Purpose: Bladder cancer treatment remains a major clinical challenge due to therapy resistance and a high recurrence rate. Profiling intratumor heterogeneity can reveal the molecular mechanism of bladder cancer recurrence. Experimental Design: Here, we performed single-cell RNA sequencing and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) on tumors from 13 patients with low recurrence risk, high recurrence risk, and recurrent bladder cancer. Results: Our study generated a comprehensive cancer-cell atlas consisting of 54,971 single cells and identified distinct cell subpopulations. We found that the cancer stem-cell subpopulation is enriched during bladder cancer recurrence with elevated expression of EZH2. We further defined a subpopulation-specific molecular mechanism whereby EZH2 maintains H3K27me3-mediated repression of the NCAM1 gene, thereby inactivating the cell invasive and stemness transcriptional program. Furthermore, taking advantage of this large single-cell dataset, we elucidated the spectrum of epithelial–mesenchymal transition (EMT) in clinical samples and revealed distinct EMT features associated with bladder cancer subtypes. We identified that TCF7 promotes EMT in corroboration with single-cell ATAC with high-throughput sequencing (scATAC-seq) analysis. Additionally, we constructed regulatory networks specific to recurrent bladder cancer. Conclusions: Our study and analytic approaches herein provide a rich resource for the further study of cancer stem cells and EMT in the bladder cancer research field.

Background: The long-term survival of patients with hepatocellular carcinoma (HCC) with portal vein tumour thrombus (PVTT) is poor. Systemic therapy, transcatheter arterial chemoembolization (TACE), and hepatic artery infusion chemotherapy are widely used in HCC patients with PVTT. This study aims to explore the efficacy of combining systemic therapy with transarterial-based therapy in HCC patients with PVTT. Materials and methods: The authors retrospectively reviewed data of HCC patients with PVTT treated with combination therapy (TACE-hepatic artery infusion chemotherapy with tyrosine kinase inhibitors and PD-1 inhibitors) or TACE alone in SYSUCC from 2011 to 2020. The overall survival (OS), progression-free survival, and overall response rate were compared. Propensity score matching was used to minimize confounding bias. Results: A total of 743 HCC patients with PVTT received combination therapy (n=139) or TACE alone (n=604). After propensity score matching, the overall response rate was significantly higher in the combination group than in the TACE group [42.1% vs. 5.0%, P < 0.001 (response evaluation criteria in solid tumours); 53.7% vs. 7.8%, P < 0.001 (modified response evaluation criteria in solid tumours)]. The combination group showed significantly better OS than the TACE group (median OS not reached vs. 10.4 months, P < 0.001). The median progression-free survival of the combination and TACE groups was 14.8 and 2.3 months (P < 0.001), respectively. Tumour downstaging followed by salvage liver resection was significantly more common for the combination therapy group than for TACE group (46.3% vs. 4.5%, P < 0.001). After salvage liver resection, 31.6% (30/95) and 1.7% (3/179) of the patients achieved a pathological complete response in the combination and TACE groups, respectively (P < 0.001). The grade 3/4 adverse events rates were similar between the two groups (28.1% vs. 35.9%, P=0.092). Conclusion: Compared with TACE alone, combination therapy was safe enough and resulted in survival benefits. This is a promising treatment option for HCC patients with PVTT.

Background: Total pancreatectomy (TP) for pancreatic cancer (PC) has been limited historically for fear of elevated perioperative morbidity and mortality. With advances in perioperative care, TP may be an alternative option to partial pancreatectomy (PP). Limited evidence clarified the indication for these two procedures in PC patients, especially in patients with different tumor staging and location. Thus, this study aims to compare the outcomes after TP and PP for PCs of different T stages and locations. Methods:The study identified 14,456 PC patients with potentially curable primary tumor (T1-3) who received TP or PP from the Surveillance, Epidemiology, and End Results (SEER) database during 2000 to 2016. Detailed clinical and tumor covariates were all collected. Overall survival (OS) and cancer-specific survival (CSS) were the primary endpoints of interest in this study. OS and CSS were compared between patients after TP and PP using log-rank analysis.Results: For all patients, except for tumor location, TP group was comparable to the PP group. OS and CSS of the TP group were worse than of the PP group (median OS: 19 vs. 20 months, P=0.0058; median CSS: 24 vs. 26 months, P=0.00098, respectively). In stratifying analyses, TP was significantly related to worse OS and CSS than PP in pancreatic head and neck cancer patients with T2-stage tumors (median OS: 18 vs. 19 months, P=0.0016; median CSS: 22 vs. 24 months, P=0.00055, respectively), whereas for patients with T1-or T3-stage pancreatic head and neck cancer as well as T1-to T3-stage pancreatic body and tail cancer or overlapping location cancer, OS and CSS of the two groups were similar (all P>0.05).Conclusions: Compared with PP, TP offered worse prognosis in pancreatic head and neck cancer patients with T2-stage tumors, furthermore, TP and PP achieved comparable prognosis in patients with T1-or T3-stage pancreatic head and neck cancer as well as T1-to T3-stage pancreatic body and tail cancer or overlapping location cancer.