[Current Status of Chemotherapy in Colorectal Cancer: Updated Treatment Strategies].

Colorectal cancer remains a significant health burden in South Korea, being the third most diagnosed cancer in the country. Despite advances in treatment, patients with metastatic colorectal cancer still face limited survival rates, with resection often deemed impossible for the majority. This review discusses the current state of chemotherapy in colorectal cancer treatment, focusing on both adjuvant chemotherapy post-surgery and palliative chemotherapy for metastatic cases. The article highlights recent updates in treatment guidelines, including the use of immunotherapy and the role of circulating tumor DNA (ctDNA) in personalized medicine. The integration of these novel approaches aims to enhance treatment efficacy, improve patient survival, and reduce recurrence rates, paving the way for more tailored and effective therapeutic strategies in colorectal cancer management.

Evolving data on risk and current screening recommendations for colorectal cancer in cystic fibrosis: Pre- and posttransplant.

Advances in treatment for cystic fibrosis (CF), including cystic fibrosis transmembrane conductor regulator (CFTR) modulators, have ushered in an era where patients with CF have much longer life expectancies. This shift in life expectancy demands increased attention to diseases of aging in patients with CF. A notable complication of CF is early-onset colorectal cancer (CRC), which is especially prevalent in patients with severe mutations and after transplant. CFTR acts as a tumor suppressor gene based on knockout models. Lack of CFTR expression promotes carcinogenic processes such as intestinal inflammation and deleterious gut microbiome changes. The consensus Cystic Fibrosis Foundation recommendations advocate treating this population as a high-risk group, using a colonoscopy-only screening strategy starting at age 40 in patients without transplant and at age 30 after transplant. Screening should be considered every 5 years if negative and every 3 years or sooner for patients with adenomatous polyps. Future research will determine the role of noninvasive CRC screening tools in this population, as well as the effects of CFTR modulators on the risk of developing CRC.

T cell receptor clonotype in tumor microenvironment contributes to intratumoral signaling network in patients with colorectal cancer.

Single-cell RNA sequencing (scRNA-seq) has contributed to understanding cellular heterogeneity and immune profiling in cancer. The aim of the study was to investigate gene expression and immune profiling in colorectal cancer (CRC) using scRNA-seq. We analyzed single-cell gene expression and T cell receptor (TCR) sequences in 30 pairs of CRC and matched normal tissue. Intratumoral lymphocytes were measured with digital image analysis. CRC had more T cells, epithelial cells, and myeloid cells than normal colorectal tissue. CRCs with microsatellite instability had more abundant T cells than those without microsatellite instability. Immune cell compositions of CRC and normal colorectal tissue were inversely correlated. CD4 + or CD8 + proliferating T cells, CD4 + effector memory T cells, CD8 + naïve T cells, and regulatory T cells of CRC showed higher TCR clonal expansion. Tumor epithelial cells interacted with immune cells more strongly than normal. T cells, myeloid cells, and fibroblasts from CRCs of expanded T cell clonotypes showed increased expression of genes related to TNF and NFKB signaling and T cell activation. CRCs of expanded T cell clonotypes also showed stronger cellular interactions among immune cells, fibroblasts, and endothelial cells. Pro-inflammatory CXCL and TNF signaling were activated in CRCs of expanded T cell clonotype. In conclusion, scRNA-seq analysis revealed different immune cell compositions, differential gene expression, and diverse TCR clonotype dynamics in CRC. TCR clonality expansion is associated with immune activation through T cell signaling and chemokine signaling. Patients with CRCs of expanded clonotype can be promising candidates for immunotherapy.

Red and Processed Meat Intake, Polygenic Risk and the Prevalence of Colorectal Neoplasms: Results from a Screening Colonoscopy Population.

High red and processed meat intake and genetic predisposition are risk factors of colorectal cancer (CRC). However, evidence of their independent and joint associations on the risk of colorectal neoplasms is limited. We assessed these associations among 4774 men and women undergoing screening colonoscopy. Polygenic risk scores (PRSs) were calculated based on 140 loci related to CRC. We used multiple logistic regression models to evaluate the associations of red and processed meat intake and PRS with the risk of colorectal neoplasms. Adjusted odds ratios (aORs) were translated to genetic risk equivalents (GREs) to compare the strength of the associations with colorectal neoplasm risk of both factors. Compared to ≤1 time/week, processed meat intake >1 time/week was associated with a significantly increased risk of colorectal neoplasm [aOR (95% CI): 1.28 (1.12-1.46)]. This risk increase was equivalent to the risk increase associated with a 19 percentile higher PRS. The association of red meat intake with colorectal neoplasm was weaker and did not reach statistical significance. High processed meat intake and PRS contribute to colorectal neoplasm risk independently. Limiting processed meat intake may offset a substantial proportion of the genetically increased risk of colorectal neoplasms.

