The associations of herpes simplex virus and varicella zoster virus infection with dementia: a nationwide retrospective cohort study.

BACKGROUND: In this study, the risk of dementia in patients with a history of herpes simplex virus (HSV) or varicella zoster virus (VZV) infection was evaluated. METHODS: This nationwide cohort study used data from the Korean National Health Insurance Service collected between 2006 and 2017. A total of 752,205 subjects ≥ 45 years of age not diagnosed with dementia until 2006 were included. A multivariate Cox regression model, adjusted for age, sex, and other comorbidities, was used to assess the hazard ratio (HR) for dementia based on VZV or HSV infection. The interaction effects of both viral infections were analysed. Viral infections are classified into four categories: eye, central nervous system (CNS), simple, and complicated. The hazard ratio (HR) of viral infection was analysed based on the type of dementia. RESULTS: In multivariable analysis, both HSV and VZV infection were associated with an increased risk of dementia (HR = 1.38, 95% confidence interval, CI:1.33-1.43) and (HR = 1.41, 95% CI:1.37-1.46), respectively. Patients who experienced both HSV and VZV infections were also at an increased risk of dementia (HR = 1.57, 95% CI:1.50-1.63). The co-infection group showed the shortest time from viral infection to dementia diagnosis (4.09 ± 3.02 years). In the subgroup analysis, all types of HSV and VZV infections were associated with an increased risk of dementia compared to the non-infection group. The eye, CNS, and complicated VZV infections were associated with a significantly higher risk than simple VZV infections. There were no significant differences between the subtypes of HSV infection. Furthermore, HSV, VSV, and co-infection were associated with an increased risk of all dementia types, including Alzheimer's disease (AD) and vascular dementia (VD). CONCLUSIONS: Individual HSV and VZV infections were associated with an increased risk of all types of dementia, including AD and VD. Patients co-infected with HSV and VZV, VZV infection in the eye, CNS, or complicated type were more vulnerable to the development of dementia.

Totally Thoracoscopic Ablation in Patients With Recurrent Atrial Fibrillation After Catheter Ablation.

BACKGROUND: The objective of this study was to evaluate the efficacy and safety of totally thoracoscopic ablation (TTA) in patients with recurrent atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). METHODS: From February 2012 to May 2020, 460 patients who underwent TTA were classified into two groups: CA (presence of RFCA history, n = 74) and nCA groups (absence of RFCA history, n = 386). Inverse probability of treatment weighting (IPTW) analyses were used to adjust for confounders. The primary endpoint was freedom from the composite of AF, typical atrial flutter, atypical atrial flutter and any atrial tachyarrhythmia, lasting more than 30 seconds during the follow-up. All patients were followed up at 3, 6, and 12 months via electrocardiogram and 24-hour Holter monitoring. RESULTS: Bilateral pulmonary vein isolation (PVI) was conducted in all patients and the conduction block tests were confirmed. In the CA group, difficult PVI occasionally occurred due to structural changes, such as pericardial adhesion and fibrosis of the pulmonary venous structure, caused by a previous catheter ablation. Early complications such as stroke and pacemaker insertion were not different between the two groups. The normal sinus rhythm was maintained in 70.1% (317/460) patients after a median follow-up period of 38.1 months. The IPTW-weighted Kaplan-Meier curves revealed that freedom from AF events at 5 years was 68.4% (95% confidence interval, 62.8-74.5) in the nCA group and 31.2% (95% confidence interval, 16.9-57.5) in the CA group (P < 0.001). In IPTW-weighted Cox regression, preoperative left atrial diameter, persistent or long-standing AF, the presence of congestive heart failure and catheter ablation history were associated with AF events. CONCLUSION: Patients in the CA group showed a higher recurrence rate of AF than those in the nCA group, while TTA was safely performed in both the groups.

Trends in Survival Rates of Non-Small Cell Lung Cancer With Use of Molecular Testing and Targeted Therapy in Korea, 2010-2020.

