancer histologic grading in surgically resected pathologic stage 1 lung adenocarcinomas: Prognostic value and association with computed tomography characteristics

OBJECTIVES

To investigate the incremental prognostic value of the 2020 International Association for the Study of Lung Cancer (IASLC) histologic grading system over traditional prognosticators in surgically resected pathologic stage 1 lung adenocarcinomas and to identify the clinical and radiologic characteristics of lung adenocarcinomas reclassified by the 2020 histologic grading system.

MATERIALS AND METHODS

We retrospectively enrolled 356 patients who underwent surgery for pathologic stage 1 adenocarcinoma between January 2016 and December 2017. The histologic grading was classified according to the predominant histologic subtype (conventional system) and the updated 2020 IASLC grading system. The clinical and computed tomography (CT) characteristics were compared according to the reclassification of the updated system. The performance of prognostic models for recurrence-free survival based on the combination of pathologic tumor size, histologic grade, and CT-based information was compared using the c-index.

RESULTS

Postoperative recurrence occurred in 6.7% of patients during the follow-up period (mean, 1589.2 ± 406.7 days). Fifty-nine of 244 (24.2%) tumors with intermediate grades in the conventional system were reclassified as grade 3 with the updated grading system. They showed significantly larger solid proportions and higher percentages of pure solid nodules on CT compared to tumors without reclassification (n = 185) (P < 0.05). Prognostic prediction models based on pathology tumor size and histologic grades had significantly higher c-indices (0.754-0.803) compared to the model based on pathologic tumor size only (c-index:0.723, P < 0.05).

CONCLUSION

The 2020 IASLC histologic grading system has significant incremental prognostic value over the pathologic stage in surgically resected pathologic stage 1 lung adenocarcinoma. Reclassified lung adenocarcinomas using the updated grading system have a larger solid proportion and a higher percentage of pure solid nodules on CT.

Pembrolizumab plus chemotherapy for advanced non-small-cell lung cancer without tumor PD-L1 expression in Asia

Aim: We pooled patient-level data from three randomized controlled studies to evaluate the combination of pembrolizumab plus chemotherapy in patients with untreated advanced/metastatic non-small-cell lung cancer (NSCLC) and programmed cell death ligand 1 (PD-L1) tumor proportion score <1% in East Asia. Methods: The analysis included 107 patients from China, Japan, Korea, Thailand and Taiwan (pembrolizumab plus chemotherapy, n = 56; chemotherapy alone, n = 51). Results: For pembrolizumab plus chemotherapy versus chemotherapy alone, median overall survival was 21.3 versus 12.6 months (HR, 0.55 [95% CI: 0.35-0.87]) and median progression-free survival was 8.4 versus 6.0 months (HR, 0.64 [95% CI: 0.43-0.96]). Conclusion: The analysis supports the use of pembrolizumab in combination with platinum-based chemotherapy for East Asian patients with PD-L1-negative, advanced NSCLC.

Incidence trends and spatial distributions of lung adenocarcinoma and squamous cell carcinoma in Taiwan

Lung cancer is the second most common cancer in Taiwan. After Taiwan implemented the Tobacco Hazards Prevention Act in 1997, smoking rates declined. However, the incidence rates of lung cancer for both sexes are still increasing, possibly due to risk factors other than smoking. We used age-period-cohort analysis to examine the secular trends of lung cancer incidence rates by histological type in Taiwan. A stabilized kriging method was employed to map these lung cancer incidence rates. Lung adenocarcinoma incidence rates increased, but lung squamous cell carcinoma incidence rates decreased, for both the sexes in recent birth cohorts, particularly in women. In Taiwan, the hotspots of lung adenocarcinoma incidence rates were in the northern, northeastern, and western coastal areas; the incidence rates increased rapidly in the western and southern coastal regions and southern mountainous regions. The high incidence rates of lung squamous cell carcinoma in men were in the southwestern and northeastern coastal areas. The incidence rates rapidly increased in the central and southern coastal and mountainous regions. For both sexes in Taiwan, lung squamous cell carcinoma incidence rates declined from 1997 to 2017, but lung adenocarcinoma increased. The increased incidence rates of lung adenocarcinoma may be related to indoor and outdoor air pollution. Some areas in Taiwan have increasing lung cancer incidence rates, including the northwestern and southern coasts and mountains, and warrant particular attention.

Five-Year Overall Survival and Prognostic Factors in Patients with Lung Cancer: Results from the Korean Association of Lung Cancer Registry (KALC-R) 2015

PURPOSE

This study aimed to provide the clinical characteristics, prognostic factors, and 5-year relative survival rates of lung cancer diagnosed in 2015.

MATERIALS AND METHODS

The demographic risk factors of lung cancer were calculated using the KALC-R (Korean Association of Lung Cancer Registry) cohort in 2015, with survival follow-up until December 31, 2020. The 5-year relative survival rates were estimated using Ederer II methods, and the general population data used the death rate adjusted for sex and age published by the Korea Statistical Information Service from 2015 to 2020.

RESULTS

We enrolled 2,657 patients with lung cancer who were diagnosed in South Korea in 2015. Of all patients, 2,098 (79.0%) were diagnosed with non-small cell lung cancer (NSCLC) and 345 (13.0%) were diagnosed with small cell lung cancer (SCLC), respectively. Old age, poor performance status, and advanced clinical stage were independent risk factors for both NSCLC and SCLC. In addition, the 5-year relative survival rate declined with advanced stage in both NSCLC (82%, 59%, 16%, 10% as the stage progressed) and SCLC (16%, 4% as the stage progressed). In patients with stage IV adenocarcinoma, the 5-year relative survival rate was higher in the presence of epidermal growth factor receptor (EGFR) mutation (19% vs. 11%) or anaplastic lymphoma kinase (ALK) translocation (38% vs. 11%).

CONCLUSION

In this Korean nationwide survey, the 5-year relative survival rates of NSCLC were 82% at stage I, 59% at stage II, 16% at stage III, and 10% at stage IV, and the 5-year relative survival rates of SCLC were 16% in cases with limited disease, and 4% in cases with extensive disease.

A global burden assessment of lung cancer attributed to residential radon exposure during 1990-2019

This study aimed to explore the spatial and temporal trends of lung cancer burden attributable to residential radon exposure at the global, regional, and national levels. Based on the Global Burden of Disease Study (GBD) 2019, we collected the age-standardized mortality rate (ASMR) and age-standardized disability-adjusted life rate (ASDR) of lung cancer attributable to residential radon exposure from 1990 to 2019. The Joinpoint model was used to calculate the annual average percentage change (AAPC) to evaluate the trend of ASMR and ASDR from 1990 to 2019. The locally weighted regression (LOESS) was used to estimate the relationship of the socio-demographic index (SDI) with ASMR and ASDR. In 2019, the global ASMR and ASDR for lung cancer attributable to residential radon exposure were 1.03 (95% CI: 0.20, 2.00) and 22.66 (95% CI: 4.49, 43.94) per 100 000 population, which were 15.6% and 23.0% lower than in 1990, respectively. According to the estimation, we found the lung cancer burden attributable to residential radon exposure declined significantly in high and high-middle SDI regions, but substantially increased in middle and low-middle SDI regions from 1990 to 2019. Across age and sex, the highest burden of lung cancer attributable to residential radon exposure was found in males and elderly groups. In conclusion, the global burden of lung cancer attributable to residential radon exposure showed a declining trend from 1990 to 2019, but a relatively large increase was found in the middle SDI regions. In 2019, the burden of lung cancer attributable to residential radon exposure remained high, particularly in males, the elderly, and high-middle SDI regions compared with other groups.

Epidemiological characteristics and risk factors of lung adenocarcinoma: A retrospective observational study from North China

Background

The main aim of the study was to determine the risk factors of lung adenocarcinoma and to analyze the variations in the incidence of lung adenocarcinoma according to time, sex, and smoking status in North China.

