Korea Central Cancer Registry Research Articles

Long-term Oncologic Outcome and Its Relevant Factors in Anal Cancer in Korea: A Nationwide Data Analysis.

PurposeAnal cancer is a rare disease in Korea, and thus survival analyses are limited by small sample sizes. This study used the Korea Central Cancer Registry (KCCR) for a survival analysis and for assessing characteristics of anal cancer in a large sample of Koreans.MethodsFrom the KCCR, data on 3,615 patients who were diagnosed and treated for anal cancer from 1993 to 2015 were retrieved. Clinicopathologic variables including age, sex, histological type, and Surveillance Epidemiology and End Results (SEER) stage were reviewed, and a survival analysis was performed according to these variables.ResultsThe 5-year relative survival rate improved from 39.7% in 1993–1995 to 66.5% in 2011–2015. Squamous cell carcinoma was the most common and showed the highest survival rate. Males and older patients (≥40 years and ≥70 years) showed poor prognoses.ConclusionThe survival rate for anal cancer in Korea has improved steadily over time. The characteristics related to survival were the histological type, sex, and age. These statistics will be fundamental for future Korean anal cancer research.

Abstract P4-17-05: Survival and clinicopathologic characteristics of male breast cancer patients using Korea national cancer incidence database

Abstract Background: Male breast cancer (MBC) is a very rare disease. There are ambiguous opinions about treatment outcomes and survival outcome. This study aimed to investigate the incidence and survival outcome of male breast cancer in Korea. Additionally, we evaluated the differences between male and female breast cancer (FBC). Method: We identified 226,612 breast cancer cases diagnosed between 1999 and 2016 in the Korea Central Cancer Registry (KCCR). We retrospectively analyzed the data that patient demographics and clinical information between MBC and FBC. Overall survival (OS) was estimated according to sex, age, histologic type, stage. Results: Of the 226,612 patients, 1,052 had male breast cancer patient and 225,560 had female breast cancer patients. The ratio of male to female was 0.0047. MBC patients were diagnosed the most frequently in those aged 60-69 years. In contrast, FBC was diagnosed the most frequently in those aged 40-49 years (p<.0001). Male patient received less adjuvant therapy than female patients (radiotherapy, MBC vs. FBC = 8% vs. 22%, chemotherapy, 41.9% vs. 55.7%, p<.0001). The 5-years OS rates after the diagnosis of breast cancer were 88.8% for all patients. MBC has a lower 5-years OS rate than FBC (76.2% for men, and 88.9% for women, p<.0001). Both groups showed lower survival in patients aged ≥60 years. The 5-years OS rates of invasive type were 75.8% for men and 89% for women. The OS rate was lower in both groups as the stage increased. Conclusion: We found that there is a difference between MBC and FBC. The survival outcomes in MBC were worse than that of FBC. This study showed the different OS patterns according to the age, histology, and stage. Based on these results, clinicians need to recognize the difference from FBC when treating MBC. Citation Format: Eungyeong Lee, Heein Jo, Jai Hong Han, So-Youn Jung, Seeyoun Lee, Han-Sung Kang, Myong Cheol Lim, Young-Joo Won, Eun Sook Lee, Eun Sook Lee. Survival and clinicopathologic characteristics of male breast cancer patients using Korea national cancer incidence database [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-17-05.

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.

Trends of Incidence and Survival Rrates of Mucosa-associated Lymphoid Tissue Lymphoma in the Korean Population: Analysis of the Korea Central Cancer Registry Database

BackgroundExtranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT-lymphoma) is an extranodal lymphoma that occurs at various sites in the body. There is a limited understanding of the incidence and survival rates of MALT-lymphoma. To investigate the nation-wide incidence and survival rates of MALT-lymphoma in Korea during 1999–2017, the data on MALT-lymphoma were retrieved from the Korea Central Cancer Registry.MethodsDuring the time period of 1999–2017, 11,128 patients were diagnosed with MALT-lymphoma. The age and sex of the patients and the Surveillance, Epidemiology, and End Results (SEER) summary stage of the tumor were analyzed, and the relative survival rates (RSRs) were calculated.ResultsThe age-standardized incidence rates of MALT-lymphoma in 2017 among males and females were 1.53 and 1.61 per 100,000 individuals, respectively, whereas those in 1999 among males and females were 0.21 and 0.20, respectively in Korea. The RSRs were more than 97% at 10 years post-diagnosis between 1993 and 2017. The 5-year RSRs were 87.4%, 94.8%, 97.8%, and 98.6% during 1996–2000, 2001–2005, 2006–2010, and 2013–2017, respectively. Based on SEER summary staging, the 5-year RSRs during 2013–2017 were 100.3%, 90.8%, 91.3%, and 97.9% for patients with localized, regional, distant, and unknown stages of MALT-lymphoma, respectively.ConclusionAlthough the incidence of MALT-lymphoma is low in Korea, it has been increasing in recent years. The prognosis of MALT-lymphoma is good even at advanced stages. These findings provide useful insights to clinicians about MALT-lymphoma and inform patients about the survival rate.

