Korea Central Cancer Registry Data Research Articles

Cohort Study Protocol: A Cohort of Korean Atomic Bomb Survivors and Their Offspring.

In 1945, atomic bombs were dropped on Hiroshima and Nagasaki. Approximately 70 000 Koreans are estimated to have been exposed to radiation from atomic bombs at that time. After Korea's Liberation Day, approximately 23 000 of these people returned to Korea. To investigate the long-term health and hereditary effects of atomic bomb exposure on the offspring, cohort studies have been conducted on atomic bomb survivors in Japan. This study is an ongoing cohort study to determine the health status of Korean atomic bomb survivors and investigate whether any health effects were inherited by their offspring. Atomic bomb survivors are defined by the Special Act On the Support for Korean Atomic Bomb Victims, and their offspring are identified by participating atomic bomb survivors. As of 2024, we plan to recruit 1500 atomic bomb survivors and their offspring, including 200 trios with more than 300 people. Questionnaires regarding socio-demographic factors, health behaviors, past medical history, laboratory tests, and pedigree information comprise the data collected to minimize survival bias. For the 200 trios, whole-genome analysis is planned to identify de novo mutations in atomic bomb survivors and to compare the prevalence of de novo mutations with trios in the general population. Active follow-up based on telephone surveys and passive follow-up with linkage to the Korean Red Cross, National Health Insurance Service, death registry, and Korea Central Cancer Registry data are ongoing. By combining pedigree information with the findings of trio-based whole-genome analysis, the results will elucidate the hereditary health effects of atomic bomb exposure.

Recent Trends in the Incidence of Salivary Gland Malignancies

Due to the low incidence and histologic diversity of salivary gland cancer, analyzing the incidence of salivary gland cancer is necessary to understand the macroscopic aspects. We intend to investigate the international trend of the reported incidence rate of salivary gland cancer. Using the Korea Central Cancer Registry data, the domestic change in the incidence rate was examined. As a result, a significant increasing trend was confirmed, consistent with the United States and Japan trends. The etiology of the change is unclear, and various factors that may influence the direction are reported. Additional research is needed to understand the pathophysiology of salivary gland cancer, and further efforts are required to understand salivary gland cancer.

Frequent low dose alcohol intake increases gastric cancer risk: the Health Examinees-Gem (HEXA-G) study.

Objective:Epidemiological studies indicate that alcohol increases gastric cancer (GC) risk, yet most studies have focused on heavy alcohol intake, leaving other factors understudied. A comprehensive investigation of the effects of the frequency and amount of alcohol intake may help elucidate the GC risk associated with drinking behavior.Methods:The Health Examinees-Gem (HEXA-G) study, a community-based large-scale prospective cohort study, enrolled Korean adults 40–69 years of age between the years 2004 and 2013. Incident GC cases were identified through linkage to Korea Central Cancer Registry data until December 31, 2017. Self-reported questionnaires were used to survey alcohol consumption-related factors (duration, frequency, amount, and type of alcoholic beverages). The frequency and amount of alcohol consumption were combined to explore GC risk according to 4 drinking patterns: “infrequent-light”, “frequent-light”, “infrequent-heavy”, and “frequent-heavy”. We used Cox proportional hazard models to estimate the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs), and investigate the relationship between alcohol intake and GC incidence.Results:A total of 128,218 participants were included in the analysis. During an average follow-up period of 8.6 years, 462 men and 385 women were diagnosed with GC. In men, current drinkers showed a 31% greater risk of GC than non-drinkers (HR 1.31, 95% CI 1.03–1.66), whereas no significant association was observed in women. In men, GC risk was associated with a higher frequency (P trend 0.02) and dose of ethanol intake in grams (P trend 0.03). In men, the “frequent-light” (≥5 times/week and <40 g ethanol/day) drinking pattern was associated with a 46% greater risk of GC (HR 1.46, 95% CI 1.02–2.07) than the “infrequent-light” pattern (<5 times/week and <40 g ethanol/day).Conclusions:This study suggests that frequent intake of alcohol, even in low quantities per session, increases GC risk. Further research is warranted to evaluate the relationship between alcohol and GC in detail.

