Korea Central Cancer Registry Research Articles

Real-World Outcomes of First-Line Chemotherapy in Metastatic Pancreatic Cancer: A Nationwide Population-Based Study in Korea.

This nationwide population-based study investigated the overall survival (OS) of patients with metastatic pancreatic cancer (mPC) receiving first-line chemotherapy. Data from the National Health Insurance Service linked to the Korea Central Cancer Registry were used. Patients with mPC receiving first-line chemotherapy (2012-2019) were included and followed up until 2020. The gemcitabine plus nab-paclitaxel (GnP) and FOLFIRINOX groups were matched according to age, sex, and comorbidities. In total, 8652 patients with mPC were treated with chemotherapy. GnP and FOLFIRINOX have been administered since 2016 and 2017, respectively. The median OS increased annually from 6 months in 2012-2013 to 10 months in 2018-2019. The median OSs in the GnP and FOLFIRINOX groups were significantly longer than those in patients receiving gemcitabine ± erlotinib. A total of 1134 patients from both the GnP and FOLFIRINOX groups were selected using propensity score matching. Before matching, the median OS was longer in the FOLFIRINOX group than in the GnP group (p = 0.0029). After matching, however, there was no significant difference in the median OS between the two groups (11 vs. 11 months, respectively, p = 0.2438). Patients with mPC receiving chemotherapy have shown improved OS since the introduction of GnP and FOLFIRINOX. After matching, OS did not differ between the GnP and FOLFIRINOX groups.

Disparities in Overall Survival Rates for Cancers across Income Levels in the Republic of Korea.

The overall survival rates among cancer patients have been improving. However, the increase in survival is not uniform across socioeconomic status. Thus, we investigated income disparities in the 5-year survival rate (5YSR) in cancer patients and the temporal trends. This study used a national cancer cohort from 2002 to 2018 that was established by linking the Korea Central Cancer Registry and the National Health Insurance Service (NHIS) claim database to calculate the cancer survival rate by income level in the Republic of Korea. Survival data were available from 2002 onward, and the analysis was based on the actuarial method. We compared the survival of the earliest available 5-year period of 2002-2006 and the latest available 5-year period of 2014-2018, observing until 31 December 2021. Income level was classified into six categories: Medical Aid beneficiaries and five NHIS subtypes according to insurance premium. The slope index of inequality (SII) and relative index of inequality were used to measure absolute and relative differences in 5YSR by income, respectively. The 5YSR between the 2002-2006 and 2014-2018 periods for all cancers improved. A significant improvement in 5-year survival rates (5YSR) over the study period was observed in lung, liver, and stomach cancer. The SII of survival rates for lung (17.5, 95% confidence interval (CI) 7.0-28.1), liver (15.1, 95% CI 10.9-19.2), stomach (13.9, 95% CI 3.2-24.7), colorectal (11.4, 95% CI 0.9-22.0), and prostate (10.7, 95% CI 2.5-18.8) cancer was significantly higher, implying higher survival rates as income levels increased. The SII for lung, liver, and stomach cancer increased, while that of thyroid, breast, cervical, prostate, and colorectal cancer decreased over the study period. Although substantial improvement in the 5YSR was observed across cancer types and income levels from 2002 to 2018, this increase was not uniformly distributed across income levels. Our study revealed persistent income disparities in the survival of cancer patients, particularly for lung and liver cancer.

Socioeconomic Disparities in Six Common Cancer Survival Rates in South Korea: Population-Wide Retrospective Cohort Study.

In South Korea, the cancer incidence rate has increased by 56.5% from 2001 to 2021. Nevertheless, the 5-year cancer survival rate from 2017 to 2021 increased by 17.9% compared with that from 2001 to 2005. Cancer survival rates tend to decline with lower socioeconomic status, and variations exist in the survival rates among different cancer types. Analyzing socioeconomic patterns in the survival of patients with cancer can help identify high-risk groups and ensure that they benefit from interventions. The aim of this study was to analyze differences in survival rates among patients diagnosed with six types of cancer-stomach, colorectal, liver, breast, cervical, and lung cancers-based on socioeconomic status using Korean nationwide data. This study used the Korea Central Cancer Registry database linked to the National Health Information Database to follow up with patients diagnosed with cancer between 2014 and 2018 until December 31, 2021. Kaplan-Meier curves stratified by income status were generated, and log-rank tests were conducted for each cancer type to assess statistical significance. Hazard ratios with 95% CIs for any cause of overall survival were calculated using Cox proportional hazards regression models with the time since diagnosis. The survival rates for the six different types of cancer were as follows: stomach cancer, 69.6% (96,404/138,462); colorectal cancer, 66.6% (83,406/125,156); liver cancer, 33.7% (23,860/70,712); lung cancer, 30.4% (33,203/109,116); breast cancer, 91.5% (90,730/99,159); and cervical cancer, 78% (12,930/16,580). When comparing the medical aid group to the highest income group, the hazard ratios were 1.72 (95% CI 1.66-1.79) for stomach cancer, 1.60 (95% CI 1.54-1.56) for colorectal cancer, 1.51 (95% CI 1.45-1.56) for liver cancer, 1.56 (95% CI 1.51-1.59) for lung cancer, 2.19 (95% CI 2.01-2.38) for breast cancer, and 1.65 (95% CI 1.46-1.87) for cervical cancer. A higher deprivation index and advanced diagnostic stage were associated with an increased risk of mortality. Socioeconomic status significantly mediates disparities in cancer survival in several cancer types. This effect is particularly pronounced in less fatal cancers such as breast cancer. Therefore, considering the type of cancer and socioeconomic factors, social and medical interventions such as early cancer detection and appropriate treatment are necessary for vulnerable populations.

