Cancer In Korea Research Articles

International comparison of trends in cancer mortality: Japan has fallen behind in screening-related cancers.

While the age-standardized mortality rate in Japan is decreasing for all cancers as a whole, this is not the case for some major site-specific cancers. We descriptively compared trends in all-cancer and site-specific cancer mortality in Japan and selected countries. Data on age-standardized cancer mortality rates in six countries (Japan, the USA, the UK, Canada, Australia and the Republic of Korea) in 1980–2016 were obtained from the World Health Organization mortality database. While stomach and liver cancer mortality rates in Japan and Korea were initially much higher than those in non-Asian countries, they have rapidly decreased over the long term. By contrast, colorectal, pancreatic and cervical cancer mortality rates in Japan, which were initially lower than those in other countries, have increased such that they are now similar or higher than the rates in non-Asian countries. For male lung cancer, Japan’s initially lower mortality rate is now comparable to that in non-Asian countries as a result of slower decline. Meanwhile, the mortality rate of female breast cancer in Japan and Korea has increased and is nearing the rates observed in non-Asian countries, which by contrast have shown a steady decrease. Thus, while Japan has been successful in reducing the burden of stomach and liver cancers, it is falling behind in reducing the mortality rate of screening-related cancers such as colorectal, female breast and cervical cancers. Control measures for these cancers need to be strengthened.

Alcohol and Gastrointestinal Cancers in Korea—Risk, Inactive Genes, and Missing Alcohol

Alcohol and Gastrointestinal Cancers in Korea—Risk, Inactive Genes, and Missing Alcohol

The incidence and survival of cervical, ovarian, and endometrial cancer in Korea, 1999-2017: Korea Central Cancer Registry.

ObjectiveThe three major gynecologic cancers are cervical, endometrial, and ovarian cancer. This study aimed to describe the 19-year trends and survival rates in cervical, endometrial, and ovarian cancer in a Korean female population.MethodsWe searched the Korea Central Cancer Registry to identify patients with gynecologic cancer between 1999 and 2017. Age-standardized rates and annual percent changes were calculated. The relative survival rate (RSR) was reported by histology, age, and stage for each gynecological cancer.ResultsThe total number of cervical, endometrial, primary peritoneal, ovarian epithelial, fallopian tube (POFT) cancer was 134,863, with the number of cases increasing every year: 6,077 in 1999 to 8,011 in 2017. The incidence of cervical cancer has decreased; however, that of POFT and endometrial cancer has increased. The 5-year RSR of cervical, POFT, and endometrial cancer was reported to be 80.8%, 61.4%, and 88.1%, respectively. In the case of cervical cancer, squamous cell carcinoma showed better survival than other histology (82.8% vs. 73.5%). Furthermore, in the case of endometrial cancer, endometrioid histology had substantially better 5-year RSR than the others (93.2% vs. 76.5%). Contrastingly, in the case of ovarian cancer, serous carcinoma had worse 5-year RSR than other types of histology.ConclusionThe incidence rates for gynecologic cancers increased from 2005 to 2017, with an annual increase of 2.76 per year until 2017. Endometrial cancer had the highest RSR, while ovarian cancer had the lowest. Active cancer screening and the introduction of effective treatments might have contributed to the improved RSRs of gynecologic cancers.

Seasonal variations in the diagnosis of the top 10 cancers in Korea: A nationwide population-based study using a common data model.