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.

Incidence trends for epithelial peritoneal, ovarian, and fallopian tube cancer during 1999-2016: a retrospective study based on the Korean National Cancer Incidence Database.

ObjectivePrimary peritoneal cancer (PPC), ovarian cancer (OC), and fallopian tube cancer (FTC) are considered as a single disease group. As knowledge of the pathogenesis and clinical presentation of peritoneal, ovarian, and fallopian tube (POFT) cancer grows, the tendencies in OC diagnosis are changing. We investigate the incidence and clinical characteristics of epithelial POFT based on cancer site and histologic type.MethodsData from the Korea Central Cancer Registry for the period between 1999 and 2016 were analyzed. The incidence rates and annual percent changes (APCs) for each tumor site were reported.ResultsAmong 27,768 women with cancer, 1,086 (3.91%) had PPC, 25,847 (93.08%) had OC, and 835 (3.01%) had FTC. Age-standardized rates increased from 0.05 to 0.24, 3.51 to 5.48, and 0.04 to 0.28 in PPC, OC, and FTC, respectively. The proportion of PPC and FTC among all the POFT cases increased consistently during the study period (from, respectively, 1.48 and 1.06 in 1999 to 4.52 and 4.76 in 2016). The APC of PPC, OC, and FTC during 1999–2016 was 9.3%, 2.7%, and 8.6%, respectively. The incidence of PPC, OC, and FTC was highest among patients in the 65–69, 50–54, and 55–59 years age group, respectively.ConclusionThe overall incidence of PPC, OC, and FTC cancer has steadily increased. The relative increase of PPC and FTC has been significant. In this study, OC incidence had a relatively young peak age, in contrast to FTC and PPC, which had an older peak age.

Milk Consumption Decreases Risk for Breast Cancer in Korean Women under 50 Years of Age: Results from the Health Examinees Study.

Epidemiologic studies regarding breast cancer risk related to milk consumption remain controversial. The aim of this study was to evaluate the association between milk consumption and the risk for breast cancer. A total of 93,306 participants, aged 40–69 years, were included in the prospective cohort study in the Health Examinees-Gem (HEXA-G) study between 2004 and 2013. Dietary intake was assessed using a validated food frequency questionnaire. Information on cancer diagnosis in the eligible cohort was retrieved from the Korea Central Cancer Registry through 31 December 2014. The Cox proportional hazards model was used to estimate multivariate hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 359 breast cancer cases were observed over a median follow-up period of 6.3 years. Milk consumption was not associated with decreased risk for breast cancer in the total population (p for trend = 0.0687). In women under 50 years of age, however, milk consumption was inversely associated with breast cancer risk. In the comparison between highest (≥1 serving/day) and lowest (<1 serving/week) intake categories of milk, the multivariate HR (95% CI) was 0.58 (0.35–0.97, p for trend = 0.0195)) among women under 50 years of age. In conclusion, our findings show that milk consumption in Korean women aged 50 or younger is associated with a decreased risk for breast cancer, when compared to those who never or rarely consumed milk. Further studies need to be conducted to assess this relationship and confirm these results.

Survey of Potential Cancer Registry Items to Enhance the Usefulness of Cancer Registry Data.

