Objective: This study aimed to compare the short-term and long-term outcomes between robotic-assisted simultaneous resection and open surgery in patients with rectal cancer and liver metastases. Background: Open simultaneous resection of colorectal cancer and synchronous liver metastases is widely performed and the potential cure for eligible patients. However, the feasibility of robotic simultaneous resection of primary and secondary liver lesions has not been established as a treatment option for metastatic rectal cancer. Patients and methods: A single-center randomized controlled trial was conducted at a hospital in China. Enrolling patients were aged from 18 to 75 years and diagnosed with surgically resectable metastatic rectal cancer (distal extension to ≤15 cm from the anal margin). Patients selected for simultaneous resection were randomly assigned to have robotic or open surgery at a 1:1 ratio. The primary endpoint was the incidence rate of complications within 30 days after surgery. Secondary endpoints were bladder, sexual function, 3-year disease-free survival, and overall survival. Results: A total of 171 patients were enrolled in this trial with 86 in the robotic group and 85 in the open group. As a result, patients in the robotic group demonstrated fewer complications within 30 days after surgery than those in the open group (31.4 vs. 57.6%, P=0.014) and no mortality seen in either group. Patients in the robotic group had less blood loss [mean (SD), 125.5 (38.3) vs. 211.6 (68.7) ml; P<0.001], faster bowel function recovery [mean (SD), 63.7 (27.4) vs. 93.8 (33.5) h P<0.001] and shorter hospital stay [mean (SD), 8.0 (2.2) vs. 10.7 (5.4) days; P<0.001] compared with those in the open group. The robotic group had a faster recovery of bladder and sexual function at 3 months after surgery than that of the open group. The 3-year disease-free survival rate (39.5 vs. 35.3%, P=0.739) and the 3-year overall survival rate (76.7 vs. 72.9%, P=0.712) were not statistically significant between the two groups. Conclusions: In our randomized clinical trial, robotic simultaneous resection treatment of patients with rectal cancer and liver metastases resulted in fewer surgical complications, and a faster recovery to those of open surgery. Oncological outcomes showed no significant difference between the two groups.

Backgrounds: Cancer-related mortality in patients with colorectal cancer (CRC) is predominantly caused by development of colorectal liver metastases (CLMs). How to screen the sensitive chemotherapy and targeted therapy is the key element to improve the prognosis of CLMs patients. The study aims to develop patient-derived organoids-based xenografted liver metastases (PDOX-LM) model of CRC, to recapitulate the clinical drug response. Methods: We transplanted human CRC primary tumor derived organoids in murine spleen to obtain xenografted liver metastases in murine liver. Immunohistochemistry (IHC) staining, whole-exome and RNA sequencing, and drug response testing were utilized to identify the homogeneity in biological and genetic characteristics, and drug response between the PDOX-LM models and donor liver metastases. Results: We successfully established PDOX-LM models from patients with CLMs. IHC staining showed that positive expression of CEA, Ki67, VEGF, FGFR2 in donor liver metastases were also well preserved in matched xenografted liver metastases. Whole-exon sequencing and transcriptome analysis showed that both xenografted and donor liver metastases were highly concordant in somatic variants (≥ 0.90 frequency of concordance) and co-expression of driver genes (Pearson’s correlation coefficient reach up to 0.99, P = 0.001). Furthermore, drug response testing showed that the PDOX-LM models can closely recapitulated the clinical response to mFOLFOX6 regiments. Conclusions: This PDOX-LM model provides a more convenient and informative platform for preclinical testing of individual tumors by retaining the histologic and genetic features of donor liver metastases. This technology holds great promise to predict treatment sensitivity for patients with CLMs undergoing chemotherapy.

Background: Colorectal cancer (CRC) is one of the lethal cancers with a high mortality rate worldwide and understanding the mechanisms behind its progression is critical for improving patients’ prognosis and developing therapeutics. MiR-500a-3p has been demonstrated to be involved in the progression of several human cancers but its role in CRC remains unclear. The aim of this study is to uncover the expression pattern and mechanisms of action of miR-500a-3p during the CRC progression. Methods: The expression of miR-500a-3p and Cyclin-dependent kinases 6 (CDK6) in 134 CRC tissues were tested by quantitative PCR (qPCR) and immunohistochemistry staining (IHC), respectively. The effect of miR-500a-3p on cell proliferation was explored in vitro and in vivo. The glycolysis of CRC cells was determined by Mass Spectrometry and Seahorse XF 96 Extracellular Flux Analyzer. A dual-luciferase reporter assay was performed to validate the relationship between miR-500a-3p and CDK6. Results: miR-500a-3p was abnormally downregulated in CRC tissues and cell lines and was negatively associated with a worse prognosis. miR-500a-3p mimics impeded CRC cell proliferation in vitro and in vivo. miR-500a-3p inhibited glucose consumption, lactate and ATP production, and down-regulated the expression of hexokinase2 (HK2). In silico prediction combined with western blot and luciferase assay confirmed that CDK6 is a direct target of miR-500a-3p. Overexpression of CDK6 phenotypically rescued the inhibitory effect of miR-500a-3p on the proliferation and glycolysis of CRC cells. Conclusions: Our study revealed a potential tumor-suppressive role of miR-500a-3p in CRC, specifically targeting CDK6 and inhibiting cancer cell proliferation and aerobic glycolysis, which may provide new insights into novel prognostic biomarkers and therapeutic targets for CRC.