Importance: Over the past 10 years, treatment of non-small cell lung cancer (NSCLC) has been continually revolutionized. However, standard clinical trials may not reflect current multiple lines of treatment and corresponding outcomes in a timely manner. Objective: To investigate outcomes associated with new treatment of NSCLC in a clinical setting. Design, Setting, and Participants: This cohort study included patients with NSCLC between January 1, 2010, and November 30, 2020, who received any anticancer treatment at Samsung Medical Center in Korea. Data were analyzed from November 2021 through February 2022. Exposures: Clinical and pathological stage, histology, and major druggable sequence variation, including epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), ROS1, RET, MET exon 14 skipping, BRAF V600E, KRAS G12C, and NTRK between 2 periods (period I: 2010-2015 vs period II: 2016-2020). Main Outcomes and Measures: The primary outcome was the 3-year survival rate of NSCLC. Secondary outcomes included median overall survival, progression-free survival, and recurrence-free survival. Results: Among 21 978 patients with NSCLC (median [range] age at diagnosis, 64.1 [57.0-71.0] years; 13 624 males [62.0%]), there were 10 110 patients in period I and 11 868 patients in period II; adenocarcinoma (AD) was the predominant histology (7112 patients [70.3%] in period I and 8813 patients [74.3%] in period II). There were 4224 never smokers [41.8%] in period I and 5292 never smokers [44.6%] in period II. Compared with patients in period I, patients during period II were more likely to undergo molecular tests in the AD (5678 patients [79.8%] vs 8631 patients [97.9%]) and non-AD (1612 of 2998 patients [53.8%] and 2719 of 3055 patients [89.0%]) groups. In patients with AD in period I, 3-year survival rates were 92.8% (95% CI, 91.8%-93.7%), 72.4% (95% CI, 68.3%-76.8%), 56.7% (95% CI, 53.4%-60.2%), and 28.7% (95% CI, 27.0%-30.4%) for stage I, II, III, and IV, respectively. In period II, 3-year survival rates of patients with AD were 95.1% (95% CI, 94.4%-95.9%), 82.5% (95% CI, 79.1%-86.1%), 65.1% (95% CI, 61.8%-68.6%), and 42.4% (95% CI, 40.3%-44.7%) for each stage, respectively. In patients without AD, 3-year survival rates were 72.0% (95% CI, 68.8%-75.3%), 60.0% (95% CI, 56.2%-64.1%), 38.9% (95% CI, 35.6%-42.5%), and 9.7% (95% CI, 7.9%-12.1%) for each stage in period I. In period II, the 3-year survival rates of patients without AD were 79.3% (95% CI, 76.3%-82.4%), 67.3% (95% CI, 62.8%-72.1%), 48.2% (95% CI, 44.5%-52.3%), and 18.1% (95% CI, 15.1%-21.6%) for each stage. Conclusions and Relevance: In this cohort study of 10 years of clinical data, survival outcomes were improved across all stages, with larger increases in patients with stage III to IV disease. The incidence of never-smokers and the use of molecular testing increased.

Added Value of Pelvic CT after Treatment of HCC.

Background In patients with hepatocellular carcinoma (HCC) who undergo follow-up with CT after treatment, the benefit of routinely including pelvic coverage is not well substantiated. Purpose To investigate the added value of pelvic coverage at follow-up liver CT in detecting pelvic metastasis or incidental tumors in patients treated for HCC. Materials and Methods This retrospective study included patients who were diagnosed with HCC between January 2016 and December 2017 and followed up with liver CT after treatment. Cumulative rates of extrahepatic metastasis, isolated pelvic metastasis, and incidental pelvic tumor were estimated by using the Kaplan-Meier method. Cox proportional hazard models were used to identify risk factors for extrahepatic and isolated pelvic metastases. Radiation dose from pelvic coverage was also calculated. Results A total of 1122 patients (mean age, 60 years ± 10 [SD]; 896 men) were included. The cumulative rates at 3 years of extrahepatic metastasis, isolated pelvic metastasis, and incidental pelvic tumor were 14.4%, 1.4%, and 0.5%, respectively. At adjusted analysis, protein induced by vitamin K absence or antagonist-II (P = .001), size of the largest tumor (P = .02), T stage (P = .008), and initial treatment method (P < .001) were associated with extrahepatic metastasis. Only T stage was associated with isolated pelvic metastasis (P = .01). Because of pelvic coverage, the radiation dose increased by 29% and 39% in liver CT with and without contrast enhancement, respectively, compared with CT scans without pelvic coverage. Conclusion The incidence of isolated pelvic metastasis or incidental pelvic tumor was low in patients treated for hepatocellular carcinoma. © RSNA, 2023.

An ensemble method based on marginal-effect models (EMM) for estimating usual food intake from single-day dietary data and internal/external two-day dietary data.

