Prediction of cancer incidence and mortality in Korea, 2015

[Guidelines for Evaluating Treatment Response Based on Bone Scan for Metastatic Castration-Resistant Prostate Cancer: Prostate Cancer Clinical Trial Working Group 3 Recommendations]

In prostate cancer, the bone is the most common site of metastasis, and it is essential to evaluate metastatic bone lesions to assess the tumor burden and treatment response. Castration-resistant prostate cancer refers to the state wherein the cancer continues to progress despite a significant reduction of the sex hormone level and is associated with frequent distant metastasis. The Prostate Cancer Working Group 3 (PCWG3) released guidelines that aimed to standardize the assessment of treatment effects in castration-resistant prostate cancer using bone scintigraphy. However, these guidelines can be challenging to comprehend and implement in practical settings. The purpose of this review was to provide an overview of a specific image acquisition method and treatment response assessment for bone scintigraphy-based evaluation of bone lesions in metastatic castration-resistant prostate cancer, in accordance with the PCWG3 guidelines.

Association of polypharmacy with all-cause mortality and adverse events among elderly colorectal cancer survivors

BACKGROUND

The risk of inappropriate drug exposure in elderly colorectal cancer (CRC) survivors after the initial cancer treatment has not been well studied. This study investigated the association of polypharmacy (PP) with overall survival, hospitalization, and emergency room (ER) visits among older CRC survivors.

METHODS

A retrospective cohort study was conducted using the Korean National Health Insurance claims data follow-up from 2002 to 2017. Participants comprised those aged ≥65 years who were hospitalized with a diagnosis of CRC received cancer treatment and survived at least 2 years from the initial CRC diagnosis between 2003 and 2012. PP was defined based on the number of individual drugs during the third year, after 2 years of survival since the initial cancer treatment. PP was categorized as follows: non-PP (zero to four prescribed drugs); PP (five to nine drugs), and excessive PP (≥10 drugs). Main outcomes are all-cause mortality, hospitalization, and ER visits.

RESULTS

Of the 55,228 participants, 44.5% died, 83.1% were hospitalized, and 46.1% visited the ER. The PP and excess PP groups showed increased risk of all-cause mortality, hospitalization, and ER visit compared with the low PP group, and was highly associated among groups including patients aged 65 to 74 years and those in low-level frailty groups.

CONCLUSIONS

These risks can be minimized by increasing awareness and enhancing behaviors among health care professionals, especially clinician and pharmacists, to be aware of potential drug interactions, review, and ongoing monitoring.

PLAIN LANGUAGE SUMMARY

The risk of inappropriate drug exposure in older colorectal cancer (CRC) survivors after the initial cancer treatment has not been well studied. Polypharmacy was associated with adverse outcomes, including all-cause mortality, hospitalization, and emergency room visits among older CRC survivors and it was particularly associated with those who were 65 to 75 years and those with low risk of frailty. When prescribing drugs, physicians should be mindful of finding a balance between adequate treatment of diseases and avoiding adverse drug effects in survivors of CRC.

Hepatic steatosis changes after early gastric cancer surgery

Background: Nonalcoholic fatty liver disease dramatically improves after bariatric surgery, primarily due to improvements in hepatic insulin sensitivity. Since the procedure for gastric cancer surgery is very similar to that for bariatric surgery, we investigated changes in fatty liver following gastrectomy for gastric cancer according to the type of surgery.Methods: We evaluated hepatic steatosis in 212 early gastric cancer patients using Hounsfield units (HUs) on non-contrast computed tomography preoperatively and 6, 12, and 24 months after surgery. We compared the preoperative and postoperative liver-to-spleen HU ratio according to the type of surgery: Billroth I, Billroth II, and total gastrectomy with Roux-en-Y reconstruction. Results: The initial results (liver/spleen HUs and the liver-to-spleen HU ratio) did not significantly differ according to surgical group. After surgery, only patients who underwent total gastrectomy with Roux-en-Y exhibited significant changes in the liver-to-spleen HU ratio at 6 months. In 26 patients who had higher initial HU levels of the spleen than the liver, the liver-to-spleen HU ratio significantly increased from 0.836 to 1.115 at 6 months, 1.109 at 12 months, and 1.102 at 24 months (P<0.01). Conclusion: Significant changes in hepatic steatosis were found in even normal patients (with higher liver than spleen HU values) who underwent total gastrectomy with Roux-en-Y. Patients who initially had fatty liver also showed a significant increase in the liver-to-spleen HU ratio. These results suggest that total gastrectomy with Roux-en-Y reconstruction can have a positive effect on the improvement of hepatic steatosis.

A visualized dynamic prediction model for survival of patients with geriatric thyroid cancer: A population-based study

OBJECTIVE

Thyroid cancer (TC) is a common malignancy with a poor prognosis with aging. However, no accurate predictive survival model exists for patients with geriatric TC.We aimed to establish prediction models of prognosis in elderly TC.

METHODS

We retrospectively reviewed the clinicopathology characteristics of patients with geriatric TC in the Surveillance, Epidemiology, and End Results database (SEER) from 2004 to 2018. The risk predictors used to build the nomograms were derived from the Cox proportional risk regression. These nomograms were used to predict 1-, 3-, and 5-year overall survival and cancer-specific survival in elderly patients with TC. The accuracy and discriminability of the new model were evaluated by the consistency index (C-index) and calibration curve. The clinical applicability value of the model was assessed using the decision curve analysis.

RESULTS

We used the SEER database to include 16475 patients with geriatric TC diagnosed from 2004 to 2018. The patients from 2004 to 2015 were randomly sorted out on a scale of 7:3. They were classified into a training group (n = 8623) and a validation group (n = 3669). Patients with TC diagnosed in 2016-2018 were classified into external validation groups (n = 4183). The overall survival nomogram consisted of 10 variables (age, gender, marital status, histologic type, grade, TNM stage, surgery status, and tumor size). A cancer-specific survival nomogram consisted of eight factors (age, tumor size, grade, histologic type, surgery, and TNM stage). The C-index values for the training, validation, and external validation groups were 0.775 (95% confidence interval [CI] 0.785-0.765), 0.776 (95% CI 0.792-0.760), and 0.895(95% CI 0.873-0.917), respectively. The overall survival was consistent with a nomogram based on the calibration curve. Besides, the decision curve analysis showed excellent clinical application value of the nomogram. Additionally, we found that surgery could improve the prognosis of patients with geriatric at high-risk (P < 0.001) but not those at low-risk (P = 0.069).

CONCLUSION

This was the first study to construct predictive survival nomograms for patients with geriatric TC. The well-established nomograms and the actual results could guide follow-up management strategies.

Feasibility and safety of fertility-sparing surgery in epithelial ovarian cancer with dense adhesion: a long-term result from a single institution

OBJECTIVE

We investigated the feasibility and safety of fertility-sparing surgery (FSS) in patients with epithelial ovarian cancer (EOC) with dense adhesions.

METHODS

Patients were divided into cases with and without dense adhesions in this retrospective study.

RESULTS

Of the 95 eligible patients, 29 patients had dense adhesions. Mean age, proportion of staging procedure, distribution of histologic type, and co-presence of endometriosis were different (p=0.003, 0.033, 0.011, and 0.011, respectively). The median follow-up period was 57.8 (0.4-230.0) months. There were no differences in the rates of recurrence (21.2% vs. 20.7%, p=1.000) or death (16.7% vs. 6.9%, p=0.332) between the 2 groups. There was no difference in the pattern of recurrence or in disease-free survival (DFS) and overall survival (OS) between the 2 groups. In multivariate analysis, pretreatment cancer antigen-125 >35 U/mL and International Federation of Gynecology and Obstetrics stage IC were significant factors of worse DFS and OS, while dense adhesion was not a prognostic factor for both DFS (hazard ratio [HR]=0.9; 95% confidence interval [CI]=0.3-2.7; p=0.792) and OS (HR=0.2; 95% CI=0.1-1.8; p=0.142), nor were age, proportion of staging procedure, histologic type, and co-presence of endometriosis. Moreover, the distribution of those 2 significant prognostic factors was not different between the 2 groups. Dense adhesions were subgrouped into non-tumor and tumor associated dense adhesions for further analysis and the results were same.

CONCLUSION

FSS is feasible and safe in EOC, regardless of the presence of dense adhesions.

