BACKGROUND:A multicenter study on the DNA mismatch repair (MMR) genes enabled us to study the profiling of germline variants in MMR genes of colorectal cancer (CRC) patients with MMR deficiency (dMMR). The clinicopathological differences between Lynch syndrome (LS) patients and sporadic dMMR CRC patients were compared by Student's t-test and χ2 test. The molecular profiling of germline variants in MMR genes in Chinese CRC patients with dMMR is clarified. METHODS:A total of 326 CRC patients with dMMR were enrolled. Next-generation sequencing (NGS) and Sanger sequencing were performed using tumor-adjacent tissues of enrolled patients. Four MMR genes (MLH1, MSH2, MSH6, and PMS2) are included in the NGS panel. RESULTS:A total of 113 germline variants were detected, including 81 pathogenic and likely pathogenic variants. The clinicopathologic differences between CRC patients with/without LS were observed in age, family history, lesion location, and dMMR patterns. The CRC cohort with IHC-MSH6 negative alone shows the highest prevalence rate of LS. MLH1 was detected with the most germline variants. The mutational hotspot region of MLH1 is Exon 8, Exon 4 for MSH6, Exon 11 for PMS2, and Exon 7 for MSH2. Several germline hotspots were labeled on each MMR gene sequence by fixed-size bin analysis. In addition, some variants were novel discovered based on the presence or absence of the RS number and allele frequency record. CONCLUSIONS:Our study classified the clinicopathological features between sporadic CRC patients and LS patients. More importantly, the molecular profiling of the MMR gene germline variant was experimentally elucidated, which deepens the knowledge of MMR genes and provides a new perspective for the subsequent studies on the landscape of germline variants of Chinese LS patients.

Purpose Radiation dose selection for neoadjuvant chemoradiation therapy (nCRT) in esophageal squamous cell carcinoma (ESCC) varies widely in clinical practice, and prospective randomized data addressing this question are lacking. This trial compared 2 commonly used radiation dose regimens in nCRT for resectable thoracic ESCC. Methods and Materials This single-center, phase 2 prospective, randomized controlled trial enrolled patients with locally advanced thoracic ESCC from February 22, 2018, to February 22, 2021. Patients were randomized 1:1 to receive nCRT with either 50.4 Gy/28F or 41.4 Gy/23F, concurrent with weekly paclitaxel and carboplatin. The primary endpoint was 2-year progression-free survival (PFS). Results A total of 147 patients were randomized (50.4 Gy, n = 72; 41.4 Gy, n = 75), of whom 101 underwent surgical resection. Pathologic complete response occurred in 23 of 46 patients (50.0%) in the 50.4-Gy group and 18 of 55 patients (32.7%) in the 41.4-Gy group (P = .078). Using major pathologic response (MPR) as an alternative endpoint, the 50.4 Gy/28F regimen significantly increased the MPR rate to 73.9%, compared with 52.7% in the low-dose group (P = .029). In the intention-to-treat population analysis, the 2-year PFS rates were 56.7% for the high-dose group and 49.3% for the low-dose group, with a hazard ratio (HR) of 0.72 (95% CI, 0.46-1.11; P = .14). Two-year overall survival (OS) rates were similar between groups. Grade ≥2 radiation esophagitis occurred more frequently in the 50.4-Gy group, whereas postoperative complication rates were comparable. Conclusions Dose escalation from 41.4 to 50.4 Gy in nCRT for resectable ESCC did not improve PFS or OS but was associated with a higher MPR rate and increased esophagitis. These findings support current evidence that routine dose escalation does not confer a survival advantage, while providing randomized ESCC-specific data to inform individualized treatment decisions.

Circular RNAs (circRNAs) are indispensable for triggering pancreatic ductal adenocarcinoma (PDAC) progression. However, the specific biological processes and mechanisms by which circRNAs influence PDAC remain largely unknown. Here, we reported that circFOXP1 is a critical promoter of PDAC progression, exhibiting marked upregulation in patient tumour tissues that correlates with advanced TNM stage and poor prognosis. Functional studies demonstrate that circFOXP1 knockdown significantly suppresses PDAC cell proliferation, migration, and invasion in vitro and in vivo. Mechanistically, circFOXP1 acts as a molecular sponge for miR-320b, leading to the upregulation of epidermal growth factor receptor (EGFR) ligand Epiregulin (EREG) and the subsequent activation of the MAPK/ERK signalling pathway, which is crucial for maintaining the aggressive phenotype of PDAC. The blockade of EREG using neutralizing antibodies in vivo substantially abrogates circFOXP1-induced tumorigenesis. Our findings underscore the potential of circFOXP1 as a novel biomarker and propose a novel therapeutic target to improve survival in PDAC patients.