Background:Cancer registry data can help plan for cancer services and to identify where further progress is needed, in order to improve the lives of patients with cancer. This study investigated the possibility of collecting additional information and the priority of the information by examining other cancer registry items. We aimed to suggest additional data items to be collected to enhance the usefulness of cancer registry data. Methods:We examined items that could potentially be added by comparing the cancer registration items in five foreign registries and large hospitals in Korea. Based on the foreign and domestic hospital cancer registry data, a questionnaire survey was administered to 272 cancer registry workers nationwide and 10 cancer experts to investigate the possibility of expanding the variables. The proportion and rank of each item were analyzed. Results:There were similar items for demographic information and cancer diagnosis between foreign cancer registries and the Korea Central Cancer Registry (KCCR). However, the KCCR had fewer items for staging, treatment, and follow-up. There were 29 items to be collected with high priority. Items under demographic information included date of birth, race and country of birth. Items for cancer diagnosis included type of cancer, smoking history and type of pathologic test. Treatment information included the date of treatment, chemotherapy and radiation. Items under the stage and prognostic factors included TNM stage, collaborative stage, and comorbidities. Finally, items under follow-up information included survival, cancer state and recurrence information. Conclusions:Cancer registration workers and cancer experts generally agreed on the need to expand the essential items for cancer registration. The findings of this study will be useful for devising plans to expand cancer registration items.

Different Patterns of Conditional Survival of Breast Cancer Patients by Age and Histologic Types: Evidence from the Korean Nationwide Registry.

Conditional relative survival (CRS), which is the survival estimate of patients who have already survived for a certain period of time after diagnosis, could provide more relevant information on the current prognosis of cancer survivors than the standard 5-year relative survival (RS). This study aimed to estimate the 5-year CRS of Korean breast cancer patients. We identified 145,083 breast cancer cases diagnosed between 2002 and 2013 in the Korea Central Cancer Registry. The CRS was estimated for every year after diagnosis, according to sex, age, histologic type, and stage. The 5-year RS at diagnosis was 90.8%, and the 10-year RS was 85.7%. The 5-year CRS was 91.0% and 94.3% at 1 year and 5 years after diagnosis, respectively. Very young and very old patients had worse 5-year CRS after 5 years of survival than those of other age groups (92.2% in the <40-year and 92.6% in the ≥70-year groups vs. 95.4% in 40-49-year, 94.3% in 50-59-year, and 93.7% in 60-69-year groups). The 5-year CRS of metaplastic carcinoma increased from 82.0% at diagnosis to 95.2% at 5 years after diagnosis, compared with that of lobular carcinoma (from 93.1% to 92.5%). Hardly any excess mortality (5-year CRS ≥ 95%) was seen within 7 years after diagnosis. This study shows that the CRS of breast cancer survivors in Korea has increased, but varies by sex, age, stage, and histologic type. These findings provide more detailed information to breast cancer survivors and clinicians.

Second primary cancers in patients with oral cavity cancer included in the Korea Central Cancer Registry

ObjectivesThe improved survival of patients with oral cavity cancer (OCC) has generated interest in factors affecting survivorship, particularly among second primary cancer (SPC) patients. This study aimed to assess the incidence, patterns, and risk factors for SPC after OCC treatment in the Korean population. Materials and methodsData from 15,261 patients with OCC (ICD-O: C01–C06) identified between 1993 and 2014 were extracted from the Korean Central Cancer Registry. The standardized incidence ratio (SIR) for SPC after index OCC was calculated, and Poisson regression analysis was performed to evaluate the risk factors for SPC among survivors. ResultsThe overall SIR for SPC among OCC survivors was 1.47 (95% confidence interval [CI] 1.39–1.56). SIR differed by sex (male: 1.51 vs. female: 1.37), age at diagnosis (<45 years: 2.47 vs. 45–64 years: 1.68 vs. ≥ 65 years: 1.10), index OCC subsite (floor of mouth: 1.95 vs. gum: 1.30), follow-up duration (6–23 months: 1.64 vs. 24–59 months: 1.51 vs. 60–119 months: 1.48 vs. ≥ 120 months: 1.24), histological OCC type (salivary gland malignancy: 1.77 vs. squamous cell carcinoma: 1.44 vs. others: 1.47), and radiation history (any: 1.94 vs. no radiation: 1.37). The risk factors for SPC development among OCC survivors included younger age at diagnosis and history of radiation therapy. ConclusionOCC survivors have significantly increased risks of SPCs, exhibiting distinctive site distributions and chronological patterns. These patients would benefit from an SPC surveillance protocol.