PM2.5 disrupts thyroid hormone homeostasis through activation of the hypothalamic-pituitary-thyroid (HPT) axis and induction of hepatic transthyretin in female rats 2.5

Fine particulate matter (PM_2.5), a ubiquitous environmental pollutant, has been indicated to affect thyroid hormone (TH) homeostasis in women, but the detailed mechanism behind this effect remains unclear. The objective of this study was to evaluate the roles of the hypothalamic-pituitary-thyroid (HPT) axis and hepatic transthyretin in the thyroid-disrupting effects of PM_2.5. Sprague Dawley rats were treated with PM_2.5 (0, 15 and 30 mg/kg) by passive pulmonary inhalation for 49 days; and recovery experimental group rats were dosed with PM_2.5 (30 mg/kg) for 35 days, and no treatment was done during the subsequent 14 days. PM_2.5 was handled twice a day by passive pulmonary inhalation throughout the study. After treatment, pathological changes were analyzed by performing haemotoxylin and eosin staining, measuring levels of THs and urine iodine (UI) in serum, plasma, and urine samples using enzyme-linked immunoabsorbent assay, and expression of proteins in the hypothalamus, pituitary, thyroid, and liver tissues of rats were analyzed by immunohistochemistry and Western blotting. The levels of oxidative stress factors, such as reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (Gpx), and nuclear factor-kappa B (NF-κB) in female rats' plasma were also evaluated by ELISA. The results of these analyses revealed that PM_2.5 treatment induced pathologic changes in rat thyroid and liver characterized by increased follicular cavity size and decreased amounts of follicular epithelial cells and fat vacuoles, respectively. Serum levels of triiodothyronine, thyroxine, and thyroid stimulating hormone were significantly decreased, plasma NF-κB level was increased and plasma redox state was unbalanced (enhanced ROS, MDA and Gpx levels; reduced SOD activities) in female rats treated with PM_2.5 (P < 0.05). PM_2.5 treatment suppressed the biosynthesis and biotransformation of THs by increasing sodium iodide symporter, thyroid transcription factor 1, thyroid transcription factor 2, and paired box 8 protein expression levels (P < 0.05). Additionally, thyroid stimulating hormone receptor and thyroid peroxidase levels were significantly decreased (P < 0.05). Both thyrotropin releasing hormone receptor and thyroid stimulating hormone beta levels were enhanced (P < 0.05). Moreover, transport of THs was inhibited due to reduced protein expression of hepatic transthyretin upon treatment with PM_2.5. In summary, PM_2.5 treatment could perturb TH homeostasis by affecting TH biosynthesis, biotransformation, and transport, affecting TH receptor levels, and inducing oxidative stress and inflammatory responses. Activation of the HPT axis and altered hepatic transthyretin levels therefore appear to play a crucial role in PM_2.5-induced thyroid dysfunction.

PROSTHODONTIC REHABILITATION OF MAXILLOFACIAL DEFECTS IN A NIGERIAN TEACHING HOSPITAL: A 9-YEAR REVIEW

OBJECTIVE

The objective was to review patients treated with maxillofacial prostheses in a Nigerian teaching hospital to assess the types of prostheses provided for them.

METHODOLOGY

This was a retrospective study of patients treated with maxillofacial prostheses over a period of nine years. The socio-demographic data of the patients, types of defect, causes of defects, location of defect, types of maxillofacial prostheses and the indications for prostheses were obtained from the patients' case records. Case records with incomplete information were excluded. All data generated were analysed using the IBM SPSS version 20. Fisher's exact test was used to test for statistical significance.

RESULTS

Case records of eighty-two patients treated with maxillofacial prostheses were reviewed. Forty-three (52.4%) of the patients were males while 39 (47.6%) were females. The age ranged from 6 to 76 years with the mean age being of 38.76 (SD±18.3) years. The majority, 58 (70.7%) of the patients were of lower social-economic class. Sixty-six (80.5%) patients had prostheses for maxillary defects, while only one (1.2%) patient had prosthesis for nasal defect. Twenty (30.3%) of the 66 patients that had maxillary defects had definitive obturators, while only three (4.5%) had all the three types of obturator. Surgical recession of tumours of the jaw was the major cause (85.4%) and mastication (70.7%) was the major indication for the prescription of obturators.

CONCLUSION

The majority of the patients were of the lower social class and maxillary obturator was the major form of maxillofacial prostheses provided for patients in this study. Most of the defects are caused by surgical recession of tumours of the jaw and mastication was the major indication for the prescription of obturators.

Long-Term Outcomes and Prognostic Factors of Endoscopic Submucosal Dissection for Early Gastric Cancer in Patients Aged ≥75 Years

Simple Summary

The number of elderly patients with early gastric cancer (EGC) who meet the indications for endoscopic submucosal dissection (ESD) is increasing. Since elderly patients have more comorbidities, and lower life expectancy than younger patients, special considerations to establish treatment strategies according to prognosis is needed. We investigate overall survival and risk factors related to survival after ESD in these patients. During the follow-up, the 3-, 5-, and 10-year overall survival was 91.2%, 83.5%, and 54.5%, respectively. Smoking, history of cancer of other organs, neutrophil to lymphocyte ratio > 1.6, Charlson comorbidity index ≥ 3, and presence of lymphovascular invasion were independent five risk factors for poor overall survival. The long-term outcome of ESD was poorer in elderly patients with risk factors than in those without. These prognostic factors can also be useful in deciding whether to recommend additive surgery and a close follow-up after non-curative endoscopic treatment in the elderly patients.

Abstract

Background and Aims: The number of elderly patients with early gastric cancer (EGC) who meet the indications for endoscopic submucosal dissection (ESD) is increasing. We aimed to evaluate the clinical outcomes and prognostic factors of overall survival (OS) in elderly patients undergoing ESD for EGC. Methods: Between January 2006 and December 2018, 439 patients aged ≥75 years who underwent ESD for EGC were analyzed. The clinical outcomes and prognosis were evaluated, and independent risk factors for OS were identified. Results: The mean patient (302 men, 137 women) age was 78.3 (range 75–92) years. En bloc, R0, and curative resections were achieved in 96.8%, 90.7%, and 75.6%, respectively, without severe adverse events. During the follow-up (median 54.2 (range 4.0–159.6) months), 86 patients died (three of gastric cancer). The 3-, 5-, and 10-year OS was 91.2%, 83.5%, and 54.5%, respectively, and the 3-, 5-, and 10-year cancer related survival rate were 99.7%, 99.1% and 97.5%, respectively. In multivariate analysis, smoking, history of cancer of other organs, NLR > 1.6, Charlson comorbidity index ≥ 3, and presence of lymphovascular invasion (hazard ratio = 3.96, 1.78, 1.83, 1.83, and 2.63, respectively, all p < 0.05) were independent five risk factors for poor OS. The high-risk group (≥3 risk factors) showed a significantly lower OS than the low-risk group (<2 risk factors) (p < 0.001). Conclusions: The five factors could be useful in predicting the long-term prognosis of elderly ESD patients or deciding the therapeutic approaches in case of non-curative resection.

The Economic Burden of Cancers Attributable to Infection in the Republic of Korea: A Prevalence-Based Study

Infection is a major cause of cancers. We estimated the economic burden of cancers attributable to infection in 2014 in Korea, where cancer causing infection is prevalent, but the economic burden of it has never been examined. Cancer patients were defined as those having made medical claims as recorded by the National Health Insurance Service, which is a mandatory insurance for all citizen. We multiplied the costs by the population-attributable fraction for each type of cancer. The study included direct and indirect costs, where direct costs comprised direct medical and non-medical costs of inpatients and outpatients, while indirect costs were estimated by identifying future income loss due to premature death, productivity loss during hospitalization/outpatient visits, and job loss. In 2014, there were 100,054 infection-related cancer patients, accounting for 10.7% of all Korean cancer cases for that year. Direct costs of cancers associated with infection stood at nearly USD 676.9 million, while indirect costs were much higher at USD 2.57 billion. The average expenditure of a typical patient was USD 32,435. Economic burden of cancers attributable to infection is substantial in Korea, accounting for 0.23% of the national gross domestic product and 1.36% of national healthcare expenditure in 2014.

Elevated platelet lymphocyte ratio is a poor prognostic factor in advanced epithelial ovarian cancer

The platelet lymphocyte ratio (PLR) is an important prognostic biomarker in various cancers. The current retrospective study was undertaken to determine the association between PLR and prognosis of advanced epithelial ovarian cancer. We determined the optimal cutoff values of PLR for predicting survival outcomes using the receiver operating characteristic curve analysis. Based on the PLR cutoff values, patients were divided into two groups: <226 and ≥226. Univariate analysis revealed a greater risk of death in the PLR ≥ 226 group than the PLR < 226 group (HR (hazard ratio), 2.7; 95 % CI (confidence interval), 1.3-5.4; P = 0.006). In multivariate analysis, PLR (HR, 1.9; 95 % CI, 1.1-3.6; P = 0.047) significantly affected the overall survival. Our data indicates that PLR can be used as an independent significant prognostic factor in advanced epithelial ovarian cancer.

Association between Five Common Plasminogen Activator Inhibitor-1 (PAI-1) Gene Polymorphisms and Colorectal Cancer Susceptibility

The plasminogen activator inhibitor-1 (PAI-1) is expressed in many cancer cell types and modulates cancer growth, invasion, and angiogenesis. The present study investigated the association between five PAI-1 gene polymorphisms and colorectal cancer (CRC) risk. Five PAI-1 polymorphisms (−844G > A [rs2227631], −675 4G > 5G [rs1799889], +43G > A [rs6092], +9785G > A [rs2227694], and +11053T > G [rs7242]) were genotyped using a polymerase chain reaction-restriction fragment length polymorphism assay in 459 CRC cases and 416 controls. Increased CRC risk was more frequently associated with PAI-1 −675 5G5G polymorphism than with 4G4G (adjusted odds ratio (AOR) = 1.556; 95% confidence interval (CI): 1.012–2.391; p = 0.04). In contrast, for the PAI-1 +11053 polymorphism, we found a lower risk of CRC with the GG genotype (AOR = 0.620; 95% CI: 0.413–0.932; p = 0.02) than with the TT genotype, as well as for recessive carriers (TT + TG vs. GG, AOR = 0.662; 95% CI: 0.469–0.933; p = 0.02). The +43AA genotype was associated with lower overall survival (OS) than the +43GG genotype. Our results suggest that the PAI-1 genotype plays a role in CRC risk. This is the first study to identify an association between five PAI-1 polymorphisms and CRC incidence worldwide.

Intensity- and domain-specific physical activity levels between cancer survivors and non-cancer diagnosis individuals: a propensity score matching analysis

PURPOSE

To examine intensity- and domain-specific physical activity (PA) levels between Korean cancer survivors compared with non-cancer individuals.