Methods

Patients with lung cancer in local household registries diagnosed and treated for the first time in the investigating hospital were enrolled from 11 cities in North China between 2010 and 2017. Baseline characteristics and tumor-related information were extracted from the patients' hospital medical record, clinical course records, and clinical examination. Some of the variables, such as smoking, alcohol consumption, medical history, and family history of cancer, were obtained from interviews with the enrolled patients. The statistical method used were the chi-square test and multi-factor logistic regression analysis. The time trend was statistically analyzed using Joinpoint regression models, and p values were calculated.

Results

A total of 23,674 lung cancer cases were enrolled. People in severely polluted cities were at higher risk for lung adenocarcinoma (p < 0.001). Most patients with lung adenocarcinoma had no history of lung-related diseases (p = 0.001). Anatomically, lung adenocarcinoma was more likely to occur in the right lung (p < 0.001). Non-manual labor workers were more likely to develop from lung adenocarcinoma than manual workers (p = 0.015). Notably, non-smokers were more likely to develop lung adenocarcinoma than smokers (p < 0.001). The proportion of lung adenocarcinoma increased significantly in Hebei Province (p < 0.001). Among non-smokers, the proportion of lung adenocarcinoma showed a higher rise than in smokers (p < 0.001).

Conclusions

Lung adenocarcinoma is the most common histological type of lung cancer in North China (Hebei Province), and the proportion of lung adenocarcinoma is increasing, especially among non-smokers. Lung adenocarcinoma is more common in women, severely polluted cities, individuals with no history of lung-related diseases, in the right lung, and in non-smokers. These can serve as a great guide in determining the accuracy of lung adenocarcinoma high-risk groups and lung cancer risk assessment models.

Lung Cancer Patients' Characteristics and Comorbidities Using the Korean National Hospital Discharge In-depth Injury Survey Data

Background

The aim of this study was to assess the incidence of lung cancer and comorbidities in Korea and analyze the lung cancer patient’s characteristics and their comorbidities over the past 12 years. This study also aimed to investigate factors related to death as treatment outcome in discharged lung cancer patients.

Methods

This study analyzed the data obtained from the Korean National Hospital Discharge In-depth Injury Survey from 2006 to 2017. The quantity of discharged lung cancer patients was assessed by year. Comorbidities were limited to those included in the Elixhauser Comorbidity Index (ECI). A Chi-square test was performed to determine statistically significant differences in the distributions of the ECI and ECI scores according to the presence or absence of metastatic cancer. Logistic regression analysis was used to analyze factors related to death as treatment outcome.

Results

From 2006 to 2017, the number of discharged male and female patients with lung cancer increased from 31,720 to 42,016 and 10,897 to 18,197, respectively. The increase in the number of lung cancer patients was greater in women than in men (67.0% vs. 32.5%, respectively). The most common associated comorbidities were hypertension, diabetes, and chronic pulmonary disease. The factors related to death as treatment outcome were found to include sex, admission route, number of hospital beds, length of stay, presence or absence of metastatic cancer, and ECI score.

Conclusion

The number of lung cancer patients in Korea has increased, and a high proportion of these patients have chronic diseases, which negatively would impact the treatment and outcome of lung cancer patients as well as their quality of life. Thus, the management of chronic diseases needs to be prioritized in patients with lung cancer.

Flake Graphene-Based Nanomaterial Approach for Triggering a Ferroptosis as an Attractive Theranostic Outlook for Tackling Non-Small Lung Cancer: A Mini Review

Lung cancer is a highly aggressive neoplasm that is now a leading cause of cancer death worldwide. One of the major approaches for killing cancer cells is related with activation of apoptotic cell death with anti-cancer drugs. However, the efficiency of apoptosis induction in tumors is limited. Consequently, the development of other forms of non-apoptotic cell death is up to date challenge for scientists worldwide. This situation motivated us to define the aim of this mini-review: gathering knowledge regarding ferroptosis-newly defined programmed cell death process characterized by the excessive accumulation of iron-and combining it with yet another interesting nanomaterial-based graphene approach. In this manuscript, we presented brief information about non-small lung cancer and ferroptosis, followed by a section depicting the key-features of graphene-based nanomaterials influencing their biologically relevant properties.

Assessment of textbook outcome after lobectomy for early‐stage non‐small cell lung cancer in a Korean institution: A retrospective study

Background

Textbook outcome (TO) has been introduced as a novel composite measure for lung cancer surgery. We investigated TO after lobectomy for early‐stage non‐small cell lung cancer (NSCLC) in a Korean tertiary hospital and its prognostic implications for overall survival and recurrence.

Methods

Between January 2012 and December 2017, 418 consecutive patients who underwent lobectomy for clinical stages I and II NSCLC were identified and retrospectively reviewed. TO was defined as complete resection (negative resection margins and sufficient lymph node dissection), no 30‐day or in‐hospital mortality, no reintervention within 30 days, no readmission to the intensive care unit, no prolonged hospital stay (<14 days), no hospital readmission within 30 days, and no major complications. Propensity score matching analysis was performed to investigate the association between TO, medical costs, and long‐term outcomes.

Results

Of 418 patients, 277 (66.3%) achieved TO. The most common events leading to TO failure were prolonged air leakage (n = 54, 12.9%) and prolonged hospital stay (n = 53, 12.7%). Male sex (odds ratio [OR] = 2.148, p = 0.036) and low diffusing capacity for carbon monoxide (OR = 0.986, p = 0.047) were significant risk factors for failed TO in multivariate analysis. In matched cohorts, achieving TO was associated with lower medical costs and better overall survival but not cancer recurrence.

Conclusions

TO is associated with low medical cost and favorable overall survival; thus, surgical teams and hospitals should make efforts to improve the quality of care and achieve TO.

Exposure to Secondhand Smoke and a Tobacco-Specific Carcinogen in Non-Smokers

Background: The International Agency for Research on Cancer classifies 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) as a known carcinogen. This study aimed to investigate the association between exposure to secondhand smoke (SHS) and NNAL concentrations in non-smokers.Methods: This was a cross-sectional study based on data from the 2016 to 2018 Korea National Health and Nutrition Examination Survey. Urine NNAL concentrations were categorized into tertiles of 3,615 study participants who were non-smokers. All sampling and weight variables were stratified, and analyses to account for the complex sampling design were conducted.Results: The overall, male, and female percentages of SHS exposure among non-smokers were 22.4%, 29.2%, and 20.4%, respectively. The geometric means of urine NNAL concentrations were 1.896±0.098 pg/mL and 1.094±0.028 pg/mL in the SHS exposure and non-exposure groups, respectively. After adjusting for confounding variables, in the total group, the geometric mean of urine NNAL concentrations was significantly higher in the SHS exposure group than in the SHS non-exposure group (adjusted P-value <0.001). Compared with the non-exposure group, the adjusted odds ratios (95% confidence intervals) for the highest NNAL tertile group of overall SHS exposure in the total, men, and women groups were 2.44 (1.95–3.05), 1.65 (1.08–2.53), and 2.73 (2.11–3.52), respectively, after full adjustment.Conclusion: The urine NNAL concentration in the SHS exposure group was significantly higher than that in the non-exposure group. Exposure to SHS was associated with a higher risk of elevated urine NNAL concentrations in non-smokers.

