[Purpose]To analyze the epidemiology and disease burden of gastric cancer in China,Japan and Republic of Korea from 1990 to 2021 and to predict changing trends from 2022 to 2031.[Methods]Data were obtained from the Global Burden of Disease(GBD)database.Age-stan-dardized incidence rate(ASIR),age-standardized mortality rate(ASMR),crude incidence rate(CIR),crude mortality rate(CMR),and disability-adjusted life years(DALY)rate for China,Japan and Republic of Korea from 1990 to 2021 were analyzed.Joinpoint regression software was used to analyze trends and calculate annual percentage changes.The autoregressive integrated moving average(ARIMA)model was applied to predict incidence and mortality from 2022 to 2031.[Results]In 2021,China had 611 799 new gastric cancer cases and 445 013 deaths,with an ASIR of 29.05/105 and an ASMR of 21.51/105,both significantly higher than those in Japan and Republic of Korea.Among men in China,both the ASIR(44.48/105)and ASMR(32.61/105)were the highest among the three countries,exceeding those in Japan(38.77/105,20.26/105)and Re-public of Korea(38.98/105,20.50/105).Among women,China had the highest number of new cases,but its ASIR(15.23/105)was slightly lower than Republic of Korea's(15.57/105)and higher than Japan's(14.66/105).However,China's ASMR among women(12.02/105)remained significantly higher than Japan's(7.64/105)and Republic of Korea's(8.08/105).From 1990 to 2021,ASIR,ASMR and DALY rates for gastric cancer declined in all three countries,but the reduction in China was significantly smaller than that in Japan and Republic of Korea,with Republic of Korea showing the steepest declines across all indicators.ARIMA model predictions indicated significant differences in disease burden among the three countries from 2022 to 2031.ASIR is projected to continue declining in China and Republic of Korea,reaching 22.87/105 and 12.45/105,respectively by 2031,while in Japan it is predicted to rise to 26.55/105.ASMR is projected to decline in all three countries,reaching 13.71/105(China),10.44/105(Japan),and 9.08/105(Republic of Korea)in 2031.[Conclusion]Among China,Japan and Republic of Korea,China had the highest ASIR and ASMR of gastric cancer in 2021.Moreover,from 1990 to 2021,the reductions in ASIR,ASMR and DALY rates for gastric cancer were the smallest in China compared to Japan and Republic of Korea.These findings suggest that the disease burden of gastric cancer remains substantial in China,high-lighting the need for increased efforts in gastric cancer screening and early diagnosis and treatment.

[Purpose]To analyze the epidemiology and disease burden of gastric cancer in China,Japan and Republic of Korea from 1990 to 2021 and to predict changing trends from 2022 to 2031.[Methods]Data were obtained from the Global Burden of Disease(GBD)database.Age-stan-dardized incidence rate(ASIR),age-standardized mortality rate(ASMR),crude incidence rate(CIR),crude mortality rate(CMR),and disability-adjusted life years(DALY)rate for China,Japan and Republic of Korea from 1990 to 2021 were analyzed.Joinpoint regression software was used to analyze trends and calculate annual percentage changes.The autoregressive integrated moving average(ARIMA)model was applied to predict incidence and mortality from 2022 to 2031.[Results]In 2021,China had 611 799 new gastric cancer cases and 445 013 deaths,with an ASIR of 29.05/105 and an ASMR of 21.51/105,both significantly higher than those in Japan and Republic of Korea.Among men in China,both the ASIR(44.48/105)and ASMR(32.61/105)were the highest among the three countries,exceeding those in Japan(38.77/105,20.26/105)and Re-public of Korea(38.98/105,20.50/105).Among women,China had the highest number of new cases,but its ASIR(15.23/105)was slightly lower than Republic of Korea's(15.57/105)and higher than Japan's(14.66/105).However,China's ASMR among women(12.02/105)remained significantly higher than Japan's(7.64/105)and Republic of Korea's(8.08/105).From 1990 to 2021,ASIR,ASMR and DALY rates for gastric cancer declined in all three countries,but the reduction in China was significantly smaller than that in Japan and Republic of Korea,with Republic of Korea showing the steepest declines across all indicators.ARIMA model predictions indicated significant differences in disease burden among the three countries from 2022 to 2031.ASIR is projected to continue declining in China and Republic of Korea,reaching 22.87/105 and 12.45/105,respectively by 2031,while in Japan it is predicted to rise to 26.55/105.ASMR is projected to decline in all three countries,reaching 13.71/105(China),10.44/105(Japan),and 9.08/105(Republic of Korea)in 2031.[Conclusion]Among China,Japan and Republic of Korea,China had the highest ASIR and ASMR of gastric cancer in 2021.Moreover,from 1990 to 2021,the reductions in ASIR,ASMR and DALY rates for gastric cancer were the smallest in China compared to Japan and Republic of Korea.These findings suggest that the disease burden of gastric cancer remains substantial in China,high-lighting the need for increased efforts in gastric cancer screening and early diagnosis and treatment.