Pilot study of acupuncture to treat anxiety in children and adolescents

Conditional relative survival (CRS) describes the survival chance of patients who have already survived for a certain period of time after diagnosis and treatment of cancer. Thus, CRS can complement the conventional 5-year relative survival, which does not consider the time patients have survived after their diagnosis. This study aimed to assess the 5-year CRS among Korean patients with oral cancer and the related risk factors.We identified 15,329 oral cavity cancer cases with a diagnosis between 1993 and 2013 in the Korea Central Cancer Registry. The CRS rates were calculated according to sex, age, subsite, histology, and stage at diagnosis.The 5-year relative survival was 57.2%, and further analysis revealed that the 5-year CRS increased during the first 2 years and reached a plateau at 86.5% after 5 years of survival. Women had better 5-year CRS than men after 5 years of survival (90.0% vs. 83.3%), and ≤45-year-old patients had better 5-year CRS than older patient groups (93.3% vs. 86.4% or 86.7%). Subsite-specific differences in 5-year CRS were observed (tongue: 91% vs. mouth floor: 73.9%). Squamous cell carcinoma had a CRS of 87.3%, compared to 85.5% for other histological types. Localized disease had a CRS of 95.7%, compared to 87.3% for regional metastasis.Patients with oral cavity cancer exhibited increasing CRS rates, which varied according to sex, age, subsite, histology, and stage at diagnosis. Thus, CRS analysis provides a more detailed perspective regarding survival during the years after the initial diagnosis or treatment.

Changes in the Diagnostic Efficiency of Thyroid Fine-Needle Aspiration Biopsy during the Era of Increased Thyroid Cancer Screening in Korea.

PurposeThe volume of thyroid cancer screening and subsequent thyroid fine-needle aspiration (FNA) have rapidly increased in South Korea. We analyzed the thyroid cancer diagnoses/thyroid FNA ratio according to the annual number of FNA to evaluate changes in the diagnosticefficiency of FNA.Materials and MethodsThis was a nationwide population-based retrospective cohort study. The overall thyroid cancer diagnoses/thyroid FNA ratio and annual incremental thyroid cancer diagnoses/incremental thyroid FNA ratio were indirectly calculated using data obtained from the Korea Central Cancer Registry database and the Korean National Health Insurance Service claims database from 2004 to 2012. Pearson correlation analyses were performed to evaluate the strength of linear associations between variables.ResultsThe number of thyroid FNA increased from 28,596 to 177,805 (6.2-fold increase) from 2004 to 2012. The overall thyroid cancer diagnoses/thyroid FNA ratio decreased from 36.5% in 2004 to 25.1% in 2012 and was negatively correlated to the number of FNA (R=‒0.977, p < 0.001). The annual incremental thyroid cancer diagnoses/incremental thyroid FNA ratios (range, 15.3% to 30.7%) were always lower than the overall thyroid cancer diagnoses/thyroid FNA ratio in each year and also worsened according to the increase in the number of FNA (R=‒0.853, p=0.007).ConclusionThe diagnostic performance of both overall and annual incremental thyroid FNA worsened, whereas the number of thyroid FNA procedures increased. More sophisticated indications for FNA are required to improve its diagnostic efficiency, considering the increased burden of screening-detected thyroid nodules.

Abstract P1-08-24: Conditional survival of breast cancer patients: Korean nationwide registry

Abstract Purpose: Conditional relative survival (CRS) could provide more relevant information on the current prognosis of cancer survivors than standard 5-year relative survival (RS). This study aimed to estimate the 5-year CRS of Korean breast cancer patients. Patients and Methods: We identified 145,083 breast cancer cases with diagnosis between 2002 and 2013 in the Korea Central Cancer Registry. The CRS was estimated for every year after diagnosis, according to sex, age, histologic types, stage, and year of diagnosis. Results: The 5-year RS at diagnosis was 90.8% and 10-year RS was 85.7%. Five-year CRS was 91.0% and 94.3% at 1-year and 5-year after diagnosis. Women had better 5-year CRS than men after 5 years of survival (94.3% vs. 79.5%), and very young and very old patients had worse 5-year CRS after 5 years of survival than other age groups (92.2% in &amp;lt;40yr, 92.6% in ≥70yr vs. 95.4% in 40-49, 94.3% in 50-59, and 93.7% in 60-69, relatively). In histologic types, CRS of metaplastic carcinoma has improved from 82.0% to 95.2%, compared to CRS of lobular carcinoma (from 93.1% to 92.5%). Hardly any excess mortality (5-year CRS ≥ 95%) was seen since 7 years after diagnosis. There was hardly any excess mortality at 5 years of survival, for the patients with 40-49 years (95.4%), with localized disease (97.8%), and with metaplastic carcinoma (95.2%). Conclusion: This study showed that CRS of breast cancer survivors in Korea has been improved, which varied by sex, age, stage, and histologic types. These CRS analysis could provide a more detailed information for survival to breast cancer survivors and clinicians. Citation Format: Jung S-Y, Jung K-W, Won Y-J, Kwon Y, Ha J, Kim YA, Kong S-Y, Lee ES. Conditional survival of breast cancer patients: Korean nationwide registry [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-08-24.