A better understanding of seasonal variations in cancer diagnosis may be the first step toward optimal resource distribution in the National Cancer Screening Program (NCSP). This study aimed to identify seasonal variations in the diagnosis of the top 10 major cancers in Korea. We conducted a retrospective, observational cohort study in participants aged≥20years between 2012 and 2016 from the Health Insurance Review and Assessment-National Patient Sample database, previously converted to a common data model. We assessed the overall seasonal variations in the 10 major cancers. We analyzed the following top 10 cancers: stomach (n=3435), colorectal (n=5368), liver (n=7605), pancreatic (n=2946), gallbladder (n=899), lung (n=1598), prostate (n=2897), thyroid (n=1966), breast (n=1313), and kidney (n=668) cancers. All cancers showed similar seasonal variations in diagnosis, with a significant winter peak. A winter peak in diagnosis was observed for NCSP-covered cancers, such as stomach, colon, liver, and breast cancers, as well as other cancers not covered by the NCSP. The winter peak for cancer diagnosis was the highest for breast cancer (74.4%) followed by thyroid (51.0%) and stomach cancers, whereas it was the lowest for pancreatic cancer followed by prostate and colorectal cancers. Significant seasonal variations were found in the diagnosis of the top 10 major cancers, with a winter peak, which may be explained by the participants' behavior pattern with respect to the NCSP. Our findings suggest that trading off of NCSP healthcare resources between winter and other seasons may be beneficial.

Current usage of stereotactic body radiotherapy for oligometastatic prostate cancer in Korea: patterns of care survey (KROG 19-08).

BackgroundGrowing evidence suggests that metastasis-directed therapy and/or prostate-directed therapy may benefit patients with oligometastatic prostate cancer (OMPC). Stereotactic body radiotherapy (SBRT) is increasingly used to treat oligometastases in various cancers. The purpose of this study was to investigate the current patterns of curative-intent SBRT for OMPC in Korea.MethodsA 20-item questionnaire was sent to 326 radiation oncologists in 93 institutions in Korea. Only 1 physician per institution was required to complete the survey. Subsequently, the second survey consisting of 3 clinical scenarios was sent to 64 physicians with clinical experience in SBRT: case 1, cT4N0M1 (direct invasion to two pelvic bones); case 2, cT2N0M1 (three bone metastases); and case 3, solitary spine metastasis after radical prostatectomy.ResultsSeventy-six physicians from 93 institutions (82%) answered the first survey. The multidisciplinary team approach was practiced in 16 institutions (21%). Most physicians (75%) agreed on the definition of oligometastases as limited lesions and/or organs ≤5: 25% agreed with low-volume disease according to CHAARTED trial. During the last year, 49 physicians (64%) treated OMPC patients with curative intent. Sixty four physicians (84%) had a clinical experience with SBRT: 48 (75%) stated that both dose and fraction number should be considered when defining SBRT, whereas others (25%) stated that only fraction size should be considered. Fifty-five faculties (86%) answered the second survey. Physicians agreed with oligometastases in 89% for case 1, in 80% for case 2, and in 100% for case 3. The rate of SBRT application was the highest in case 3 (70%).ConclusionsThere was diversity in the patterns of SBRT for OMPC in Korea. Additional prospective studies are necessary to strengthen evidence regarding role of SBRT in OMPC.

Factors influencing quality of life among childhood cancer survivors in Korea: A quantile regression approach.

Cancer treatment in childhood may negatively affect survivors' quality of life. In this study, we aimed to determine the contributing factors for health-related quality of life (HRQOL) in survivors of childhood cancer in Korea using quantile regression analysis. This study was a secondary analysis. Data were collected from 130 childhood cancer survivors (CCS) from November 2018 to July 2019. Participants completed the Memorial Symptom Assessment Scale, Depression Anxiety Stress Scale, Health-Promoting Lifestyle Profile-II, and 36-Item Short Form Health Survey (physical component summary [PCS] and mental component summary [MCS]). Quantile and multiple linear regressions were used to analyze the factors contributing to HRQOL. The quantile and linear regression models revealed different results on the contributing factors to HRQOL in CCS. Mean PCS and MCS scores were 78.55 (SD = 15.08) and 64.02 (SD = 18.00), respectively. Symptoms (e.g., difficulty concentrating, worrying, pain, and lack of energy), physical activity, spiritual growth, interpersonal relationships, stress management, depression, and anxiety were significant influencing factors in some PCS quantiles, while symptoms, spiritual growth, interpersonal relationships, depression, and stress were significant influencing factors in some MCS quantiles. The findings of this study showed specific contributing factors in CCS with different levels of HRQOL. There is a need for targeted interventions related to risk reduction and stratification for CCS with different HRQOL levels. Symptom management strategies, early detection programs for CCS with psychological distress, and clinical and counseling interventions for CCS with poor HRQOL need to be developed.

