Peritoneal cell-free DNA as a sensitive biomarker for detection of peritoneal metastasis in colorectal cancer: a prospective diagnostic study: A prospective diagnostic study.

BACKGROUND: The detection of peritoneal metastasis (PM) is limited by current imaging tools. In this prospective study, we aimed to evaluate the sensitivity and specificity of peritoneal cell-free DNA (cfDNA) for diagnosis of PM. METHODS: Colorectal cancer (CRC) patients with/without PM were enrolled. The cfDNA experimental personnel and statists were blinded to the diagnosis of PM. Ultradeep sequencing covering large genomic regions (35000X, Next-generation sequencing) of cfDNA in peritoneal lavage fluid (FLD) and matched tumor tissues was performed. RESULTS: A total of 64 cases were recruited prospectively and 51 were enrolled into final analysis. In training cohort, 100% (17/17) PM patients obtained positive FLD cfDNA, comparing to 5/23 (21.7%) in patients without PM. Peritoneal cfDNA had a high sensitivity of 100% and specificity of 77.3% for diagnosis of PM (AUC: 0.95). In validation group of 11, 5/6 (83%) patients with PM obtained positive FLD cfDNA, comparing to 0/5 in non-PM (P = 0.031) with a sensitivity of 83.3% and specificity of 100%. Positive FLD cfDNA was associated with poor recurrence-free survival (P = 0.013) and was preceding radiographic evidence of recurrence. CONCLUSIONS: Peritoneal cfDNA is a promising sensitive biomarker for earlier detection of PM in CRC than current radiological tools. It can potentially guide selection for targeted therapies and serve as a surrogate instead of laparoscopic explore in the future. Trial Registration Chinese Clinical Trial Registry at chictr.org.cn (ChiCTR2000035400). URL: http://www.chictr.org.cn/showproj.aspx?proj=57626.

Epigenetic silencing and tumor suppressor gene of HAND2 by targeting ERK signaling in colorectal cancer.

BACKGROUND: The screening biomarkers for early detection of colorectal cancer (CRC) is lacking. The aim is to identify epigenetic silenced genes and clarify its roles and underlying mechanism in CRC. We conducted integrative analyses of epigenome-wide Human Methylation 450 K arrays and transcriptome to screen out candidate epigenetic driver genes with transcription silencing. Methylated silencing HAND2 were identified and verified in large CRC cohort. The mechanism of HAND2 expression by promoter inhibition were clarified both in vitro and vivo assays. Cell biofunctional roles of HAND2 methylation was investigated in CRC cells. HAND2 reconstitution were constructed by lentivirus plasmid and tumor xenograft model of HAND2 were built subcutaneously. Genomic mRNA analysis by RNA-sequencing and subsequent GSEA analysis were performed to identify potential target of HAND2 and qPCR/WB was conducted to identify the results. RESULTS: We firstly reported high frequency of HAND2 methylation in promoter in CRC and hypermethylation was negatively correlated with expression silencing and leaded to poor survival in several CRC cohort patients. 5-Aza treatment to demethylated HAND2 could revert its expression in CRC cells. Functionally, HAND2 reconstitution can inhibit cell proliferation, invasion and migration in vitro. In tumor xenograft, HAND2 reconstruction significantly repressed tumor growth when compared to control vector. Thousands of aberrant expressed genes were observed in the heatmap of RNA-sequencing data. HAND2 reconstitution could bind to ERK and reduce its phosphorylation by CoIP assay. These above results showed HAND2 reconstitution perturbed the activation of MAPK/ERK signaling by reduction of ERK phosphorylation. CONCLUSIONS: HAND2 is one tumor suppressor by targeting ERK signaling and one potential epigenetic driver gene in CRC. Video Abstract.

Risk factors for developing peritoneal metastases after curative surgery for colorectal cancer: A systematic review and meta-analysis.

AIM: Proactive detection and treatment strategies have achieved encouraging survival outcomes for patients with early peritoneal metastases (PM), but these costly and invasive approaches can only be applied to selected high-risk patients. This meta-analysis aimed to identify the risk factors for metachronous PM after curative surgery for colorectal cancer (CRC). METHOD: The study was registered at PROSPERO (CRD42020219187). Databases were searched for studies comparing clinical and histopathological characteristics between patients with metachronous peritoneal metastases from colorectal cancer (pmCRC) and patients without (non-pmCRC). RESULTS: Thirty-six studies were included. Metachronous PM were positively associated with perforation (OR 1.920; 95% CI 1.144-3.223; P = 0.014), poor differentiation (OR 2.291; 1.603-3.275; P < 0.001), T4 (OR 2.897; 1.248-6.726; P = 0.013), N1-2 (OR 3.429; 2.684-4.381; P < 0.001), mucinous adenocarcinoma (OR 4.175; 1.798-9.692; P = 0.001), obstruction (OR 4.467; 1.919-10.398; P = 0.001), synchronous ovarian metastases (OR 5.005; 1.140-21.977; P = 0.033), positive peritoneal carcinoembryonic antigen mRNA (OR 9.472; 3.643-24.631; P < 0.001), elevated serum carcinoembryonic antigen (preoperative group, OR 3.545, 1.486-8.459, P = 0.004; postoperative group, OR 13.673, 2.222-84.129, P = 0.005), elevated serum cancer antigen 19-9 (preoperative group, OR 5.281, 2.146-12.994, P < 0.001; postoperative group, OR 18.646, 6.429-54.083, P < 0.001) and positive peritoneal cytology (OR 25.884; 11.372-58.913; P < 0.001). CONCLUSION: These evidence-based risk factors are conducive to designing early detection and proactive treatment strategies, enabling precision medicine.