Distinct prognosis of biliary tract cancer according to tumor location, stage, and treatment: a population-based study

Biliary tract cancer (BTC) has been inconsistently identified according to its location in epidemiological and clinical studies. This study retrospectively reviewed the treatment pattern and prognosis of BTC according to tumor location using the Korea Central Cancer Registry data of 97,676 patients with BTC from 2006 to 2017. The proportion of localized and regional Surveillance, Epidemiology, and End Results (SEER) stage was the highest in ampulla of Vater (AoV, 78.2%) cancer, followed by extrahepatic bile duct (BD, 68.3%), gallbladder (GB, 52.6%), and intrahepatic BD (49.5%) cancers. Overall, the “no active anti-cancer treatment” rate was the highest in intrahepatic BD (52.8%), followed by extrahepatic BD (49.5%), GB (39.6%), and AoV cancers (28.9%). The 5-year relative survival rate was the highest in AoV (48.5%), followed by GB (28.5%), extrahepatic BD (19.9%), and intrahepatic BD (10.8%) cancers, which significantly improved over time, except for intrahepatic BD cancer. In the localized and regional stage, older patients had a higher risk of receiving no active anti-cancer treatment in each tumor location after adjusting for period and sex. BTC statistics should be reported separately according to tumor location due to its distinct SEER stage distribution, treatment pattern, and prognosis. Care should be taken in elderly patients to reduce the rate of no active anti-cancer treatment.

Distinct Prognosis of Biliary Tract Cancer According to Stage, Treatment and Tumor Location: A Population-Based Study

Introduction: Biliary tract cancer (BTC) has a wide variety of tumor location which were inconsistently captured in epidemiological and clinical studies. This study aimed to investigate the treatment pattern and prognosis of BTC according to the tumor location, using a national population-based cancer registry data. Method: The Korea Central Cancer Registry data of 97,676 patients with BTC from 2006 to 2017 were retrospectively reviewed. The Surveillance, Epidemiology, and End Results (SEER) stage, first course of treatment (FT) administered within four months after cancer diagnosis, and 5-year relative survival rates (5YRS) were analyzed for gallbladder (GB), intrahepatic bile duct (IHBD), extrahepatic bile duct (EHBD), and ampulla of Vater (AoV) cancers. Results: The proportion of localized and regional (L&R) SEER stage was the highest in AoV (78.2%), followed by EHBD (68.3%), GB (52.6%), and IHBD (49.5%) cancer. Surgical FT rates among L&R stage patients increased over time, which were the highest in AoV (76.6%), followed by GB (69.4%), EHBD (54.1%), and IHBD (36.8%) cancer. The proportion of "no active treatment (NT)" in L&R stage was 38.9%. In each tumor location, elder patients had higher risk of receiving NT after adjusting for period and sex (p<0.001). The overall 5YRS was the highest in AoV (48.5%), followed by GB (28.5%), EHBD (19.9%), and IHBD (10.8%) cancer. Conclusions: BTC statistics should be reported separately according to tumor location, having distinct distribution of SEER stage, treatment pattern, and prognosis. Efforts are required to reduce NT to improve overall survival outcomes of BTC, especially in elder patients.

Epidemiology of Gastric Cancer in Korea: Trends in Incidence and Survival Based on Korea Central Cancer Registry Data (1999-2019).

This study investigated the trends of gastric cancer in Korea by adding the latest updated gastric cancer data from 2019. Gastric cancer incidence between 1999 and 2019 was reviewed using data from the Korea Central Cancer Registry. The study period was divided into 3 periods: period I (1999–2005), period II (2006–2012), and period III (2013–2019). The incidence, mortality, tumor location, histology, stage, and treatment were analyzed. Between 1999 and 2019, 577,502 patients were newly diagnosed with gastric cancer in Korea, accounting for 33.2% of patients aged ≥70 years. The age-standardized incidence rate (per 100,000) significantly decreased from 2011 (43.0) to 2019 (29.6), with an annual percent change of −4.50. Additionally, the age-standardized mortality rate (per 100,000) markedly decreased from 1999 (23.9) to 2019 (6.7). The proportions of patients with cardia and fundus cancers remained consistent. The proportion of localized stage cases increased, while those of regional and distant stages decreased. The rate of surgical treatment increased in localized and regional stages from 2006 to 2019. The overall 5-year relative survival (5YRS) rate of gastric cancer (per 100,000) increased from 55.7% in period I to 77.0% in period III. From 2013 to 2019, the 5YRS rates of patients (per 100,000) who underwent surgical treatment were 100.6% and 70.5% in the localized and regional stages, respectively. The results of this study demonstrated several changes in the epidemiology of gastric cancer in Korea. This study provides information to help understand the current trends in gastric cancer in Korea.