Clinical characteristics of patients in their forties who underwent surgical resection for colorectal cancer in Korea

BACKGROUNDThe proportion of young patients with colorectal cancer (CRC), especially in their 40s, is increasing worldwide. AIMTo confirm the clinical characteristics of such patients, we planned a study comparing them to patients in their 30s and 50s.METHODSPatients undergoing primary resection for CRC, patients in their 30s, 40s and 50s were included in the study. Patient and tumor characteristics, and perioperative and oncologic outcomes were compared. RESULTSMost clinical characteristics of 451 (10.5%) patients in their 40s were more similar to those of patients in their 30s than those in their 50s. On pathology data, there were more metastatic lesions (30s vs 40s vs 50s; 17.5% vs 21.1% vs 14.9%, P = 0.012) in patients in their 40s. There was a trend toward less frequent K-ras mutations among patients in their 40s (48.5% vs 33.3% vs 44.5%, P = 0.064). The proportion of patients receiving postoperative chemotherapy was also significantly greater among patients in their 40s (58.3% vs 63.9% vs 56.3%, P = 0.032). Five-year overall survival (OS) and disease-free survival (DFS) did not differ between the three groups (5-year OS, 92.2% vs 89.8% vs 92.2%, P = 0.804; 5-year total DFS, 98.6% vs 95.7% vs 96.1%, P = 0.754; 5-year local DFS, 98.6% vs 94.3% vs 94.9%, P = 0.579; 5-year systemic DFS, 86.4% vs 87.9 % vs 86.4%, P = 0.908).CONCLUSIONPatients with CRC in their 40s showed significantly more numerous metastatic lesions. The oncologic outcome of stage 1-3 patients in their 40s was not inferior compared to that of those in their 30s and 50s.

A Deep Recurrent Neural Network-Based Explainable Prediction Model for Progression from Atrophic Gastritis to Gastric Cancer

Gastric cancer is the fifth most common cancer type worldwide and one of the most frequently diagnosed cancers in South Korea. In this study, we propose DeepPrevention, which comprises a prediction module to predict the possibility of progression from atrophic gastritis to gastric cancer and an explanation module to identify risk factors for progression from atrophic gastritis to gastric cancer, to identify patients with atrophic gastritis who are at high risk of gastric cancer. The data set used in this study was South Korea National Health Insurance Service (NHIS) medical checkup data for atrophic gastritis patients from 2002 to 2013. Our experimental results showed that the most influential predictors of gastric cancer development were sex, smoking duration, and current smoking status. In addition, we found that the average age of gastric cancer diagnosis in a group of high-risk patients was 57, and income, BMI, regular exercise, and the number of endoscopic screenings did not show any significant difference between groups. At the individual level, we identified that there were relatively strong associations between gastric cancer and smoking duration and smoking status.

PSY7-5 Current status and future perspectives in biliary tract cancer in Korea

PSY7-5 Current status and future perspectives in biliary tract cancer in Korea

P-246 Comparison of microbiome diversity in gastric cancer patients and in non-cancerous patients