Objective To study the expression of kynureninase(KYNU)in pancreatic cancer tissue and its relationship with immune invasion and prognosis.Methods A total of 49 patients with resectable pancreatic cancer who underwent surgical treatment in Department of General Surgery,Wuxi Fifth People's Hospital from January 2019 to June 2021 were selected as the study subjects.All patients were diagnosed with resectable pancreatic cancer by pathology and imaging,and their TNM stagings of tumors were stages Ⅰ-Ⅲ,which received neoadjuvant therapy before surgery.Cancer tissue and corresponding paracancer tissue samples(≥4cm from the cancer focus)of all patients were collected.Immunohistochemical staining was used to detect the expression of KYNU protein in pancreatic cancer tissues and corresponding adjacent tissues,and the infiltration of CD8+TILs,CD103+TILs,CD68+TAMs,CD204+TAMs,and CD11c+DCs in cancer tissues.Real-time fluorescence quantitative PCR was used to detect the relative expression of KYNU mRNA.The relationship between KYNU mRNA expression and immune infiltration and prognosis was analyzed by Pearson correlation analysis,Kaplan Meier survival curve,and COX proportional hazards regression model.Results The positive rate of KYNU protein(77.6%)and mRNA expression(2.9±0.7)in pancreatic cancer tissues were higher than those in adjacent normal tissues(38.8%,0.8±0.5),and the differences were significant(χ2=15.138,t=17.088,all P<0.05).The infiltration number of CD8+TILs,CD103+TILs,CD68+TAMs,CD204+TAMs and CD11c+DCs in KYNU high expression group was higher than those in KYNU low expression group,and the differences were significant(t=2.533～5.806,all P<0.05).The expression of KYNU in pancreatic cancer was positively correlated with the invasion numbers of CD8+TILs,CD103+TILs,CD68+TAMs,CD204+TAMs and CD11c+DCs(r=0.514,0.502,0.319,0.415,0.438,all P<0.05).The cumulative OS and DFS of high KYNU expression group were lower than those of low KYNU expression group(20.0%vs 42.9%,14.3%vs 35.7%),and the differences were significant(Log Rank χ2=4.358,4.273,P = 0.039,0.042).Multivariate COX regression analysis showed that TNM stageⅢ(HR:1.653,95%CI:1.294～1.937),low differentiation(HR:1.671,95%CI:1.284～2.003),lymph node metastasis(HR:1.582,95%CI:1.117～1.896)and KYNU high expression(HR:1.591,95%CI:1.106～1.902)were independent risk factors for pancreatic cancer prognosis(all P<0.05).Conclusion KYNU was highly expressed in pancreatic cancer tissues,which was closely related to immune infiltration and clinical prognosis of pancreatic cancer.It may be a potential biomarker for predicting prognosis of pancreatic cancer.