Decreased aggressive care at the end of life among advanced cancer patients in the Republic of Korea: a nationwide study from 2012 to 2018

BackgroundThis study aimed to investigate the trends of aggressive care at the end-of-life (EoL) for patients with advanced cancer in Korea and to identify factors affecting such care analyzing nationwide data between 2012 to 2018.MethodsThis was a population-based, retrospective nationwide study. We used administrative data from the National Health Insurance Service and the Korea Central Cancer Registry to analyze 125,350 patients aged 20 years and above who died within one year of a stage IV cancer diagnosis between 2012 and 2018.ResultsThe overall aggressiveness of EoL care decreased between 2012 and 2018. In patients’ last month of life, chemotherapy use (37.1% to 32.3%; p < 0.05), cardiopulmonary resuscitation (13.2% to 10.4%; p < 0.05), and intensive care unit admission (15.2% to 11.1%; p < 0.05) decreased during the study period, although no significant trend was noted in the number of emergency room visits. A steep increase was seen in inpatient hospice use in the last month of life (8.6% to 26.6%; p < 0.05), while downward trends were observed for hospice admission within three days prior to death (13.9% to 11%; p < 0.05). Patients were more likely to receive aggressive EoL care if they were younger, women, had treatment in tertiary hospitals, or had hematologic malignancies. In the subgroup analysis, the overall trend of aggressive EoL care decreased for all five major cancer types.ConclusionThe aggressiveness of EoL care in stage IV cancer patients showed an overall decrease during 2012–2018 in Korea.

Exploring age-standardized cancer incidence rates and regional disparities: A retrospective cohort study of 8 major cancers in South Korea

BackgroundWe analyzed trends in cancer incidence and regional disparities of eight major types of cancer in Korea. MethodsThis retrospective cohort study used the data of 17 cities/provinces from the Korea Central Cancer Registry (1999–2020) in South Korea. Age-standardized incidence rates (per 100,000 person-years), between-group variance (per 100,000 person-years)2, and annual percentage changes ( %) were calculated for the eight most common malignancies. Joinpoint regression was utilized to identify the points at which significant changes occur in cancer incidence or regional disparity trends over time to characterize these trends. ResultsThe incidence of stomach cancer decreased as regional disparity decreased and that of colorectal cancer initially increased but recently declined, showing fluctuations in regional disparity. The incidence and regional disparity in liver cancer decreased. The incidence of lung cancer remained stable, with reduced regional disparities. The incidence of breast cancer rose with increasing regional disparity, whereas the incidence of cervical cancer decreased, accompanied by decreased regional disparity. A significant increase in prostate cancer was found, with initially reduced regional disparities but later showed a resurgence. The incidence of thyroid cancer fluctuated alongside variations in regional disparities. ConclusionThis study revealed cancer incidence and regional variations in each cancer type in Korea. More studies are needed to understand the underlying factors and potential interventions for reducing cancer incidence and addressing regional disparity.

Geographic disparities in brachytherapy accessibility for cervical cancer.