A Nationwide, Population-Based Epidemiologic Study of Childhood Brain Tumors in Korea, 2005-2014: A Comparison with United States Data.

We investigated the epidemiologic characteristics of childhood brain tumors (CBT) in Korea, and compared our findings with those from the United States. We searched the Korea National Cancer Incidence Database of the Korea Central Cancer Registry (KCCR) from 2005 to 2014, which included all Korean patients with CBT aged 0 to 19 years at diagnosis. The age-standardized incidence rates (ASR) and the 5-year relative survival rate (RSR) were determined. The Central Brain Tumor Registry of the United States (CBTRUS) classification and definitions were applied to allow direct comparison with U.S. A total of 6,027 CBTs were identified. The ASR of all CBTs was 5.08 per 100,000 population, which was significantly lower than that in the United States (5.57). However, the ASR of nonmalignant CBTs in Korea (2.48) was significantly higher than that in the United States (2.15). Embryonal tumors (ASR: 0.99 and 0.72 in the 0-4 and 5-9 year age groups, respectively) were the most common CBTs in these respective age groups. Germ cell tumors (0.78) and pituitary tumors (1.63) were the most common CBTs in the 10-14 and 15-19 year age groups, respectively. The 5-year RSR of CBTs was 84% and varied according to histology. High incidences of nonmalignant and germ cell tumors are distinct CBT features in Korean children and adolescents. To our knowledge, this is the first and largest population-based epidemiologic study of CBTs in Asia. Our findings support the notion that East Asian populations have a higher incidence of central nervous system germ cell tumors than other races.

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

This corrects the article on p. 118 in vol. 82, PMID: 29926550.

Incidence of cervical, endometrial, and ovarian cancer in Korea during 1999-2015.

ObjectiveTo investigate the incidence and trends of cervical (C53), endometrial (C54.1), and ovarian cancer (C56) among Korean females between 1999 and 2015.MethodsThe incidence of the three major gynecological cancers between 1999 and 2015 was analyzed based on the data from the Korea Central Cancer Registry. The age-standardized rates (ASRs) and the annual percent changes (APCs) for each site were calculated.ResultsThe absolute incidence rates of the three major gynecological cancers increased from 6,394 in 1999 to 8,288 in 2015. ASR for gynecologic cancer decreased from 23.7 per 100,000 in 1999 to 21.1 in 2015. This was mainly due to a definitive decrease in the incidence of cervical cancer, which recorded an APC of −3.7%. The trends of APC for gynecologic cancer were variable, being −1.36% between 1999 and 2006 and −0.11% between 2006 and 2015. A definitive but variable increase was noted for endometrial cancer, and the APC for this cancer was 7.4% between 1999 and 2009 and 3.5% between 2009 and 2015. The incidence of ovarian cancer gradually increased, with an APC of 1.8% between 1999 and 2015.ConclusionOverall, ASRs and APCs for the three major gynecological cancers are decreasing, with a recent reduction in the width of the change. However, there has been a progressive increase in the incidence of endometrial and ovarian cancers.

Trends and Outcomes of Non-compliance with Treatment for Gastric Cancer in Korea over the 16 years from 1999 to 2015.

PurposeThe aim of this study was to evaluate the trend of non-compliance with treatment (NCT) among gastric cancer patients in the Korean population.Materials and MethodsUsing data from the Korea Central Cancer Registry from 1999 to 2015, patients who did not receive any treatment for gastric cancer within 4 months after diagnosis were defined as the NCT group. The annual incidence rate, distributions according to age group and stage, and 5-year relative survival of the patients exhibiting NCT were analyzed.ResultsThe number of NCT patients was 5,871 (30.6%) in 1999 and continuously decreased to 4,434 (15.3%) in 2015. Between 2006 and 2015, the proportions of NCT patients decreased from 72.9% to 55.0% among those 80 years old or older and from 9.2% to 5.4% among patients younger than 40 years. In patients with distant metastases, this proportion decreased from 35.5% to 32.7%, and this proportion also decreased from 17.6% to 8.2% among those with localized disease. The 5-year relative survival rates of NCT patients between 2011 and 2015 were significantly lower than those of the treated patients in each stage (60.2% vs. 99.7%, 13.8% vs. 67.1%, and 2.0% vs. 8.3% among those with localized, regional, and distant disease, respectively).ConclusionsThe proportion of NCT gastric cancer patients has decreased during the last 16 years. However, considerable numbers of elderly patients are still NCT. There must be a strategy to decrease NCT and improve the nationwide survival rate of patients with gastric cancer.