Trends in lung cancer incidence by gender, histological type and stage at diagnosis in Japan, 1993-2015: A multiple imputation approach

Continued decrease in smoking prevalence and increasing use of sensitive diagnostic procedures necessitate updated monitoring of trends in lung cancer incidence in Japan. We analyzed histology- and stage-specific trends in 1993-2015 using data from 62,870 diagnosed cases from the Monitoring of Cancer Incidence in Japan project. After applying a multiple imputation approach to impute missing/unknown values of stage and histology, we estimated age-standardized incidence rates and applied joinpoint regression analyses. We observed long-term growth trends in adenocarcinoma (ADC) and localized cancer among both genders, long-term declining trends among men and leveling-off trends among women in small-cell carcinoma (SMC) and squamous cell carcinoma (SQC). Stratifying by gender, we observed an increase in localized ADC with average annual percentage changes (AAPC) of 4.5 (95% confidence interval: 3.9 to 5.0) and 5.7 (5.0 to 6.4), a decrease in regional ADC with AAPC of -1.5 (-2.5 to -0.6) and -2.3 (-4.6 to 0.0), but an increase in distant ADC with AAPC of 1.5 (1.1 to 1.9) and 1.6 (0.9 to 2.3) among males and females, respectively. Additionally, increasing trends in female-to-male incidence rate ratios were observed in localized ADC with significantly above one in the most recent diagnosis period. Our results revealed evidence for a partial shift from advanced to early cancer stage, which may suggest the modest effectiveness of nationwide organized screening programs. The observed increasing localized and distant ADC may be linked to improved diagnostic procedures, especially for metastasis detection. Further investigation is needed for more accurate quantification of these factors.

Differences in detection patterns, characteristics, and outcomes of central and peripheral lung cancers in low-dose computed tomography screening

Background

Although low-dose computed tomography (LDCT) screening is known to be effective for the detection of lung cancers localized in peripheral lung regions at a curable stage, limited data is available regarding the characteristics and outcomes of central lung cancers diagnosed in a screening cohort. This study aimed to determine whether LDCT screening could effectively detect central lung cancers at an early stage and offer survival benefits.

Methods

We analyzed 52,615 adults who underwent lung cancer screening with LDCT between May 2003 and Dec 2019 at a tertiary center in South Korea. Characteristics and outcomes of those diagnosed with lung cancer, stratified by screen-detection status and cancer location, were evaluated.

Results

A total of 352 individuals (281 screen-detected, 71 non-screen-detected) were diagnosed with lung cancer. Compared to screen-detected cancers, non-screen-detected cancers tended to be centrally-located (11.4% vs. 64.8%, P<0.001). Most non-screen-detected central cancers (89.1%) had a negative result on prior LDCT screening. Multivariable regression analyses revealed that for peripheral cancers, screen-detection was associated with a significantly lower probability of diagnosis at an advanced stage [III/IV, odds ratio (OR) =0.15, 95% confidence interval (CI): 0.05-0.45] and mortality [hazard ratio (HR) =0.33, 95% CI: 0.13-0.84]; however, the association was insignificant for central cancers. For screen-detected cancers, central location, compared to peripheral location, was significantly associated with a higher risk of diagnosis at an advanced stage (OR =20.83, 95% CI: 6.67-64.98) and mortality (HR =4.98, 95% CI: 2.26-10.97).

Conclusions

Unlike for peripheral cancers, LDCT screening did not demonstrate an improvement in outcomes of central lung cancers, indicating an important limitation of LDCT screening and the need for developing novel modalities to screen and treat central lung cancer.

Survival outcomes of patients with nonsmall cell lung cancer concomitantly receiving proton pump inhibitors and immune checkpoint inhibitors

Recent evidence suggests that gut microbiota dysbiosis adversely affects the efficacy of immune checkpoint inhibitors (ICIs). Our objective was to investigate the association between concomitant use of proton pump inhibitors (PPIs) and ICIs, and poor prognosis in patients with nonsmall cell lung cancer (NSCLC). We conducted a cohort study using a completely enumerated lung cancer cohort from a nationwide healthcare database in South Korea. We identified 2963 patients treated with ICIs as second-line or later therapy for stage ≥IIIB NSCLC. PPI use was ascertained within 30-days before and on the date of ICI initiation, and nonuse was defined as no prescription of PPIs during this period. Using national vital statistics in South Korea, we assessed the risk of all-cause mortality associated with concomitant PPI use through a propensity score-matched Cox proportional hazard model. Among 1646 patients included after 1:1 propensity score-matching, concomitant PPI use was associated with a 28% increased risk of all-cause mortality, compared to nonuse (adjusted hazard ratio [HR] 1.28; 95% confidence intervals [CIs], 1.13-1.46). We observed an increased risk when we restricted the analysis to new users of PPI (adjusted HR = 1.64; 95% CI = 1.25-2.17). Subgroup analysis showed that PPI use was associated with high mortality risk among patients with viral hepatitis (adjusted HR = 2.72; 95% CI = 1.54-4.78; P_interaction  = .048). Our study indicates that PPI use is associated with poor prognosis in NSCLC patients treated with ICIs. Further prospective studies are required to determine the risk-benefit balance of concomitant use of PPIs and ICIs.

Distribution of Lung-RADS categories according to job type in a single shipyard workers

Background

Recently, lung cancer screenings based on age and smoking history using low-dose computed tomography (LDCT) have begun in Korea. This study aimed to evaluate the distribution of lung imaging reporting and data system (Lung-RADS) categories in shipyard workers exposed to lung carcinogens such as nickel, chromium, and welding fumes according to job type, to provide basic data regarding indications for LDCT in shipyard workers.

Methods

This study included 6,326 workers from a single shipyard, who underwent health examinations with LDCT between January 2010 and December 2018. Data on age, smoking status and history, medical history, and job type were investigated. The participants were categorized into high-exposure, low-exposure, and non-exposure job groups based on the estimated exposure level of nickel, chromium, and welding fumes according to job type. Cox proportional hazard regression analysis was used to determine the difference between exposure groups in Lung-RADS category ≥ 3 (3, 4A, and 4B).

Results

Out of all participants, 97 (1.5%) participants were classified into Lung-RADS category ≥ 3 and 7 (0.1%) participants were confirmed as lung cancer. The positive predictive value (ratio of diagnosed lung cancer cases to Lung-RADS category ≥ 3) was 7.2%. The hazard ratio (HR) of Lung-RADS category ≥ 3 was 1.451 (95% confidence interval [CI]: 0.911–2.309) in low-exposure and 1.692 (95% CI: 1.007–2.843) in high-exposure job group. Adjusting for age and pack-years, the HR was statistically significant only in the high-exposure job group (HR: 1.689; 95% CI: 1.004–2.841).

Conclusions

Based on LDCT and Lung-RADS, among male shipyard workers, Lung-RADS category ≥ 3 were significantly higher in the high-exposure job group. Their HR tended to be > 1.0 and was statistically significant in the high-exposure job group. Additional studies should be conducted to establish more elaborate LDCT indications for occupational health examination.

Individual 5-Year Lung Cancer Risk Prediction Model in Korea Using a Nationwide Representative Database

Early detection of lung cancer by screening has contributed to reduce lung cancer mortality. Identifying high risk subjects for lung cancer is necessary to maximize the benefits and minimize the harms followed by lung cancer screening. In the present study, individual lung cancer risk in Korea was presented using a risk prediction model. Participants who completed health examinations in 2009 based on the Korean National Health Insurance (KNHI) database (DB) were eligible for the present study. Risk scores were assigned based on the adjusted hazard ratio (HR), and the standardized points for each risk factor were calculated to be proportional to the b coefficients. Model discrimination was assessed using the concordance statistic (c-statistic), and calibration ability assessed by plotting the mean predicted probability against the mean observed probability of lung cancer. Among candidate predictors, age, sex, smoking intensity, body mass index (BMI), presence of chronic obstructive pulmonary disease (COPD), pulmonary tuberculosis (TB), and type 2 diabetes mellitus (DM) were finally included. Our risk prediction model showed good discrimination (c-statistic, 0.810; 95% CI: 0.801-0.819). The relationship between model-predicted and actual lung cancer development correlated well in the calibration plot. When using easily accessible and modifiable risk factors, this model can help individuals make decisions regarding lung cancer screening or lifestyle modification, including smoking cessation.

Using Population-Based Cancer Registration Data and Period Analysis to Accurately Assess and Predict 5-Year Relative Survival for Lung Cancer Patients in Eastern China

Background

The assessment of long-term survival of lung cancer patients based on data from population-based caner registries, using period analysis, was scarce in China. We aimed to accurately assess the long-term survival of lung cancer patients, and to predict the long-term survival in the future, using cancer registry data from Taizhou City, eastern China.

