Sohee Park

Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2008

PURPOSE This paper overviews the nationwide cancer statistics including incidence, mortality, survival and prevalence, and their trends in Korea based on the year 2008 cancer incidence data. MATERIALS AND METHODS Incidence data from 1993 to 2008 were obtained from the Korea National Cancer Incidence Database, and the vital status was followed through December 31, 2009. Mortality data from 1983 to 2008 were obtained from the Korea National Statistics Office. Crude rates and age-standardized rates for incidence, mortality, prevalence and relative survival were calculated. RESULTS There were 178,816 cancer cases and 68,912 cancer deaths observed during year 2008 and 724,663 10-year cancer prevalent cases as of January 1, 2009 in Korea. The incidence rate for all cancer combined showed an annual increase of 3.1% from 1999 to 2008. CONCLUSION With significantly increasing cancer incidence, Korea faces a large cancer burden and efficient cancer control programs are essential.

Cancer Statistics in Korea: Incidence, Mortality and Survival in 2006-2007

Cancer has been the leading cause of death in Korea. Korea is facing a very rapid change and increase in cancer incidence, which draws much attention in public health. This paper overviews the nationwide cancer statistics, including incidence, mortality, and survival rates, and their trends in Korea based on the cancer incidence data from The Korea Central Cancer Registry (KCCR) in year 2006 and 2007. In Korea, there were 153,237 cancer cases and 65,519, cancer deaths observed in 2006, and 161,920 cancer cases and 67,561 cancer deaths in 2007, respectively. The incidence rate for all cancer combined showed an annual increase of 2.8% from 1999 to 2007. Specifically, there was significant increase in the incidence of colorectal, thyroid, female breast, and prostate cancers. The number of cancer deaths has increased over the past two decades, due mostly to population aging, while the age-standardized mortality rates have decreased in both men and women since 2002. Notable improvement has been observed in the 5-yr relative survival rates for most major cancers and for all cancer combined, with the exception of pancreatic cancer. The nationwide cancer statistics in this paper will provide essential data for cancer research and evidence-based health policy in Korea.

Prediction of Cancer Incidence and Mortality in Korea, 2011

Purpose To estimate the current cancer burden in Korea, cancer incidence and mortality were projected for the year 2011. Materials and Methods The cancer incidence data from 1999-2008 were obtained from the Korea National Cancer Incidence Database, and the cancer mortality data from 1993-2009 were obtained from the Korea National Statistics Office. Cancer incident cases and rates in 2011 were projected from fitting a linear regression model on observed age-specific cancer incidence rates against observed years, then multiplying the projected age-specific rates by the age-specific population. For cancer mortality, a similar procedure was applied for projection except that a Joinpoint regression model was used to determine at which year the linear trend significantly changed. Results A total of 216,809 new cancer cases and 71,036 cancer deaths are projected to occur in Korea in 2011. For all sites combined, the crude incidence rates are projected to be 437.9 and 420.5 and the age-standardized incidence rates are projected to be 336.5 and 279.7 per 100,000 for men and women, respectively. Conclusion Cancer has become an important public health concern in Korea, and as Korea becomes an aged society, the cancer burden will continue to increase.

Depression in Family Caregivers of Cancer Patients: The Feeling of Burden As a Predictor of Depression

PURPOSE The purpose of this study was to explore the prevalence of and to identify the predictors of depression in family caregivers of cancer patients. PATIENTS AND METHODS We enrolled 310 caregivers of cancer patients from the National Cancer Center, Korea, on this study and obtained demographic information for both patients and caregivers. To assess caregiver depression and its predictors, we used the Beck Depression Inventory (BDI), the Caregiver Quality of Life Index-Cancer, and the Family Impact Questionnaire. We used logistic regression analysis to identify independent predictors of caregiver depression. RESULTS The majority (67%) of caregivers had high depression scores (BDI > 13), and 35% had very high depression scores (BDI > 21). In a multiple logistic regression model, caregivers who were women, the spouse of the patient, in poor health, feeling burdened, adapting poorly, unable to function normally, or caring for a patient with poor Eastern Cooperative Oncology Group performance status were more likely to experience depression (P < .01 for all values). CONCLUSION Depression was highly prevalent among cancer patient family caregivers, and care burden was its best predictor. Interventions aimed at reducing the psychiatric effects of cancer should focus not only on the patient but also on the caregiver.