METHODS

We used data from the 2014-2016 Korean National Health and Nutrition Examination Survey (KNHNES) to compare PA levels between 639 cancer survivors and 15,352 non-cancer individuals. Using the 1:5 propensity score matching analysis by sex, age, body mass index (BMI), and education level, 3195 non-cancer individuals were selected. Global Physical Activity Questionnaire (GPAQ) was used to assess PA levels.

RESULTS

Cancer survivors were more likely to participate in a leisure-time PA (64.5 ± 157.9 vs. 51.8 ± 145.3 min/week, p < 0.002) compared with non-cancer individuals, while no difference was observed between groups in work and transportation. Cancer survivors undergoing treatment participated in more leisure-time PA (80.9 ± 169.2 vs. 56.6 ± 151.8 min/week, p < 0.02) compared with cancer survivors who completed cancer treatment. However, we found no significant difference in vigorous-intensity PA (18.8 ± 113.9 vs. 20.5 ± 156.1 min/week, p = 0.56) and moderate-intensity PA (186.2 ± 313.1 vs. 203.1 ± 355.3 min/week, p = 0.17) levels between cancer survivors and non-cancer individuals.

CONCLUSIONS

This study showed that cancer survivors were more participated in leisure-time PA compared with age, gender, BMI, and education levels matched non-cancer individuals.

Targeted next-generation sequencing for locally advanced prostate cancer in the Korean population

Purpose

This study aimed to evaluate the feasibility of pan-cancer panel analysis for locally advanced prostate cancer in the Korean population.

Materials and Methods

We analyzed 20 patients with locally advanced prostate cancer who underwent radical prostatectomy. A pan-cancer panel (1.9 Mbp) developed by Seoul National University Hospital (SNUH), composed of 183 target genes, 23 fusion genes, and 45 drug target regions was used for this analysis. We compared the SNUH pan-cancer panel results with The Cancer Genome Atlas (TCGA) database to search for different mutations in the Korean population. Clinical data were analyzed with univariate and multivariate analysis, and p-values <0.05 were considered statistically significant. Kaplan-Meier curve and log-rank tests were performed to evaluate survival.

Results

The average age of the patients and initial prostate-specific antigen values were 69.3±7.8 years and 66.3±16.9 ng/dL, respectively. Average sequencing depth was 574.5±304.1×. Ninety-nine genetic mutations and 5 fusions were detected. SPOP (25%), KMT2D (20%), and BRAF (15%) were frequently detected. ERG fusions were recurrently detected in 20% of the patients, with SLMAP and SETD4 as novel fusion partners. BRAF mutation was frequently detected in this study, but not in the TCGA database. Multivariate analysis showed BRAF mutation as an independent prognostic factor for biochemical recurrence (hazard ratio, 9.84; p=0.03).

Conclusions

The pan-cancer panel comprising genes related to prostate cancer is a useful tool for evaluating genetic alterations in locally advanced prostate cancers. Our results suggest that the BRAF mutation is associated with biochemical recurrence in the Korean population.

Socioeconomic status and survival outcomes in elderly cancer patients: A national health insurance service-elderly sample cohort study

BACKGROUND

We hypothesized that lower socioeconomic status (SES) was associated with higher all-cause mortality in patients newly diagnosed with cancer, particularly in the elderly population.

METHODS

We collected study patients from the stratified random sample of Korean National Health Insurance Elderly Cohort (2002-2015). The Cox's proportional hazards model was used to investigate the risk factors for mortality. Income level and composite deprivation index (CDI) 2010 were used to define the SES: low, intermediate, and high SES groups. The comorbidities were measured using Charlson Comorbidity Index score. After a wash-out period (2002), the final study population was 108 626 (2003-2015).

RESULTS

In multivariate analysis, low SES was associated with poor overall survival (OS) (HR = 1.08, 95% CI: 1.05-1.12, P < 0.001) and cancer-specific survival (CSS) (HR = 1.11, 95% CI: 1.06-1.16, P < 0.001) particularly for patients aged 70-79 years. High SES was favorable prognostic factor of OS in patients aged 60-69 years (HR = 0.85, 95% CI: 0.81-0.89, P < 0.001), 70-79 years (HR = 0.90, 95% CI: 0.87-0.93, P < 0.001), and ≥80 years (HR = 0.91, 95% CI: 0.87-0.96, P < 0.001). However, SES was not associated with CSS in advanced age patients (≥80 years). Patients with low SES manifesting colorectal, urinary, liver, gastric, melanoma, and esophageal cancers demonstrated worse OS, compared to patients with intermediate SES. Also, low SES patients with urinary, liver, or colorectal cancers or melanoma demonstrated worse CSS compared to those with intermediate SES.

CONCLUSION

Low SES at the time of cancer diagnosis is associated with increased risk of OS and CSS in elderly patients. Depending on cancer sites, different patterns of OS and CSS were observed according to SES. Further elucidation of the causes underlying these phenomena is needed along with appropriate support for elderly cancer patients with low SES.

The economic burden of cancers attributable to smoking in Korea, 2014

INTRODUCTION

Associations between smoking, cancer and mortality are well established. Although cancer mortality rates have decreased in recent years, the economic burden of smoking-related cancers continues to increase. This study investigates the economic costs of cancers related to smoking in Korea in 2014.

METHODS

Cancer patients were identified through National Health Insurance Services medical claims with ICD-10 cancer codes. We multiplied the costs by the population attributable fraction for each type of cancer and calculated direct and indirect costs, where direct costs comprise direct medical and non-medical costs of inpatients and outpatients, and indirect costs include estimates of future income loss due to premature death, productivity loss during hospitalization and outpatient visits, and job loss.

RESULTS

In 2014, there were 79297 smoking-related cancer patients, accounting for 8.47% of all Korean cancer cases for that year. The direct cost of cancers due to smoking was approximately 595 million USD, whereas indirect costs were much higher, at nearly 2.2 billion USD. The average expenditure of a typical patient was 34815 USD. Lung, liver and stomach cancers were most prevalent and represented the most significant share of the economic burden, whereas the largest per-patient spending was for pancreatic, liver, and lung cancers. Lung, liver and stomach cancers had the highest economic impact on men, while lung, liver and ovarian cancers had the most significant economic impact on women.

CONCLUSIONS

It is imperative that more stringent steps be taken to reduce the huge economic burden of cancers linked to smoking.

ABBREVIATIONS

IARC: International Agency for Research on Cancer, PAF: population attributable fraction, NHIS: National Health Insurance Services, ICD-10: International Statistical Classification of Diseases and Related Health Problem 10th Revision, GDP: Gross Domestic Product, DALYs: Disability-Adjusted-Life-Years, WHO: World Health Organization, FCTC: Framework Convention on Tobacco Control.

Single-stranded DNA binding protein 2 expression is associated with patient survival in hepatocellular carcinoma

Background

SSBP2, single-stranded DNA binding protein 2, is a subunit of the ssDNA-binding complex that is involved in the maintenance of genome stability. The majority of previous studies have suggested a tumor-suppressive role of SSBP2, which is silenced by promoter hypermethylation in several human malignancies, such as hematologic malignancies, prostate cancer, esophageal squamous cell carcinoma, ovarian cancer, and gallbladder cancer. However, an oncogenic role of SSBP2 has been suggested in glioblastoma patients. We investigated the clinicopathologic significance of SSBP2 expression in hepatocellular carcinoma.

Methods

We constructed tissue microarrays consisting of 21 normal liver parenchyma and 213 hepatocellular carcinoma tissues with corresponding adjacent non-neoplastic tissues. SSBP2 expression was investigated by immunohistochemistry, and positive expression was defined as more than 10% of the tumor cells to show nuclear staining. We then analyzed the correlations between SSBP2 expression and various clinicopathologic characteristics, and further studied the role of SSBP2 in cell growth and migration.

Results

Hepatocytes were negative for SSBP2 immunohistochemistry in all normal liver samples, whereas the nuclei of normal bile duct epithelium and sinusoidal endothelium were immunoreactive. Positive immunoreactivity was found in one (0.6%) out of 180 non-neoplastic liver tissue samples adjacent to the tumor and in 16 (8.5%) out of 189 hepatocellular carcinomas. Positive SSBP2 expression was significantly correlated with tumor multifocality (P = 0.027, chi-square test), high histologic grade (P = 0.003, chi-square test), and frequent vascular invasion (P = 0.001, chi-square test). Kaplan-Meier survival curves revealed that patients with SSBP2 expression had poor prognosis in both disease-free and overall survival (P = 0.004 and P = 0.026, respectively, log-rank test). SSBP2-positive tumors also had a higher Ki-67 proliferation index (P <  0.001, t-test). Furthermore, downregulation of SSBP2 in the Huh7 cell line inhibited cell migration (P = 0.022, t-test) with altered expression of epithelial-mesenchymal transition markers.

Conclusions

The minority of hepatocellular carcinomas expressed SSBP2 by immunohistochemistry, whereas normal hepatocytes were negative. SSBP2-positive hepatocellular carcinomas were significantly associated with aggressive phenotypes and poor clinical outcome.

Oncological safety of use of ultrasonic activated shears in gastric cancer surgery: Long-term results of randomized controlled trial

Objective

Ultrasonically activated shears (UAS) have been applied in open gastric surgeries with no or little evidence. It was previously reported about the surgical outcome and effectiveness of UAS based on a randomized controlled trial of 256 patients with gastric cancer. We aimed to clarify the long-term oncological safety of the use of UAS in the aspect of overall survival and recurrence.