Methods

Four cancer registries with high-quality data were selected. Patients diagnosed with lung cancer during 2004–2018 were included. The long-term survival was evaluated using period analysis, with further stratification by sex, age at diagnosis and region. Additionally, projected 5-year relative survival (RS) of lung cancer patients for 2019-2023 was evaluated, using model-based period analysis.

Results

The 5-year RS of lung cancer patients diagnosed during 2014–2018 was 40.2% (31.5% for men and 56.2% for women). A moderate age gradient was observed for the period estimate, with the estimate decreasing from 50.5 to 26.5% in the age group of 15–44 years and ≥75 years, respectively. The 5-year RS of urban area was higher than that of rural area (52.3% vs. 38.9%). The overall projected 5-year RS of lung cancer patients was 52.7% for 2019–2023, with estimate of 43.0 and 73.2% for men and women, respectively. A moderate age gradient was also observed for the projected estimate. Moreover, estimate reached nearly 50% for rural and urban areas.

Conclusion

Period analysis tended to provide the up-to-date and precise survival estimates for lung cancer patients, which is worth further application, and provides important evidence for prevention and intervention of lung cancer.

Efficacy of concurrent chemoradiotherapy for patients with limited-disease small-cell lung cancer: a retrospective, nationwide, population-based cohort study

Background

Small-cell lung cancer (SCLC) is a highly proliferative, rapidly growing tumor with a poor prognosis, even in cases of limited disease (LD). Timely and accurate high-intensity therapy is necessary. For concurrent chemoradiotherapy (CCRT), etoposide/platinum (EP)-based regimens are recommended, although irinotecan/platinum (IP)-based regimens are also effective with radiotherapy. This large-scale, retrospective, nationwide cohort study aimed to analyze the efficacy of CCRT in patients with LD-SCLC.

Methods

Population data registered between January 2008 and December 2018 was extracted from the Health Insurance Review and Assessment Service of Korea database. Survival outcomes of 4446 LD-SCLC patients who received CCRT were analyzed.

Results

Patients who received EP-CCRT (n = 4187) showed better time to first subsequent therapy (TFST: 11.2 months) and overall survival (OS: 22.2 months) than those who received IP-CCRT (n = 259; TFST: 9.6 months, P = 0.0477; OS: 16.4 months, P <  0.0001). When CCRT failed, dual-agent chemotherapy (n = 925; OS: 9.1 months) provided a better survival benefit than single-agent chemotherapy (n = 815; OS: 7.5 months). IP-based chemotherapy resulted in better OS (9.6 months) than EP-based chemotherapy (7.1 months, P = 0.017) in platinum-resistant relapsed patients; the opposite was observed for platinum-sensitive relapsed patients (OS: EP, 17.2 months; IP, 6.6 months; P <  0.0001). Poisson regression analysis demonstrated that age, EP-CCRT, and hypercholesterolemia retained significant associations with OS after adjustment for all variables.

Conclusion

In the Korean population, the effects of EP-CCRT on OS and TFST are significantly more favorable than those of IP-CCRT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08082-2.

Treatment Outcomes of 9,994 Patients With Extensive-Disease Small-Cell Lung Cancer From a Retrospective Nationwide Population-Based Cohort in the Korean HIRA Database

To investigate the efficacy of irinotecan-based (IP) and etoposide-based (EP) platinum combinations, and of single-agent chemotherapy, for treatment of extensive-disease small cell lung cancer (ED-SCLC), we performed a large-scale, retrospective, nationwide, cohort study. The population data were extracted from the Health Insurance Review and Assessment Service of Korea database from January 1, 2008, to November 30, 2016. A total of 9,994 patients were allocated to ED-SCLC and analyzed in this study. The primary objectives were to evaluate the survival outcomes of systemic first-line treatments for ED-SCLC. For first-line treatment, patients who received IP showed a better time to first subsequent therapy (TFST) of 8.9 months (95% confidence interval [CI], 8.50–9.40) than those who received EP, who had a TFST of 6.8 months (95% CI, 6.77–6.97, P < 0.0001). In terms of overall survival (OS), IP was superior to EP (median OS, 10.8 months; 95% CI, 10.13–11.33 vs. 9.5 months; 95% CI, 9.33–9.73; P < 0.0001). Taken together, in the Korean population, first-line IP combination chemotherapy had significantly favorable effects on OS and TFST.

Recent Trends of Lung Cancer in Korea

Lung cancer is one of the leading causes of cancer-related deaths in Korea. Although the smoking rate has decreased over time, the prevalence of lung cancer still remains high. In this study, we reviewed recent trends on the incidence, epidemiology, screening, diagnosis, and treatment of lung cancer in Korea by analyzing data from the national lung cancer registry and recently-published studies. Although approximately 40% of patients with non-small cell lung cancer (NSCLC) were diagnosed as stage IV, the 5-year relative survival rate improved from 11.3% (1993-1995) to 30.2% (2013-2017), possibly due to advances in methods of diagnosis and therapy. In addition, the 2019 implementation of the national lung cancer screening program with low-dose computed tomography may have also contributed to these improvements in survival rates. Recently, molecular diagnosis has become more widely used in the identification of genetic mutations in tissue specimens. Target therapy and immune checkpoint inhibitors have also been successfully used, particularly in cases of advanced NSCLC. In the future, further research on the optimal management of lung cancer remains necessary.

Estimating the disease burden of lung cancer attributable to residential radon exposure in Korea during 2006-2015: A socio-economic approach

Estimating the lung cancer disease burden can provide evidence for public health practitioners, researchers, and policymakers. This study uses claim data from lung cancer patients for 2006-2015 from the Korean National Health Insurance Service to estimate the lung cancer burdens attributable to residential radon in Korea using disability-adjusted life years (DALY) and patients' annual economic burden with societal perspectives using the cost-of-illness (COI) method. The number of patients increased during our study period (from 35,866 to 59,168). The disease burden and that attributable to residential radon, respectively, increased from 517.57 to 695.74 and 64.62 (95%; CIs 61.33-67.69) to 86.99 (95%; CIs 82.7-91.1) DALYs per 100,000 patients. The percentage of years lost due to disability among the DALY doubled from 8% to 17%. The cost for all the patients was US$2.33 billion, with US$292 (95%; CIs 278-306) million attributable to residential radon. During the last decade, the lung cancer disease burden increased by 1.34 times, with a doubled percentage of non-fatal burden and average annual growth rate of 9.5% of the total cost. Hence, the burden and cost of lung cancer in Korean provinces have been steadily increasing. The findings could be used as input data for future cost-effectiveness analysis of policies regarding radon reduction.

Low-dose chest computed tomographic screening and invasive diagnosis of pulmonary nodules for lung cancer in never-smokers

BACKGROUND

Although lung cancer screening using low-dose computed tomography (LDCT) is now widely used in clinical practice, the characteristics and outcomes of diagnostic procedures related to screen-detected nodules in never-smokers remain unclear. We aimed to determine the incidence of nodules considered for invasive biopsy and evaluate the final diagnoses and procedure-related complications in never-smokers in comparison to ever-smokers who underwent LDCT screening.

METHODS

We evaluated 37 436 asymptomatic adults (17 968 never-smokers and 19 468 ever-smokers) who underwent LDCT screening for lung cancer between January 2009 and December 2018 at a tertiary centre in South Korea. The rates of invasive diagnostic procedures for detected nodules and related complications, and the diagnostic outcomes were determined in the never-smoker and ever-smoker groups.

