ImportanceCurrently, surgical resection of distant metastatic lesions has become the preferred treatment for select colorectal cancer (CRC) patients with liver metastasis (LM) and/or pulmonary metastasis (PM). Metastasectomy is the most common curative method. However, evidence of the factors affecting the prognosis of CRC patients after resection of LM and/or PM is still insufficient.ObjectiveTo explore the prognostic factors of CRC patients with LM and/or PM who have undergone resection of metastatic tumors and to provide reliable selection factors for surgical treatment in patients affected by LM and/or PM from CRC.MethodsThe SEER database was used to identify eligible CRC LM and/or PM patients who underwent resection of the primary tumor and distant metastases from January 1, 2010, to December 31, 2018. The Kaplan–Meier method was used to calculate survival, and comparisons were performed using the log-rank test for univariate analysis. A Cox proportional hazards regression model was used to identify prognostic factors for the multivariate analysis. The outcomes included overall survival (OS) and cancer-specific survival (CSS).ResultsA total of 3,003 eligible colorectal cancer patients with LM and/or PM were included in this study. The 3-year and 5-year OS rates were 53% and 33.6%, respectively, and the 3-year and 5-year CSS rates were 54.2% and 35.3%, respectively. In the adjusted multivariate analysis, age < 65 years (OS: p=0.002, CSS: p=0.002) was associated with better long-term outcomes, and primary tumors located on the left side of the colon (OS: p=0.004, CSS: p=0.006) or rectum (OS: p=0.004, CSS: p=0.006), T3 stage (OS: p<0.001, CSS: p<0.001), number of regional lymph nodes examined ≥ 12 (OS: p<0.001, CSS: p=0.001), and CRC LM (OS: p<0.001, CSS: p<0.001) were positive prognostic factors for survival after resection of metastatic tumors.ConclusionAge < 65 years is associated with better long-term outcomes in colorectal cancer patients with LM and/or PM, analogously to the left sided primary tumor, T3 stage, number of regional lymph nodes examined ≥ 12 and liver metastases.

BackgroundImmune checkpoint inhibitor (ICI) therapy has proven to be a promising treatment for colorectal cancer (CRC). We aim to investigate the relationship between DNA methylation and tumor mutation burden (TMB) by integrating genomic and epigenetic profiles to precisely identify clinical benefit populations and to evaluate the effect of ICI therapy.MethodsA total of 536 CRC tissues from the Cancer Genome Atlas (TCGA) with mutation data were collected and subjected to calculate TMB. 80 CRC patients with high TMB and paired normal tissues were selected as training sets and developed the diagnostic and prognostic methylation models, respectively. In the validation set, the diagnostic model was validated in our in-house 47 CRC tissues and 122 CRC tissues from the Gene Expression Omnibus (GEO) datasets, respectively. And a total of 38 CRC tissues with high TMB from the COLONOMICS dataset verified the prognostic model.ResultsA positive correlation between differential methylation positions and TMB level was observed in TCGA CRC cohort (r=0.45). The diagnostic score that consisted of methylation levels of four genes (ADHFE1, DOK6, GPR75, and MAP3K14-AS1) showed high diagnostic performance in the discovery (AUC=1.000) and two independent validation (AUC=0.946, AUC=0.857) datasets. Additionally, these four genes showed significant positive correlations with NK cells. The prognostic score containing three genes (POU3F3, SYN2, and TMEM178A) had significantly poorer survival in the high-risk TMB samples than those in the low-risk TMB samples (P=0.016). CRC patients with low-risk scores combined with TMB levels represent a favorable survival.ConclusionsBy integrating analyses of methylation and mutation data, it is suggested that DNA methylation patterns combined with TMB serve as a novel potential biomarker for early screening in more high-TMB populations and for evaluating the prognostic effect of CRC patients with ICI therapy.

Hepatic metastasis is a major cause of colorectal cancer (CRC)-related deaths. Presently, the role of long non-coding RNAs (lncRNAs) in hepatic metastases from CRC is elusive. We dissected possible interplay between LINC00858/miR-132-3p/IGF2BP1 via bioinformatics approaches. Subsequently we analyzed mRNA expression of LINC00858, miR-132-3p and IGF2BP1 through qRT-PCR. Western blot was used to detect protein expression of IGF2BP1. RNA immunoprecipitation chip and dual-luciferase assay validated interaction between LINC00858 and miR-132-3p, as well as miR-132-3p and IGF2BP1. Cell viability, invasion, and migration were examined via CCK-8, colony formation, transwell and wound healing assays. Effect of LINC00858 on CRC hepatic metastases was validated via in vivo assay. Upregulated LINC00858 and IGF2BP1, and downregulated miR-132-3p were predicted in tumor tissues of patients with hepatic metastases from CRC. There were targeting relationships between LINC00858 and miR-132-3p, as well as miR-132-3p and IGF2BP1. Besides, LINC00858 facilitated progression of CRC cells. Rescue assay suggested that silencing LINC00858 suppressed CRC cell progression, while further silencing miR-132-3p or overexpressing IGF2BP1 reversed such effects. LINC00858 could facilitate CRC tumor growth and hepatic metastases. LINC00858 induced CRC hepatic metastases via regulating miR-132-3p/ IGF2BP1, and this study may deliver a new diagnostic marker for the disease.