Methods

Gastric cancer patients who underwent gastrectomy with D2 lymph node dissection were enrolled and randomly assigned to either the conventional surgery group (n=125) or the UAS group (n=128). Survival, recurrence and long-term postoperative complications were compared between the two groups. The median follow-up period was 56 months.

Results

Gastric cancer-related death was higher in patients of the UAS group compared with the conventional group (P=0.019). Overall survival rates stratified by stage were not significantly different between the two groups (P=0.170). Disease-free survival rates stratified by stage and recurrence-free survival rates of gastric cancer were similar between the conventional group and the UAS group (P=0.313 and 0.199, respectively). The postoperative complication rate was not significantly different between the groups (P=1.000).

Conclusions

It is suggested that the use of UAS in gastrectomy for gastric cancer showed oncologically acceptable safety compared with conventional electric instruments even in long-term period.

Risk factors for cytological progression in HPV 16 infected women with ASC-US or LSIL: The Korean HPV cohort

Objective

This study was to identify the risk factors for cytological progression in women with atypical squamous cells of undetermined significance (ASC-US) or low-grade squamous intraepithelial lesions (LSIL).

Methods

We analyzed data from women infected with the human papillomavirus (HPV) who participated in the Korean HPV cohort study. The cohort recruited women aged 20-60 years with abnormal cervical cytology (ASC-US or LSIL) from April 2010. All women were followed-up at every 6-month intervals with cervical cytology and HPV DNA testing.

Results

Of the 1,158 women included, 654 (56.5%) and 504 (43.5%) women showed ASC-US and LSIL, respectively. At the time of enrollment, 143 women tested positive for HPV 16 (85 single and 58 multiple infections). Cervical cytology performed in the HPV 16-positive women showed progression in 27%, no change in 23%, and regression in 50% of the women at the six-month follow-up. The progression rate associated with HPV 16 infection was higher than that with infection caused by other HPV types (relative risk [RR], 1.75; 95% confidence interval [CI], 1.08-2.84; P=0.028). The cytological progression rate in women with persistent HPV 16 infection was higher than that in women with incidental or cleared infections (P<0.001). Logistic regression analysis showed a significant relationship between cigarette smoking and cytological progression (RR, 4.15; 95% CI, 1.01-17.00).

Conclusion

The cytological progression rate in HPV 16-positive women with ASC-US or LSIL is higher than that in women infected with other HPV types. Additionally, cigarette smoking may play a role in cytological progression.

Social Media Use for Cancer Education at a Community-Based Cancer Center in South Korea

The main purpose of this study was to evaluate the effectiveness of the education system using social media. Eight educational video clips were developed instructing the viewer on cancer-related issues such as prevention, treatment, and survivorship. Each video was made with participation of medical professors and posted on a YouTube channel. A mobile phone application was produced containing a scheduler function, introduction of a community cancer center program, and cancer information. A medical blog was established to provide stationary materials such as images and articles. Descriptive analysis was done by Google analytics. From May of 2014 to June of 2016, 15,247 total views were recorded on the YouTube channel, and the average view duration was about 3 min. The most popular video was about chemotherapy treatment; 5409 (36%) people watched this video, and 3615 (23.5%) people viewed a video on balanced dietary habits. As well as South Korea, 1,113 (7%) views were confirmed in the United States and 175 (1%) in Japan. The equipment used to watch the contents were mobile phones (59%), laptops (33%), and tablets (6%). Five hundred people installed the smartphone application from March of 2015 to July of 2016. Three hundred eighty-three medical contents were posted on the blog since March of 2015. Cancer education is necessary to address the education needs of patients with cancer and their caregivers. Education based on social media could be an effective method that reaches beyond geographical boundaries.

Comparison of the PANArray HPV Genotyping Chip Test with the Cobas 4800 HPV and Hybrid Capture 2 Tests for Detection of HPV in ASCUS Women

PURPOSE

This study aimed to evaluate the performance of the PANArray human papilloma virus (HPV) test, a PCR-based DNA microarray assay, in detecting HPV from patient samples and its concordance with the cobas 4800 HPV and Hybrid Capture 2 (HC2) tests.

MATERIALS AND METHODS

The PANArray HPV, cobas 4800 HPV, and HC2 tests were performed on 504 cervical swab samples from patients with atypical cells of undetermined significance at five hospitals. The samples that were interpreted as 'HPV-other' type positive in the PANArray HPV test were confirmed by direct sequencing.

RESULTS

The concordance rates were 80.8% between the cobas 4800 HPV and PANArray HPV tests [κ=0.59, 95% confidence interval (CI) 0.52-0.66] and 80.2% (κ=0.6, 95% CI 0.55-0.68) between the HC2 and PANArray HPV tests. Among the 62 patients negative on PANArray HPV (defined as the absence of high risk HPV), but positive on both cobas 4800 HPV and HC2 tests, 42 (67.7%) tested positive for 'HPV-other' types on the PANArray HPV test, and 31 (50.0%) had gray zone results [relative light unit/control (RLU/CO), 1.4-9.25] in the HC2 test. Of the patients deemed positive by the PANArray HPV test, 43 tested positive for high-risk (HR) HPV in cobas 4800 HPV and HC 2 tests. Among them, 58.2% showed HR HPV, including HPV 16, by direct sequencing, of which 25% had gray results.

CONCLUSION

Results classified as 'HPV-other' type by the PANArray HPV test, or gray zone results by HC2 (RLU/CO ratio level 1-10) should be carefully interpreted using comprehensive clinical information.

Postoperative Helicobacter pylori Infection as a Prognostic Factor for Gastric Cancer Patients after Curative Resection

Background/Aims

Few studies have evaluated the effect of Helicobacter pylori infection on the prognosis of patients diagnosed with gastric cancer (GC) after curative surgery. We investigated the association between the H. pylori infection status and clinical outcome after surgery.

Methods

We assessed the H. pylori status of 314 patients who underwent curative resection for GC. The H. pylori status was examined using a rapid urease test 2 months after resection. Patients were followed for 10 years after surgery.

Results

An H. pylori infection was observed in 128 of 314 patients. The median follow-up period was 93.5 months. A Kaplan-Meier analysis indicated that patients with H. pylori had a higher cumulative survival rate than those who were negative for H. pylori. Patients with stage II cancer who tested negative for H. pylori were associated with a poor outcome. In a multivariate analysis, H. pylori-negative status was a significant independent prognostic factor for poor overall survival.

Conclusions

Having a negative H. pylori infection status seems to indicate poor prognosis for patients with GC who have undergone curative resection. Further prospective controlled studies are needed to evaluate the mechanism by which H. pylori affects GC patients after curative surgery in Korea.

Clinical outcomes and costs of robotic surgery in prostate cancer: a multiinstitutional study in Korea

Background

This study compared the surgical, functional, and oncologic outcomes of robot-assisted laparoscopic radical prostatectomy (RALP), laparoscopic radical prostatectomy (LRP), and retropubic radical prostatectomy (RRP) in Korean men.

Methods

The study population included 864 patients who underwent radical prostatectomy for prostate cancer in the departments of urology of five tertiary hospitals between 2010 and 2011. RALP, LRP, and RRP perioperative, oncological, and functional outcomes as well as complications were assessed. Medical cost data were analyzed for 682 of 864 patients.

Results

No significant differences were found among the three groups regarding the length of stay, biochemical recurrence, complications, and metastasis. The RALP group had a significantly higher rate of pelvic lymph node dissection (64.6% vs. 35.3% or 53.3%, P value <0.0001) and bilateral nerve-sparing procedures (15.7% vs. 10.0% or 8.9%, P value <0.0001) and less blood loss (median 250 mL vs. 300 mL or 700 mL, P value <0.0001) than the LRP and RRP groups. The 12-month continence recovery rate was higher in the RALP group (92.1%) than in the LRP (86.5%) and RRP (84.4%) groups (P value <0.0001). Medical costs for RALP were approximately twofold to threefold higher than those for LRP or RRP.

Conclusions

Our findings suggest that surgical and functional outcomes are better with robot-assisted surgery than with laparoscopic or open surgery in terms of estimated blood loss and urinary continence; however, no differences were found among groups in terms of biochemical recurrence and the rate of complications.

Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2015

Purpose

This study presents the 2015 nationwide cancer statistics in Korea, including the incidence, survival, prevalence, and mortality.

Materials and Methods

Cancer incidence data from 1999 to 2015 was obtained from the Korea National Cancer Incidence Database and followed until December 31, 2016. Mortality data from 1983 to 2015 were obtained from Statistics Korea. The prevalence was defined as the number of cancer patients alive on January 1, 2016, among all cancer patients diagnosed since 1999. Crude and age-standardized rates (ASRs) for incidence, mortality and prevalence and 5-year relative survivals were also calculated.

Results

Herein, 214,701 and 76,855 Koreans were newly diagnosed and died from cancer in 2015, respectively. The ASRs for cancer incidence and mortality in 2015 were 258.9 and 82.0 per 100,000, respectively. The overall cancer incidence rate has increased significantly by 3.4% annually from 1999 to 2012, and started to decrease after 2012 (2012-2015, annual percent change, –6.1%). However, the overall cancer mortality has decreased 2.7% annually since 2002. The 5-year relative survival rate for patients diagnosed with cancer between 2011 and 2015 was 70.7%, an improvement from the 41.2% for patients diagnosed between 1993 and 1995.