Background: Regorafenib improves progression-free survival (PFS) and overall survival (OS) in patients with refractory metastatic colorectal cancer (mCRC). Here, we report the treatment patterns of regorafenib in the third- or late-line setting for mCRC in four centers in China.Patients and Methods: Patients with refractory mCRC in four centers in China administered regorafenib from February 1, 2018 to June 31, 2021 were enrolled. Patients were grouped into 3 cohorts, namely, the monotherapy (regorafenib alone), chemo (regorafenib plus chemotherapy), and immune [regorafenib plus anti-PD1 (programmed cell death 1) antibodies] groups. Demographic, clinical, survival and safety data were retrospectively analyzed.Results: A total of 177 patients were included in this study. Of them, 116 (65.5%) were treated with regorafenib alone, while 28 (15.9%) and 33 (18.6%) were administered regorafenib plus chemotherapy and anti-PD1 antibodies, respectively. The median followed-up time was 9.2 months. The disease control rate (DCR) was 40.7%. The median PFS (mPFS) was 2.43 months and the median OS (mOS) was 12.2 months. The immune group had longer median PFS (3.5 m vs. 2.2 m, p = 0.043) compared with the monotherapy group. Patients administered regorafenib plus chemotherapy had longer median OS (15.9 m vs. 8.4 m, p = 0.032) compared with the monotherapy group. Patients who began regorafenib treatment at 120 mg had longer median PFS and OS compared with those who began at 80 mg (PFS: 3.7 m vs. 2.0 m; p <0.001; OS: 13.4 m vs. 10.2 m; p = 0.005). Patients with a final dose of 120 mg had longer median PFS and OS compared with the 80 mg or less group (PFS: 5.0 m vs. 2.3 m; p = 0.045; OS: UR (unreach) vs. 10.9 m; p = 0.003). There were 87.0% (154/177) patients who experienced AEs. Three groups had similar rates of AEs (86.2% vs. 89.3% vs. 87.9%; p = 0.89).Conclusion: Patients administered regorafenib alone or regorafenib in combination with other agents were relieved to some extent, with a disease control rate of 40.7%. Regorafenib plus anti-PD1 antibodies showed better PFS, while regorafenib plus chemotherapy had the most benefit in OS. There was no significant difference among three groups in terms of AEs.

Background: The type of liver resection (anatomical resection, AR or non-anatomical resection, NAR) for colorectal liver metastases (CRLM) is subject to debate. The debate may persist because some prognostic factors, associated with aggressive tumor biological behavior, have been overlooked. Objective: Our study aimed to investigate the characteristics of patients who would benefit more from anatomical resection for CRLM. Methods: Seven hundred twenty-nine patients who underwent hepatic resection of CRLM were retrospectively collected from June 2012 to May 2019. Treatment effects between AR and NAR were compared in full subgroup analyses. Tumor relapse-free survival (RFS) was evaluated by a stratified log-rank test and summarized with the use of Kaplan–Meier and Cox proportional hazards methods. Results: Among 729 patients, 235 (32.2%) underwent AR and 494 (67.8%) underwent NAR. We showed favorable trends in RFS for AR compared with NAR in the patients with KRAS/NRAS/BRAF mutation (interaction P<0.001) or right-sidedness (interaction P<0.05). Patients who underwent AR had a markedly improved RFS compared with NAR in the cohorts of RAS/NRAS/BRAF mutation (median RFS 23.2 vs. 11.1 months, P<0.001) or right-sidedness (median RFS 31.6 vs. 11.5 months, P<0.001); upon the multivariable analyses, AR [gene mutation: hazard ratio (HR)=0.506, 95% CI=0.371–0.690, P<0.001; right-sidedness: HR=0.426, 95% CI=0.261–0.695, P=0.001) remained prognostic independently. In contrast, patients who underwent AR had a similar RFS compared with those who underwent NAR, in the cohorts of patients with gene wild-type tumors (median RFS 20.5 vs. 21.6 months, P=0.333). or left-sidedness (median RFS 15.8 vs. 19.5 months, P=0.294). Conclusions: CRLM patients with gene mutation or right-sidedness can benefit more from AR rather than from NAR.

Background: N6-methyladenosine (m6A) modification plays crucial roles in cancers. However, its alteration in colorectal cancer (CRC) is still poorly described. The purpose of this study is to explore the change of m6A modification and the function of m6A binding protein YTHDC2 in CRC. Methods: The global level of m6A modification was detected by mass spectrometry and dot blotting assay. The expression of YTHDC2 was investigated using The Cancer Genome Atlas and using real-time polymerase chain reaction (RT-qPCR), western blotting, and immunohistochemistry based on CRC tissues. Kaplan–Meier analysis and Cox proportional hazards regression were performed to analyze the prognostic value of YTHDC2. RNA immunoprecipitation (RIP)-seq and m6A immunoprecipitation (MeRIP)-seq were used to explore the direct targets of YTHDC2. Gene oncology (GO) and Gene Set Enrichment Analysis (GSEA) were used to explore the pathways that could be influenced by YTHDC2. Results: No significant difference was observed in the global level of m6A modification on total RNA or mRNA between CRC and adjacent nontumor tissues. We further found a significant decreasing of YTHDC2 in CRC tissues. Kaplan–Meier analysis indicated that lower expression of YTHDC2 was related to the worse disease-free survival and overall survival. In addition, lower expression of YTHDC2 was an independent worse prognostic factor in univariate and multivariate Cox regression analysis. Using YTHDC2-RIP-seq and MeRIP-seq, we identified that YTHDC2 could participate in several important biological signal pathways. Conclusions: In summary, this study suggested that the global level of m6A did not change in CRC and identified that lower YTHDC2 as a prognostic marker for worse survival of CRC.