Early stage colon cancer: Current treatment standards, evolving paradigms, and future directions

CtDNA's prognostic value in patients with early-stage colorectal cancer after surgery: A meta-analysis and systematic review

BACKGROUND

Circulating tumor DNA (ctDNA) positivity has been shown to suggest the presence of minimally residual tumor cells in numerous investigations. We aimed to assess the prognostic value of ctDNA positivity for recurrence-free survival in patients with early-stage colorectal cancer after radical surgery and following adjuvant chemotherapy.

METHODS

We systematically reviewed studies published in English until August 15, 2022, concerning ctDNA and tumor-node-metastasis I to III colorectal cancer after surgery, and quantified the correlation between ctDNA positivity and early-stage (tumor-node-metastasis stage I-III) colorectal cancer using meta-analysis methods.

RESULTS

In total, the meta-analysis comprised 1713 patients from 6 studies. Patients with ctDNA-positive colorectal cancer after surgery had a significantly higher risk of recurrence than patients with ctDNA-negative colorectal cancer (hazard ratio 4.64, 95% confidence interval 2.17-9.92, z = 3.96; P < .001). After adjuvant chemotherapy, patients who were ctDNA-positive had a significantly higher risk of recurrence than those who were ctDNA-negative (hazard ratio 7.27, 95% confidence interval 4.50-11.75, z = 8.1; P < .001).

CONCLUSIONS

CtDNA positivity may potentially be a predictor for early-stage colorectal tumor recurrence following surgery and adjuvant chemotherapy.

Expression patterns and prognostic value of key regulators associated with m7G RNA modification based on all gene expression in colon adenocarcinoma

BACKGROUND

N7-methylguanosine (m7G) is present in a wide variety of organisms and has important roles. m7G has been reported to be involved in multiple biological processes, and recent studies have reported that changes in RNA modifications result in tumor cellular transformation and cancer, such as colon adenocarcinoma, lung cancer, and intrahepatic cholangiocarcinoma. However, little is known about the function of the m7G in colon adenocarcinoma.

METHODS

We established two clusters based on the expression of all genes associated with m7G to explore the expression pattern of 31 key regulatory factors of m7G RNA and assess the prognostic value of regulatory factors. Wilcoxon test and differential box line plots were applied for bioinformatics analysis. Receiver Operating and Kaplan‒Meier curves were utilized to evaluate the prognostic value. Finally, four genes' expression in the colon cancer cell line was confirmed by qRT-PCR.

RESULTS

From The Cancer Genome Atlas database, we found that the expression levels of 25 out of the 31 key N7-methylguanosine RNA modification regulators were significantly different in colon adenocarcinoma. According to 25 methylation regulators' expression, we identified two subgroups by consensus clustering, in which the prognosis was worse in Group 2 than in Group 1 and was significantly correlated with age. Cluster 2 was significantly enriched in tumor-associated pathways, and immune cells were highly infiltrated in Cluster 1 but weakly infiltrated in Cluster 2. Further results indicated that this risk profile may serve as a standalone predictive factor for colon adenocarcinoma, and the four genetic risk profiles' prognostic relatedness was successfully verified through Gene Expression Omnibus dataset. At last, A nomogram for prognosis was created according to age, sex, histological grading, clinicopathological staging, and hazard score to accurately predict patient prognosis in colon adenocarcinoma. We successfully validated the differential expression of four genes using qRT-PCR.

CONCLUSIONS

In the present study, we revealed the important contribution of key regulators associated with m7G RNA modifications based on all gene expression in colon adenocarcinoma and developed a signature of risk that serves as a promising prognostic marker for patients with colon adenocarcinoma.

Copy Number Variations as Determinants of Colorectal Tumor Progression in Liquid Biopsies

Over the years, increasing evidence has shown that copy number variations (CNVs) play an important role in the pathogenesis and prognosis of Colorectal Cancer (CRC). Colorectal adenomas are highly prevalent lesions, but only 5% of these adenomas ever progress to carcinoma. This review summarizes the different CNVs associated with adenoma-carcinoma CRC progression and with CRC staging. Characterization of CNVs in circulating free-RNA and in blood-derived exosomes augers well with the potential of using such assays for patient management and early detection of metastasis. To overcome the limitations related to tissue biopsies and tumor heterogeneity, using CNVs to characterize tumor-derived materials in biofluids provides less invasive sampling methods and a sample that collectively represents multiple tumor sites in heterogeneous samples. Liquid biopsies provide a source of circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), tumor-derived exosomes (TDE), circulating free RNA, and non-coding RNA. This review provides an overview of the current diagnostic and predictive models from liquid biopsies.