BACKGROUND: With collection of repeated 24-hour recalls, there exist challenges in usual intake estimation, including infeasibility of multiple dietary assessments, and shortage of non-zero intakes for episodically consumed foods. OBJECTIVES: We developed an ensemble method based on marginal-effect models (EMM), which estimates usual intake distribution using single-day data with internal or external two-day data. METHODS: The performance of the EMM was evaluated and compared with the National Cancer Institute (NCI) method and NCI 1-d method, via simulations with various scenarios and real data analyses of red meat, fish, and protein from Korea National Health and Nutrition Examination Survey (KNHANES). RESULTS: Simulations indicated the EMM (maximum bias of 1.67, 3.17, 8.57, 11.63 for average, median, 75%-tile, 95%-tile, respectively) provided more accurate estimation than the NCI method (maximum bias of 4.18, 9.43, 7.56, 37.43) across various scenarios on intake probability and within-person variation. The EMM showed robust estimation when an insufficient number of people have positive consumption on two days. In simulations with various external variance ratios, the EMM showed similar or superior performance to the NCI 1-d method. The EMM produced more stable estimates of usual intake distributions for red meat, fish, and protein than the two NCI methods. CONCLUSION: The proposed EMM showed substantial improvement over the NCI methods when data contain a relatively small number of people with positive consumption on two days; is robust when food intake probability is very low or high; and estimates an external variance ratio with relatively low bias.

Durvalumab with chemoradiotherapy for limited-stage small-cell lung cancer.

BACKGROUND: The current standard treatment for limited-stage small-cell lung cancer (LS-SCLC) is chemotherapy with concurrent chemoradiotherapy (CCRT). METHODS: In this single-arm phase II study, patients with LS-SCLC received four cycles of etoposide, cisplatin, and durvalumab every 3 weeks. Thoracic radiotherapy of 52.5 Gy in 25 once-daily fractions was started with the third cycle of chemoimmunotherapy. After CCRT plus durvalumab, patients received durvalumab consolidation therapy every 4 weeks for a maximum of 2 years after study enrolment. Prophylactic cranial irradiation (PCI) was recommended. RESULTS: Fifty-one patients were enrolled, and 50 were included in the full analysis set. With the median follow-up duration of 26.6 months, the median PFS was 14.4 months (95% confidence interval: 10.3-NA), and the 24-month PFS rate was 42.0%. The median overall survival was not reached with a 24-month overall survival rate of 67.8%. The positive PD-L1 group (n = 22) was not associated with longer PFS (hazard ratio, 0.70; 0.31-1.58) and overall survival (0.64; 0.22-1.84) compared with the negative PD-L1 group (n = 20). Among the 43 patients who were candidates for PCI treatment, the PCI group (n = 22) had significantly fewer events of brain metastasis as the first failure sites compared to the no PCI group (n = 21) (13.6% vs. 42.9%, P = 0.033). There were several grade 3 or 4 adverse events which were well managed with appropriate supportive care. CONCLUSIONS: Durvalumab with CCRT for LS-SCLC exhibited promising clinical efficacy with a tolerable safety profile, prompting its validation in a randomized study. TRIAL REGISTRATION: NCT03585998.

Durvalumab and tremelimumab with definitive chemoradiotherapy for locally advanced esophageal squamous cell carcinoma.

BACKGROUND: The current standard treatment for patients with inoperable, locally advanced esophageal squamous cell carcinoma (ESCC) is definitive concurrent chemoradiotherapy (CCRT). METHODS: Patients with locally advanced ESCC received 2 cycles of 5-fluorouracil, cisplatin, durvalumab, and tremelimumab every 3 weeks with concurrent radiation therapy (60.2 or 64.5 grays). After completing CCRT plus immunotherapy, patients received 2 cycles of consolidative durvalumab and tremelimumab followed by durvalumab monotherapy every 4 weeks for 2 years after enrollment. Their survival outcomes were compared with those from a propensity score-matched historical control group that had received CCRT alone. RESULTS: In total, 40 patients were enrolled and analyzed. The 24-month progression-free survival (PFS) and overall survival rates were 57.5% and 75%, respectively. Compared with the historical control group (n = 75), the study population had significantly longer PFS (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.28-0.97; P = .040) and overall survival (HR, 0.49; 95% CI, 0.25-0.98; P = .043). In the study population, patients who had PD-L1-positive tumors (n = 28) had significantly longer PFS (HR, 0.20; 95% CI, 0.07-0.54; P < .001) and overall survival (HR, 0.16; 95% CI, 0.05-0.56; P = .001) compared with those who had PD-L1-negative tumors (n = 11). However, there was no difference in survival outcomes according to PD-L1 status in the historical control group, indicating a strong interaction between PD-L1-positive status and survival outcomes in the treatment groups (PFS, P for interaction = .003; overall survival, P for interaction = .002). CONCLUSIONS: Durvalumab and tremelimumab with definitive CCRT had promising efficacy in patients with locally advanced ESCC. In addition, PD-L1 expression had strong predictive value in the study population.