1577 Background: While brachytherapy stands as a crucial component of the treatment for locally advanced cervical cancer, the issue of geographic disparities in brachytherapy accessibility has become a noteworthy public health concern in South Korea. Moreover, the specific factors contributing to these disparities have not been clearly elucidated. In light of this, we conducted a nationwide ecologic study to comprehensively investigate the socioeconomic factors associated with brachytherapy accessibility. Methods: A total of 2,998 patients newly diagnosed with cervical cancer in 2020 were identified through the Korea Central Cancer Registry (KCCR). Across 17 administrative districts in South Korea, 32 brachytherapy facilities were available. To capture unique socioeconomic factors for each region, including the number of Korean Medicaid (K-Medicaid), Medicare (K-Medicare) beneficiaries, marriage immigrants, registered foreigners, and total residents, data were obtained from the Korean Statistical Information Service (KOSIS). Notably, K-Medicaid and K-Medicare represent governmental medical insurance assistance for patients in poverty and those aged over 65, respectively. The brachytherapy accessibility rate (BAR) was defined as the number of brachytherapy procedures divided by new cervical cancer cases. Additionally, each district's socioeconomic factor was normalized by the number of residents. Univariate and multivariate logistic regression analyses were conducted to explore the relationships between BAR and socioeconomic factors. Results: The capital city and its adjoining metropolitan area accounted for 46.9% of the total brachytherapy facilities, with Seoul having 25% (8 out of 32) and Gyeonggi having 21.9% (7 out of 32). Conversely, three non-metropolitan regions had no brachytherapy facilities. In the multivariate logistic regression analysis, the brachytherapy accessibility rate (BAR) demonstrated an inverse association with both the number of K-Medicare beneficiaries and the total immigrant population (Odds ratios of 0.66 and -2.85, respectively). Conclusions: To the best of our knowledge, this is the inaugural study highlighting the robust associations between older age and foreign residency status with reduced accessibility to brachytherapy. The observed inaccessibility to brachytherapy has the potential to impede the delivery of standard care, consequently leading to a poorer prognosis for vulnerable populations. Future research endeavors and targeted social interventions will be imperative to rectify geographic disparities in brachytherapy accessibility and ensure equitable healthcare outcomes.

Data Resource Profile: The Cancer Public Library Database in South Korea.

This paper provides a comprehensive overview of the Cancer Public Library Database (CPLD), established under the Korean Clinical Data Utilization for Research Excellence project (K-CURE). The CPLD links data from four major population-based public sources: the Korea National Cancer Incidence Database in the Korea Central Cancer Registry, cause-of-death data in Statistics Korea, the National Health Information Database in the National Health Insurance Service, and the National Health Insurance Research Database in the Health Insurance Review & Assessment Service. These databases are linked using an encrypted resident registration number. The CPLD, established in 2022 and updated annually, comprises 1,983,499 men and women newly diagnosed with cancer between 2012 and 2019. It contains data on cancer registration and death, demographics, medical claims, general health checkups, and national cancer screening. The most common cancers among men in the CPLD were stomach (16.1%), lung (14.0%), colorectal (13.3%), prostate (9.6%), and liver (9.3%) cancers. The most common cancers among women were thyroid (20.4%), breast (16.6%), colorectal (9.0%), stomach (7.8%), and lung (6.2%) cancers. Among them, 571,285 died between 2012 and 2020 owing to cancer (89.2%) or other causes (10.8%). Upon approval, the CPLD is accessible to researchers through the K-CURE portal. The CPLD is a unique resource for diverse cancer research to investigate medical use before a cancer diagnosis, during initial diagnosis and treatment, and long-term follow-up. This offers expanded insight into healthcare delivery across the cancer continuum, from screening to end-of-life care.

Advancing Korean nationwide registry for hepatocellular carcinoma: a systematic sampling approach utilizing the Korea Central Cancer Registry database.

Hepatocellular carcinoma (HCC) presents a substantial public health challenge in South Korea as evidenced by 10,565 new cases annually (incidence rate of 30 per 100,000 individuals), in 2020. Cancer registries play a crucial role in gathering data on incidence, disease attributes, etiology, treatment modalities, outcomes, and informing health policies. The effectiveness of a registry depends on the completeness and accuracy of data. Established in 1999 by the Ministry of Health and Welfare, the Korea Central Cancer Registry (KCCR) is a comprehensive, legally mandated, nationwide registry that captures nearly all incidence and survival data for major cancers, including HCC, in Korea. However, detailed information on cancer staging, specific characteristics, and treatments is lacking. To address this gap, the KCCR, in partnership with the Korean Liver Cancer Association (KLCA), has implemented a systematic approach to collect detailed data on HCC since 2010. This involved random sampling of 10-15% of all new HCC cases diagnosed since 2003. The registry process encompassed four stages: random case selection, meticulous data extraction by trained personnel, expert validation, anonymization of personal data, and data dissemination for research purposes. This random sampling strategy mitigates the biases associated with voluntary reporting and aligns with stringent privacy regulations. This innovative approach positions the KCCR and KLCA as foundations for advancing cancer control and shaping health policies in South Korea.

Prognostic impact of limited resection vs. inadequate adjuvant therapy in patients with pathologic stage II or III non-small cell lung cancer: results from the Korean Association of Lung Cancer Registry.