Reducing information avoidance: The effectiveness of humour, cute animals and coping messages.

OBJECTIVES: Guided by the hedonic surplus/mood-as-resource hypotheses, we sought to identify message components that prevent health information avoidance by inducing hedonic psychological states. DESIGN: Two experimental studies. METHODS: Participants, age 45-75, recruited from the online survey platform, Prolific (Study 1 N = 288, Study 2 N = 505), completed a survey of their colorectal cancer (CRC) information avoidance tendency and demographics. They were reinvited to participate in a study where they were randomized to view one of four types of images: humorous comics, cute animals, coping messages or streetscapes images (control condition). To assess CRC information avoidance behaviour after viewing the stimuli, participants choose whether to be directed to a website to complete a CRC risk calculator (Study 1), or whether to view a CRC information video or a video about foot care (Study 2). Using logistic regression, we regressed each outcome variable on interactions between self-reported CRC information avoidance tendency and experimental condition. We then used the PROCESS macro to test if mood mediated these interaction effects. RESULTS: In Study 1, to the degree participants reported CRC information avoidance tendency, viewing humorous comics compared to control images increased their odds of choosing to view the risk calculator (OR = 5.26, p = .02). The same was true in Study 2 for choosing to watch the video about CRC vs. foot care (OR = 2.42, p = .04). Effects were not mediated through mood and there were no effects for the cute animals or coping messages. CONCLUSIONS: Using humour at the outset of a health message may increase reach to people who otherwise avoid CRC or other health messaging.

Schwannoma in the Rectum: A Case Report.

A woman in her 60s with a past medical history of recurrent Helicobacter pylori (H. pylori) presented for surgical consultation after a colonoscopy revealed a mass in the rectum. Preoperative biopsy revealed mucosal excrescence with no dysplasia or malignant changes. The final pathology showed a solid, submucosal rectal mass that was positive for SOX10 and S100 on immunohistochemistry, supporting our diagnosis of Schwannoma. This case emphasizes the importance of considering schwannomas in the differential diagnosis of patients presenting with a rectal mass no matter how rare it may be.

The Outcomes of Colorectal Endoscopic Submucosal Dissection in Patients with Chronic Kidney Disease: A Honam Association for the Study of Intestinal Disease (HASID) Multicenter Study.

Colorectal neoplasms are prevalent in patients with chronic kidney disease (CKD); however, the safety and efficacy of colorectal endoscopic submucosal dissection (ESD) are not well understood. This retrospective analysis included ESD procedures performed in 1266 patients with CKD across five tertiary medical institutions from January 2015 to December 2020. Patients were categorized based on their estimated glomerular filtration rate (eGFR), which ranged from CKD1 to CKD5 (including those on dialysis). We found that en bloc resection rates remained high across all CKD stages, affirming the procedural efficacy of ESD. Notably, the prevalence of cardiovascular comorbidities, such as ischemic heart disease and diabetes mellitus, significantly increased with an advancing CKD stage, with a corresponding increase in the Charlson Comorbidity Index, highlighting the complexity of managing these patients. Despite these challenges, the complete resection rate was lower in the CKD5 group (50%) than in the CKD1 group (83.4%); however, procedural complications, such as perforation and bleeding, did not significantly differ among the groups. The predictive models for complete resection and major complications showed no significant changes with a decreasing eGFR. These findings underscore that ESD is a feasible and safe treatment for colorectal neoplasms in patients with CKD, successfully balancing the inherent procedural risks with clinical benefits.

Different modifiable risk factors for the development of non-advanced adenoma, advanced adenomatous lesion, and sessile serrated lesions, on screening colonoscopy.