RESULTS

Among the never-smokers, 2908 (16.2%) out of 17 968 had positive nodules. Overall, 139 (0.77%) out of 17 968 never-smokers and 194 (1.00%) out of 19 468 ever-smokers underwent invasive biopsy (p=0.022). Lung cancer was diagnosed in 84 (0.47%) out of 17 968 never-smokers and 123 (0.63%) out of 19 468 ever-smokers (p=0.032). The proportions of participants diagnosed with benign disease after invasive biopsy (false-positive) were 50 (0.28%) out of 17 968 and 69 (0.35%) out of 19 468 in the never-smoker and ever-smoker groups, respectively (p=0.191). Multivariate analyses revealed no significant associations of smoking with the risk of a false-positive diagnosis (OR 0.98, 95% CI 0.62-1.57) and complications (OR 1.33, 95% CI 0.65-3.73) after biopsy. Of the 84 never-smokers with lung cancer, 82 (97.6%) had adenocarcinoma, and 75 (89.3%) were in stage I with a favourable prognosis.

CONCLUSIONS

LDCT screening in never-smokers resulted in a notable detection rate of lung nodules, which warranted invasive biopsy. The lung cancer detection rate was lower in never-smokers than in ever-smokers. However, no significant differences in the false-positive and complication rates were observed between the two groups. Accordingly, a more specifically tailored management strategy is needed for screen-detected nodules in Asian never-smokers.

Patterns of percutaneous transthoracic needle biopsy (PTNB) of the lung and risk of PTNB-related severe pneumothorax: A nationwide population-based study

Background

As percutaneous transthoracic needle biopsy (PTNB) of the lung is a well-established diagnostic method for the evaluating pulmonary lesions, evidence of safety based on representative data is limited. This study investigated the practice patterns of PTNB of the lung and assessed the incidence and risk factors of PTNB-related severe pneumothorax in Korea.

Methods

We used a national-level health insurance database between January 1, 2007 and December 31, 2015. Patients who underwent PTNB of the lung were identified using procedure codes for organ biopsy, fluoroscopy, computed tomography, chest radiography, and lung-related diagnosis codes. The annual age-/sex-standardized rate of PTNB and the incidence of PTNB-related severe pneumothorax were calculated. We defined severe pneumothorax as the pneumothorax requiring intervention. The odds ratios of risk factors were assessed by a generalized estimating equation model with exchangeable working correlation matrix to address clustering effect within institution.

Results

A total of 66,754 patients were identified between 2007 and 2015. The annual age-/sex-standardized rate of PTNB per 100,000 population was 19.6 in 2007 and 22.4 in 2015, and it showed an increasing trend. The incidence of severe pneumothorax was 2.4% overall: 2.5% in men and 1.2% in women, and 2.6%, 2.7%, 2.1%, 2.1%, 1.9%, 2.4%, and 2.4% from 2009 to 2015. Older age (≥60), male sex, presence of chronic obstructive pulmonary disease, receiving treatment in an urban or rural area versus a metropolitan area, and receiving treatment at a general hospital were significantly associated with the risk of severe pneumothorax.

Conclusions

Considering the increasing trend of PTNB, more attention needs to be paid to patients with risk factors for severe pneumothorax.

Impact of Sarcopenia on Early Postoperative Complications in Early-Stage Non-Small-Cell Lung Cancer

Background

Risk assessment for pulmonary resection in patients with early-stage non–small-cell lung cancer (NSCLC) is important for minimizing postoperative morbidity. Depletion of skeletal muscle mass is closely associated with impaired nutritional status and limited physical ability. We evaluated the relationship between skeletal muscle depletion and early postoperative complications in patients with early-stage NSCLC.

Methods

Patients who underwent curative lung resection between 2016 and 2018 and who were diagnosed with pathological stage I/II NSCLC were included, and their records were retrospectively analyzed. The psoas volume index (PVI, cm³/m³) was calculated based on computed tomography images from routine preoperative positron emission tomography-computed tomography. Early postoperative complications, defined as those occurring within 90 days of surgery, were compared between the lowest sex-specific quartile for PVI and the remaining quartiles.

Results

A strong correlation was found between the volume and the cross-sectional area of the psoas muscle (R²=0.816). The overall rate of complications was 57.6% among patients with a low PVI and 32.8% among those with a normal-to-high PVI. The most common complication was prolonged air leak (low PVI, 16.9%; normal-to-high PVI, 9.6%), followed by pneumonia (low PVI, 13.6%; normal-to-high PVI, 7.9%) and recurrent pleural effusion (low PVI, 11.9%; normal-to-high PVI, 6.8%). The predictors of overall complications were low PVI (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.07–4.09; p=0.03), low hemoglobin level (OR, 0.686; 95% CI, 0.54–0.87; p=0.002), and smoking history (OR, 3.93; 95% CI, 2.03–7.58; p<0.001).

Conclusion

Low PVI was associated with a higher rate of early postoperative complications in patients with early-stage NSCLC.

Artificial intelligence and lung cancer treatment decision: agreement with recommendation of multidisciplinary tumor board

Background

IBM Watson for Oncology (WFO) is a cognitive computing system helping physicians quickly identify key information in a patient’s medical record, surface relevant evidence, and explore treatment options. This study assessed the possibility of using WFO for clinical treatment in lung cancer patients.

Methods

We evaluated the level of agreement between WFO and multidisciplinary team (MDT) for lung cancer. From January to December 2018, newly diagnosed lung cancer cases in Chonnam National University Hwasun Hospital were retrospectively examined using WFO version 18.4 according to four treatment categories (surgery, radiotherapy, chemoradiotherapy, and palliative care). Treatment recommendations were considered concordant if the MDT recommendations were designated ‘recommended’ by WFO. Concordance between MDT and WFO was analyzed by Cohen’s kappa value.

Results

In total, 405 (male 340, female 65) cases with different histology (adenocarcinoma 157, squamous cell carcinoma 132, small cell carcinoma 94, others 22 cases) were enrolled. Concordance between MDT and WFO occurred in 92.4% (k=0.881, P<0.001) of all cases, and concordance differed according to clinical stages. The strength of agreement was very good in stage IV non-small cell lung carcinoma (NSCLC) (100%, k=1.000) and extensive disease small cell lung carcinoma (SCLC) (100%, k=1.000). In stage I NSCLC, the agreement strength was good (92.4%, k=0.855). The concordance was moderate in stage III NSCLC (80.8%, k=0.622) and relatively low in stage II NSCLC (83.3%, k=0.556) and limited disease SCLC (84.6%, k=0.435). There were discordant cases in surgery (7/57, 12.3%), radiotherapy (2/12, 16.7%), and chemoradiotherapy (15/129, 11.6%), but no discordance in metastatic disease patients.

Conclusions

Treatment recommendations made by WFO and MDT were highly concordant for lung cancer cases especially in metastatic stage. However, WFO was just an assisting tool in stage I–III NSCLC and limited disease SCLC; so, patient-doctor relationship and shared decision making may be more important in this stage.

Ten-year patient journey of stage III non-small cell lung cancer patients: A single-center, observational, retrospective study in Korea (Realtime autOmatically updated data warehOuse in healTh care; UNIVERSE-ROOT study)

INTRODUCTION

Until the recent approval of immunotherapy after completing concurrent chemoradiotherapy (CCRT), there has been little progress in treating unresectable stage III non-small cell lung cancer (NSCLC). This prompted us to search real-world data (RWD) to better understand diagnosis and treatment patterns, and outcomes.

METHODS

This non-interventional observational study used a unique, novel algorithm for big data analysis to collect and assess anonymized patient electronic medical records from a clinical data warehouse (CDW) over a 10-year period to capture real-world patterns of diagnosis, treatment, and outcomes of stage III NSCLC patients. We describe real-world patterns of diagnosis and treatment of patients with newly-diagnosed stage III NSCLC, and patients' characteristics, and assessment of treatment outcomes.

