Descriptive epidemiology of cancer of unknown primary in South Korea, 1999-2017.

BACKGROUND: Cancers of unknown primary (CUPs) are tumors found after metastasizing from unidentified primary sites; these tumors generally have unknown treatment strategies, expected treatment results, and prognosis. We assessed the epidemiological characteristics of CUPs in Korea. METHODS: We extracted records for 1999 through 2017 from the Korea Central Cancer Registry using the International Statistical Classification of Diseases and Related Health Problems (10th revision) codes for CUP as defined by the International Agency for Research on Cancer. Age-standardized rates and relative survival rates were calculated. RESULTS: The CUPs constituted 2.1 % of the total number of cancer registrations in 1999, declining to 0.7 % in 2017. The incidence rate decreased for both sexes (5.35 to 2.20 for men, 3.15 to 1.77 for women). Patients aged 80 years and older had the highest incidence rate at 40.2, and 86.3 % of CUPs occurred in those 50 years of age or older. The cases of retroperitoneum and peritoneum sites increased over time. Cases diagnosed by microscopic methods and death certification only were 62.3 % and 7.9 %, respectively. The malignant neoplasm of the retroperitoneum and peritoneum and unknown primary site had the highest and lowest survival rates, respectively. The 5-year relative survival rate increased over time from 14.2 % (1999-2002) to 27.3 % (2013-2017). CONCLUSIONS: Our analysis of data from the Korea Central Cancer Registry found decreasing rates of CUP, although with consistent disparities by patient age and sex. Advancements in diagnostic technology may be decreasing the number of CUP diagnoses. Expanding the amount of information recorded in the registry may further improve diagnostic accuracy.

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.

Qualitative Improvement Methods Through Analysis of Inquiry Contents for Cancer Registration

Background: In Korea, the national cancer database was constructed after the initiation of the national cancer registration project in 1980, and the annual national cancer registration report has been published every year since 2005. Consequently, data management must begin even at the stage of data collection in order to ensure quality. Objectives: To determine the suitability of cancer registries' inquiry tools through the inquiry analysis of the Korea Central Cancer Registry (KCCR), and identify the needs to improve the quality of cancer registration. Methods: Results of 721 inquiries to the KCCR from 2000 to 2014 were analyzed by inquiry year, question type, and medical institution characteristics. Using Stata version 14.1, descriptive analysis was performed to identify general participant characteristics, and chi-square analysis was applied to investigate significant differences in distribution characteristics by factors affecting the quality of cancer registration data. Results: The number of inquiries increased in 2005­2009. During this period, there were various changes, including the addition of cancer registration items such as brain tumors and guideline updates. Of the inquirers, 65.3% worked at hospitals in metropolitan cities and 60.89% of hospitals had 601­1000 beds. Tertiary hospitals had the highest number of inquiries (64.91%), and the highest number of questions by type were 353 (48.96%) for histological codes, 92 (12.76%) for primary sites, and 76 (10.54%) for reportable. Conclusions: A cancer registration inquiry system is an effective method when not confident about codes during cancer registration, or when confronting cancer cases in which previous clinical knowledge or information on the cancer registration guidelines are insufficient.

Cancer Registration Manual Understanding by Medical Record Administrators

Background: This study examined: (a) whether medical record administrators (MRAs) properly understand and apply a cancer registration manual; (b) weaknesses in cancer registration: and (c) factors influencing the accuracy of cancer registration. Methods: MRAs dealing with cancer registration in 81 national member hospitals were asked by mail to answer 17 questions about cancer information among registration items. After calculating rates of correct and incorrect answers to each question, an analysis was conducted of whether they were related to particular factors (hospital type, hospital location, number of hospital beds, experience of cancer registration, and experience of consulting cancer registration). Results: A total of 45.7% of the participants gave approximately 90% correct answers. The rates for correct answers about general rules were under 90% for objectives of cancer registration and treatment. The rate concerning histologic type was over 90%, while few correct answers exceeded 50% to questions concerning newly revised rules for the colorectal system. For questions about initial treatment, date of diagnosis, and method of final diagnosis, as well as four questions on checking the validity of registered data, the correct answer rates were 70-90%. Regarding the features of hospitals and respondents, number of hospital beds and prior experience in cancer registration questions were found to contribute to the high rate of correct answers. Conclusion: To improve the accuracy of cancer registration, the manual needs to be supplemented in areas demonstrating low correct answer rates. Education opportunities and methods for MRAs should be diversified.

Implementation plans for the Korean certified tumor registrar qualification system.

BACKGROUND: Cancer registration data is used to understand the nation's cancer burden, and to provide significant baseline data for cancer control efforts, as well as, research on cancer incidence, mortality, survival, and prevalence. A system that approves, assesses, and manages the qualification of specialists, responsible for performing cancer registration, has not been developed in Korea. This study presents ways to implement a certification system designed for the qualification of tumor registrars in Korea. MATERIALS AND METHODS: Requirements for implementing a certified tumor registrar qualification system were determined by reviewing the system for establishing qualifications in Korea and the American qualification system via the National Cancer Registrars Association (NCRA). Moreover, a survey was conducted on Korean medical records administrators, who had taken the U.S. Certified Tumor Registrar (CTR) examination, in order to review their opinions regarding these requirements. RESULTS: This study verified the feasibility of a qualification examination based on the opinions of CTR specialists by determining the following: items, and the associated ratings, of the qualifications necessary to register individuals as certified tumor registrars in a private qualification system; status of human resources required for the examination or training processes; plans regarding the organization needed for management, and operation of qualifications, examination standards, subject areas, examination methods, examination qualifications, or education and training programs. CONCLUSIONS: The implementation of a certified tumor registrar qualification system will lead to enhanced job competency for specialists and a qualitative improvement of cancer registration data. It will also reliably foster human resources that will lay the groundwork needed to establish scientific and reasonable national cancer management policies.