p53 abnormality (p53 abn) subtype is a critical category in endometrial carcinoma (EC) molecular classification, yet clinical diagnosis often relies solely on p53 immunohistochemistry (IHC) staining or TP53 gene sequencing. This study aimed to explore the correlation between TP53 genotype and p53 protein expression in EC with TP53 missense mutations, as well as the clinical and prognostic significance of their discordance. A total of 253 EC specimens from Zhejiang Cancer Hospital (January 2021-November 2023) were retrospectively collected; 103 cases with isolated TP53 missense mutations were screened via next-generation sequencing (NGS) and subjected to p53 IHC. Variant interpretation revealed that six mutations in six patients were of uncertain significance. Among the remaining patients, 54 (involving 36 variants) showed concordance between IHC phenotype and genotype: high frequency mutations such as R273H, Y220C, M237I, and V272L all exhibited mutant p53 expression, whereas V31I showed wild-type expression. Another 43 patients (involving 13 variants) displayed discordance between genotype and IHC phenotype. Clinicopathological comparison revealed that the discordant group was younger (<60 years) and dominated by non-aggressive histology (all P < 0.05). The discordant group showed better survival trends than the concordant group, with no statistically significant difference in disease-free survival (DFS) (P = 0.057). In conclusion, p53 expression is heterogeneous in EC with TP53 missense mutations; gene-protein discordance correlates with distinct clinicopathological features. Integrating genetic and protein detection results is recommended for risk stratification and individualized treatment.

BACKGROUND:The efficacy of immune checkpoint blockade (ICB) is heterogeneous across patients. Tumour immune phenotype classification (immune-inflamed, -excluded, and -desert) represents a foundational but inadequate framework for predicting ICB efficacy. Here we aimed to develop an integrated immunogenomic classification to improve ICB response prediction and identify subtype-specific therapeutic vulnerabilities. METHODS:We analysed 13 public ICB cohorts and an in-house cohort. Using RNA-seq data, we developed ImmPred, a seven-gene classifier trained on IHC-defined immune phenotypes, and integrated it with TMB to define immunogenomic subtypes. Subtype-specific resistance mechanisms were investigated via pathway analysis and validated in syngeneic mouse models. FINDINGS:Patients with cancers can be stratified into five immunogenomic subtypes with divergent responses to ICB, which are TMB-High (H) inflamed, TMB-Low (L) inflamed, TMB-H excluded, TMB-L excluded, and desert phenotypes. In immune-excluded tumours, MTAP deficiency contributes to ICB resistance in TMB-H excluded subtype and PRMT5 inhibitors enhances ICB efficacy in MTAP-KO B16-F10 and CT26 syngeneic mouse model, whereas TGF-β hyperactivation drives intrinsic resistance of TMB-L excluded subtype and TGF-β blockade potentiates anti-tumour immunity in MB49 and EMT6 mouse model. In TMB-H inflamed tumours, IFN-γ is a critical determinant of ICB efficacy, and TLR7 agonist, via enhancing IFN-γ signalling, improves anti-PD-L1 efficacy in MC38 mouse model. In TMB-L inflamed tumours, targeting COX-2-PGE2 axis with celecoxib sensitises ICB in LLC1 mouse model. INTERPRETATION:Leveraging clinical feasible RNA-seq and TMB analysis, our model exhibits robust predictive efficacy of ICB response in multiple cancers, enabling subtype-tailored therapeutic combinations to improve immunotherapy response. FUNDING:This work was supported by grants from National Key Research and Development Program of China (2021YFA1300602), National Natural Science Foundation of China (82025026, 82230091, 82472775), Guang Dong Basic and Applied Basic Research Foundation (2023A1515012412 and 2023A1515011214), Guangdong Science and Technology Department (2023B1212060013, 2023B1111030006), Key R&D Program of Zhejiang (2024C03160), Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang Province (2024R01005 and 2025R01009).