Multifactorial causation of early onset colorectal cancer

Obesity and early-onset colorectal cancer risk: emerging clinical evidence and biological mechanisms

Early-onset colorectal cancer (EOCRC) is defined as diagnosed at younger than 50 years of age and indicates a health burden globally. Patients with EOCRC have distinct risk factors, clinical characteristics, and molecular pathogenesis compared with older patients with CRC. Further investigations have identified different roles of obesity between EOCRC and late-onset colorectal cancer (LOCRC). Most studies have focused on the clinical characteristics of obesity in EOCRC, therefore, the mechanism involved in the association between obesity and EOCRC remains inconclusive. This review further states that obesity affects the carcinogenesis of EOCRC as well as its development and progression, which may lead to obesity-related metabolic syndrome, intestinal dysbacteriosis, and intestinal inflammation.

Early Onset Metastatic Colorectal Cancer: Current Insights and Clinical Management of a Rising Condition

Despite a recent overall decrease in colorectal cancer (CRC) incidence and mortality, there has been a significant rise in CRC diagnoses in young adults. Early onset colorectal cancer (EOCRC) is defined as CRC diagnosed before the age of 50. Possible predisposing conditions include not only genetic syndromes but also other risk factors, such as microbiome alteration, antibiotic exposure, obesity, diabetes mellitus, and inflammatory bowel disease. EOCRC tends to be diagnosed later than in the older counterpart because of a lack of awareness and the fact that screening for CRC usually starts at the age of 50. Furthermore, CRC in young adults seems to be related to unique molecular features and more aggressive clinical behavior. This paper aims to provide an in-depth review of this poorly understood subject, with a comprehensive review of the state of the art and considerations for future perspectives.

High Expression of circ_0001821 Promoted Colorectal Cancer Progression Through miR-600/ISOC1 Axis

It has been reported that circRNAs play an important regulatory role in the progression of colorectal cancer (CRC). However, the molecular role of circ_0001821 in CRC development is unclear. In this study, we aimed to investigate the regulatory role and molecular mechanisms of circ_0001821 in CRC. Reverse transcription-quantitative PCR and western blot assays were used to detect the expression of circ_0001821, miR-600 and isochorismatase domain containing 1 (ISOC1) in CRC tissues as well as its cell lines. Colony formation assay and EDU assay were used to detect the proliferative capacity of cells. Transwell assay was used to assess cell migration and invasion ability. Flow cytometry was used to analyze cell apoptosis. ELISA was used to measure the glycolytic capacity of cells. Dual-luciferase reporter assay and RNA pull-down assay were used to analyze the relationships between circ_0001821, miR-600 and ISOC1. Animal experimentation was used to validate the functional study of circ_0001821 in vivo. Immunohistochemistry (IHC) of Ki67 staining analysis was conducted to assess tumor growth. Circ_0001821 and ISOC1 were significantly increased in CRC tissues and its cell lines, and miR-600 was significantly decreased in CRC tissues and its cell lines. Silencing circ_0001821 inhibited cell proliferation, migration, invasion and glycolytic capacity, while inducing apoptosis. And it could inhibit tumor growth in vivo. Circ_0001821 could act as a sponge for miR-600 to regulate CRC processes. ISOC1 was identified as a downstream regulator of miR-600, also miR-600 could regulate the expression of ISOC1. In addition, circ_0001821 could regulate ISOC1 expression changes through miR-600. Mechanistically, either miR-600 inhibitor or overexpression of ISOC1 could reverse the effects of knockdown of circ_0001821 on cell biological properties. Circ_0001821 regulated the developmental process of CRC through miR-600/ISOC1 axis.

Hypothesis: Mutations and Immunosurveillance in Obesity-Associated Colorectal Cancer

Tumorigenesis typically requires the accumulation of several driver gene mutations; therefore, there is a mutation threshold for the completion of the neoplastic process. Obesity increases the risk of cancer, and we have proposed that one mechanism whereby obesity raises the risk of microsatellite stable (MSS) colon cancer is by decreasing the mutation threshold. Therefore, obese MSS colon cancer patients should exhibit fewer driver gene mutations compared to normal body-mass index (BMI) patients. Our hypothesis is supported by results from analyses of The Cancer Genome Atlas (TCGA) data, which revealed that cancer genomes of obese MSS colon patients exhibit both fewer somatic mutations and fewer driver gene mutations. These findings could be explained by the high levels of obesity-associated cytokines and factors, the signaling pathways of which substitute for the additional driver gene mutations detected in normal-weight MSS colon cancer patients. Therefore, obesity-induced aberrant cell signaling might cooperate with initiating driver gene mutations to promote neoplastic development. Consistent with this possibility, we observed a lower number of KRAS mutations in high-BMI MSS colon cancer patients. This paper extends our hypothesis to address the interactions between obesity, immune surveillance in neoplastic development, and colorectal cancer (CRC) risk. A better understanding of these interactions will inform future preventive and therapeutic approaches against MSS CRC. We propose that the individual variations in the major histocompatibility class 1 (MHC-1) genotype interact with obesity to shape the tumor mutational landscape. Thus, the efficiency of the immune surveillance mechanisms to select against specific mutations may depend on both the MHC-1 genotype variant and the BMI of an individual. A high BMI is expected to reduce the number of driver gene mutations required to evade the MHC-1 surveillance mechanism and support an accelerated cancer progression.