RESULTS

We analyzed clinical variables from 23,735 NSCLC patients. Stage III patients (N = 4138, 18.2 %) were diagnosed as IIIA (N = 2,547, 11.2 %) or IIIB (N = 1,591. 7.0 %). Treated stage III patients (N = 2530, 61.1 %) had a median age of 64.2 years, were mostly male (78.5 %) and had an ECOG performance status of 1 (65.2 %). Treatment comprised curative-intent surgery (N = 1,254, 49.6 %) with 705 receiving neoadjuvant therapy; definitive CRT (N = 648, 25.6 %); palliative CT (N = 270, 10.7 %), or thoracic RT (N = 170, 6.7 %). Median OS (range) for neoadjuvant, surgery, CRT, palliative chemotherapy, lung RT alone, and supportive care was 49.2 (42.0-56.5), 52.5 (43.1-61.9), 30.3 (26.6-34.0), 14.7 (13.0-16.4), 8.8 (6.2-11.3), and 2.0 (1.0-3.0) months, respectively.

CONCLUSIONS

This unique in-house algorithm enabled a rapid and comprehensive analysis of big data through a CDW, with daily automatic updates that documented real-world PFS and OS consistent with the published literature, and real-world treatment patterns and clinical outcomes in stage III NSCLC patients.

The impact of systemic treatment on brain metastasis in patients with non-small-cell lung cancer: A retrospective nationwide population-based cohort study

To compare the incidence of brain metastases of advanced non-small cell lung cancer (NSCLC) treated with systemic cytotoxic chemotherapy (CC) and targeted therapy (TT), we performed a large-scale, retrospective, nationwide, cohort study. The population data were extracted from the Health Insurance Review and Assessment Service of Korea database from January 1, 2011, to November 30, 2016. Of the 29,174 patients newly diagnosed with stage IIIB or IV NSCLC who received systemic treatment, we investigated the initial and subsequent incidence of brain metastases. Besides, among 22,458 patients without initial brain metastasis, the overall cumulative incidence of subsequent brain metastases was compared according to systemic treatment administered. In total, 1,126 (5.0%) patients subsequently developed brain metastasis. The overall cumulative incidence of brain metastasis was significantly higher in the TT group than in the CC group (1-year cumulative incidence: 8.7% vs. 3.8%; 3-year: 17.2% vs. 5.0%; P < 0.001). Younger age, female sex, and first-line TT were significant risk factors for subsequent brain metastasis. In conclusion, the overall cumulative incidence of brain metastasis was significantly higher in patients received TT as the first-line treatment than in those received CC.

Results of low-dose computed tomography as a regular health examination among Chinese hospital employees

OBJECTIVE

Lung cancer is traditionally more prevalent in the elderly patients, men, and smokers. However, as low-dose computed tomography (LDCT) is increasingly popular, we hypothesized the disease spectrum might change.

METHODS

LDCT was performed as a part of regular health examinations in 8392 of 15,686 employees from 6 hospitals in different regions of China in 2012 to 2018. Clinicopathologic characteristics, including age, sex, smoking status, radiologic features, tumor histology, and pathologic stage, were retrospectively analyzed.

RESULTS

LDCT incidentally detected lung cancer (pathologically confirmed) in a total of 179 (2.1%) hospital employees. The lung cancer detection rate was significantly greater in female than male (2.5% vs 1.3%, P = .001) patients. There was also a greater detection rate among nonsmokers than smokers, although statistical significance was not reached (2.2% vs 1.4%, P = .092). The lung cancer detection rate was 1.0% in the "age ≤40 years" group, 2.6% in the "40 < age ≤55 years" group, and 2.9% in the "age >55 years" group (P < .001). Among the hospital employees with lung cancer, 171 (95.5%) presented as ground-glass opacity, 177 (98.9%) were lung adenocarcinoma, 170 (95.0%) were early stage 0/IA, and 177 (98.9%) received curative surgical resection as the initial treatment. After a median follow-up of 38 months, no disease recurrence or death was observed among these patients.

CONCLUSIONS

LDCT detected lung cancer in a significant proportion of young, female, and nonsmoking employees. The vast majority of these lung cancers were early stage, with extremely good prognosis.

Survival benefit of first-generation epidermal growth factor receptor-tyrosine kinase inhibitors in female with advanced lung cancer

BACKGROUND

This study aimed to estimate therapeutic effects of first-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in real-world practice, by analyzing survival outcomes in an unselected, Korean female population with advanced lung cancer based on the National Health Insurance Service database.

METHODS

We identified women with newly diagnosed advanced lung cancer from January 2004 to December 2013. For progression-free survival (PFS) and overall survival (OS) analyses, patients were defined into the following subgroups: group A, treated with first-generation EGFR-TKI ⩾6 months; group B, treated with EGFR-TKIs <6 months but at least >1 month; and group C, treated with cytotoxic chemotherapy as follows: monotherapy or combination therapy with gemcitabine or pemetrexed; or monotherapy with docetaxel, paclitaxel, or vinorelbine.

RESULTS

Among 11,045 enrolled patients, 6170 (55.8%) were treated with first-generation EGFR-TKIs for at least 1 month. The median OS for patients treated with EGFR-TKIs was significantly longer than that of EGFR-TKI-naive patients (19.1 months [95% confidence interval (CI) 18.5-19.7] vs 9.5 months [95% CI 9.1-9.8], P<0.001). In subgroup analysis, group A had a significantly longer median OS compared with group B (30.3 months [95% CI 29.5-31.2] vs 12.3 months [95% CI 11.9-12.7], P<0.001). The median PFS of group A was significantly longer than that of group B (15.8 vs 3.7 months, P<0.001).

CONCLUSIONS

Our analysis demonstrates that EGFR-TKIs confer significant PFS and OS benefits in the real-world practice for Korean female with advanced lung cancer.

Stereotactic body radiation therapy for pulmonary large cell neuroendocrine carcinoma: a case report

The incidence of large cell neuroendocrine carcinoma (LCNEC) of the lung is rare, and the treatment methods and prognosis for such patients are still subjects of debate. We report a case of a 78-year-old male LCNEC patient for whom stereotactic body radiation therapy was performed. A four-dimensional computed tomography scan was used for simulation, and radiotherapy was planned using the volumetrically modulated arc technique. A total of 55 Gy was delivered in five daily fractions. The treatment was safely completed, and the patient did not report any discomfort. The only side-effect was an intermittent cough. Currently, the patient has received 18 months of outpatient follow-up care with no evidence of disease. In conclusion, stereotactic body radiation therapy can be a valuable treatment option for early stage LCNEC.

Gender as an independent prognostic factor in small-cell lung cancer: Inha Lung Cancer Cohort study using propensity score matching

Introduction

The prognostic relevance of gender is undetermined in patients with small-cell lung cancer (SCLC). Therefore, we investigated whether gender is a prognostic factor in a SCLC cohort after controlling for confounding factors.

Materials and methods

Fifteen prognostic factors were classified into four groups (patient, stage migration, tumor, and treatment). The prognostic relevance of gender was evaluated using propensity score matching, Cox proportional hazards regression, and stepwise fashion adjustments.

Results

Of 591 patients with SCLC, 88 were women (14.9%). Women were more likely than men to have no history of smoking (48.9% vs. 2.0%, P < 0.001) and limited disease (48.9% vs. 37.8%, P = 0.050). Women had less progressive disease in M stage than men (52.3% vs. 62.8%, P = 0.031). Women had better survival than men in the entire cohort (median survival times [MSTs] and 95% confidence intervals [CIs]: 9.7 months and 7.8–11.6 for women, 8.0 months and 7.0–8.9 for men, log-rank P = 0.034) and in the matched cohort (MSTs and 95% CIs: 8.8 months and 5.8–11.8 for women, 5.9 months and 4.5–7.4 for men, log-rank P = 0.013). Female gender was a prognostic factor predicting better survival, even after stepwise and full adjustment with all prognostic variables (adjusted hazard ratios and 95% CIs: 0.51 and 0.34–0.77, P = 0.001 for entire cohort, 0.42 and 0.24–0.75, P = 0.003 for matched cohort).