Nationwide Cancer Incidence in Korea, 2003-2005

PURPOSE To estimate the current cancer burden in Korea, newly diagnosed cancer cases and cancer incidence rates were calculated for the years 2003~2005. MATERIALS AND METHODS The cancer incidence cases and rates were calculated from the Korea National Cancer Incidence Database. Crude and age-standardized incidence rates were calculated by gender for specified cancer sites in 5-year age groups. RESULTS From 2003 to 2005, 398,824 cases of cancer were newly diagnosed in Korea (218,856 in men and 179,968 in women). For all sites combined, the crude incidence rate (CR) was 300.0 and 248.2 for men and women and the age-standardized incidence rate (ASR) was 297.0 and 191.2 per 100,000, respectively. Among men, five leading cancers were stomach (CR 66.0, ASR 64.2), lung (CR 48.5, ASR 50.3), liver (CR 44.9, ASR 42.1), colon and rectum (CR 37.9, ASR 37.2), and prostate cancer (CR 12.7, ASR 13.8). Among women, five leading cancers were breast (CR 37.3, ASR 29.0), thyroid (CR 36.2, ASR 28.8), stomach (CR 34.1, ASR 25.4), colon and rectum (CR 28.0, ASR 21.1), and lung cancer (CR 17.9, ASR 12.8). In the 0~14-year-old group, leukemia was the most common in both sexes; in the 15~34 group, the most common cancer was stomach cancer for men and thyroid cancer for women; in the 35~64 group, stomach cancer for men and breast cancer for women; among those 65 and over, lung cancer for men and stomach cancer, for women, respectively. CONCLUSION The cancer incidence rates have increased in recent years, and more cancers are expected to develop as Korea is quickly becoming an aged society. The cancer incidence statistics in this report can be used as an important source to effectively plan and evaluate the cancer control program in Korea.

Gastric Cancer Epidemiology in Korea

Gastric cancer has been the most commonly diagnosed cancer in Korea although the age-standardized mortality and incidence has decreased gradually during last two decades. Helicobacter pylori infection and cigarette smoking are well-established risk factors, and the role of dietary factors, such as salted foods, fresh vegetables and fruits, soy foods, and processed or grilled meats on gastric carcinogenesis has been suggested. In this review, we review national and international gastric cancer statistics, studies on environmental risk factors conducted in the Korean population, and gastric cancer screening activities.

Comparison of Circulating Plasma DNA Levels between Lung Cancer Patients and Healthy Controls

Although the biological functions of tumor-originated cell-free DNA have not been previously clarified, such molecular characteristics as mutations, hypermethylation, and microsatellite instability have confirmed its tumor origin. Therefore, to investigate the use of plasma DNA level as a biomarker of lung cancer, we compared plasma DNA concentrations in 102 patients with lung cancer and 105 healthy individuals using quantitative PCR analyses. The median plasma DNA concentrations for the healthy and cancer groups were 10.4 and 22.6 ng/ml, respectively (P < 0.0001), and elevated plasma DNA levels were also detected in patients with either stage I or II disease. Neither smoking status nor the number of packs per year had an effect on the level of circulating cell-free DNA. Increased concentrations of circulating cell-free DNA showed the potential power to discriminate lung cancer (area under the receiver operating characteristic curve = 0.86, 95% CI = 0.81 to 0.91). When subjects were classified into three groups based on their plasma DNA concentrations, subjects in the upper tertile (ie, those with the highest concentration) had a significantly increased risk of lung cancer as compared with those in the lowest tertile (adjusted odds ratio = 50.6, P < 0.001). These results suggest that elevated circulating plasma DNA levels may serve as a potential diagnostic indicator and be an important risk factor for lung cancer.