Gastric cancer is the fifth most common cancer worldwide and it is the most commonly diagnosed cancer in Korea. The most clearly known microbiologic risk factor is Heliobacter pylori infection. H.pylori-induced gastritis reduces acid secretion from gastric mucosa and causes atrophic gastritis and intestinal metaplasia, which are known to be pre-cancerous lesions. According to previous studies, H.pylori is rarely detected in atrophic mucosa or in mucosa with intestinal metaplasia. This suggests that the hypochlorhydric conditions created by H.pylori provide a suitable environment for carcinogenesis, rather than H.pylori working as the direct carcinogen itself. This raises the possibility that bacteria other than H.pylori could contribute to carcinogenesis of gastric cancer. The aim of the present study was to compare the composition of the gastric microbiome of advanced gastric cancer patients and non-cancerous individuals. Gastric mucosa collected by biopsy during esophagogastroduodenoscopy (EGD) from seven patients with advanced gastric cancer (AGC) and six non-cancerous patients (control group) was evaluated. Gastric biopsies were obtained from the margin of cancer in cancer patients. In the control group, biopsies were done from antrum with normal mucosal morphology. DNA was extracted from the gastric mucosal tissues and 16s rRNA genes were amplified from the isolated DNA. Then they were analyzed using the molecular profiling approach terminal restriction fragment length polymorphism (T-RFLP). Cloning and sequencing of 16S rRNA genes was performed to discover the identities of bacteria residing in the gastric mucosa. A higher number of species were detected in the control group, with an average of 102 species, compared to the cancer group, with an average of 72 species. The gastric cancer microbiome was characterized by reduced microbial diversity compared to that of the control group. Many different bacterial species were found in both groups but distribution was quite different between the two groups. Fusobacteria was more dominant in the cancer group and Rhodobacterales was found more prominent in the control group. Gastric H.pylori was detected only in one patient from each group. A more diverse gastric microbiome was observed in non-cancerous patients and the composition of species was different between the two groups. These results suggest that microbial dysbiosis may be involved in gastric carcinogenesis, but it is not yet clear that microbial transition accelerates carcinogenesis. Further studies should include a more detailed analysis of the spatial and temporal composition of the gastric microbiome. A better understanding of microbial differences and changes in healthy and gastric cancer patients could verify the carcinogenesis of gastric cancer.

Initial treatment pattern and prognosis of exocrine pancreatic cancer in Korea from 2006 to 2017

Hospital-based database had limitations in holistic analysis of cancer treatment and prognosis, omitting those who are out-of-hospital. In addition, elderly patients with pancreatic cancer were under-represented in clinical studies. "First course of treatment (FT)" recorded by cancer registries refers to actually administered treatments within four months of diagnosis. Trends in initial treatment pattern and resultant prognosis of exocrine pancreatic cancer (EPC) in Korea from 2006 to 2017 were investigated based on data of the Korea Central Cancer Registry. Of all 62,209 EPC cases, localized and regional SEER stage (LR), patients over 70 years-old, and adenocarcinoma and its variants (ADC) accounted for 40.6%, 50.1%, and 95.9%, respectively. The most frequent FT was "no active treatment (NAT)" (46.5%), followed by chemotherapy with/without/or radiotherapy (28.7%) and surgery (22.0%). Among 25,198 LR EPC patients, surgical FT increased from 35.9% to 46.3% and NAT decreased from 45.0% to 29.5%. NAT rate was higher in octogenarian (81.2%) and septuagenarian (44.7%) compared to those younger than 70 years-old (19.6%, p < 0.001). Patients with LR ADC had lower rate of surgery (39.6%) compared to cystic cancer variants (86.7%) or acinar cell carcinoma (82.8%, p < 0.001). Five-year relative survival rates of LR ADC were higher after surgery (46.1% [localized], 23.6% [regional]) compared to NAT (12.9%, 4.9%, respectively). Over 55% of patients with LR EPC in their 70s or 80s do not receive active treatment within four months of diagnosis. Clinicians should pay attention to elderly EPC patients to provide proper medical advice.

Epidemiology and future prediction of Korean liver, pancreatic and biliary cancer

Epidemiology and future prediction of Korean liver, pancreatic and biliary cancer

Regional Differences in Access to Clinical Trials for Cancer in Korea

Regional Differences in Access to Clinical Trials for Cancer in Korea

Association of Family History with the Development of Breast Cancer: A Cohort Study of 129,374 Women in KoGES Data.