Conclusion

Age-standardized cancer incidence rates have decreased since 2012 and mortality rates have declined since 2002; however, the 5-year survival rates have improved remarkably from 1993-1995 to 2011-2015 in Korea.

Preoperative Predictive Factors for Complete Cytoreduction and Survival Outcome in Epithelial Ovarian, Tubal, and Peritoneal Cancer After Neoadjuvant Chemotherapy

OBJECTIVE

The study aims to identify preoperative predictors of complete cytoreduction and early recurrence and death in epithelial ovarian, tubal, and peritoneal cancer after neoadjuvant chemotherapy (NACT).

METHODS

We performed a retrospective analysis of 85 patients who underwent 3 cycles of NACT. Patients were divided into 2 groups according to residual tumor at interval debulking surgery (IDS), and clinicopathologic, surgical, and follow-up data were compared.

RESULTS

Cancer antigen 125 (CA-125) levels before the IDS after completion of NACT were higher in the residual tumor group (42.0 vs 116.6 U/mL, P = 0.006). The drop rate of CA-125 after NACT was higher in the no residual tumor group (96.8% vs 89.9%, P = 0.001). Patients with residual tumor showed lower disease-free and overall survival outcomes than patients with no residual tumor. In univariate analysis, CA-125 of 100 U/mL or less before IDS and a drop rate after NACT greater than 80% were preoperative predictive factors for complete cytoreduction. In multivariate analysis, a drop rate of CA-125 after NACT greater than 80% was an independent preoperative predictive factor for complete cytoreduction (P = 0.002). Progressive disease on follow-up image during NACT was an independent preoperative predictive factor for early recurrence and death (P < 0.001, both).

CONCLUSIONS

A significant drop of CA-125 after NACT and progressive disease on follow-up image are independent preoperative predictors for complete cytoreduction and early recurrence and death.

Significance of Ovarian Endometriosis on the Prognosis of Ovarian Clear Cell Carcinoma

Introduction

The aim of this study was to evaluate the significance of ovarian endometriosis on the prognosis of ovarian clear cell carcinoma (OCCC).

Methods

Patients with OCCC were divided into 2 groups according to the presence of ovarian endometriosis: group 1, no coexisting ovarian endometriosis; group 2, clear cell carcinoma arising from ovarian endometriosis or the presence of ovarian endometriosis elsewhere in the ovary. Clinicopathologic characteristics, disease-free survival (DFS), and overall survival (OS) were compared between the 2 groups.

Results

Of 155 patients with OCCC, 77 were categorized into group 1 and 78 into group 2. Group 2 patients were younger than group 1 (median age, 48 vs 51 years; P = 0.005) and had higher incidence of early-stage disease (stage I, 77% vs 58%; P = 0.001) and lower incidence of lymph node metastasis (4% vs 17%; P = 0.008). Group 2 patients were observed to have a significantly higher 5-year DFS (P < 0.001) and OS (P = 0.001) compared with group 1. In stage I disease, group 2 had a significantly higher 5-year DFS (P = 0.004) and OS (P = 0.016) than did group 1. In the multivariate analysis, coexisting endometriosis and advanced International Federation of Obstetrics and Gynecology stage were significant factors for both DFS and OS rates.

Conclusions

Ovarian clear cell carcinoma with endometriosis was found more frequently in younger women and had a higher incidence of early-stage disease and a lower incidence of lymph node metastasis compared with OCCC without endometriosis. Ovarian endometriosis was associated with improved prognostic factors and a better DFS and OS even in stage I disease. Ovarian endometriosis was an independent prognostic factor for OCCC.

Atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesion triage in Korean women: Revisiting the 2012 American Society of Colposcopy and Cervical Pathology screening guidelines

Objective

To determine whether triage for atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL) from the updated American Society for Colposcopy and Cervical Pathology cervical cancer screening guidelines is applicable in Korean women.

Methods

We investigated women with ASC-US or LSIL including referred from local hospitals visited for cervical cancer screening at Korea University Guro Hospital from February 2004 to December 2014. Detailed information on the results of Papanicolaou (Pap) smears, human papillomavirus (HPV) DNA tests, and cervical biopsies were collected through chart review. Cervical biopsy results were compared in eligible women according to individual Pap smear findings and HPV DNA status.

Results

Of 216,723 possible cases, 3,196 were included. There were 212 (6.6%) women with ASC-US and 500 (15.6%) with LSIL. The risk of ≥cervical intraepithelial neoplasia (CIN) 2 was significantly higher in women who were ASC-US/HPV+ than ASC-US/HPV- and LSIL/HPV+ than LSIL/HPV- (93.3% vs. 6.7% and 96.7% vs. 3.3%, P<0.001 and P<0.001, respectively). The risk of ≥CIN 3 was also significantly higher in women who were ASC-US/HPV+ than ASC-US/HPV- and LSIL/HPV+ than LSIL/HPV- (97.0% vs. 3.0% and 93.0% vs. 7.0%, P<0.001 and P<0.001, respectively). Age-stratified analysis revealed that more CIN 2 or CIN 3 was diagnosed in women aged 30 to 70 with ASC-US or LSIL when HPV DNA was present.

Conclusion

Observation with Pap and HPV DNA tests rather than immediate colposcopy is a reasonable strategy for ASC-US or LSIL when the HPV DNA test is negative, especially in women aged 30 to 70. Reflection of these results should be considered in future Korean screening guidelines.

Prognostic value of positron emission tomography/computed tomography for adjuvant chemotherapy of colon cancer

BACKGROUND

To assess the prognostic value of preoperative ¹⁸ F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with high-risk stage II or stage III colon cancer who underwent FOLFOX chemotherapy.

METHODS

The study included 166 patients with high-risk stage II or stage III colon cancer who received FOLFOX4 chemotherapy. Retrospective patient data were analysed including pathological stage, histology, disease-free survival (DFS) and the maximum standardized uptake value (SUV_max ) of the primary tumour on ¹⁸ F-fluorodeoxyglucose positron emission tomography/computed tomography. The primary end point was DFS.

RESULTS

There were recurrences in 29 of the 166 patients (17.4%). Measuring the area under the receiver operating characteristic curve, the cut-off value of SUV_max with maximum sensitivity and specificity was 10.95. Using the Kaplan-Meier method, the DFS of the patients categorized by SUV_max tended to differ (P = 0.055). In univariate analyses, the risk factors for DFS were age over 70 years, higher N stage and neural invasion. SUV_max ≤ 10.95 showed a tendency, but was not significant (P = 0.0604). In multivariate analyses, the risk factors for DFS were age over 70 and neural invasion.

CONCLUSIONS

The results of this study suggest that high fluorodeoxyglucose uptake of the primary mass in high-risk stage II and stage III colon cancer does not significantly correlate with DFS.

Effectiveness of Gastric Cancer Screening on Gastric Cancer Incidence and Mortality in a Community-Based Prospective Cohort

Purpose

This study was performed to investigate the effectiveness of gastric cancer (GC) screening methods in a community-based prospective cohort of the Korean Multi-center Cancer Cohort (KMCC) with over a 10-year follow-up.

Materials and Methods

A total 10,909 and 4,773 subjects from the KMCC with information on gastroendoscopy (GE) and upper gastrointestinal series (UGIS) were included in this study. Cox proportional hazard model adjusted for age, sex, Helicobacter pylori infection, cigarette smoking, and alcohol drinking was used to estimate the hazard ratios (HRs) and 95% confidence interval (CI).

Results

The GE screened subjects had almost half the risk of GC-specific death than that of unscreened subjects (HR, 0.58; 95% CI, 0.36 to 0.94). Among the GC patients, GE screenees had a 2.24-fold higher survival rate than that of the non-screenees (95% CI, 1.61 to 3.11). In particular, GE screenees who underwent two or more screening episodes had a higher survival rate than that of the non-screenees (HR, 13.11; 95% CI, 7.38 to 23.30). The effectiveness of GE screening on reduced GC mortality and increased survival rate of GC patients was better in elderly subjects (≥ 65 years old) (HR, 0.47; 95% CI, 0.24 to 0.95 and HR, 8.84; 95% CI, 3.63 to 21.57, respectively) than that in younger subjects (< 65 years old) (HR, 0.66; 95% CI, 0.34 to 1.29 and HR, 1.83; 95% CI, 1.24 to 2.68, respectively). In contrast, UGIS screening had no significant relation to GC mortality and survival.

Conclusion

The findings of this study suggest that a decreased GC-specific mortality and improved survival rate in GC patients can be achieved through GE screening.

The prognostic significance of KRAS and BRAF mutation status in Korean colorectal cancer patients

Background

BRAF and KRAS mutations are well-established biomarkers in anti-EGFR therapy. However, the prognostic significance of these mutations is still being examined. We determined the prognostic value of BRAF and KRAS mutations in Korean colorectal cancer (CRC) patients.

Methods

From July 2010 to September 2013, 1096 patients who underwent surgery for CRC at Seoul St. Mary’s Hospital were included in the analysis. Resected specimens were examined for BRAF, KRAS, and microsatellite instability (MSI) status. All data were reviewed retrospectively.

Results

Among 1096 patients, 401 (36.7%) had KRAS mutations and 44 (4.0%) had BRAF mutations. Of 83 patients, 77 (92.8%) had microsatellite stable (MSS) or MSI low (MSI-L) status while 6 (7.2%) patients had MSI high (MSI-H) status. Patients with BRAF mutation demonstrated a worse disease-free survival (DFS, HR 1.990, CI 1.080–3.660, P = 0.02) and overall survival (OS, HR 3.470, CI 1.900–6.330, P < 0.0001). Regarding KRAS status, no significant difference was noted in DFS (P = 0.0548) or OS (P = 0.107). Comparing the MSS/MSI-L and MSI-H groups there were no significant differences in either DFS (P = 0.294) or OS (P = 0.557).