Incidence Patterns and Outcomes of Ewing Sarcoma in South Korea (1999-2017): A Retrospective Analysis Using Korea Central Cancer Registry Data.

PurposeDue to low incidence, epidemiologic data of Ewing sarcoma in the Asian population are scarce. We aimed to examine the incidence pattern and outcome of patients with Ewing sarcoma in the Republic of Korea.Materials and MethodsData of patients with Ewing sarcoma diagnosed between 1999 and 2017 were obtained from the Korea Central Cancer Registry (KCCR). Incidence, clinical characteristics, and survival rates were analyzed and compared between different age groups.ResultsThere were 788 cases (459 males, 329 females), with a median age at diagnosis of 20 years. The age-standardized rate of Ewing sarcoma was 1.01. The number of cases and incidence rates in each age group were as follows: children, 1.6; adolescents and young adults (AYA), 0.93; adults, 0.44; and elderly, 0.53. There were more male cases in children and the AYA group (p < 0.001). Extraskeletal tumors (p < 0.001), primary sites other than extremity (p=0.007), and presence of metastasis at diagnosis (p=0.031) were more frequent in the adults and elderly group. With a median survival time of 78 months, the 5-year overall survival (OS) rate of the entire cohort was 52%. Children fared best (5-year OS, 75%), and the 5-year OS of AYA patients (51%) approximated the OS of the entire cohort. A two-fold difference of 5-year OS was observed between adults and elderly patients (42% vs. 19%). On univariate and multivariate analyses, age ≥ 15 years and presence of metastasis were adverse prognostic factors.ConclusionThis was the first epidemiologic study of Ewing sarcoma using the KCCR data. With a similar incidence to other Asian countries, the survival rate was slightly lower than that of Euro-American cases. Collaborative clinical studies are necessary to improve the outcome of Ewing sarcoma in low-incidence populations.

First Course of treatment and Prognosis of Exocrine Pancreatic Cancer in Korea from 2006 to 2017.

PurposeHospital-based clinical studies have limitations in holistic assessment of cancer treatment and prognosis, as they omit out-of-hospital patients including elderly individuals. This study aimed to investigate trends in initial treatment and corresponding prognosis of patients with exocrine pancreatic cancer (EPC) in Korea.Materials and MethodsThe Korea Central Cancer Registry data of patients with EPC from 2006 to 2017 were retrospectively reviewed. We defined the first course of treatment (FT) as the cancer-directed treatment administered within four months after cancer diagnosis according to the Surveillance, Epidemiology, and End Results (SEER) program.ResultsAmong 62,209 patients with EPC, localized and regional (LR) SEER stage; patients over 70 years old; and ductal adenocarcinoma excluding cystic or mucinous (DAC) accounted for 40.6%, 50.1%, and 95.9%, respectively. “No active treatment” (NT, 46.5%) was the most frequent, followed by non-surgical FT (28.7%) and surgical FT (22.0%). Among 25,198 patients with LR EPC, surgical FT increased (35.9% to 46.3%) and NT decreased (45.0% to 29.5%) from 2006 to 2017. The rate of surgical FT was inversely related to age (55.1% [< 70 years], 37.3% [70–79 years], 10.9% [≥ 80 years]). Five-year relative survival rates of LR DAC were higher after surgical FT than after NT in localized (46.1% vs. 12.9%) and regional stage (23.6% vs. 4.9%) from 2012 to 2017.ConclusionLess than half of overall patients with LR EPC underwent surgical FT, and this proportion decreased significantly in elderly individuals. Clinicians should focus attention on elderly patients with EPC to provide appropriate medical advice.