Incidence and Characteristics of Intraocular Lens Dislocation after Phacoemulsification: An Eight-Year, Nationwide, Population-Based Study.

BACKGROUND: We investigate the incidence and characteristics of IOL dislocation among the pseudophakic population after phacoemulsification. METHODS: National data were collected from the health claims recorded with the Health Insurance Review and Assessment Service of South Korea from 2009 to 2016. Pseudophakic patients aged 40 years or older were included. The incidence estimates of phacoemulsification and IOL dislocation were analyzed, and the cumulative probabilities of IOL dislocation among the pseudophakic population and general population were calculated as a proportion. RESULTS: Of 51,307,821 total subjects, 25,271,917 of whom were aged 40 years or older, 3,906,071 cataract cases in 2,650,104 pseudophakic patients were identified, and 72,309 patients experienced IOL dislocation. The cumulative probability was 2.73% per person and 1.85% per surgery among patients 40 years of age or older. The eight-year incidence rate for IOL dislocation in the pseudophakic population aged 40 years or older was 7671 per 1,000,000 person-years (95% CI: 7616-7727), including 10,341 cases in men and 5814 in women. Incidence peaked in the seventh decade of life for cataract surgery but in the fifth decade of life for IOL dislocation. The cumulative probability of IOL dislocation after phacoemulsification was approximately 2%, and the incidence rate was about 7000 per 1,000,000 pseudophakic patients. CONCLUSIONS: There was a significantly higher incidence of IOL dislocation among young males, even though the higher incidence of cataract surgery was observed among older females. These estimates of the nationwide, population-based incidence of IOL dislocation can help increase understanding of the population vulnerable to IOL dislocation.

Visual impairment increases the risk of dementia, especially in young males in a 12-year longitudinal follow-up study of a national cohort.

We investigated the effect of visual impairment (VI) on dementia development in a national cohort. In this 12-year nationwide population-based retrospective cohort study, national data were collected from National Health Insurance Cooperation of South Korea from 2002 to 2017, comprising 799,074 subjects selected from the dementia-free cohort representative of the Korean population. Crude hazard ratios (HRs) as well as age- and sex-adjusted HRs and confidence intervals (CIs) for the development of dementia were estimated using multivariable Cox regression models. VI significantly increased the risk of dementia with a HR of 2.726 (95% CI 2.251-3.300, p < 0.0001) after adjusting for age, sex, and interaction between age, sex, and VI. HR of interaction between VI and age for dementia was 0.539 (95% CI 0.436-0.667, p < 0.0001). In the sensitivity analysis after adjustment for age, sex, household income level, BMI and other comorbidities, VI showed higher risk for all the type of dementia (p < 0.0001). In subgroup analysis of VI, young males showed the highest risk for development of dementia with a HR of 2.687 (95% CI 2.219-3.254, p < 0.0001). VI significantly increased the risk of dementia in the study cohort, and young males with VI appeared to be the most susceptible to the development of dementia.

Risk Factors for Intraocular Lens Dislocation After Phacoemulsification: A Nationwide Population-Based Cohort Study.