Conclusions

BRAF mutation, rather than KRAS, was a significant prognostic factor in Korean CRC patients at both early and advanced stages. The subgroup analysis for MSI did not show significant differences in clinical outcome. BRAF should be included in future larger prospective biomarker studies on CRC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3381-7) contains supplementary material, which is available to authorized users.

Validation of Nomograms for Survival and Metastases after Hysterectomy and Adjuvant Therapy in Uterine Cervical Cancer with Risk Factors

Background. Three nomogram models for early stage uterine cervical cancer have been developed (KROG 13-03 for overall survival [OS], SNUH/AMC for disease-free survival [DFS], and KROG 12-08 for distant metastases-free survival [DMFS]) after radical hysterectomy (RH) and pelvic lymph node dissection (PLND). This study aimed to validate these models using our cohort with adjuvant radiotherapy. Methods. According to the eligibility criteria of nomogram studies, patients were enrolled in Group A (N = 109) for the two KROG models (RH with PLND and whole pelvic irradiation) and Group B (N = 101) for the SNUH/AMC model (RH with PLND and squamous histology). Using Cox-regression hazard models, the prognostic factors of our cohorts were evaluated. The risk probabilities induced from published nomogram scores were calculated and the concordance indices were evaluated. Results. Group A had 88.1% 5-year OS and 86.0% 5-year DMFS. Group B had 83.0% 5-year DFS. In multivariate analyses, large tumor size for OS (HR 8.62, P < 0.001) and DMFS (HR 5.13, P = 0.003), young age (≤40 versus 41-64 years) for OS (HR 4.63, P = 0.097) and DFS (HR 3.44, P = 0.051), and multiple lymph node metastases (0 versus ≥3) for DMFS (HR 4.03, P = 0.031) and DFS (HR 3.90, P = 0.038) were significantly correlated. The concordance indices for OS, DMFS, and DFS were 0.612 (P = 0.002), 0.597 (P = 0.014), and 0.587 (P = 0.020), respectively. Conclusion. The developed nomogram models after RH and PLND are clinically useful in predicting various types of survival with significance.

Clinical features of recently diagnosed papillary thyroid carcinoma in elderly patients aged 65 and older based on 10 years of sonographic experience at a single institution in Korea

Purpose

The aim of this study was to assess the characteristics of papillary thyroid carcinoma (PTC) in patients aged 65 and older in order to predict postoperative recurrence based on the results of ultrasonographic surveillance.

Methods

Among 1,494 patients (200 male and 1,294 female; mean age, 46.6±11.3 years) who underwent surgery for thyroid cancer at our institution between 2006 and 2015, we retrospectively enrolled 150 PTC patients (29 male and 121 female; mean age, 69.4±4.2 years). To identify the risk factors for recurrence, we analyzed age, gender, multiplicity, size, number, extrathyroidal extension (ETE) of the tumor, lymph node metastasis (LNM), type of surgery, and the dose of radioactive ablation using a Cox regression model to identify hazard ratios (HRs).

Results

Among the 115 asymptomatic patients with PTCs detected by screening ultrasonography (n=86), other cross-sectional imaging modalities (computed tomography or positron emission tomography-computed tomography, n=13), or incidentally through a surgical specimen (n=16), 78 patients were confirmed to have papillary thyroid microcarcinomas (PTMCs). The other 35 patients presented with palpable neck masses (n=25), vocal cord palsy (n=9) or blood-tinged sputum (n=1). During the follow-up period (mean, 43.6 months), 17 patients (12.5%) experienced recurrence in the neck. None of the patients died due to PTC-related recurrence or distant metastasis during the follow-up period. Cox regression analysis demonstrated that tumor size (HR, 2.12; P<0.001) and LNM (central LNM: HR, 9.08; P=0.004; lateral LNM: HR, 14.71; P=0.002; both central and lateral LNM: HR, 58.41; P<0.001) significantly increased the recurrence rate. ETE, LNM, and recurrence were significantly less frequent in PTMCs than in non-PTMC (all P<0.001).

Conclusion

PTCs of small size and absent LNM showed significantly better prognoses in patients 65 years and older.

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.

Tetraarsenic hexoxide induces G2/M arrest, apoptosis, and autophagy via PI3K/Akt suppression and p38 MAPK activation in SW620 human colon cancer cells

Tetraarsenic hexoxide (As₄O₆₎ has been used in Korean folk medicines for the treatment of cancer, however its anti-cancer mechanisms remain obscured. Here, this study investigated the anti-cancer effect of As₄O₆ on SW620 human colon cancer cells. As₄O₆ has showed a dose-dependent inhibition of SW620 cells proliferation. As₄O₆ significantly increased the sub-G1 and G2/M phase population, and Annexin V-positive cells in a dose-dependent manner. G2/M arrest was concomitant with augment of p21 and reduction in cyclin B1, cell division cycle 2 (cdc 2) expressions. Nuclear condensation, cleaved nuclei and poly (adenosine diphosphate‑ribose) polymerase (PARP) activation were also observed in As₄O₆-treated SW620 cells. As₄O₆ induced depolarization of mitochondrial membrane potential (MMP, ΔΨm) but not reactive oxygen species (ROS) generation. Further, As₄O₆ increased death receptor 5 (DR5), not DR4 and suppressed the B‑cell lymphoma‑2 (Bcl-2) and X-linked inhibitor of apoptosis protein (XIAP) family proteins. As₄O₆ increased the formation of AVOs (lysosomes and autophagolysosomes) and promoted the conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3)-I to LC3-II in a dose- and time- dependent manner. Interestingly, a specific phosphoinositide 3-kinase (PI3K)/Akt inhibitor (LY294002) augmented the As₄O₆ induced cell death; whereas p38 mitogen-activated protein kinases (p38 MAPK) inhibitor (SB203580) abrogated the cell death. Thus, the present study provides the first evidence that As₄O₆ induced G2/M arrest, apoptosis and autophagic cell death through PI3K/Akt and p38 MAPK pathways alteration in SW620 cells.

Variability in target delineation of cervical carcinoma: A Korean radiation oncology group study (KROG 15-06)

PURPOSE

To determine inter-observer variability in target volume definition of cervical cancer in radical and adjuvant radiotherapy (RT) settings.

METHODS

Eight physicians contoured CTVs of 2 patients underwent definitive and postoperative RT. Each volume was analyzed using the individual/median volume ratio and generalized conformity index (CIgen). And center of mass (COM) of each contour was calculated. Expert agreement was quantified using an expectation maximization algorithm for Simultaneous Truth and Performance Level Estimation (STAPLE).

RESULTS

For definitive RT, the individual/median volume ratio ranged from 0.51 to 1.41, and CIgen was 0.531. Mean 3-dimensional distances of average to each COM were 7.8 mm. For postoperative RT setting, corresponding values were 0.65-1.38, 0.563, and 5.3 mm. Kappa value of expert agreement was 0.65 and 0.67, respectively. STAPLE estimates of the sensitivity, specificity, and kappa measures of inter-physician agreement were 0.73, 0.98, and 0.65 for the definitive and 0.75, 0.98, and 0.67 for the adjuvant radiotherapy setting. The largest difference was observed in the superior-inferior direction, particularly in the upper vagina and the common iliac area.

CONCLUSION

As there was still some variability in target delineation, more detailed guidelines for target volume delineation and continuing education would help to reduce this uncertainty.

Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2014

PURPOSE

This study presents the 2014 nationwide cancer statistics in Korea, including cancer incidence, survival, prevalence, and mortality.

MATERIALS AND METHODS

Cancer incidence data from 1999 to 2014 was obtained from the Korea National Cancer Incidence Database and followed until December 31, 2015. Mortality data from 1983 to 2014 were obtained from Statistics Korea. The prevalence was defined as the number of cancer patients alive on January 1, 2015, among all cancer patients diagnosed since 1999. Crude and age-standardized rates (ASRs) for incidence, mortality, prevalence, and 5-year relative survivals were also calculated.

RESULTS

In 2014, 217,057 and 76,611 Koreans were newly diagnosed and died from cancer respectively. The ASRs for cancer incidence and mortality in 2014 were 270.7 and 85.1 per 100,000, respectively. The all-cancer incidence rate has increased significantly by 3.4% annually from 1999 to 2012, and started to decrease after 2012 (2012-2014; annual percent change, -6.6%). However, overall cancer mortality has decreased 2.7% annually since 2002. The 5-year relative survival rate for patients diagnosed with cancer between 2010 and 2014 was 70.3%, an improvement from the 41.2% for patients diagnosed between 1993 and 1995.

CONCLUSION

Age-standardized cancer incidence rates have decreased since 2012 and mortality rates have also declined since 2002, while 5-year survival rates have improved remarkably from 1993-1995 to 2010-2014 in Korea.