Investigation of the Effects of Glabridin on the Proliferation, Apoptosis, and Migration of the Human Colon Cancer Cell Lines SW480 and SW620 and Its Mechanism Based on Reverse Virtual Screening and Proteomics

Colon cancer is a relatively common malignant tumor of the digestive tract. Currently, most colon cancers originate from adenoma carcinogenesis. By screening various licorice flavonoids with anticancer effects, we found that glabridin (GBN) has a prominent anticolon cancer effect. First, we initially explored whether GBN can inhibit proliferation, migration, and invasion and induce apoptosis in SW480 and SW620 cells. Next, we exploited reverse virtual and proteomics technologies to screen out closely related target pathways on the basis of a drug and target database. At the same time, we constructed the structure of the GBN target pathway in colon cancer. We predicted that GBN can regulate the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT)-mammalian target of the rapamycin pathway (mTOR) pathway to fight colon cancer. Finally, through Western blot analysis and qRT-PCR, we verified that the expression levels of the PI3K, AKT, and mTOR proteins and genes in this pathway were significantly reduced after GBN administration. In short, the promising discovery of the anticolon cancer mechanism of GBN provides a reliable experimental basis for subsequent new drug development.

Chemotherapy and Abdominal Wall Closure Technique Increase the Probability of Postoperative Ventral Incisional Hernia in Patients With Colon Cancer

BACKGROUND

Chemotherapy is associated with postoperative ventral incisional hernia (PVIH) after right hemicolectomy (RHC) for colon cancer, and abdominal wall closure technique may affect PVIH. We sought to identify clinical predictors of PVIH.

METHODS

We retrospectively analyzed patients who underwent RHC for colon cancer from 2008-2018 and later developed PVIH. Time to PVIH was analyzed with Kaplan-Meier analysis, clinical predictors were identified with multivariable Cox proportional hazards modeling, and the probability of PVIH given chemotherapy and the suture technique was estimated with Bayesian analysis.

RESULTS

We identified 399 patients (209 no adjuvant chemotherapy and 190 adjuvant chemotherapy), with an overall PVIH rate of 38%. The 5-year PVIH rate was 55% for adjuvant chemotherapy, compared with 38% for none (log-rank P < .05). Adjuvant chemotherapy (hazard ratio [HR] 1.65, 95% confidence interval [CI] 1.18-2.31, P < .01), age (HR .99, 95% CI .97-1.00, P < .01), body mass index (HR 1.02, 95% CI 1.00-1.04, P < .01), and neoadjuvant chemotherapy (HR 1.92, 95% CI 1.21-3.00, P < .01) were independently associated with PVIH. Postoperative ventral incisional hernia was more common overall in patients who received adjuvant chemotherapy (46% compared with 30%, P < .01). In patients who received adjuvant chemotherapy, the probability of PVIH for incision closure with #1 running looped polydioxanone was 42%, compared with 59% for incision closure with #0 single interrupted polyglactin 910.

DISCUSSION

Exposure to chemotherapy increases the probability of PVIH after RHC, and non-short stitch incision closure further increases this probability, more so than age or body mass index. The suture technique deserves further study as a modifiable factor in this high-risk population.

Anti-Colorectal Cancer Effects of a Novel Camptothecin Derivative PCC0208037 In Vitro and In Vivo

Colorectal cancer is one of the most common malignancies, and the topoisomerase inhibitor irinotecan (CPT-11)-based chemotherapeutic regimen is currently the first-line treatment with impressive therapeutic efficacy. However, irinotecan has several clinically significant side effects, including diarrhea, which limit its clinical utility and efficacy in many patients. In an effort to discover better and improved pharmacotherapy against colorectal cancer, we synthesized a novel topoisomerase inhibitor, PCC0208037, examined its anti-tumor efficacy and related molecular mechanisms, and characterized its toxicity and pharmacokinetic profiles. PCC0208037 suppressed colorectal cancer cell (CRC) proliferation and increased cell cycle arrest, which may be related to its effects on up-regulating DNA damage response (DDR)-related molecules and apoptosis-related proteins. PCC0208037 demonstrated robust anti-tumor activity in vivo in a colorectal cancer cell xenograft model, which was comparable to or slightly better than CPT-11. In a preliminary toxicology study, PCC0208037 demonstrated much weaker tissue damage to colorectal tissue than CPT-11, and its impacts on food intake and body weight loss were more transient and recovered faster than CPT-11 in mice. This could be partially explained by the pharmacokinetic findings, which showed that PCC0208037 and its active metabolite, SN-38, were more accumulated in tumor tissue than in the intestine, as compared to CPT-11. Taken together, these results described a novel Topo I inhibitor with a comparative advantage over the standard treatment of colorectal cancer CPT-11 and could be a promising candidate compound for the treatment of colorectal cancer that warrants further investigation.