PURPOSE: Few studies have measured the incidence and risk factors of intraocular lens (IOL) dislocation in the total population. We investigate the risk factors for IOL dislocation in a nationwide Korean cohort. DESIGN: Retrospective cohort study. METHODS: National data on 2,162,191 subjects who underwent cataract surgery were collected from the Health Insurance Review and Assessment service database of health claims from 2009 to 2016. The Health Insurance Review and Assessment database was used to identify potential risk factors for IOL dislocation, including age, sex, and various pre- and postoperative ophthalmic conditions. The hazard ratios (HRs) and confidence intervals (CIs) of these risk factors were assessed with a multivariable-adjusted Cox regression model. RESULTS: IOL dislocation occurred in 15,170 patients (0.7%) in the cataract surgery cohort (2,162,191 patients). The incidence rate of IOL dislocation peaked at 40-50 years of age, although the mean age of IOL dislocation was 65.25 ± 10.81 years. The average male:female ratio was 1.8. The adjusted HR for IOL dislocation in patients with partial vitrectomy was 11.93 (95% CI 10.95-12.99; P < .0001). Posterior capsulotomy performed within 1 year after the cataract surgery significantly decreased IOL dislocation, with an adjusted HR of 0.48 (95% CI 0.44-0.51; P < .0001). CONCLUSIONS: IOL dislocation tended to occur in young males. Anterior vitrectomy was a significant risk factor for IOL dislocation, while posterior capsulotomy after surgery was associated with a decreased risk of IOL dislocation.

Use of cyclooxygenase inhibitor and the risk of hepatocellular carcinoma in patients with chronic hepatitis B: A nested case-control study using a nationwide population-based data.

The study aimed to investigate the relationship between the use of COX inhibitors and the risk of hepatocellular carcinoma (HCC) development in patients with chronic hepatitis B (CHB) using a nationwide population-based data. A nested case-control study was conducted using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) from 2002 to 2013 in Korea. We compared the use of COX inhibitors between HCC cases and matched controls by categorizing 5 groups according to the cumulative defined daily dose (cDDD, <28, 28-90, 91-180, 181-360, and >360) adjusting the use of antiviral agents. A total of 4980 patients with CHB were analysed as 996 HCC cases and 3984 matched controls. The number of COX inhibitor users (≥28 cDDD) was 358 patients (36%) and 1814 patients (45%) in the HCC group and control group, respectively. The use of COX inhibitors was significantly associated with a decreased risk of HCC development compared with nonusers (adjusted odds ratio [OR] 0.62, 95% confidence interval [CI] 0.52-0.73, P < .001). There was a dose-dependent inverse relationship between the use of COX inhibitors and the risk of HCC. The adjusted ORs were 0.75 (95% CI: 0.63-0.90), 0.41 (95% CI: 0.31-0.56), 0.38 (95% CI: 0.25-0.57) and 0.49 (95% CI: 0.31-0.79) for the 28-90, 91-180, 181-360 and >360 cDDDs, respectively (P < .01). In conclusion, the use of COX inhibitors was associated with a reduced risk of HCC in CHB. COX inhibitor may have a chemopreventive role in HCC development in patients with chronic liver disease.

K-Sample comparisons using propensity analysis.

In this paper, we investigate K-group comparisons on survival endpoints for observational studies. In clinical databases for observational studies, treatment for patients are chosen with probabilities varying depending on their baseline characteristics. This often results in noncomparable treatment groups because of imbalance in baseline characteristics of patients among treatment groups. In order to overcome this issue, we conduct propensity analysis and match the subjects with similar propensity scores across treatment groups or compare weighted group means (or weighted survival curves for censored outcome variables) using the inverse probability weighting (IPW). To this end, multinomial logistic regression has been a popular propensity analysis method to estimate the weights. We propose to use decision tree method as an alternative propensity analysis due to its simplicity and robustness. We also propose IPW rank statistics, called Dunnett-type test and ANOVA-type test, to compare 3 or more treatment groups on survival endpoints. Using simulations, we evaluate the finite sample performance of the weighted rank statistics combined with these propensity analysis methods. We demonstrate these methods with a real data example. The IPW method also allows us for unbiased estimation of population parameters of each treatment group. In this paper, we limit our discussions to survival outcomes, but all the methods can be easily modified for any type of outcomes, such as binary or continuous variables.

Iodized Oil Transarterial Chemoembolization and Radiofrequency Ablation for Small Periportal Hepatocellular Carcinoma: Comparison with Nonperiportal Hepatocellular Carcinoma.