Comparison of some biochemical markers between early‐onset and late‐onset colorectal precancerous lesions: A single‐center retrospective study

Objective

Given that the onset of diseases including colorectal cancer precursors is affecting younger individuals and that obesity is an important risk factor for early‐onset, we conducted a study to explore the biochemical profile of differences in serum between early‐onset patients and late‐onset colorectal precancerous lesions.

Methods

A total of 1447 patients, including 469 early‐onset patients and 978 late‐onset patients, were enrolled from the First Affiliated Hospital of Nanchang University (FAHNU), of which there were 311 sessile serrated adenoma/polyps (SSA/P) and 1136 normal adenomas. The distribution of the included categorical variables was compared via Pearson's chi‐squared test, whereas continuous variables were compared by using the nonparametric Kruskal–Wallis test and anova.

Results

Compared with late‐onset patients, the levels of total bilirubin and HDL‐C were lower (p < 0.05), whereas triglyceride and uric acid levels were higher, in early‐onset patients. Interestingly, in the subgroup analysis, triglyceride and uric acid levels remained at higher levels, whereas HDL‐C remained at lower levels, in early‐onset patients than in late‐onset patients. Other characteristics, such as LDL‐C, drinking, γ‐GT, and the N/L ratio, were similar between the two groups. An additional analysis of the association of tumor size with markers showed that lower levels of HDL‐C and higher levels of uric acid were associated with increased tumor size (p < 0.05).

Conclusions

Early‐onset CRC precursor cases exhibit higher levels of triglycerides and lower levels of HDL‐C than late‐onset cases. Additionally, levels of HDL‐C are negatively associated with tumor size, whereas uric acid was positively correlated with tumor size.

A Real-World Study of the Incidence and Outcomes of Early-Onset Well-differentiated Neuroendocrine Neoplasms

OBJECTIVE

The objective of this study was to evaluate the incidence and outcomes of adults with early-onset (20 to 34 y) diagnosis of well-differentiated neuroendocrine neoplasms.

METHODS

Surveillance, Epidemiology, and End Results (SEER)-18 database was accessed, and patients with well-differentiated lung or digestive tract neuroendocrine neoplasms diagnosed 2000 to 2018 were reviewed. Annual percent changes (APCs) were calculated for the 3 disease subsites (foregut, midgut, and hindgut) stratified by age group. Kaplan-Meier survival estimates/log-rank testing were used to examine differences in overall survival between the 3 age groups. Multivariable Cox regression analyses were used to evaluate factors affecting overall and cancer-specific survivals.

RESULTS

Throughout the study period, patients with early-onset disease (20 to 34 y) have experienced the greatest APC (20 to 34 y: 9.7; 35 to 49 y: 5.4; ≥50 y: 4.1). When APCs were stratified by disease subsite, this difference in APCs appears to be driven by midgut tumors (20 to 34 y: 19.2; 35 to 49: 8.4; ≥50 y: 3.8). Using multivariable Cox regression modeling, the following variables were associated with a higher risk of all-cause death (worse overall survival): male sex (hazard ratio [HR] 1.27; 95% confidence interval [CI]: 1.22-1.31), African American race (HR vs. white race: 1.20; 95% CI: 1.15-1.26), nonhindgut primary (HR foregut vs. hindgut primary: 2.02; 95% CI: 1.91-2.13; HR midgut vs. hindgut primary: 2.09; 95% CI: 1.95-2.24), distant disease (HR vs. regional disease: 2.06; 95% CI: 1.96-2.18), no surgery to the primary (HR: 2.34; 95% CI: 2.24-2.46), and older age (HR: 5.80; 95% CI: 4.87-6.91).

CONCLUSION

Cases of early-onset well-differentiated neuroendocrine neoplasms have disproportionately increased over the past 2 decades (compared with other age groups), and this appears to have been driven mainly by midgut tumors.