Air Pollution and Incidence of Lung Cancer by Histological Type in Korean Adults: A Korean National Health Insurance Service Health Examinee Cohort Study.

Studies have reported associations between long-term exposure to ambient air pollution and lung cancer. However, there have been inconsistent reports of such associations with lung cancer by histological type. Thus, the aim of this study was to assess the association of long-term exposure to particulate matter with an aerodynamic diameter up to 10 μm (PM10) and nitrogen dioxide (NO2) with lung cancer incidence by histological subtype in South Korea. This population-based cohort study included 6,567,909 cancer-free subjects from the Korean National Health Insurance Service (NHIS) database for 2006–2007. We linked population data to Korea Central Cancer Registry data to confirm lung cancer incidence for 2006–2013. Individual exposures to PM10 and NO2 were assessed as five-year average concentrations predicted at subjects’ district-specific home addresses for 2002–2007. We divided these exposures into two categories based on the 75th percentile. Cox proportional hazards models were used to estimate hazard ratios (HRs) of lung cancer incidence for the upper 25% exposure compared to the low 75% by histological subtypes at diagnosis after adjusting for potential confounders. A total of 27,518 lung cancer were found between 2006 to 2013. The incidence of lung cancer was higher in males, smokers, drinkers and subjects with chronic obstructive pulmonary disease. Overall, we did not find an increased risk of lung cancer with higher exposure to PM10 or NO2. However, high exposure to PM10 was associated with increased risk of adenocarcinoma in comparison with lower exposure in males and current smokers (HR, 1.14; 95% CI, 1.03–1.25). This study showed that long-term air pollution exposures were associated with an elevated risk of lung adenocarcinoma in male smokers in Korea.

Breast Cancer Statistics in Korea in 2017: Data from a Breast Cancer Registry.

This article describes the breast cancer statistics in Korea, including the incidence, type of surgical procedure, stage, and molecular subtype, using the Korean Breast Cancer Society (KBCS) and Korea Central Cancer Registry data. There were a total of 26,534 new breast cancer diagnoses in 2017 in Korea, of which 4,139 were carcinoma in situ cases and 22,395 were invasive cancer cases. The age standardized rate of breast cancer was 75.3 per 100,000 women in 2017 (63.0 of invasive carcinoma and 12.3 of carcinoma in situ), and it has been steadily increasing across all age groups. Breast cancer occurred most commonly in the 40–49 age group. Compared to 2016, breast conserving surgery (BCS) has increased, and 67.4% of patients were treated with BCS in 2017. The proportions of stage 0 and stage I have continued to increase, accounting for 60.7%. The most common subtype of breast cancer was hormone receptor (HR) positive and human epidermal growth factor receptor-2 (HER2) negative type comprising 65.9% of the cases, whereas HR negative and HER2 positive type was the rarest comprising 10.2% of the cases. The 5-year relative survival rate of breast cancer patients had increased by 14.0% from 79.2% in 1993–1995 to 93.2% in 2013–2017. It is essential to actively enter breast cancer data into the KBCS registry to improve our understanding.

Trend analysis of major cancer statistics according to sex and severity levels in Korea.

Existing epidemiologic reports or studies of cancer statistics in Korea lack sufficient data on cancer severity distributions and observed survival rates. This study analyzed trends in major cancer statistics according to sex and severity levels in Korea from 2006 to 2013. We included eight cancers (hepatocellular carcinoma, and thyroid, colorectal, gastric, lung, prostate, breast, and cervical cancer), using Korea Central Cancer Registry data. Severity level was classified by Surveillance, Epidemiology, and End Results (SEER) stage as follows: localized, regional, distant, or unknown. Numbers of incident cancer cases from 2006 to 2013 were described by sex and SEER stage. We estimated up to 8-year observed survival rates of major cancers by sex and SEER stage, and provided prevalence rates by sex and SEER stage in 2011, 2012, and 2013. Although increases in new cancer cases are slowing and the total number of incident cancer cases in 2013 decreased for the first time since 2006, the number of prevalent cancer cases was 663,530 in 2013, an increase of 13.3% compared to 2011. Among the five cancers affecting both sexes, sex-related differences in 5-year observed survival rates for lung cancer were greatest in the localized stage (men, 31.9%; women, 48.1%), regional stage (men, 20.0%; women, 31.3%), and unknown stage (men, 24.3%; women, 37.5%). The sum of the proportions of localized and regional stages for thyroid and breast cancer was over 90% in 2013, while the sum of the proportions of localized and regional stages for lung cancer was only 56.7% in 2013. Differences in observed survival rates between men and women were prominent in lung cancer for all SEER stages. The reported epidemiologic data from this study can be used to obtain a more valid measure of cancer burden using a summary measure of population health.