Using Circulating Tumor DNA in Colorectal Cancer: Current and Evolving Practices

There exists a tremendous opportunity in identifying and determining the appropriate predictive and prognostic biomarker(s) for risk stratification of patients with colorectal cancers (CRCs). Circulating tumor DNA (ctDNA) has emerged as a promising prognostic and possibly predictive biomarker in the personalized management of patients with CRCs. The disease is particularly suited to a liquid biopsy-based approach since there is a great deal of shedding of circulating tumor fragments (cells, DNA, methylation markers, etc). ctDNA has been shown to have several potential applications, including detecting minimal residual disease (MRD), monitoring for early recurrence, molecular profiling, and therapeutic response prediction. The utility of ctDNA has broadened from its initial use in the advanced/metastatic setting for molecular profiling and detection of acquired resistance mechanisms, toward identifying MRD, as well as early detection. Prospective studies such as CIRCULATE, COBRA, Dynamic II/III, and ACT3 are underway in the MRD setting to further understand how ctDNA may be used to inform clinical decision making using both tumor-informed and tumor-agnostic platforms. These prospective studies use ctDNA to guide management of patients with CRC and will be critical to help guide how and where ctDNA should or should not be used in clinical decision making. It is also important to understand that there are different types of ctDNA liquid biopsy platforms, each with advantages and disadvantages in different clinical indications. This review provides an overview of the current and evolving use of ctDNA in CRC.

Identification of a novel cellular senescence-related signature for the prediction of prognosis and immunotherapy response in colon cancer

The study was conducted to construct a cellular senescence-related risk score signature to predict prognosis and immunotherapy response in colon cancer. Colon cancer data were acquired from the Gene Expression Omnibus and The Cancer Genome Atlas databases. And cellular senescence-related genes were obtained from the CellAge database. The colon cancer data were classified into different clusters based on cellular senescence-related gene expression. Next, prognostic differential genes among clusters were identified with survival analysis. A cellular senescence-related risk score signature was developed by performing the LASSO regression analysis. Finally, PCA analysis, t-SNE analysis, Kaplan-Meier survival analysis, ROC analysis, univariate Cox regression analysis, multivariate Cox regression analysis, C-index analysis, meta-analysis, immune infiltration analysis, and IPS score analysis were used to evaluate the significance of the risk signature for predicting prognosis and immunotherapy response in colon cancer. The colon cancer data were classified into three clusters. The patients in cluster A and cluster B had longer survival. A cellular senescence-related risk score signature was developed. Patients in the low-risk score group showed a better prognosis. The risk score signature could predict colon cancer patients’ prognosis independently of other clinical characteristics. The risk score signature predicted the prognosis of colon cancer patients more accurately than other signatures. Patients in the low-risk score group showed a better response to immunotherapy. The opposite was true for the high-risk score group. In conclusion, the cellular senescence-related risk score signature could be used for the prediction of prognosis and immunotherapy response in colon cancer.

MACC1 Promotes the Progression and Is a Novel Biomarker for Predicting Immunotherapy Response in Colorectal Cancer

Aims

As one of the most prevalent malignant diseases in the world, the mechanisms of metastasis in colon cancer are poorly understood. The aim of this study was to investigate the role of the HGF/c-MET axis in the proliferation and metastasis in colon cancer.

Methods

The effect of MACC1 on cell proliferation and metastasis was analyzed through a series of in vitro experiments. The role of MACC1 in cancer cells was demonstrated by overexpression and silencing of MACC1 in gain or loss function experiments. To investigate the relationship between MACC1 and c-MET/HGF, we detected c-MET protein expression by disrupting with or overexpressing MACC1. The bioinformatics analysis was used to investigate the correlation between MACC1 and c-MET, and the c-MET expression after the interference of HGF with MACC1 was determined. Subsequently, the function of c-MET was verified in colon cancer cells by a series of experiments. The mouse tumor transplantation model experiment is most suitable in vivo.