For patients with stage II and III non-small cell lung cancer (NSCLC), various multi-modality treatments are required. However, depending on the individual conditions of patients, there will be a significant difference in prognosis. Therefore, this study investigated the clinical impact of inadequate treatment (limited surgery and inadequate adjuvant therapy) in patients with NSCLC stage II or III using data from the Korean Association of Lung Cancer Registry (KALC-R) between 2014 and 2016. Of the 8,110 new lung cancer cases registered at the Korea Central Cancer Registry in 2014-2016, 721 patients with stage II or III NSCLC were selected and divided into three groups according to differences in cancer treatment methods. In group A, patients underwent standard surgery and completed adjuvant therapy. In group B, patients underwent standard surgery without completing adjuvant therapy. In group C, patients received adjuvant therapy after limited surgery. After performing propensity score matching (PSM) for selected patients, overall survival (OS) and disease-free survival (DFS) rates of the three groups of patients with stage II and III NSCLC patients were then compared. Of the 721 patients with NSCLC, 239, 437, and 45 belonged to groups A, B, and C, respectively. After 1:3 PS matching for groups B and C, the 5-year survival rate of patients with stage II or III NSCLC were 68.0% and 26.7% for groups B and C, respectively and the DFS rate was 59.1% and 16.2% for groups B and C, respectively. The therapeutic effect of the standard surgery was the best. Although patients received adjuvant therapy, limited resection resulted in a poorer prognosis in compromised patients compared with omitting adjuvant therapy followed by standard surgery. Thus, surgical treatment should be considered in patients who are unable to complete surgical and adjuvant therapy.

Incidence and treatment outcomes of ovarian carcinosarcoma from the national cancer registry of Korea.

To investigate the incidence and survival outcomes of ovarian carcinosarcoma in Korea between 1999 and 2018. Patients diagnosed with ovarian carcinosarcoma between 1999 and 2018 were identified from the Korea Central Cancer Registry (KCCR) and their information was collected. Age-standardized incidence rates (ASRs), annual percent changes (APC), and relative survival rates of ovarian carcinosarcoma were calculated and compared to those of epithelial ovarian cancer. According to the KCCR, 458 cases of ovarian carcinosarcoma were detected, and accounted for 1.5% (458/30,679) of all epithelial ovarian cancers in Korea between 1999 and 2018. The ASR of ovarian carcinosarcoma between 1999 and 2018 was 0.064 per 100,000 women. The incidence rate of ovarian carcinosarcoma increased during the study period, with an ASR of 0.029 per 100,000 in 1999 and 0.073 per 100,000 in 2018. The APC of ovarian carcinosarcoma during 1999-2018 was 5.86 (p<0.001). The median overall survival (OS) of patients with ovarian carcinosarcoma was 39 months, and the 5-year OS rate was 42.5%. Among ovarian carcinosarcomas, patients with localized stages showed better clinical outcomes than those with regional or distant stages (5-year OS, 60.8%, 57.9%, and 32.8%, respectively; p<0.001). In addition, younger (<50 years) patients showed better OS than older (≥50 years) patients (5-year OS, 52.6% vs. 40.2%; p<0.001). Our nationwide registry-based study demonstrated that the incidence of ovarian carcinosarcoma increased from 1999 to 2018 in Korea. Patients with advanced-stage disease and older age (≥50 years) had poorer survival outcomes.

Trends in the incidence and survival outcomes of endometrial cancer in Korea: a nationwide population-based cohort study.

To evaluate trends in the incidence and survival outcomes of endometrial cancer (EC) based on the year of diagnosis, stage, age, and histologic types. Women with primary EC diagnosed between 1999 and 2018, and who were followed up with until 2019, were identified from the Korea Central Cancer Registry using the International Classification of Diseases, 10th revision. The age-standardized rates (ASRs) of incidence, annual percent changes (APCs), and survival were estimated according to age, stage, histology, and year of diagnosis. The ASR for EC increased from 2.38 per 100,000 in 1999 to 7.29 per 100,000 in 2018 across all histologic types (APCs of 9.82, 15.97, and 7.73 for endometrioid, serous, and clear cell, respectively, p<0.001). There were significant differences in the 5-year survival rates based on histology (90.9%, 55.0%, and 68.5% for endometrioid, serous, and clear cell, respectively, p<0.001), stage (93.4%, 77.0%, and 31.0% for localized, regional, and distant, respectively, p<0.001), and age (93.0% for <50 years and 80.6% for ≥50 years, p<0.001). The 5-year survival was significantly better in the group diagnosed between 2000 and 2018 (85.9%) than that in the 1999-2008 group (83.3%) (p<0.001). This trend was only observed for endometrioid cancer (p<0.001). The incidence of EC increased across the all 3 subtypes. Survival of patients with endometrioid histology improved over the past two decades, but remained static for serous or clear cell histology. Healthcare strategies to prevent EC incidence in at-risk populations and apply effective treatments for high-risk histology are needed.

Impact of guideline adherence on the prognosis of Barcelona clinic liver cancer stage B hepatocellular carcinoma.