Characteristics and Survival of Korean Patients With Colorectal Cancer Based on Data From the Korea Central Cancer Registry Data.

PurposeThe incidence of colorectal cancer (CRC) in Korea has increased remarkably during the past few decades. The present study investigated the characteristics and survival of patients with CRC in Korea as a function of time, tumor distribution, stage, sex, and age.MethodsWe retrieved clinical data on 326,712 CRC patients diagnosed between 1996 and 2015 from the Korea Central Cancer Registry. The incidence and the 5-year relative survival rates were compared across time period, tumor distribution, stage, sex, and age group.ResultsThe percentage of patients with colon cancer increased from 49.5% in 1996–2000 to 66.4% in 2011–2015 while the percentage of patients with rectal cancer decreased from 50.5% to 33.6%. The 5-year relative survival rates for all CRCs improved from 58.7% in 1996–2000 to 75.0% in 2011–2015. For 1996–2000, survival rates were highest for patients with left-sided colon cancers, followed by those with right-sided, transverse, rectal, rectosigmoid cancers. For 2011–2015, the survival rates for patients with left-sided cancers were highest, followed by those with rectosigmoid, rectal, transverse, and right-sided colon cancers. Patients with local and regional, but not distant, SEER (Surveillance, Epidemiology, and End Results) stage tumors experienced significantly increased survival rates for 2006–2010 and 2011–2015. The proportion of CRC patients by age decreased in the order ≥70, 60–69, 50–59, 40–49, ≤39 years whereas survival rates decreased in the order 50–59, 60–69, 40–49, ≤39, ≥70 years.ConclusionKorean CRC has some distinct characteristics and survival patterns in terms of tumor distribution, stage, sex, and age. With time, survival outcomes have improved for both local and regional, but not distant, stage tumors.

Commentary on "Characteristics and Survival of Korean Anal Cancer From the Korea Central Cancer Registry Data"

To the editor: I read with great interest Park et al. [1]'s study, which is one the largest reports on anal canal cancer published in the literature. It provides valuable information regarding the characteristics of and the outcomes for Korean patients with anal canal cancer. The study has mainly focused on the prognostic impact of age, sex, stage, and study duration on the 5 year relative overall survival rates. However, as declared by the authors, due to the limitations of their database, the study lacks important clinical data. Kim [2] well pointed out some of the study's limitations in the editorial entitled, Anal Cancer Study Based on Korea Central Cancer Registry Data: One Step Forward in Clinical Research. Park et al. [1]'s study did not address a mean or a median age for the entire study population. Malignant neoplasms of the anal canal tend to present in the sixth and the seventh decades of life and rarely before the second decade [3]. The distributions of tumor characteristics such as histologic type, stage and tumor grade between themselves and among different sex and age groups have not been provided. In addition, the modalities used to treat different stages and histological types were not addressed. The treatment approach is usually based on histological type, disease stage, and patient's performance status and desire [3, 4]. Finally, the authors did not compare the patients' and the tumor's characteristics and the 5 year overall survival rates in their study to those previously reported in the literature for large series [5, 6]. Herein, we provided a table (Table 1) to present and compare the patients demographics, the histological types and the 5 year overall survival rates in Park et al. [1]'s study and in two of the largest reports of anal canal cancer from Australia and the United States [1, 5, 6]. Accordingly, the female/male ratio of Korean patients with anal canal cancer is comparable to the values reported in the literature [3, 5, 6]. Park et al. [1] found a lower (50% vs 70% and 77%) proportion for squamous cell carcinomas and a higher (32% vs 27.5% and 19%) one for adenocarcinomas, which is different from most reported series. Furthermore, the average 5-year-survival of Korean patients with anal canal cancer is consistent with the values for most reported series [3, 5, 6]. Table 1 Patient characteristics, clinicopathologic features and overall survival for patients with anal canal cancer based on the three largest reported series in the literature

