Lymphatic drainage patterns of malignant skin tumors in the head and neck region: a single-center retrospective study.

BACKGROUND: This study aimed to clarify the relationship between primary site and lymphatic drainage pattern for malignant skin tumors in the head and neck region. Malignant melanoma and squamous cell carcinoma in the head and neck region are known to have poor prognosis because of lymph node metastasis. Nevertheless, numerous aspects of lymphatic drainage patterns remain elusive. METHODS: We statistically analyzed data of 47 patients with malignant skin tumors in the head and neck region. Information was collected on the patients' clinical characteristics, primary tumor site, and lymphatic drainage patterns. RESULTS: The parotid lymph nodes drained the greatest amount of lymph from skin tumors of the head and neck. Important lymphatic drainage pathways were the superficial cervical nodes for primary tumors in the buccal/nasal region, level IA and level IB nodes for primary tumors in the lip region, the occipital nodes, posterior auricular nodes, and level VA nodes in the parietal/occipital region, and the preauricular nodes in the auricular region. CONCLUSION: These findings have considerable significance in terms of understanding lymphatic drainage patterns for malignant skin tumors in the head and neck and may be useful for clinical decision-making and when planning treatment. Further research and clinical applications are expected to contribute to an improved prognosis in patients with cutaneous head and neck malignancies.

The Short- and Long-Term Surgical Results of Consecutive Hepatopancreaticoduodenectomy for Wide-Spread Biliary Malignancy.

BACKGROUND: Cancer-free resection (R0) is one of the most important factors for the long-term survival of biliary carcinoma. For some patients with widespread invasive cancer located between the hilar and intrapancreatic bile duct, hepatopancreaticoduodenectomy (HPD) is considered a radical surgery for R0 resection. However, HPD is associated with high morbidity and mortality rates. Furthermore, previous reports have not shown lymph node metastasis (LNM) status, such as the location or number, which could influence the prognosis after HPD. In this study, first, we explored the prognostic factors for survival, and second, we evaluated whether the LNM status (number and location of LNM) would influence the decision on surgical indications in patients with widely spread biliary malignancy. METHODS: We retrospectively reviewed the medical records of 54 patients who underwent HPD with hepatectomy in ≥2 liver sectors from January 2003 to December 2021 (HPD-G). We also evaluated 54 unresectable perihilar cholangiocarcinoma patients who underwent chemotherapy from January 2010 to December 2021 (CTx-G). RESULTS: R0 resection was performed in 48 patients (89%). The median survival time (MST) and 5-year overall survival rate of the HPD-G and CTx-G groups were 36.9 months and 31.1%, and 19.6 months and 0%, respectively. Univariate and multivariate analyses showed that pathological portal vein involvement was an independent prognostic factor for survival (MST: 18.9 months). Additionally, patients with peripancreatic LNM had worse prognoses (MST: 13.3 months) than CTx-G. CONCLUSIONS: Patients with peripancreatic LNM or PV invasion might be advised to be excluded from surgery-first indications for HPD.

Prevalence and associated metabolic factors of nonalcoholic fatty liver disease in the general population from 2014 to 2018 in Japan: A large-scale multicenter retrospective study.

AIM: The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing worldwide. The aim of this study was to determine the recent prevalence and clinical characteristics of NAFLD in Japan. METHODS: This study initially included 410 061 retrospectively enrolled adults from the medical health checkup registry for metabolic syndrome, chronic kidney disease, and fatty liver in Japan (MIRACLE-J; UMIN-CTR no. UMIN000049419), who were evaluated between 2014 and 2018 at 13 health centers in Japan. Individuals consuming >20 g of alcohol/day or with chronic liver disease were excluded. Fatty liver was diagnosed by ultrasonography. The probability of NAFLD with advanced fibrosis was estimated based on the fibrosis-4 index and NAFLD fibrosis score. RESULTS: A total of 71 254 participants were included in the final analysis. The overall prevalence of NAFLD was 25.8%. There was a significant, twofold difference in NAFLD prevalence between men (37.4%) and women (18.1%). Nonalcoholic fatty liver disease prevalence increased linearly with body mass index, triglycerides, and low-density lipoprotein cholesterol regardless of threshold values, even in the absence of obesity. Among patients with NAFLD, 14% had diabetes mellitus, 31% had hypertension, and 48% had dyslipidemia. The estimated prevalence of NAFLD with advanced fibrosis was 1.7% and 1.0% according to the fibrosis-4 index and NAFLD fibrosis score, respectively. CONCLUSIONS: The prevalence of NAFLD was approximately one-quarter of the general population in Japan. There was a linear relationship between NAFLD prevalence and various metabolic parameters, even in nonobese participants. The prevalence of NAFLD with advanced fibrosis was estimated to be 1%-2%.

