Background:The current World Health Organization (WHO) classiifcation of nasopharyngeal carcinoma (NPC) con?veys little prognostic information. This study aimed to propose an NPC histopathologic classiifcation that can poten?tially be used to predict prognosis and treatment response. Methods:We initially developed a histopathologic classiifcation based on the morphologic traits and cell differentia?tion of tumors of 2716 NPC patients who were identiifed at Sun Yat?sen University Cancer Center (SYSUCC) (training cohort). Then, the proposed classiifcation was applied to 1702 patients (retrospective validation cohort) from hospitals outside SYSUCC and 1613 patients (prospective validation cohort) from SYSUCC. The effcacy of radiochemotherapy and radiotherapy modalities was compared between the proposed subtypes. We used Cox proportional hazards models to estimate hazard ratios (HRs) with 95% conifdence intervals (CI) for overall survival (OS). Results:The 5?year OS rates for all NPC patients who were diagnosed with epithelial carcinoma (EC; 3708 patients), mixed sarcomatoid?epithelial carcinoma (MSEC; 1247 patients), sarcomatoid carcinoma (SC; 823 patients), and squamous cell carcinoma (SCC; 253 patients) were 79.4%, 70.5%, 59.6%, and 42.6%, respectively (P<0.001). In mul?tivariate models, patients with MSEC had a shorter OS than patients with EC (HR=1.44, 95% CI=1.27–1.62), SC (HR=2.00, 95% CI=1.76–2.28), or SCC (HR=4.23, 95% CI=3.34–5.38). Radiochemotherapy signiifcantly improved survival compared with radiotherapy alone for patients with EC (HR=0.67, 95% CI=0.56–0.80), MSEC (HR=0.58, 95% CI=0.49–0.75), and possibly for those with SCC (HR=0.63; 95% CI=0.40–0.98), but not for patients with SC (HR=0.97, 95% CI=0.74–1.28). Conclusions:The proposed classiifcation offers more information for the prediction of NPC prognosis compared with the WHO classiifcation and might be a valuable tool to guide treatment decisions for subtypes that are associ?ated with a poor prognosis.

Objective To investigate the epidemiological characteristics and spatial distribution characteristics of Clonorchis sinensis human infections in Guangdong Province from 2016 to 2022, so as to provide insights into formulation of the clonorchiasis control measures in the province. Methods Xinhui District of Jiangmen City, Longmen County of Huizhou City and Wengyuan County of Shaoguan City in Guangdong Province were selected as fixed surveillance sites for human clonorchiasis from 2016 to 2022, and additional 10% to 15% counties (districts) endemic for clonorchiasis were sampled from Guangdong Province as mobile surveillance sites each year from 2016 to 2022. A village (community) was randomly selected from each surveillance site according to the geographical orientations of east, west, south, north and middle, and subjects were randomly sampled from each village (community). C. sinensis eggs were detected in subjects’ stool samples using the Kato-Katz technique, and the prevalence and intensity of C. sinensis infections were calculated. In addition, subjects’ gender, age, ethnicity, educational level and occupation were collected. The Guangdong Provincial 1:1 million electronic map in vector format was downloaded from the National Geomatics Center of China, and kernel density analysis and spatial autocorrelation analysis of C. sinensis human infections in Guangdong Province from 2016 to 2022 were performed using the software ArcGIS 10.7. Results A total of 153 188 residents were tested for C. sinensis infections in Guangdong Province from 2016 to 2022, including 75 596 men (49.35%) and 77 592 women (50.65%), and there were 5 369 residents infected with C. sinensis, with 3.50% overall prevalence of infections. The prevalence rates of severe, moderate and mild C. sinensis infections were 0.76%, 7.26% and 91.97% among C. sinensis-infected residents in Guangdong Province from 2016 to 2022, and there were age-, gender-, ethnicity-, occupation- and educational level-specific prevalence of C. sinensis human infections (χ² = 2 578.31, 637.33, 52.22, 2 893.28 and 1 139.33, all P values < 0.05). Global spatial autocorrelation analysis showed a cluster in the prevalence of C. sinensis human infections in Guangdong Province (Moran’s I = 0.63, Z = 27.31, P < 0.05). Kernel density analysis showed that the prevalence of C. sinensis human infections with a high kernel density in Guangdong Province was mainly distributed along the Zhujiang River basin in Pearl River Delta areas, followed by in eastern and northern Guangdong Province. In addition, local spatial autocorrelation analysis identified 73 high-high clusters of the prevalence of C. sinensis human infections in Guangdong Province. Conclusions The prevalence of C. sinensis human infections was high in Guangdong Province from 2016 to 2022, and mild infection was predominant among all clonorchiasis cases, with spatial clusters identified in the prevalence of C. sinensis human infections. Targeted clonorchiasis control measures are required among high-risk populations and areas.