The development of premalignant colorectal polyps is significantly influenced by various lifestyle and modifiable risk factors. In our study, we used a large cohort of 9025 patients, who underwent screening colonoscopies at a university hospital, to assess the risk factors associated with the development of three different colorectal cancer precursor lesions: non-advanced adenomas (NAs), advanced adenomatous lesions (ADLs), and sessile serrated lesions (SSLs). Among the participants, 3641 had NAs, 836 had ADLs, and 533 had SSLs. We identified obesity, current smoking, and appendicular skeletal muscle mass as modifiable lifestyle risk factors that increase the development of NAs and ADLs (all P < 0.05). Furthermore, we found a positive correlation between the degree of obesity and an increased risk of developing NAs and ADLs (all P for trend < 0.001), while non-smoking was associated with a decreased risk (P for trend < 0.001 and 0.003, respectively). Smoking was the only modifiable risk factor for developing SSLs (adjusted odds ratio [aOR] 1.58; 95% confidence interval [CI] 1.20-2.07), and the risk was even higher in patients with metabolic syndrome (aOR 1.71; 95% CI 1.05-2.77). Addressing modifiable lifestyle factors such as smoking and obesity could play an important role in reducing the risk of both non-advanced and advanced adenomatous lesions. Smoking cessation is especially important as it is a significant modifiable risk factor for sessile serrated lesions.

Trends in and factors associated with family physician-performed screening colonoscopies in the United States: 2016-2021.

PURPOSE: Family physician (FP)-performed screening colonoscopies can serve as 1 strategy in the multifaceted strategy necessary to improve national colorectal cancer screening rates, particularly in rural areas where specialist models can fail. However, little research exists on the performance of this strategy in the real world. In this study, we evaluated trends in and factors associated with FP-performed screening colonoscopies in the United States between 2016 and 2021. METHODS: Using national data from Merative's Marketscan insurance claims database, we estimate the proportion of screening colonoscopies performed by FPs. We use logistic regression models to evaluate factors independently associated with FP-performed colonoscopies. RESULTS: The percentage of screening colonoscopies performed by FPs exhibited a downward trend from 11.32% in 2016 to 6.73% in 2021, with the largest decrease occurring among patients from the most rural areas. FPs were more likely to perform colonoscopies on slightly older patients, male patients, and rural patients. Patients were less likely to receive FP-performed colonoscopies in large metropolitan areas compared to lesser populated areas. Patients were more likely to receive FP-performed colonoscopies in the Midwest, South, and West, even after accounting for urban-rural classification. CONCLUSION: Despite a downward trajectory, FPs perform a substantial proportion of screening colonoscopies in the United States. Changes to the business side of health care delivery may be contributing to the observed decreasing rate. Whether through spatial or relational proximity, FPs may be better positioned to provide colonoscopy to some rural, male, and older patients who otherwise may not have been screened. Policy changes to expand the FP workforce, particularly in rural areas, are likely necessary to slow or reverse the downward trend of FP-performed screening colonoscopies.

Scissor-assisted vs. conventional endoscopic submucosal dissection for colorectal lesions: Systematic review and meta-analysis.

OBJECTIVES: Colorectal endoscopic submucosal dissection (ESD) is a technically complex procedure. The scissor knife mechanism may potentially provide easier and safer colorectal ESD. The aim of this meta-analysis is to evaluate the efficacy and safety of scissor-assisted vs. conventional ESD for colorectal lesions. METHODS: A search strategy was conducted in MEDLINE, Embase, and Lilacs databases from January 1990 to November 2023 according to PRISMA guidelines. Fixed and random-effects models were used for statistical analysis. Heterogeneity was assessed using I2 test. Risk of bias was assessed using the ROBINS-I and RoB-2 tools. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool. RESULTS: A total of five studies (three retrospective and two randomized controlled trials, including a total of 1575 colorectal ESD) were selected. The intraoperative perforation rate was statistically lower (risk difference [RD] -0.02; 95% confidence interval [CI] -0.04 to -0.01; P = 0.001; I2 = 0%) and the self-completion rate was statistically higher (RD 0.14; 95% CI 0.06, 0.23; P = 0.0006; I2 = 0%) in the scissor-assisted group compared with the conventional ESD group. There was no statistical difference in R0 resection rate, en bloc resection rate, mean procedure time, or delayed bleeding rate between the groups. CONCLUSION: Scissor knife-assisted ESD is as effective as conventional knife-assisted ESD for colorectal lesions with lower intraoperative perforation rate and a higher self-completion rate.