Results

The results indicated that the overexpression of MACC1 could accelerate proliferation and facilitate metastasis in colon cancer cell lines. Furthermore, c-MET was determined to be the downstream regulator of MACC1. The addition of HGF could stimulate the expression of MACC1. With further exploration, we proved that c-MET is downstream of MACC1 in colon cancer and that overexpression of c-MET in colon cancer enhances cell proliferation and migration capability. At last, MACC1 expression level negatively correlates with the infiltration levels and several immune checkpoint biomarkers. High MACC1 expression has a lower response rate with ICIs in COAD.

Conclusions

We found that, under the regulation of the MACC1/HGF/c-MET axis, the proliferation and metastasis of colorectal cancer are increased by MACC1, which can be a novel biomarker for predicting ICIs response in colorectal cancer. Our findings provide a new idea for the targeted treatment of colorectal cancer.

Detection of methylated BCAT1 and IKZF1 after curative-intent treatment as a prognostic indicator for colorectal cancer recurrence

BACKGROUND

The risk of recurrence after completion of curative-intent treatment of colorectal cancer (CRC) is hard to predict. Post-treatment assaying for circulating tumor DNA (ctDNA) is an encouraging approach for stratifying patients for therapy, but the prognostic value of this approach is less explored. This study aimed to determine if detection of methylated BCAT1 and IKZF1 following completion of initial treatment identified patients with a poorer recurrence-free survival (RFS).

METHODS

142 CRC stage I-III cases with at least 2 years of follow up (unless recurrence was evident sooner) and a methylated BCAT1/IKZF1 test result between 2 weeks and 12 months after completion of initial treatment were eligible for study inclusion. The association between BCAT1/IKZF1 and RFS was assessed by the log-rank (Mantel-Cox) method. Cox proportional hazard regression analysis was used for multivariable survival analysis.

RESULTS

Thirty-three (23.2%) had recurrence at a median 1.6y (interquartile range: 0.8-2.4). Methylated BCAT1/IKZF1 was detected in 19 of the 142 patients (13.4%) and was associated with a significant risk of recurrence (hazard ratio [HR] 5.7, 95%CI: 1.9-17.3, p = 0.002). Three-year RFS for patients with or without detectable methylated BCAT1/IKZF1 was 56.5% and 83.3%, respectively. Multivariable analysis showed that detection of methylated BCAT1/IKZF1 (HR = 2.6, p = 0.049) and site of the primary tumor (HR = 4.2, p = 0.002) were the only significant prognostic indicators of poor RFS.

CONCLUSIONS

BCAT1/IKZF1 methylation testing after curative-intent treatment is an independent prognostic indicator for RFS and identifies a subgroup at high risk. Personalized surveillance is warranted for patients with these ctDNA biomarkers detectable after curative-intent treatment.

Relationship between pre‑operative glycated haemoglobin and surgical site infection in patients undergoing elective colon cancer surgery

Surgical site infections remain a significant cause of morbidity following colon cancer surgery. Although diabetes has been recognised as a risk factor, patients with asymptomatic diabetes are likely underdiagnosed. The aim of the present study was to determine the relationship between preoperative glycated haemoglobin (HbA1C), clinicopathological characteristics and the influence on surgical site infection in a cohort of patients undergoing potentially curative colon cancer surgery. Patients who underwent elective, potentially curative colon cancer surgery between January 2011 and December 2014 were assessed for HbA1C levels (mmol/mol) measured within 3 months preoperatively. Clinicopathological data were recorded in a maintained database. A multivariate binary logistic regression model was used to assess the relationship between HbA1C, clinicopathological characteristics and surgical site infections. A total of 362 patients had HbA1C levels preoperatively recorded. HbA1C was significantly associated with body mass index (BMI), diabetes, smoking status, visceral fat area and skeletal muscle index. As determined by multivariate analysis, preoperative HbA1C levels remained independently associated with an increased risk of surgical site infections (OR 1.69, 95% CI 1.05-2.7; P=0.031) together with BMI (OR 1.91, 95% CI 1.36-2.67; P<0.001). Notably, in the present study, tumour-based factors, such as tumour location and TNM status, were not associated with infective complications. By contrast, host factors, such as BMI and pre-operative HbA1C were associated with surgical site infections suggesting that these factors were of more importance in determining short-term outcomes. In conclusion, objective measurements of BMI and HbA1C effectively stratified the risk of developing surgical site infection from 8 to 59%; therefore, HbA1C levels should be determined to allow for preoperative optimisation.