Reply on "Characteristics and Survival of Korean Anal Cancer From the Korea Central Cancer Registry Data"

Reply on "Characteristics and Survival of Korean Anal Cancer From the Korea Central Cancer Registry Data"

Anal Cancer Study Based on Korea Central Cancer Registry Data: One Step Forward in Clinical Research

See Article on Page 182-185 First of all, I would like to congratulate the authors of this work, which focused especially on rare tumors and anal cancer based on National Cancer Registry data. For colorectal surgeons, knowledge of oncologic outcomes for anal cancer is important for making a therapeutic decision. Furthermore, these outcomes should be based on Korean Cancer Registry data. Anal cancer constitutes a relatively small portion of gastrointestinal tract cancers [1]. However, anal cancers are probably underreported because some anal canal tumors are misclassified as rectal tumors. Wide geographical and racial variations in the incidence of cancers are observed around the world. The incidence and the survival rates are generally well publicized for the more common cancers, such as lung, breast, and colorectal tumors; however, little is written regarding the incidence and the survival rates for anal canal cancer. Although some authors have reported clinicopathologic features or prognostic factors for anal cancers [2, 3], the characteristics of and the survival rate for anal cancer in Korea are largely unknown because no population-based study has been performed to address these issues in Korea. For decades, in many countries and regions, registration of cancers has been mandatory. National cancer registration is rooted in public health, helps in the planning of health services, and can be an important tool in clinical research. However, sometimes clinicians are frustrated because the cancer registry cannot provide all the information they need. A limitation in this study based on Korea Central Cancer Registry data is that the database lacks information on interventions such as surgery, radiation, and chemotherapy, on time to any type of recurrence, or on aspects of quality of care for anal canal cancer. The authors compared the survival between males and females by Surveillance, Epidemiology and End Results (SEER) stage and found that survival rates showed a diffference according to sex and age which was related to the distinct features of Korean patients with anal cancer [4]. This study is the largest to date that reports population-based survival data for anal canal cancer in Korea, and it provides an updated picture of anal canal cancer during the past 17 years. Even though the results could be representative of the population in Korea and should be more meaningful than single-institution experiences, this study has some limitations. The study did not analyze oncologic oucomes according to TNM stage, therapeutic modality, or recurrence pattern. In the future, the detailed parameters must be checked before analyzing Korean Cancer Registry database. Additionally, current data needs to be compared with published single-institution anal cancer data. Finally, prospective multicenter studies based using clinical databases on rare cancers need to be done to improve the quality of the data.

Characteristics and Survival of Korean Anal Cancer From the Korea Central Cancer Registry Data

PurposeIn Korea, anal cancer is rare disease entity with specific clinical characteristics. Therefore, no survival analysis with a sufficient patient population has been performed. The aim of this study was to evaluate the characteristics of Korean anal cancer, focusing on the survival according to tumor histologies, sex, and a specific age group, using the nationwide cancer registry.MethodsUsing the Korea Central Cancer Registry, we analyzed a total of 2,552 cases from 1993 to 2010. We assessed the 5-year relative survival by using tumor histology. In addition, survival differences of Surveillance Epidemiology and End Results (SEER) stage were analyzed for both sexes and for young-age cancer (younger than 40 years) and advanced-age cancer (older than 70 years).ResultsThe 5-year relative survival among anal cancer patients increased from 38.9% for the period 1993-1995 to 65.6% for the period 2006-2010. The anal squamous cell carcinoma was the most common histology and showed better survival than other types of cancer. Females demonstrated better survival than males in all SEER stages. The 5-year survivals for patients in whom anal cancer developed before the age of 40 and at or after the age of 40 were 62.4% and 51.6%, respectively. The 5-year survival for patients in whom cancer developed at or after the age of 70 was much worse than that for patients in whom the cancer had developed prior to that age.ConclusionKorean anal cancer has certain distinctive characteristics of survival according to tumor histology, sex, and age. Despite limitations on available data, this study used the nationwide database to provide important information on the survival of Korean patients with anal cancer.