Second malignant neoplasms after childhood cancer: A nationwide population-based study in Korea.

BackgroundSecond malignant neoplasm is one of the most devastating late effects of childhood cancers. This study aimed to evaluate the incidence and survival outcomes of patients developing second malignant neoplasms (SMNs) after surviving childhood cancer in Korea.MethodsMedical data of childhood cancer patients diagnosed between 1993 and 2012 were obtained from the Korea Central Cancer Registry. The risk of developing SMNs was calculated using standardized incidence ratio (SIR), excess absolute risk (EAR), and cumulative risk. Kaplan-Meier survival curves were estimated, stratified by SMN status.ResultsA total of 28,405 childhood cancer patients were diagnosed in the study period, and 337 (1.2%) developed SMN. The total follow-up period was 197,359 person-years at risk (PYR), with a median follow-up duration of 5.6 years. Overall SIR was 20.0, which was 23.2 in women, and 17.6 in men. The overall EAR was 16.4 per 10,000 PYR. The most common types of SMNs, in order of incidence, were other malignant epithelial neoplasms, leukemia, and soft tissue sarcomas. The cumulative incidence of developing SMNs was 0.7% at 5 years, 1.2% at 10 years, and 2% at 15 years. After primary cancer diagnosis, the 10-year overall survival rate of patients with SMNs was 65.1%, which was lower than the 73.4% in patients without SMN. After SMN diagnosis, the 10-year overall survival rate was 55.8%.ConclusionThrough this registry-based study of 5.6 years of follow up, childhood cancer survivors were found to be at 20-fold higher risk of developing a malignant neoplasm compared to the general population. The majority of malignant neoplasms are malignant epithelial neoplasms, leukemia, and soft tissue sarcomas. Continued surveillance for assessing long-term risks, and guidance for appropriate long-term follow up of childhood cancer survivors, are needed.

National Epidemiologic Survey of Thyroid cancer (NEST) in Korea.

The Korea Central Cancer Registry conducted the National Epidemiologic Survey of Thyroid cancer (NEST) to investigate changes in the epidemiological and clinical characteristics of thyroid cancer patients between 1999 and 2008. The NEST was designed to collect representative samples of patients with thyroid cancer diagnosed in the years 1999, 2005, and 2008 using a proportionally stratified and systematic random sampling method. Among 42,891 participants diagnosed with thyroid cancer, 5,796 participants were included in the final study population. This survey collected information on diagnostic methods and date, route of diagnosis, prior medical history and history of thyroid-related disease, tumor, lymph node, metastasis and collaborative stage, and treatment. The NEST dataset was also linked to the cause-of-death database from Statistics Korea. The mean age of the study participants was 46.9 years. The ratio of men to women was 1:5.5. In the analysis of the histologic type of cancer, the proportion of papillary thyroid carcinoma showed an increasing trend (p<0.01). In contrast, the proportion of distant metastasis and the mean tumor size of thyroid cancers showed decreasing trends over time (p<0.01, respectively).

The Development of the Korean Lung Cancer Registry (KALC-R)

Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer-related deaths worldwide. Globally, there were an estimated 1.8 million new cases and 1.59 million deaths in 2012. In Korea, the incidence of lung cancer is increasing and 24,267 (47.6/100,000) patients with lung cancer were registered at the Korea Central Cancer Registry in 2015. Previous nationwide surveys of lung cancer were performed in 1998 by the Korean Academy of Tuberculosis and Respiratory Diseases and in 2007 by the Korean Association for Lung Cancer (KALC), but the studies faced difficulties in maintaining lung cancer registry because of limitations regarding the Private Information Protection Act. To produce unbiased and reliable epidemiological data, the KALC and Korean Central Cancer Registry developed a detailed lung cancer registry (KALC-R) data structure. Following a pilot survey of 489 lung cancer cases in 2013, about 10% of the sampled lung cancer cases from the Korean Central Cancer Registry are surveyed each year. With the analysis of detailed data from the KALC-R, an important epidemiological background for scientific research or policy development is expected to be generated.