Transcranial direct current stimulation to the left dorsolateral prefrontal cortex enhances early dexterity skills with the left non-dominant hand: a randomized controlled trial.

BACKGROUND: The left dorsolateral prefrontal cortex (DLPFC) is involved in early-phase manual dexterity skill acquisition when cognitive control processes, such as integration and complexity demands, are required. However, the effectiveness of left DLPFC transcranial direct current stimulation (tDCS) on early-phase motor learning and whether its effectiveness depends on the cognitive demand of the target task are unclear. This study aimed to investigate whether tDCS over the left DLPFC improves non-dominant hand dexterity performance and determine if its efficacy depends on the cognitive demand of the target task. METHODS: In this randomized, double-blind, sham-controlled trial, 70 healthy, right-handed, young adult participants were recruited. They were randomly allocated to the active tDCS (2 mA for 20 min) or sham groups and repeatedly performed the Purdue Pegboard Test (PPT) left-handed peg task and left-handed assembly task three times: pre-tDCS, during tDCS, and post tDCS. RESULTS: The final sample comprised 66 healthy young adults (mean age, 22.73 ± 1.57 years). There were significant interactions between group and time in both PPT tasks, indicating significantly higher performance of those in the active tDCS group than those in the sham group post tDCS (p < 0.001). Moreover, a greater benefit was observed in the left-handed assembly task performance than in the peg task performance (p < 0.001). No significant correlation between baseline performance and benefits from tDCS was observed in either task. CONCLUSIONS: These results demonstrated that prefrontal tDCS significantly improved early-phase manual dexterity skill acquisition, and its benefits were greater for the task with high cognitive demands. These findings contribute to a deeper understanding of the underlying neurophysiological mechanisms of the left DLPFC in the modulation of early-phase dexterity skill acquisition. TRIAL REGISTRATION: This study was registered in the University Hospital Medical Information Network Clinical Trial Registry in Japan (UMIN000046868), Registered February 8, 2022 https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000053467.

Impact of correlations between prioritized outcomes on the net benefit and its estimate by generalized pairwise comparisons.

Benefit-risk balance is gaining interest in clinical trials. For the comprehensive assessment of benefits and risks, generalized pairwise comparisons are increasingly used to estimate the net benefit based on multiple prioritized outcomes. Although previous research has demonstrated that the correlations between the outcomes impact the net benefit and its estimate, the direction and magnitude of this impact remain unclear. In this study, we investigated the impact of correlations between two binary or Gaussian variables on the true net benefit values via theoretical and numerical analyses. We also explored the impact of correlations between survival and categorical variables on the net benefit estimates based on four existing methods (Gehan, Péron, Gehan with correction, and Péron with correction) in the presence of right censoring via simulation and application to actual oncology clinical trial data. Our theoretical and numerical analyses revealed that the true net benefit values were impacted by the correlations in various directions depending on the outcome distributions. With binary endpoints, this direction was governed by a simple rule with a threshold of 50% for a favorable outcome. Our simulation showed that the net benefit estimates based on Gehan's or Péron's scoring rule could be substantially biased in the presence of right censoring, and that the direction and magnitude of this bias were associated with the outcome correlations. The recently proposed correction method greatly reduced this bias, even in the presence of strong outcome correlations. The impact of correlations should be carefully considered when interpreting the net benefit and its estimate.

A simulation study of regression approaches for estimating risk ratios in the presence of multiple confounders.

BACKGROUND: Risk ratio is a popular effect measure in epidemiological research. Although previous research has suggested that logistic regression may provide biased odds ratio estimates when the number of events is small and there are multiple confounders, the performance of risk ratio estimation has yet to be examined in the presence of multiple confounders. METHODS: We conducted a simulation study to evaluate the statistical performance of three regression approaches for estimating risk ratios: (1) risk ratio interpretation of logistic regression coefficients, (2) modified Poisson regression, and (3) regression standardization using logistic regression. We simulated 270 scenarios with systematically varied sample size, the number of binary confounders, exposure proportion, risk ratio, and outcome proportion. Performance evaluation was based on convergence proportion, bias, standard error estimation, and confidence interval coverage. RESULTS: With a sample size of 2500 and an outcome proportion of 1%, both logistic regression and modified Poisson regression at times failed to converge, and the three approaches were comparably biased. As the outcome proportion or sample size increased, modified Poisson regression and regression standardization yielded unbiased risk ratio estimates with appropriate confidence intervals irrespective of the number of confounders. The risk ratio interpretation of logistic regression coefficients, by contrast, became substantially biased as the outcome proportion increased. CONCLUSIONS: Regression approaches for estimating risk ratios should be cautiously used when the number of events is small. With an adequate number of events, risk ratios are validly estimated by modified Poisson regression and regression standardization, irrespective of the number of confounders.