Background: Breast cancer is the most common cancer among women. The Korean Genome and Epidemiology Study (KoGES) is a large cohort study that is available to the public. Using this large cohort study, we aimed to unravel the relationship between breast cancer development and a family history of breast cancer in Korea. Methods: This cohort study relied on data from the KoGES from 2001 through 2013. A total of 211,725 participants were screened. Of these, 129,374 women were evaluated. They were divided into two groups, including participants with and without breast cancer. A logistic regression model was used to retrospectively analyze the odds ratio of breast cancer history in families of women with and without breast cancer. Results: Of 129,374 women, 981 had breast cancer. The breast cancer group had more mothers and siblings with histories of breast cancer (p < 0.001). A history of breast cancer in the participant’s mother resulted in an odds ratio of 3.12 (1.75–5.59), and a history of breast cancer in the participant’s sibling resulted in an odds ratio of 2.63 (1.85–3.74). There was no interaction between the history of maternal breast cancer and the history of sibling breast cancer. Based on the subgroup analysis, family history was a stronger factor in premenopausal women than in menopausal and postmenopausal women. Conclusions: A family history of breast cancer is a significant risk factor for breast cancer in Korea. Premenopausal women with a maternal history of breast cancer are of particular concern. Intensive screening and risk-reducing strategies should be considered for this vulnerable subpopulation.

Clinicopathological Features of BRCA1/2 Mutation-Positive Breast Cancer

Purpose: The BRCA1/2 gene is the most well-known and studied gene associated with hereditary breast cancer. BRCA1/2 genetic testing is widely performed in high-risk patients of hereditary breast cancer in Korea. This study aimed to investigate the clinicopathological characteristics of BRCA1/2 mutation-positive breast cancer patients. Methods: The clinical data of 188 Korean breast cancer patients who underwent genetic testing of BRCA1/2 mutation between March 2015 and February 2020 at Pusan National University Yangsan Hospital were retrospectively reviewed. The characteristics of breast cancer according to the expression of BRCA1 and BRCA2 mutations were analyzed using the Health Insurance Review and Assessment Service guideline criteria and other clinicopathological factors. Results: The factor associated with BRCA1/2 gene expression was cancer stage, and mutation expression was significantly decreased in stage I compared to stage 0 (p = 0.033; odds ratio [OR], 0.169; 95% confidence interval [CI], 0.033–0.867), and there was a tendency to increase in stage II (p = 0.780; OR, 1.150; 95% CI, 0.432–3.064). BRCA1 was significantly associated with triple-negative breast cancer (TNBC) (p = 0.004; OR, 5.887; 95% CI, 1.778–19.498). Gene expression of BRCA2 was significantly reduced under 40 years of age (p = 0.040; OR, 0.198; 95% CI, 0.042–0.930). There was no difference in disease-free survival (p = 0.900) and overall survival (p = 0.733) between the BRCA1/2 mutation-positive and -negative groups. Conclusion: In this study, the clinicopathological characteristics of breast cancer patients with BRCA1/2 gene mutations were identified. BRCA1 gene expression was highly correlated with TNBC. BRCA1/2 mutation did not have a poor prognosis regarding recurrence and death.

Inter-institutional Variation in Intensity-modulated Radiotherapy for Breast Cancer in Korea (KROG 19-01).