PURPOSE: This study aims to evaluate the treatment outcomes of iodized oil transarterial chemoembolization (TACE) and subsequent radiofrequency ablation (RFA) for small (≤3 cm) periportal hepatocellular carcinoma (HCC) compared with nonperiportal HCC. METHODS: Twenty-three patients [periportal group (PG); mean age, 59.8 years; 22 men, 1 woman] with periportal HCC (in contact with the portal vein >3 mm in diameter) and 279 patients [nonperiportal group (NPG); mean age, 59.1 years; 234 men, 45 women] with nonperiportal HCC were treated between March 2010 and January 2014. All cases were contraindicated for ultrasound-guided RFA or resection. Mean tumor size was 1.2 cm in each group. The baseline characteristics were not different between the groups, except for alpha-fetoprotein level (41.0 ng/dL in NPG vs. 8.8 ng/dL in PG, p = 0.001). Local tumor progression (LTP), disease-free survival (DFS), overall survival (OS), intrasegmental recurrence, and complications were analyzed using the Kaplan-Meier method and Fisher's exact test. RESULTS: TACE and RFA were successfully performed in all patients. Mean follow-up period of PG and NPG was 33.8 and 42.8 months, respectively. LTP (p = 0.701), DFS (p = 0.718), and OS (p = 0.359) were not different between the two groups. Intrasegmental recurrence occurred in two patients (one in each group), and its incidence was not different (p = 0.212). Complications requiring further treatment occurred in 1/23 (4.3%) in PG and 5/279 (1.8%) in NPG. No procedure-related mortality occurred. CONCLUSIONS: Iodized oil TACE and subsequent RFA are effective alternative treatments for small periportal HCC (≤3 cm) when percutaneous ultrasound- or CT-guided RFA or resection is not feasible.

Predictive Model for Neoplastic Potential of Gallbladder Polyp.

GOAL: To provide the statistical predictive model for neoplastic potential of gallbladder polyp (GBP). BACKGROUND: Many studies have attempted to define the risk factors for neoplastic potential of GBP. It remains difficult to precisely adapt the reported risk factors for the decision of surgery. Estimating the probability for neoplastic potential of GBP using a combination of several risk factors before surgical resection would be useful in patient consultation. STUDY: We collected data of patients confirmed as GBP through cholecystectomy at Samsung Medical Center between January 1997 and March 2015. Those with a definite evidence for malignancy, such as adjacent organ invasion, metastasis on preoperative imaging studies, polyp >15 mm, and absence of proper preoperative ultrasonographic imaging were excluded. A total of 1976 patients were enrolled. To make and validate the predictive model, we divided the cohort into the modeling group (n=979) and validation group (n=997). Clinical information, ultrasonographic findings, and blood tests were retrospectively analyzed. RESULTS: Clinical factors of older age, single lesion, sessile shape, and polyp size showed statistical significance for neoplastic potential of GBP in the modeling group. A predictive model for neoplastic potential of GBP was constructed utilizing the statistical outcome of the modeling group. Statistical validation was performed with the validation group to determine the optimal clinical sensitivity and specificity of the predictive model. Optimal cut-off value for neoplastic probability was 7.4%. CONCLUSIONS: The predictive model for neoplastic potential of GBP may support clinical decisions before cholecystectomy.

Patterns of Initial Recurrence in Completely Resected Papillary Thyroid Carcinoma.

BACKGROUND: Despite improvements in the surgical and medical treatment of papillary thyroid carcinoma (PTC), subsets of patients suffer from structural recurrence after initial treatment. This study evaluated the timing and patterns of recurrence in completely resected PTC patients. METHODS: A retrospective review of a prospectively maintained thyroid cancer database was performed. The timing and patterns of recurrence were reviewed in 2250 patients with PTC >1 cm who achieved complete remission after total thyroidectomy and/or radioactive iodine treatment. Univariate and multivariate analyses were performed to identify factors predictive of recurrence patterns. RESULTS: During 8.1 years of mean follow-up, 68 (3.0%) patients developed structural recurrences: 53 lymph node recurrences (LNR), 11 local soft tissue recurrences (LR), and four distant recurrences (DR). Two patients died of DR. Younger patients had a higher proportion of LNR, and older patients had a tendency toward LR/DR. LNR showed a peak incidence between one and three years after remission, but LR/DR showed a delayed peak incidence between two and four years. The factors that significantly increased the risk of LNR were multifocal tumor and lymph node metastasis (central/lateral). The factors that increased the risk of LR/DR were old age, large tumor size (>2 cm), and lateral lymph node metastasis. In addition, central neck dissection significantly reduced subsequent LR/DR. CONCLUSION: Patterns of recurrence after complete PTC resection are variable and associated with specific clinicopathologic factors. Understanding the timing and patterns of recurrence may lead to more effective adjuvant treatment and improved long-term follow-up strategies.