Conclusions

Our results confirmed that gender is an independent prognostic factor in patients with SCLC.

High Receipt of Statins Reduces the Risk of Lung Cancer in Current Smokers With Hypercholesterolemia: The National Health Insurance Service-Health Screening Cohort

BACKGROUND

The incidence and mortality of lung cancer have risen steadily with the increasing popularity of tobacco smoking. Observational studies suggest that statins, which are widely used to lower cholesterol, may prevent lung cancer; however, other studies have produced conflicting results. We investigated the effect of statin receipt on lung cancer risk in Korean men according to smoking status.

PATIENTS AND METHODS

We collected data from the 2002-2015 National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS). We included a total of 16,588 men in the final analysis. We classified the participants as having high or low statin receipt or as not receiving statins. We used Cox proportional hazards regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for lung cancer risk by statin receipt after adjusting for potential confounders.

RESULTS

We identified 363 patients with a new diagnosis of lung cancer from 2005 to 2015. Compared to participants who did not receive statins, high statin receipt resulted in a reduced lung cancer risk (HR = 0.64; 95% CI, 0.47, 0.85) after adjustment for confounders. Among current smokers, the fully adjusted HR for high statin receipt compared to those who did not receive statin therapy was 0.50 (95% CI, 0.32, 0.79).

CONCLUSION

High statin receipt was associated with lower risk of lung cancer in Korean men with hypercholesterolemia, especially current smokers.

Comprehensive analysis of the tumor immune micro-environment in non-small cell lung cancer for efficacy of checkpoint inhibitor

Characterizing the molecular immune subtype and micro-environment of lung cancer is necessary to understand immunogenic interactions between infiltrating immune and stromal cells, and how tumor cells overcome immune checkpoint blockades. This study seeks to identify computational methodologies for subtyping gene expression-based tumor-immune micro-environment interactions, which differentiate non-small cell lung cancer (NSCLC) into immune-defective and immune-competent subtypes. Here, 101 lung squamous cell carcinomas (LUSCs) and 87 lung adenocarcinomas (LUADs) tumor samples have been analyzed. Several micro-environmental factors differentially induce LUAD or LUSC immune subtypes, as well as immune checkpoint expression. In particular, tumor-associated macrophages (TAMs) are key immune cells play a vital role in inflammation and cancer micro-environments of LUSCs; whereas, regulatory B cells are immunosuppressive and tumorigenic in LUADs. Additionally, cytolytic activity upon CD8⁺ T cell activation is decreased by the abundance of B cells and macrophages in immune-competent subtypes. Therefore, identifying immune subtypes in lung cancer and their impact on tumor micro-environment will lead to clinical tools for assessing LUADs and LUSCs in patients, as well as maximize the efficacy of immune checkpoint inhibitors.

Identification of Serial DNA Methylation Changes in the Blood Samples of Patients with Lung Cancer

Background

The development of lung cancer results from the interaction between genetic mutations and dynamic epigenetic alterations, although the exact mechanisms are not completely understood. Changes in DNA methylation may be a promising biomarker for early detection and prognosis of lung cancer. We evaluated the serial changes in genome-wide DNA methylation patterns in blood samples of lung cancer patients.

Methods

Blood samples were obtained for three consecutive years from three patients (2 years before, 1 year before, and after lung cancer detection) and from three control subjects (without lung cancer). We used the MethylationEPIC BeadChip method, which covers the 850,000 bp cytosine-phosphate-guanine (CpG) site, to conduct an epigenome-wide analysis. Significant differentially methylated regions (DMRs) were identified using p-values <0.05 in a correlation test identifying serial methylation changes and serial increase or decrease in β value above 0.1 for three consecutive years.

Results

We found three significant CpG sites with differentially methylated β values and 7,105 CpG sites with significant correlation from control patients without lung cancer. However, there were no significant DMRs. In contrast, we found 11 significant CpG sites with differentially methylated β values and 10,562 CpG sites with significant correlation from patients with lung cancer. There were two significant DMRs: cg21126229 (RNF212) and cg27098574 (BCAR1).

Conclusion

This study revealed DNA methylation changes that might be implicated in lung cancer development. The DNA methylation changes may be the possible candidate target regions for the early detection and prevention of lung cancer.

Real-world treatment patterns for patients 80 years and older with early lung cancer: a nationwide claims study

Background

Old age is an important factor that could affect the treatment of early-stage lung cancer. In this study, we evaluated the treatment patterns and outcomes of patients over the age of 80 years who had been diagnosed with early-stage lung cancer in real-world practice.

Methods

Elderly patients who were diagnosed with early-stage lung cancer between 2008 and 2016 were identified using claims data provided by the Health Insurance Review and Assessment Service. The proportion of patients who underwent surgical resection or stereotactic body radiation therapy (SBRT), practice pattern trends, and overall survival (OS) were analyzed from the population-based data.

Results

Over 9 years, 1,684 patients underwent surgical resection (74.9%) or SBRT (25.1%) as a localized treatment. From 2008 to 2016, the treatment modality changed: the percentage of patients who underwent surgical resection decreased from 90.6 to 71.4%, and those who underwent SBRT increased from 9.4 to 28.6%. The percentage of patients treated with SBRT increased over time (p < 0.001). The median OS was 56.4 months in the surgery group and 35.5 months in the SBRT group. The SBRT group showed worse OS compared with the surgery group (Adjusted hazard ratio, 1.44; 95% confidence interval, 1.21–1.72; p < 0.001).

Conclusion

Changes in local treatment patterns in elderly lung cancer patients were observed and SBRT increased its role in this population. Surgical resection or SBRT should be considered the treatment of choice in elderly patients with localized lung cancer. Further prospective studies are required to elucidate the benefits of surgery and SBRT.

The Disease Burden of Lung Cancer Attributable to Residential Radon Exposure in Korean Homes

BACKGROUND

Residential radon exposure is known to be an important risk factor for the development of lung cancer. The objective of this study was to calculate the disease burden of lung cancer attributable to residential radon exposure in Korea.

METHODS

We calculated the national exposure level using Korean national radon survey data from 2011 to 2014, and house structure distribution data from each administrative region. Using the exposure-risk function, the population attributable fraction (PAF) was calculated and applied to calculate the disease burden for lung cancer attributable to residential radon exposure.

RESULTS

Residential radon exposure levels were the highest, at 116.4 ± 50.4 Bq/m³ (annual mean radon concentration ± standard deviation) in detached houses, followed by 74.1 ± 30.0 Bq/m³ in the multi-family dwellings, and 55.9 ± 21.1 Bq/m³ in apartments. The PAF for lung cancer, due to long-term radon exposure in Korean homes, was 6.6% and 4.7% in men and women, respectively. The total disease burden of lung cancer attributable to residential radon exposure was 14,866 years of life lost (YLL) and 1,586 years lost due to disability (YLD) in 2013. Overall, 1,039 deaths occurred due to residential radon exposure, of which 828 were in men and 211 in women.

CONCLUSION

The smoking rate of men in Korea exceeded 70% in the 1990s, and is still near 40%. Although the size of the effect varies depending on the estimation method, it is a critical aspect as a risk factor of lung cancer because of the synergistic relationship between smoking and radon exposure. Because the Korean society is rapidly aging, population who were formerly heavy-smokers are entering a high-risk age of lung cancer. Therefore, it is necessary to inform the public about the health benefits of reduced radon exposure and to strengthen the risk communication.

Clinical Characteristics and Prognostic Factors of Lung Cancer in Korea: A Pilot Study of Data from the Korean Nationwide Lung Cancer Registry

Background

Lung cancer is a leading cause of morbidity and mortality worldwide, and the incidence continues to rise. Although many prognostic factors have been identified, the clinical characteristics and outcomes in Korean lung cancer patients are not well defined.

Methods

Of the 23,254 new lung cancer cases registered at the Korea Central Cancer Registry in 2013, total 489 patients from 19 hospitals were abstracted by the Korean Central Cancer Registry. The clinical data retrospectively analyzed, patients were followed up until December 2015.