Web-Based Tailored Education Program for Disease-Free Cancer Survivors With Cancer-Related Fatigue: A Randomized Controlled Trial

PURPOSE To determine whether an Internet-based tailored education program is effective for disease-free cancer survivors with cancer-related fatigue (CRF). PATIENTS AND METHODS We randomly assigned patients who had completed primary cancer treatment within the past 24 months in any of four Korean hospitals and had reported moderate to severe fatigue for at least 1 week to participate in a 12-week, Internet-based, individually tailored CRF education program or to receive routine care. We based the program on the CRF guidelines of the National Comprehensive Cancer Network (NCCN) and incorporated the transtheoretic model (TTM). At baseline and 12 weeks, we used the Brief Fatigue Inventory (BFI) and Fatigue Severity Scale (FSS) as primary outcomes and the Hospital Anxiety and Depression Scale (HADS) and European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) for secondary outcomes. RESULTS We recruited 273 participants and randomly assigned 136 to the intervention group. Compared with the control group, the intervention group had an improvement in fatigue as shown by a significantly greater decrease in BFI global score (-0.66 points; 95% CI -1.04 to -0.27) and FSS total score (-0.49; 95% CI, -0.78 to -0.21). In secondary outcomes, the intervention group experienced a significantly greater decrease in HADS anxiety score (-0.90; 95% CI, -1.51 to -0.29) as well as global quality of life (5.22; 95% CI, 0.93 to 9.50) and several functioning scores of the EORTC QLQ-C30. CONCLUSION An Internet-based education program based on NCCN guidelines and TTM may help patients manage CRF.

Increasing Trend of Colorectal Cancer Incidence in Korea, 1999-2009

Purpose This study was conducted in order to demonstrate changing trends in colorectal cancer incidence according to sex, age group, and anatomical location in the Korean population. Materials and Methods Data from the Korea Central Cancer Registry between 1999 and 2009 were analyzed. Annual percent changes (APCs) of sex- and age-specific incidence rates for cancer of the proximal colon (International Statistical Classification of Diseases and Related Health Problems, 10th revision [ICD-10] code C18.0-18.5), distal colon (C18.6-18.7), and rectum (C19-20), and male-to-female incidence rate ratios (IRR) were calculated. Results The age-standardized incidence rate (ASR) of colorectal cancer was 27 (per 100,000) in 1999 and increased to 50.2 in 2009 among men (APC, 6.6%). The ASR for women was 17.2 in 1999 and 26.9 in 2009 (APC, 5.1%). The rectum was the most common site of cancer among both men and women during 1999 and 2009. However, the distal colon had the highest APC (10.8% among men and 8.4% among women), followed by the proximal colon (7.9% among men and 6.6% among women), and rectum (5.2% among men and 2.4% among women). The proportion of rectal cancer decreased from 51.5% in 1999 to 47.1% in 2009 among men, and from 50.5% to 42.8% among women. An increase in the male-to-female IRR was observed for distal colon cancer and rectal cancer, whereas the IRR for proximal colon cancer was stable. Conclusion The rapid increase in colorectal cancer incidence is mainly attributed to the increase in colon cancer, especially distal colon cancer, and may be explained by a transition of risk factors for subsites or by the effect of colorectal cancer screening.

Coinfection of hepatitis B and C viruses and risk of hepatocellular carcinoma: Systematic review and meta‐analysis

A subadditive effect of hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection is possible because superinfection of one virus tends to inhibit infection of the other virus. However, studies have reported inconsistent findings, and two meta‐analyses of studies from various countries (1998) and China (2005) reported a supraadditive effect for hepatocellular carcinoma (HCC) risk. Thus, we reevaluate HBV/HCV monoinfection and coinfection. Of 411 reports, we included 59 studies that assessed the association between HBV/HCV monoinfection and coinfection for HCC risk. HCC risk because of high/detectable HBV DNA and HBeAg infection was higher than HBsAg infection, whereas anti‐HCV vs anti‐HCV/HCV RNA was not different. Geographically, HCC risk was significantly higher in nonendemic than in HBV or HCV endemic areas. Subadditive effect for HCC risk was presented in recently published studies, cohort studies and studies conducted in HBV/HCV nonendemic areas; an additive effect was presented in studies conducted in HBV endemic areas; a supraadditive effect was presented in previously published studies, case‐control studies and studies conducted in HCV endemic areas. Our results suggest HBV/HCV coinfection for HCC risk is not significantly greater than HBV/HCV monoinfection, and HCC risk due to HBV or HCV is higher in nonendemic than endemic areas. The p‐heterogeneity was significant for most analyses, except HBV(+)/HCV(+) and HBV biomarker analyses. Prevention strategies targeted toward HBV or HCV monoinfected patients are needed. In addition, tailored prevention to reduce infectivity such as HBV markers (HBeAg, HBV DNA) is needed.