Patients with Barcelona clinic liver cancer (BCLC) stage B hepatocellular carcinoma (HCC) are considerably heterogeneous in terms of tumor burden, liver function, and performance status. To improve the poor survival outcomes of these patients, treatment approaches other than transarterial chemoembolization (TACE), which is recommended by HCC guidelines, have been adopted in real-world clinical practice. We hypothesize that this non-adherence to treatment guidelines, particularly with respect to the use of liver resection, improves survival in patients with stage B HCC. To assess guideline adherence in South Korean patients with stage B HCC and study its impact on survival. A retrospective analysis was conducted using data from 2008 to 2016 obtained from the Korea Central Cancer Registry. Patients with stage B HCC were categorized into three treatment groups, guideline-adherent, upward, and downward, based on HCC guidelines recommended by the Asian Pacific Association for the Study of the Liver (APASL), the European Association for the Study of the Liver (EASL), and the American Association for the Study of Liver Diseases (AASLD). The primary outcome was HCC-related deaths; tumor recurrence served as the secondary outcome. Survival among the groups was compared using the Kaplan-Meier method and the log-rank test. Predictors of survival outcomes were identified using multivariable Cox regression analysis. In South Korea, over the study period from 2008 to 2016, a notable trend was observed in adherence to HCC guidelines. Adherence to the EASL guidelines started relatively high, ranging from 77% to 80% between 2008 and 2012, but it gradually declined to 58.8% to 71.6% from 2013 to 2016. Adherence to the AASLD guidelines began at 71.7% to 75.9% from 2008 to 2010, and then it fluctuated between 49.2% and 73.8% from 2011 to 2016. In contrast, adherence to the APASL guidelines remained consistently high, staying within the range of 90.14% to 94.5% throughout the entire study period. Upward treatment, for example with liver resection, liver transplantation, or radiofrequency ablation, significantly improved the survival of patients with BCLC stage B HCC compared to that of patients treated in adherence to the guidelines (for patients analyzed according to the 2000 EASL guidelines, the 5-year survival rates were 63.4% vs 27.2%, P < 0.001), although results varied depending on the guidelines. Progression-free survival rates were also significantly improved upon the use of upward treatments in certain groups. Patients receiving upward treatments were typically < 70 years old, had platelet counts > 105/μL, and serum albumin levels ≥ 3.5 g/dL. Adherence to guidelines significantly influences survival in South Korean stage B HCC patients. Curative treatments outperform TACE, but liver resection should be selected with caution due to disease heterogeneity.

Conditional Relative Survival of Exocrine Pancreatic Cancer: A Population-Based Study.

Adjusted prognostic information is important for treatment decisions, especially in elderly patients or survivors of exocrine pancreatic cancer (EPC). This study aims to investigate conditional relative survival (CS) rates and conditional probabilities of death in patients with EPC. Data of 77,975 individuals diagnosed with EPC between 1999 and 2019 were obtained from the Korea Central Cancer Registry. CS was analyzed across strata including histology groups (ductal adenocarcinoma excluding cystic or mucinous [group I, PDAC] and ductal adenocarcinoma specified as mucinous or cystic adenocarcinoma [group II]), and age. For PDAC, the overall 5-year relative survival (RS) rate at diagnosis, 3-year CS of 2-year survivors, and 5-year CS of 5-year survivors were 8.5%, 50.1%, and 77.6%, respectively. Overall conditional probabilities of death were 85.2% (≥ 80 years), 73.5% (70-79 years), and 62.0% (60-69 years) in year 1 after diagnosis. Among patients with localized or regional stage who underwent surgery, conditional probabilities of death of ≥ 80, 70-79, and 60-69 years were 37.7%, 32.5%, and 22.6% in the first year, and 26.6%, 27.2%, and 26.0% in year 2 after diagnosis. Half of patients with EPC who survived for 2 years survived for an additional 3 years. However, 5-year PDAC survivors require follow-up as more than 20% do not survive for a further 5 years. Elderly patients should not be excluded from active treatment for localized or regional-stage PDAC, as the CS of elderly patients who are fit enough to undergo surgery is not inferior to that of younger patients.