Beyond precision surgery: Molecularly motivated precision care for gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide. Despite the high disease prevalence, gastric cancer research has not gained much attention. Recently, genome-scale technology has made it possible to explore the characteristics of gastric cancer at the molecular level. Accordingly, gastric cancer can be classified into molecular subtypes that convey more detailed information of tumor than histopathological characteristics, and these subtypes are associated with clinical outcomes. Furthermore, this molecular knowledge helps to identify new actionable targets and develop novel therapeutic strategies. To advance the concept of precision patient care in the clinic, patient-derived xenograft (PDX) models have recently been developed. PDX models not only represent histology and genomic features, but also predict responsiveness to investigational drugs in patient tumors. Molecularly curated PDX cohorts will be instrumental in hypothesis generation, biomarker discovery, and drug screening and testing in proof-of-concept preclinical trials for precision therapy. In the era of precision medicine, molecularly tailored therapeutic strategies should be individualized for cancer patients. To improve the overall clinical outcome, a multimodal approach is indispensable for advanced cancer patients. Careful, oncological principle-based surgery, combined with a molecularly guided multidisciplinary approach, will open new horizons in surgical oncology.

Capecitabine and cisplatin (XP) combination systemic chemotherapy in heavily pre-treated HER2 negative metastatic breast cancer

PURPOSE/OBJECTIVE(S)

After taxane and anthracycline failure, no standard chemotherapy regimen is established in metastatic breast cancer (MBC). Capecitabine and cisplatin (XP) combination shows promising results in gastrointestinal cancer, but there are relatively scarce data in MBC. We reviewed the clinical outcome of XP regimen in anthracycline and taxane resistant, heavily pretreated MBC patients.

MATERIALS/METHODS

Between Jan. 2010 to Feb. 2016, 48 HER2 negative MBC patients who failed anthracycline and taxane based chemotherapy were enrolled. In 43.8% of patients, more than 4 regimens were administrated before XP. Thirty-four patients (70.8%) were hormone receptor (HR) positive MBC. Patients were treated with XP (capecitabine [2000mg/m2 per oral; day 1-14] plus cisplatin [60mg/m2 IV; day 1], every 3 weeks) regimen.

RESULTS

Median progression-free survival (PFS) in total population was 4.33 months (range 1.1~33.57 months). HR positive patients showed trends for superior PFS compared to triple negative breast cancer (TNBC), without statistical significance (6.53 vs. 3.83 months, P = 0.168). In HR positive group, patients receiving 3 or less lines of chemotherapy showed superior PFS compared to others (10.1 vs. 3.0 months, P = 0.039). In multivariate analysis, HR positive patients receiving 3 or less lines of regimens still showed superior PFS (HR = 2.624, 95% CI; 1.071~6.43, P = 0.032). Most common toxicity was grade 3-4 neutropenia, without treatment-related deaths.

CONCLUSIONS

XP combination regimen showed clinical benefit with tolerable toxicity in heavily pretreated patients, including HR positive patients. After anthracycline and taxane failure, early administration of XP regimen in selected patients may have improve clinical outcome in breast cancer.

Postoperative Quality of Life after Total Gastrectomy Compared with Partial Gastrectomy: Longitudinal Evaluation by European Organization for Research and Treatment of Cancer-OG25 and STO22

PURPOSE

The European Organization for Research and Treatment of Cancer quality-of-life questionnaire-OG25 was developed to evaluate the quality of life in patients with stomach and esophageal cancer. The following are included in the OG25 but not in the STO22: odynophagia, choked when swallowing, weight loss, trouble eating with others, trouble swallowing saliva, trouble talking, and trouble with coughing. In this study, we evaluated the quality of life of gastrectomized patients using both, the OG25 and the STO22.

MATERIALS AND METHODS

A total of 138 patients with partial gastrectomy (PG) (distal gastrectomy=91; pylorus-preserving gastrectomy= 47) and 44 patients with total gastrectomy (TG) were prospectively evaluated. Body weight and scores from the OG25 and STO22 were evaluated preoperatively and at 3 weeks, 3 months, and 6 months after surgery.

RESULTS

Patients with TG had significant weight loss compared to patients with PG. At 3 months, TG was associated with worse scores for dysphagia, eating, odynophagia, trouble eating with others, trouble with taste, and weight loss on the OG25. TG was also associated with dysphagia, eating restrictions, and anxiety on the STO22. The OG25 helped differentiate between the groups with respect to weight loss, odynophagia, choked when swallowing, and trouble eating with others. The OG25 scores changed over time and were significantly different.

CONCLUSIONS

The OG25 is a more sensitive and useful scale than the STO22 for evaluating the quality of life of gastrectomized patients, especially those with total gastrectomy.

Associations of perceived risk and cancer worry for colorectal cancer with screening behaviour

We investigated the associations of perceived risk and cancer worry with colorectal cancer screening by the faecal occult blood test, colonoscopy or both. This study was based on the 2013 Korean National Cancer Screening Survey, including 2154 randomly selected, cancer-free and over 50-year-old adults. Individuals with higher cancer worry were 1.53 times more likely to undergo colorectal cancer screening, influenced by emotional reaction; individuals with greater perceived risk were 1.61 times more, affected by subjective awareness. However, cancer worry was only associated with the faecal occult blood test. Better understanding of cancer worry and perceived risk on screening behaviours may help to increase colorectal cancer screening rates.

Development of a Protein Biomarker Panel to Detect Non-Small-Cell Lung Cancer in Korea

BACKGROUND

Lung cancer screening using low-dose computed tomography reduces lung cancer mortality. However, the high false-positive rate, cost, and potential harms highlight the need for complementary biomarkers. We compared the diagnostic performance of modified aptamer-based protein biomarkers with Cyfra 21-1.

PATIENTS AND METHODS

Participants included 100 patients diagnosed with lung cancer, and 100 control subjects from Asan Medical Center (Seoul, Korea). We investigated candidate biomarkers with new modified aptamer-based proteomic technology and developed a 7-protein panel that discriminates lung cancer from controls. A naive Bayesian classifier was trained using sera from 75 lung cancers and 75 controls. An independent set of 25 cases and 25 controls was used to verify performance of this classifier. The panel results were compared with Cyfra 21-1 to evaluate the diagnostic accuracy for lung nodules detected by computed tomography.

RESULTS

We derived a 7-protein biomarker classifier from the initial train set comprising: EGFR1, MMP7, CA6, KIT, CRP, C9, and SERPINA3. This classifier distinguished lung cancer cases from controls with an area under the curve (AUC) of 0.82 in the train set and an AUC of 0.77 in the verification set. The 7-marker naive Bayesian classifier resulted in 91.7% specificity with 75.0% sensitivity for the subset of individuals with lung nodules. The AUC of the classifier for lung nodules was 0.88, whereas Cyfra 21-1 had an AUC of 0.72.

CONCLUSION

We have developed a protein biomarker panel to identify lung cancers from controls with a high accuracy. This integrated noninvasive approach to the evaluation of lung nodules deserves further prospective validation among larger cohorts of patients with lung nodules in screening strategy.

Clinical characteristics of young-age onset gastric cancer in Korea

Background

Gastric cancer is the fourth most common cancer worldwide and more frequently detected in Asian countries including Korea and Japan. The incidence of young-age gastric cancer (GC) is increasing worldwide, but clinical behavior of young-age GC patients is not well established. We retrospectively analyzed the clinical features and outcomes of GC diagnosed at young-age population.

Methods

Between Jan. 2009 to Jan. 2015, 163 patients diagnosed as early, advanced, recurrent, or metastatic GC at ages between 22 ~ 39 years were analyzed. Based on medical records, authors analyzed the clinicopathologic characteristics and survival outcomes including overall survival (OS), disease free survival (DFS), and progression free survival (PFS).

Results

One-hundred and four patients (82.8 %) were diagnosed as GC at their thirties; especially 81 patients (31.2 %) patients were diagnosed over 35 years of age. The ratio of early GC and advanced GC were relatively similar (47.2 % vs. 52.8 %, respectively). Among stage II and III patients, 45 patients received 5-FU based adjuvant chemotherapy and recurrence rate was 48.9 %. Among patients diagnosed as recurrent or metastatic GC, recurrent GC patients showed relatively superior PFS and OS after cancer recurrence, compared to metastatic GC patients, but without statistical significance. Among metastatic GC patients, patients receiving palliative debulking surgery for ovary metastases showed superior PFS compared to patients who only received palliative systemic chemotherapy (P = 0.021, PFS 7.7 vs. 3.37 months, respectively).

Conclusions

Young age GC were commonly diagnosed at their thirties, without sexual predominance. The incidence of advanced GC in young age patients were higher compared to general patient population. Among recurrent GC patients, palliative debulking surgery might have role for superior survival outcomes. Considering relatively higher incidence for advanced GC, active surveillance for gastric cancer is warranted.

A pilot study of concurrent chemoradiotherapy with gemcitabine and cisplatin in patients with locally advanced biliary tract cancer

PURPOSE

Combination chemotherapy with gemcitabine and cisplatin is a standard treatment for patients with advanced biliary tract cancer. This study aimed to evaluate the efficacy and safety of gemcitabine- and cisplatin-based concurrent chemoradiotherapy in patients with unresectable biliary tract cancer.

METHODS

Patients with pathologically proven, unresectable, non-metastatic biliary tract cancer were enrolled. Gemcitabine was administered intravenously at a dose of 1000 mg/m(2) on days 1, 8, and 15. Cisplatin was administered intravenously at a dose of 70 mg/m(2) on day 1. All the patients underwent concurrent radiotherapy with 45 Gy in 1.8-Gy daily fractions. After treatment completion, tumor response was evaluated by using computed tomography.