Results

The median age was 69 years (interquartile range, 60–74 years); 65.4% were male and 62.1% were ever-smokers. Cough was the most common initial symptom (33.5%); 13.1% of patients were asymptomatic. While squamous cell carcinoma was the most common subtype in male patients (37.2%), adenocarcinoma was the most frequent histological type in all patients (48.7%) and females (76.3%). The majority of patients received treatment (76.5%), which included surgery, radiation therapy, and chemotherapy. Older age (hazard ratio [HR], 1.037), lower body mass index (HR, 0.904), ever-smoker (HR, 2.003), small cell lung cancer (HR, 1.627), and distant metastasis (HR, 3.990) were independent predictors of mortality. Patients without symptoms (HR, 0.387) and without treatment (HR, 0.364) were associated with a favorable outcome in multivariate Cox analysis.

Conclusion

Lung cancer in Korea occurs predominantly in elderly patients, with adenocarcinoma being the most frequent subtype. The prognosis was poorer in ever-smokers and older, malnourished, and untreated patients with advanced lung cancer.

Updates on Cancer Epidemiology in Korea, 2018

Cancer is a major cause of morbidity and the most common cause of death in Korea. There are currently approximately 200,000 incident cancer cases and 78,000 individuals die from cancer every year. The factors directly related to cancer incidence, including aging, smoking, obesity, and Westernized dietary habits, have been increasing during the past several decades. Since 1999, trends toward increased incidence have been observed for thyroid, breast (in women), colorectal, and prostate cancer. Currently, these trends have changed direction, and the incidence of stomach and liver cancer in both sexes, and cervical cancer in women have continually declined. Although the number of cancer deaths increased by a factor of 2.7 from 1983 to 2016, the age-standardized mortality associated with cancer has been decreasing by 3% every year. The 5-year relative survival rate (RSR) has also improved over the past several decades, especially for stomach, prostate, and breast cancer, which had 5-year RSRs greater than 90% in the most recent report.

GAB2 Amplification in Squamous Cell Lung Cancer of Non-Smokers

Lung squamous cell cancer (SCC) is typically found in smokers and has a very low incidence in non-smokers, indicating differences in the tumor biology of lung SCC in smokers and non-smokers. However, the specific mutations that drive tumor growth in non-smokers have not been identified. To identify mutations in lung SCC of non-smokers, we performed a genetic analysis using arrays comparative genomic hybridization (ArrayCGH). We analyzed 19 patients with lung SCC who underwent surgical treatment between April 2005 and April 2015. Clinical characteristics were reviewed, and DNA was extracted from fresh frozen lung cancer specimens. All of copy number alterations from ArrayCGH were validated using The Cancer Genome Atlas (TCGA) copy number variation (CNV) data of lung SCC. We examined the frequency of copy number changes according to the smoking status (non-smoker [n = 8] or smoker [n = 11]). We identified 16 significantly altered regions from ArrayCGH data, three gain and four loss regions overlapped with the TCGA lung squamous cell carcinoma (LUSC) patients. Within these overlapped significant regions, we detected 15 genes that have been reported in the Cancer Gene census. We also found that the proto-oncogene GAB2 (11q14.1) was significantly amplified in non-smokers patients and vice versa in both ArrayCGH and TCGA data. Immunohistochemical analyses showed that GAB2 protein was relatively upregulated in non-smoker than smoker tissues (37.5% vs. 9.0%, P = 0.007). GAB2 amplification may have an important role in the development of lung SCC in non-smokers. GAB2 may represent a potential biomarker for lung SCC in non-smokers.

Quantification of circulating cell-free DNA to predict patient survival in non-small-cell lung cancer

We used computed tomography (CT) to explore the prognostic value of cell-free (cf) DNA quantification and its predictive efficacy over time after chemotherapy in non-small-cell lung cancer (NSCLC) patients. In total, 177 NSCLC patients were enrolled in a prospective biomarker trial. Consecutive paired blood collection was performed to determine cfDNA concentrations at baseline CT and throughout serial follow-ups. The best cfDNA cut-off value to predict progression-free and overall survival was determined using X-tile analysis. Among 112 chemo-naive patients with stage IV adenocarcinoma, 43 were available for follow-up analysis. Cox regression multivariate analysis indicated that a high cfDNA concentration was an independent negative prognostic factor for progression-free survival (hazard ratio: 2.60; 95% confidence interval: 1.65-4.10; p = 0.008) and overall survival (hazard ratio: 2.63; 95% confidence interval: 1.66-4.17; p < 0.001). However, cfDNA concentration changes during treatment did not correlate with radiological CT responses at first follow-up or best response. No pattern was noted in the percent change in the cfDNA concentration from baseline or subsequently measured level to progression. The serum cfDNA concentration is thus associated with NSCLC patient prognosis, but does not appear to be a clinically valid marker for tumor responses.

Trend Analysis for the Choice and Cost of Lung Cancer Treatment in South Korea, 2003-2013

Purpose

Our study aimed to report the annual changes in lung cancer statistics and analyze trends in sociodemographic, medical, and financial factors from 2003 to 2013 in the national database from the Korean National Health Insurance (KNHI).

Materials and Methods

Among 7,489 patients with code C34 in KNHI database, only lung cancer patients newly diagnosed after 2003 were included in the study population, for a total of 4,582 patients. Descriptive statistics were used to characterize treatment patterns and medical costs according to sociodemographic factors.

Results

Approximately 70% of subjects were male, and the mean age was 67 years. Around 46% of patients were over 70 years old, and 12% were over 80 years old. The medical costs were highest for patients younger than 60 and lowest for those over 80 years old. Surgery was more common in younger patients, while “no treatment” increased greatly with age. In trend analysis, the proportions of aging (p for trend < 0.001), female (p for trend=0.003), metropolitan/urban (p for trend=0.041), and lowest or highest-income patients (p for trend=0.004) increased over time, along with the prevalence of surgery as the primary treatment (p for trend < 0.001). There was also a trend with regard to change in medical costs (p for trend < 0.001), in that those of surgery and radiotherapy increased.

Conclusion

Surgery as a curative treatment has increased over the past decade. However, the elderly, suburban/rural residents, and low-income patients were more likely to be untreated. Therefore, active measures are required for these increasingly vulnerable groups.

Prevalence of Mutations in Discoidin Domain-Containing Receptor Tyrosine Kinase 2 (DDR2) in Squamous Cell Lung Cancers in Korean Patients

Purpose

The discoidin domain-containing receptor tyrosine kinase 2 (DDR2) is known to contain mutations in a small subset of patients with squamous cell carcinomas (SCC) of the lung. Studying the DDR2 mutations in patients with SCC of the lung would advance our understanding and guide the development of therapeutic strategies against lung cancer.

Materials and Methods

We selected 100 samples through a preliminary genetic screen, including specimens from biopsies and surgical resection, and confirmed SCC by histologic examination. DDR2 mutations on exons 6, 15, 16, and 18 were analyzed by Sanger sequencing of formalin-fixed, paraffin-embedded tissue samples. The functional effects of novel DDR2 mutants were confirmed by in vitro assays.

Results

We identified novel somatic mutations of DDR2 in two of the 100 SCC samples studied. One mutation was c.1745T>A (p.V582E) and the other was c.1784T>C (p.L595P), and both were on exon 15. Both patients were smokers and EGFR/KRAS/ALK-triple negative. The expression of the mutant DDR2 induced activation of DDR2 by the collagen ligand and caused enhanced cell growth and tumor progression. Moreover, dasatinib, a DDR2 inhibitor, showed potential efficacy against DDR2 L595P mutant–bearing cells.

Conclusion

Our results suggest that a mutation in DDR2 occurs naturally with a frequency of about 2% in Korean lung SCC patients. In addition, we showed that each of the novel DDR2 mutations were located in a kinase domain and induced an increase in cell proliferation rate.