Survival Impact of the Second Malignancies Among the Lymphoid Neoplasm

Background: The development of the lymphoma treatment increased the number of patients with long-term survival. Due to the nature of lymphoma heterogeneous group of hematological malignancies, lymphoma treatment varies based on histopathological features. Various cytotoxic chemotherapy or radiotherapy could increase patients' risk of secondary cancer. Few studies evaluated the impact on survival of co-occurring cancers in mature lymphoid malignancies. Methods: 3953 adult patients were diagnosed with lymphoma between January 2000 and April 2021 at Yeoido and Seoul St. Mary's Hospital. The cohorts compared cohorts Standardized incidence ratio applying the Korea Central Cancer Registry (KCCR). Results: Among the patients Initially diagnosed with Mature-B cell neoplasm were 3001 patients (76.3%) and 711(18%) with mature T and NK cell neoplasm (5.6%) for Hodgkin lymphoma. Among the B cell neoplasm, 57% diffuse large B cell lymphomas (DLBCL) were the most common form of B cell type, followed by follicular lymphoma (FL) and marginal zone lymphoma. PTCL NOS was the most dominant in the T cell lymphoma, accounting for 26%, followed by Extranodal NK/T cell lymphoma 23% and angioimmunoblastic T cell lymphoma. Among B cell lymphoma, 10% of solid cancer co-occurred, and 1% of hematological can be combined; in T cell types, 6% were solid ca and 12% were hematological ca. Two hundred one (4.8%) patients had historic or newly diagnosed solid cancer cases; the median diagnosed age was 64 (27-92) years. The median time to secondary cancer after diagnosis is 2 years, most common type of secondary were hung cancer, followed by thyroid and colorectal cancer. Comparing with the Korean register, the standardized Incidence Ratio of patients with lymphoma showed the highest in thyroid ca (hazard ratio (HR) = 2.65, [95% CI 1.45-4.45]), followed by lung (HR=2.14), stomach (HR=1.79), and colon (HR=1.59), In total lymphoma patients, secondary ca. doesn't offer a poor prognostic factor in total cohorts- In the case of MZL and FL (n=737), development of secondary cancer (n=131) acts as a poor prognostic factor 5 years in than count parts (n=565), 79.4 vs. 89.1%, respectively ( p &amp;lt;0.001). Multivariate analysis showed colorectal ca ( p &amp;lt;0.001, HR = 4.83, [95% CI 5.19-1103]) and transformation to DLBCL ( p &amp;lt;0.001, HR = 4.85, [95% CI 2.68-5.79]) affect worse outcomes on OS. In the case of CLL, multivariate analysis, treatment-related AML or MDS affects inferior survival outcomes ( p =0.02, HR = 3.99, [95% CI 1.25-12.79]). Conclusions: Secondary cancers could increase mortality in low-grade B cell lymphoma patients. There were different types of secondary cancer affected overall survival by each subtype. In the low-grade lymphoma, secondary hematologic malignancies or Richter syndrome poorer patient results. This study suggested awareness of various combined malignancies by subtypes of patients with lymphoma.

Incidence and survival of gynecologic cancer including cervical, uterine, ovarian, vaginal, vulvar cancer and gestational trophoblastic neoplasia in Korea, 1999-2019: Korea Central Cancer Registry.

To investigate the incidence, trends, and survival rates of all gynecologic cancers using the Korea Central Cancer Registry (KCCR) database from 1999-2019. Gynecologic cancer data were obtained from the KCCR database between 1999 and 2019. Age-standardized incidence rates (ASRs), annual percentage changes, and average annual percentage changes (AAPCs) were calculated. The relative survival rate (RSR) was reported by age group, stage, and 6-year period (I: 1999-2005, II: 2006-2012, III: 2013- 2019). The gynecologic cancer ASRs were 26.2 and 24.9 per 100,000 individuals in 1999 and 2019, respectively. Trends of incidence in gynecologic cancer revealed a decrease in cervical cancer and gestational trophoblastic neoplasia (GTN) with AAPCs of -3.4 and -4.3, respectively. Conversely, the incidence of uterine, ovarian, and vulvar cancers increased with AAPCs of 4.7, 2.3, and 2.1, respectively. AAPC for vaginal cancer showed no change. The 5-year survival rate was highest for GTN (90.5%) and lowest for vaginal cancer (56.6%). An increase in age was correlated with poorer survival rates across all gynecologic cancers, excluding vaginal cancer. For all gynecologic cancer types, the prognosis deteriorates with advancing cancer stages. The RSR of uterine cancer improved consistently across all periods. The ovarian cancer RSR improved more in period III than in periods I or II. Additionally, the vulvar cancer RSR improved more in periods II and III than in period I. In Korea, the incidence of cervical cancer and GTN decreased, whereas the incidence of uterine, ovarian, and vulvar cancer increased from 1999 to 2019. The RSR for uterine, ovarian, and vulvar cancers showed consistent improvements over different periods. Effective screening programs and the adoption of advanced treatments may be necessary to further reduce the burden of gynecologic cancer.

Exocrine pancreatic cancer as a second primary malignancy: A population-based study.