RESULTS

Eighteen patients were enrolled between June 2007 and October 2011. Their median age was 61 years (range, 38-72 years). Eight patients (44.5 %) were diagnosed with gallbladder cancer, six (33.3 %) with Klatskin's tumor, and four (22.2 %) with distal common bile duct cancer. After treatment completion, partial response was achieved in five patients (27.8 %) and stable disease in 13 patients (72.2 %). The overall response rate was 27.8 %, and the disease stabilization rate was 100 %. No grade 4 adverse events or treatment-related deaths occurred. The most common grade 3 adverse events were thrombocytopenia (33.3 %) and anemia (11.1 %). The median progression-free and overall survival times were 6.8 months (range, 4.5-19.8 months) and 9.6 months (5.4-30.4 months), respectively.

CONCLUSIONS

This study shows that gemcitabine- and cisplatin-based concurrent chemoradiotherapy is feasible and tolerable in patients with unresectable and non-metastatic biliary tract cancer.

High resolution metabolomics to discriminate compounds in serum of male lung cancer patients in South Korea

BACKGROUND

The cancer death rate escalated during 20th century. In South Korea, lung cancer is expected to contribute 12,736 deaths in men, the highest amount among all cancers. Several risk factors may increase the chance to acquiring lung cancer, with mostly related to exogenous compounds found in cigarette smoke and synthetic manufacturing materials. As the mortality rate of lung cancer increases, deeper understanding is necessary to explore risk factors that may lead to this malignancy. In this regard, this study aims to apply high resolution metabolomics (HRM) using LC-MS to detect significant compounds that might contribute in inducing lung cancer and find the correlation of these compounds to the subjects' smoking habit.

METHODS

The comparison was made between healthy control and lung cancer groups for metabolic differences. Further analyses to determine if these differences are related to tobacco-induced lung cancer (past-smoker control vs. past-smoker lung cancer patients (LCPs) and non-smoker control vs. current-smoker LCPs) were selected. The univariate analysis was performed, including a false discovery rate (FDR) of q = 0.05, to determine the significant metabolites between the analyses. Hierarchical clustering analysis (HCA) was done to discriminate metabolites between the control and case subjects. Selected compounds based on significant m/z features of human serum then experienced MS/MS examination, showing that for many m/z, the patterns of ion dissociation matched with standards. Then, the significant metabolites were identified using Metlin database and features were mapped on the human metabolic pathway mapping tool of the Kyoto Encyclopedia of Genes and Genomes (KEGG).

RESULTS

Using metabolomics-wide association studies, metabolic changes were observed among control group and lung cancer patients. Bisphenol A (211.11, [M + H-H2O](+)), retinol (287.23, [M + H](+)) and L-proline (116.07, [M + H](+)) were among the significant compounds found to have contributed in the discrimination between these groups, suggesting that these compounds might be related in the development of lung cancer. Retinol has been seen to have a correlation with smoking while both bisphenol A and L-proline were found to be unrelated.

CONCLUSIONS

Two potential biomarkers, retinol and L-proline, were identified and these findings may create opportunities for the development of new lung cancer diagnostic tools.

The Role of Laparoscopic Radical Hysterectomy in Early-Stage Adenocarcinoma of the Uterine Cervix

OBJECTIVE

To compare long-term survival outcomes and patterns of recurrence of laparoscopic radical hysterectomy (LRH) and open radical hysterectomy (ORH) in early-stage cervical adenocarcinoma.

METHODS

The medical records of 293 patients with stage IA2-IIA cervical adenocarcinomas who underwent radical hysterectomy were retrospectively reviewed.

RESULTS

In total, 186 patients underwent LRH and 107 underwent ORH. There was no difference between the two surgery groups in clinicopathologic characteristics. There were no differences in disease-free survival (DFS) and overall survival (OS) between the LRH and ORH groups (88.7 vs. 84.1 %, P = 0.725; and 93.0 vs. 86.9 %, P = 0.735) for univariate analysis and multivariate analysis after adjusting for other significant prognostic factors. There was no difference in the patterns of recurrence between the two surgery groups (P = 0.220). The median time interval between surgery and the first recurrence were 25 months (range, 3-100 months) for LRH group and 14 months (range, 3-128 months) for ORH group (P = 0.230). The LRH group showed significantly fewer postoperative complications (P < 0.001), less estimated blood loss (P < 0.001), faster bowel movement recovery (P < 0.001), shorter postoperative hospital stay (P < 0.001), and a lower rate of wound dehiscence, ileus, lymphedema, infected lymphocele, and pelvic abscess (P = 0.004, 0.011, 0.017, and 0.040, respectively).

CONCLUSIONS

LRH has comparable survival outcomes with ORH and did not affect the pattern of recurrence in early-stage adenocarcinoma of the uterine cervix. The surgical outcomes were more favorable than ORH.

Forecasting Cause-Specific Mortality in Korea up to Year 2032

Forecasting cause-specific mortality can help estimate the future burden of diseases and provide a clue for preventing diseases. Our objective was to forecast the mortality for causes of death in the future (2013-2032) based on the past trends (1983-2012) in Korea. The death data consisted of 12 major causes of death from 1983 to 2012 and the population data consisted of the observed and estimated populations (1983-2032) in Korea. The modified age-period-cohort model with an R-based program, nordpred software, was used to forecast future mortality. Although the age-standardized rates for the world standard population for both sexes are expected to decrease from 2008-2012 to 2028-2032 (males: -31.4%, females: -32.3%), the crude rates are expected to increase (males: 46.3%, females: 33.4%). The total number of deaths is also estimated to increase (males: 52.7%, females: 41.9%). Additionally, the largest contribution to the overall change in deaths was the change in the age structures. Several causes of death are projected to increase in both sexes (cancer, suicide, heart diseases, pneumonia and Alzheimer's disease), while others are projected to decrease (cerebrovascular diseases, liver diseases, diabetes mellitus, traffic accidents, chronic lower respiratory diseases, and pulmonary tuberculosis). Cancer is expected to be the highest cause of death for both the 2008-2012 and 2028-2032 time periods in Korea. To reduce the disease burden, projections of the future cause-specific mortality should be used as fundamental data for developing public health policies.

Effect of dietary vitamin C on gastric cancer risk in the Korean population

AIM: To investigate the effects of dietary vitamin C and foods containing vitamin C on gastric cancer risk.

METHODS: Our study included 830 control subjects and 415 patients. Data regarding demographics, medical history, and lifestyle, including dietary and nutrient intake, were collected using reliable self-administered questionnaires. Dietary intake information was collected from the participants using a food frequency questionnaire that has been previously reported as reliable and valid. A rapid urease test and a histological evaluation were used to determine the presence of Helicobacter pylori (H. pylori) infection. Twenty-three vitamin C-contributing foods were selected, representing over 80% of the cumulative vitamin C contribution.

RESULTS: In analyses adjusted for first-degree family history of gastric cancer, education level, job, household income, smoking status, and regular exercise, an inverse association between vitamin C intake and gastric cancer risk was observed for the highest (≥ 120.67 mg/d) vs the lowest (< 80.14 mg/d) intake category [OR (95%CI): 0.64 (0.46-0.88)], with a significant trend across the three intake categories (P = 0.007). No protective effect of vitamin C was detected after stratification by gender. No effect of vitamin C intake on the gastric cancer incidence was found in either men or women infected with H. pylori. Vitamin C-contributing foods, including cabbage [0.45 (0.32-0.63), 0.50 (0.34-0.75), 0.45 (0.25-0.81)], strawberries [0.56 (0.40-0.78), 0.49 (0.32-0.74), 0.52 (0.29-0.93)], and bananas [0.40 (0.29-0.57), 0.41 (0.27-0.62), 0.34 (0.19-0.63)], were protective factors against the risk of gastric cancer based on the results of the overall adjusted analyses and the results for men and women, respectively.

CONCLUSION: A protective effect of vitamin C and vitamin C-contributing foods against gastric cancer was observed. Further studies using larger sample sizes are required to replicate our results.

Current Trends of Lung Cancer Surgery and Demographic and Social Factors Related to Changes in the Trends of Lung Cancer Surgery: An Analysis of the National Database from 2010 to 2014

PURPOSE

We investigated current trends in lung cancer surgery and identified demographic and social factors related to changes in these trends.

MATERIALS AND METHODS

We estimated the incidence of lung cancer surgery using a procedure code-based approach provided by the Health Insurance Review and Assessment Service (http://opendata.hira.or.kr). The population data were obtained every year from 2010 to 2014 from the Korean Statistical Information Service (http://kosis.kr/). The annual percent change (APC) and statistical significance were calculated using the Joinpoint software.

RESULTS

From January 2010 to December 2014, 25,687 patients underwent 25,921 lung cancer surgeries, which increased by 45.1% from 2010 to 2014. The crude incidence rate of lung cancer surgery in each year increased significantly (APC, 9.5; p < 0.05). The male-to-female ratio decreased from 2.1 to 1.6 (APC, -6.3; p < 0.05). The incidence increased in the age group of ≥ 70 years for both sexes (male: APC, 3.7; p < 0.05; female: APC, 5.96; p < 0.05). Furthermore, the proportion of female patients aged ≥ 65 years increased (APC, 7.2; p < 0.05), while that of male patients aged < 65 years decreased (APC, -3.9; p < 0.05). The proportions of segmentectomies (APC, 17.8; p < 0.05) and lobectomies (APC, 7.5; p < 0.05) increased, while the proportion of pneumonectomies decreased (APC, -6.3; p < 0.05). Finally, the proportion of patients undergoing surgery in Seoul increased (APC, 1.1; p < 0.05), while the proportion in other areas decreased (APC, -1.5; p < 0.05).

CONCLUSION

An increase in the use of lung cancer surgery in elderly patients and female patients, and a decrease in the proportion of patients requiring extensive pulmonary resection were identified. Furthermore, centralization of lung cancer surgery was noted.