Improving accuracy and completeness in the collaborative staging system for stomach cancer in South Korea.

BACKGROUND: Cancer staging enables planning for the best treatments, evaluation of prognosis, and predictions for survival. The Collaborative Stage (CS) system makes it possible to significantly reduce the proportion of patients labeled at an "unknown" stage as well as discrepancies among different staging systems. This study aims to analyze the factors that influence the accuracy and validity of CS data. MATERIALS AND METHODS: Data were randomly selected (233 cases) from stomach cancer cases enrolled for CS survey at the Korea Central Cancer Registry. Two questionnaires were used to assess CS values for each case and to review the cancer registration environment for each hospital. Data were analyzed in terms of the relationships between the time spent for acquisition and registration of CS information, environments relating to cancer registration in the hospitals, and document sources of CS information for each item. RESULTS: The time for extracting and registering data was found to be shorter when the hospitals had prior experience gained from participating in a CS pilot study and when they were equipped with full-time cancer registrars. Evaluation of the CS information according to medical record sources found that the percentage of items missing for Site Specific Factor (SSF) was 30% higher than for other CS variables. Errors in CS coding were found in variables such as "CS Extension," "CS Lymph Nodes," "CS Metastasis at Diagnosis," and "SSF25 Involvement of Cardia and Distance from Esophagogastric Junction (EGJ)." CONCLUSIONS: To build CS system data that are reliable for cancer registration and clinical research, the following components are required: 1) training programs for medical records administrators; 2) supporting materials to promote active participation; and 3) format development to improve registration validity.

The national status of tuberculosis using nationwide medical records survey of patients with tuberculosis in Korea.

BACKGROUND: The epidemiology of tuberculosis (TB) has been assessed based on the data of the analysis of TB patients notified to the surveillance system in Korea. However, the national status of TB is not validated through this surveillance system. The objective is to determine the epidemiology of TB and to understand the accurate status of TB patients treated in private institutions. METHODS: Medical records of 53,579 patients who had been diagnosed with TB in 2008 were analyzed. RESULTS: Among 53,579 patients, the number of sputum smear positive cases was 15,639(29.2%) and the number of new cases was 39,191 (73.1%). The drug resistance rate of new cases was 5.3%, while the rate stood at 13.3% for TB patients with treatment history. The number of multi-drug resistant TB (MDR-TB) patients was 2,472 (4.6%), which consists of 2.9% of new cases and 9.3% of TB patients with prior treatment history. The number of extensively drug-resistant TB patients was 749 (1.4%), consisting of 1.1% of new cases and 2.2% of TB patients with prior treatment history. In terms of treatment outcomes, 66.4% of all TB patients, 70.5% of new cases, 64.4% of relapse cases, and 46.8% of MDR-TB cases were cured or completed. It was inferred that in 2008, the total number of TB patients reached 70,767, 145.6 per 100,000 people (95% confidence interval, 145.5~145.7). CONCLUSION: We conclude that the medical records review of the Health Insurance Review and Assessment Service (HIRA) data can be very effective in promoting the understanding of the current status of TB in private institutions.

Incidence trends in invasive uterine cervix cancer and carcinoma in situ in Incheon, South Korea.

INTRODUCTION: This study examined trends of invasive uterine cervix cancer and carcinoma in situ (CIS) in terms of the incidence and mortality in Incheon over a twelve year period. METHODS: Uterine cervical cancer data were retrieved from the Incheon Cancer Registry (ICR) and Korea Central Cancer Registry (KCCR) from 1997 to 2008. The time trends in age-standardized incidence rates (ASR) of invasive uterine cervix cancer patients and CIS were calculated and compared with the nation-wide cancer registry data for each year. Mortality/incidence (M/I) ratios according to age and the incidence of the pathologic subtype in Incheon each year were also examined, along with an international comparison. RESULTS: A total of 3,096 cases of invasive cervical cancer and 2,079 cases of carcinoma in situ were analyzed from 1997 to 2008. The time trend incidence of the total ASR in uterine cervical cancer decreased from 25.7 in 1997 to 13.4 in 2008, but the incidence of CIS increased from 7.6 to 15.8 in same period. In invasive cancers, the age-specific incidence rates were highest in those in their sixties while patients in their forties showed highest CIS values. The mortality rate in ICR was 3.7 from 1998 to 2002. Compared to the other countries which have high risk factors for cervix cancer, the peak incidence zone was different in Incheon. CONCLUSION: The ICR showed a decrease in the incidence of invasive cervical cancer that was similar to the nation-wide data. An early increase zone is a characteristic pattern in the age specific incidence curve. Early screening and a vaccination program should be activated for prevention of young age cervical cancer.