Although cancer survivors are at higher risk of developing second primary malignancies, cancer surveillance strategies for them have not yet been established. This study aimed to identify first primary cancers that had high risks of developing second primary exocrine pancreatic cancer (EPC). Data on individuals diagnosed with primary cancers between 1993 and 2017 were obtained from the Korea Central Cancer Registry. The standardized incidence ratios (SIRs) of second primary EPCs were analyzed according to the primary tumor sites and follow-up periods. Among the 3,205,840 eligible individuals, 4,836 (0.15%) had second primary EPCs, which accounted for 5.8% of the total EPC patients in Korea. Between 1 and 5 years after the diagnosis of first primary cancers, SIRs of second primary EPCs were increased in patients whose first primary cancers were in the bile duct (males 2.99; females 5.03) in both sexes, and in the small intestine (3.43), gallbladder (3.21), and breast (1.26) in females. Among those who survived 5 or more years after the diagnosis of first primary cancers, SIRs of second primary EPCs were elevated in patients whose first primary cancers were in the bile duct (males 2.61; females 2.33), gallbladder (males 2.29; females 2.22), and kidney (males 1.39; females 1.73) in both sexes, and ovary (1.66) and breast (1.38) in females. Survivors of first primary bile duct, gallbladder, kidney, ovary, and female breast cancer should be closely monitored for the occurrence of second primary EPCs, even after 5 years of follow-up.

Risk of fractures in thyroid cancer patients with postoperative hypoparathyroidism: A nationwide cohort study in Korea.

Postoperative hypoparathyroidism (PO-hypoPT) is an uncommon complication of total thyroidectomy in thyroid cancer patients. While long-term hypoPT causes characteristic changes in bone metabolism, the risk of fractures in hypoPT remains inconclusive. We investigated the risk of fractures in Korean thyroid cancer patients with PO-hypoPT. This was a retrospective cohort study using data from the Korea Central Cancer Registry and Korean National Health Insurance Service. We analyzed 115,821 thyroid cancer patients aged ≥18 years, who underwent total thyroidectomy between 2008 and 2016. The risk of any fractures, including vertebral, hip, humerus, and wrist fractures, according to parathyroid function after total thyroidectomy was analyzed using the multivariable Cox proportional hazard model. The PO-hypoPT and preserved parathyroid function groups included 8,789 (7.6%) and 107,032 (92.4%) patients, respectively. Over a mean follow-up duration of 4.8 years, 159 (1.8%) and 2,390 (2.2%) fractures occurred in the PO-hypoPT and preserved parathyroid function groups, respectively. The risk of any fractures was significantly lower in the PO-hypoPT group than in the preserved parathyroid function group (HR, 0.83; 95% CI, 0.70-0.98; P=0.037) after adjusting for confounders. Regarding the fracture site, only the risk of vertebral fractures was significantly lower in the PO-hypoPT group compared to the preserved parathyroid function group (HR, 0.67; 95% CI, 0.47-0.96; P=0.028) after adjusting for confounders. Subgroup analyses showed that bone mineral density measurements and calcium supplementation interacted with the relationship between PO-hypoPT and the risk of any fractures (P for interactions=0.010 and 0.017, respectively). PO-hypoPT was associated with a lower risk of fractures in thyroid cancer patients, especially at the vertebra. The relatively low bone turnover caused by PO-hypoPT and appropriate management for PO-hypoPT with active vitamin D and calcium may prevent the deterioration of skeletal health in thyroid cancer patients who can easily be exposed to long-term overtreatment with levothyroxine. This article is protected by copyright. All rights reserved.

Associations between physical activity and incidence of cancer among overweight adults in Korea: Results from the Health Examinees-G study.

Although the protective effects of physical activity against several cancers are well established, evidence is inconsistent concerning Asian populations. Therefore, we assessed the association between the characteristics of physical activity and overall and type-specific cancer incidence in Koreans and examined the differences in association according to obesity status. Using prospective data from 112,108 participants in the Health Examinees study-G from 2004 to 2013, we evaluated the association between leisure-time physical activity (LTPA) and the incidence of overall and type-specific cancers using the Cox proportional hazards model. Self-reported LTPA participation, duration per week, intensity, type, and diversity were assessed. The incidence of overall and type-specific cancers, including colorectal, gastric, lung, breast, and prostate cancer and 13 obesity-related cancers, was identified using the Korea Central Cancer Registry from 1999 to 2018. Analyses were also stratified according to obesity status. In overweight males, participation in vigorous LTPA (hazard ratio [HR]: 0.84, 95% confidence interval [CI]: 0.72-0.97) and walking (HR: 0.84, 95% CI: 0.72-0.98) were associated with a lower risk of cancer overall. Regarding cancer types, climbing was marginally associated with a lower risk of colorectal cancer in overweight males (HR: 0.61, 95% CI: 0.37-1.00). In normal-weight females, although there was an increased risk in those performing recreational activities, this risk was attenuated when those diagnosed with thyroid cancer were excluded. In the analysis for 13 obesity-related cancers, consistent associations were found. These findings suggest the need for greater public awareness regarding physical activity among overweight individuals within the Asian population.