To present the variations in the target delineation and the planning results of intensity-modulated radiation therapy (IMRT) for breast cancers. We requested the target volumes and organs at risk delineation for two cases of left breast cancers, and evaluated the IMRT plans including the supraclavicular and internal mammary node irradiation. Twenty-one institutions participated in this study. Differences in the planning target volume among institutions reached up to three-times for breast-conserving surgery (BCS) case and five-times for mastectomy case. Mean heart doses ranged from 3.3 to 24.1 Gy for BCS case and from 5.0 to 26.5 Gy for mastectomy case. Ipsilateral lung volumes receiving more than 20 Gy ranged from 4.7 to 57.4% for BCS case and from 16.4 to 55.5% for mastectomy case. There were large variations in the target delineation and planning results of IMRT for breast cancers among institutions. Considering the increased use of breast IMRT, more standardized protocols are needed.

PCN154 Real-World Assessment of the Treatment Patterns, Healthcare Resource Use, and Survival Outcomes Associated with Non-Resectable Advanced Esophageal Cancers in South Korea

To describe patient demographics, clinical status, treatment patterns, healthcare resource use and outcomes (survival, clinical outcomes, disease recurrence, and cost) that are associated with patients with non-resectable advanced (NRA) esophageal cancer (EC) in South Korea (SK).

The Awareness and Usage of Big Data for Cancer in Korea: A Survey Study

The Awareness and Usage of Big Data for Cancer in Korea: A Survey Study

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.

Multicenter study for brain metastasis from breast cancer in Korea: The significance of molecular subtype (Korean Radiation Oncology Group 1612).

e14008 Background: We analyzed the treatment outcome of breast cancer patients with brain metastases (BM) in Korea to identify the prognostic factors and the role of whole brain radiation therapy (WBRT). Methods: Seven hundred thirty patients of breast cancer with BM treated at 17 institutions in Korea from 2000 to 2014 were analyzed. The median follow-up duration was 12 months. The analysis consisted of three cohorts: in cohort A, a total of 730 patients were included; in cohort B, 538 patients with available follow-up imaging after initial brain-directed treatment; and in cohort C, 54 patients receiving salvage WBRT due to recurrent BM after initial Stereotactic radiosurgery or WBRT. Overall survival (OS) was calculated from BM diagnosis in cohort A or from the last day of salvage WBRT in cohort C. Results: Median OS of cohort A was 15 months. In multivariate analysis, histologic grade 3, extracranial metastasis, number of BM &gt; 4, hormone receptor (HR) or HER2 negativity, and shorter time interval to diagnosis of BM were associated with inferior OS. Among 538 patients in cohort B, 201 showed subsequent development of new BM at a median of 11 months after stereotactic radiosurgery or WBRT for the management of initial BM (at 1 year, HR+/HER2- 51.9%, HER2+ 44.0%, and TNBC 69.6%, respectively; p = 0.008). Upfront WBRT reduced subsequent development of new BM, which showed the significant difference among molecular subtypes (HR+/HER2-, 42% reduction at 1 year, p &lt; 0.001; HER2+, 18.5%, p = 0.004; TNBC, 16.9%, p = 0.071). Multivariate analysis showed that shorter time interval to BM, TNBC subtype, extracranial systemic disease, number of BM &gt; 4, and involvement of both tentoria increased subsequent development of new BM. Anti-HER2 therapy for HER2+ patients and upfront WBRT significantly reduced risk of new BM. In cohort C, upfront WBRT prolonged the salvage WBRT-free duration (median 6.9 vs. 8.7 months, p = 0.058). Median OS was 6.8 months after salvage WBRT. Longer interval to salvage WBRT, controlled primary tumor, high dose of salvage WBRT (BED10 &gt; 37.5 Gy), and systemic treatment after salvage WBRT showed better OS. Uncontrolled extracranial systemic disease and salvage WBRT due to local progression without distant intracranial failure showed worse OS. Conclusions: The rates of new BM showed the significant differences among molecular subtypes. Upfront WBRT decreased subsequent development of new BM and this effect was dependent on the molecular subtype as well. Anti-HER2 therapy for HER2+ patients significantly decreased the subsequent development of new BM. On salvage WBRT setting, the patients having high dose of salvage WBRT, stable extracranial systemic disease and subsequent systemic therapy showed better OS.