Abstract 4242: High sugar food consumption and breast cancer risk in a prospective cohort study

Abstract Background: The association between excessive sugar intake and the risk of breast cancer has been considered in epidemiologic studied, however, the results are unclear. This study examined to evaluated between high-sugar food intake and breast cancer in a prospective cohort study. Methods: This prospective cohort study included a total of 71,266 women aged 40-69 years from the Health Examinees-Gem (HEXA-G) study between 2004 and 2013. Information on cancer diagnosis was retrieved from the Korea Central Cancer Registry until 31 December 2018. Multivariate hazard ratios (HRs) and 95% of confidence intervals (CIs) for the risk of gastric cancer according to the consumption of high-sugar food were estimated using Cox proportional hazards models with age as the time scale. Results: A total of 713 incident cases of breast cancer occurred over an average follow-up period of 9.20 years. The top food contributing to total sugar intake was fruit (42.89%). We found that increased consumption of sugary cereal was associated with increased risk of breast cancer; HR for sugary cereal consumption of more than one servings/two months vs. almost never consumed was 1.34 (95% CI: 1.08, 1.65; p for trend = 0.01). Also, consumption of loaf bread (p for trend = 0.03), ice cream (HR for ice cream consumption of more than one servings/week vs. almost never consumed = 1.26; 95% CI: 1.00, 1.58; p for trend = 0.03), and added sugar food (HR for all sugary food groups consumption of more than two servings/week vs. less than one serving/month consumed =1.28; 95% CI: 1.02, 1.61; p for trend = 0.05) was associated with increased risk of breast cancer. Conclusion: Our results suggest that a high-sugar food consumption was associated with an increased risk of breast cancer among Korean women. Key words: Sugar, High-sugar foods, Breast cancer, the Health Examinees (HEXA) study, prospective cohort study. Citation Format: Woo-Kyoung Shin, Dan Huang, Katherine De la Torre, Sukhong Min, Aesun Shin, Jong-koo Lee, Wonshik Han, Jung Eun Lee, Daehee Kang. High sugar food consumption and breast cancer risk in a prospective cohort study. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4242.

Abstract 6460: Smoking initiation at young age increases risk of gastric cancer among Korean men

Abstract Objective: Early initiation of smoking is associated with adverse health outcomes. This study aimed to investigate the association of various smoking-related factors with the risk of gastric cancer in a population with a high incidence rate of gastric cancer. Method: From 2004 to 2013, Korean adults 40-69 years of age were enrolled in the large-scale prospective cohort, the Health Examinees-Gem study. Incident gastric cancer cases were identified until December 31, 2017, through linkage to the Korea Central Cancer Registry. Participants’ information regarding socio-demographics, smoking-related factors, and other lifestyle factors was obtained via self-reported questionnaires. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for gastric cancer risk associated with smoking-related factors such as smoking duration, amount, pack-years, and age of smoking initiation. Results: Among 44,207 men included in the final analysis, 565 gastric cancer cases were identified during a mean (±SD) follow-up period of 8.6 (±2.0) years. Compared to non-smokers, current smokers who smoked for more than 35 years (HR 1.44, 95% CI 1.06-1.96) or with ≥30 pack-years of smoking (HR 1.40, 95% CI 1.05-1.87) were positively associated with gastric cancer. These associations were shown to be significant with increasing smoking years (p trend 0.019) and pack-years (0.016) as well. Compared to non-smokers, current smokers who initiated smoking at a younger age, before or at 20 years, were at a higher risk of gastric cancer (HR 1.46, 95% CI 1.10-1.93). No significant associations were observed among former smokers. When stratified by smoking duration, increased risk of gastric cancer was observed among those who smoked for more than 25 years in the younger smoking initiation age group (≤20 years; HR 1.50, 95% CI 1.15-1.94). In terms of smoking intensity, those who smoked less than 20 cigarettes or 1 pack a day showed an increased risk of gastric cancer in the younger smoking initiation age group that began smoking before or at 20 years of age (HR 1.78, 95% CI 1.30-2.44). Conclusion: Our findings suggest that earlier initiation of smoking is associated with a greater risk of gastric cancer. Among those who began smoking early, longer duration is an important factor, but increased gastric cancer risk was also observed among those who smoked moderate amount on a daily basis. Thus, measures to manage and control onset age of cigarette smoking among teenagers may be considered when taking actions against the health burden of gastric cancer. Citation Format: Hwi-Won Lee, Woo-Kyoung Shin, Dan Huang, Katherine De la Torre, Jae Jeong Yang, Minkyo Song, Aesun Shin, Kyoung-Mu Lee, Hyuk-Joon Lee, Jong-koo Lee, Daehee Kang. Smoking initiation at young age increases risk of gastric cancer among Korean men. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6460.