Finding Waldo: The Evolving Paradigm of Circulating Tumor DNA (ctDNA)-Guided Minimal Residual Disease (MRD) Assessment in Colorectal Cancer (CRC)

Circulating tumor DNA (ctDNA), the tumor-derived cell-free DNA fragments in the bloodstream carrying tumor-specific genetic and epigenetic alterations, represents an emerging novel tool for minimal residual disease (MRD) assessment in patients with resected colorectal cancer (CRC). For many decades, precise risk-stratification following curative-intent colorectal surgery has remained an enduring challenge. The current risk stratification strategy relies on clinicopathologic characteristics of the tumors that lacks precision and results in over-and undertreatment in a significant proportion of patients. Consequently, a biomarker that can reliably identify patients harboring MRD would be of critical importance in refining patient selection for adjuvant therapy. Several prospective cohort studies have provided compelling data suggesting that ctDNA could be a robust biomarker for MRD that outperforms all existing clinicopathologic criteria. Numerous clinical trials are currently underway to validate the ctDNA-guided MRD assessment and adjuvant treatment strategies. Once validated, the ctDNA technology will likely transform the adjuvant therapy paradigm of colorectal cancer, supporting ctDNA-guided treatment escalation and de-escalation. The current article presents a comprehensive overview of the published studies supporting the utility of ctDNA for MRD assessment in patients with CRC. We also discuss ongoing ctDNA-guided adjuvant clinical trials that will likely shape future adjuvant therapy strategies for patients with CRC.

Young-Onset Gastrointestinal Adenocarcinoma Incidence and Survival Trends in the Northern Territory, Australia, with Emphasis on Indigenous Peoples

Background and Aims: A concerning rise in incidence of young-onset cancers globally led to the examination of trends in incidence and survival of gastrointestinal (GI) adenocarcinomas in the Northern Territory (NT), Australia, over a 28-year period, with a special emphasis on Indigenous peoples. Methods: This cross-sectional analysis of a prospective longitudinal database, NT Cancer Registry (1990−2017), includes all reported cases of GI (oesophagus, gastric, small intestinal, pancreas, colon, and rectum) adenocarcinomas. Poisson regression was used to estimate incidence ratio ratios, and survival was modelled using Cox proportional hazard models separately for people aged 18−50 years and >50 years. Results: A total of 1608 cases of GI adenocarcinoma were recorded during the time of the study. While the overall incidence in people 18−50 years remained unchanged over this time (p = 0.51), the rate in individuals aged >50 years decreased (IRR = 0.65 (95% CI 0.56−0.75; p < 0.0001)). Incidence rates were significantly less in females >50 years (IRR = 0.67 95% CI 0.59−0.75; p < 0.0001), and their survival was significantly better (HR = 0.84 (95%CI 0.72−0.98; p < 0.03)) compared to males. Overall survival across all GI subsites improved in both age cohorts, especially between 2010 and 2017 (HR = 0.45 (95%CI 0.29−0.72; p < 0.0007) and HR = 0.64 (95%CI 0.52−0.78; p < 0.0001), respectively) compared to 1990−1999, driven by an improvement in survival in colonic adenocarcinoma alone, as the survival remained unchanged in other GI subsites. The incidence was significantly lower in Indigenous patients compared to non-Indigenous patients, in both age cohorts (18−50 years IRR = 0.68 95% CI 0.51−0.91; p < 0.009 and >50 years IRR = 0.48 95% CI 0.40−0.57; p < 0.0001). However, Indigenous patients had worse survival rates (18−50 years HR = 2.06 95% CI 1.36−3.11; p < 0.0007 and >50 years HR = 1.66 95% CI 1.32−2.08; p < 0.0001). Conclusions: There is a trend towards an increased incidence of young-onset GI adenocarcinomas in the NT. Young Indigenous patients have lower incidence but worse survival across all GI subsites, highlighting significant health inequities in life expectancy. Targeted, culturally safe Indigenous community-focussed programs are needed for early detection and patient-centred management of GI adenocarcinomas.

Organ Preservation in Colon Cancer: An Illustrative Case Report

The organ preservation strategy in non-metastatic rectal cancer is a rapidly evolving, novel treatment paradigm that is offered outside of a clinical trial in many advanced cancer centers. However, for non-metastatic colon cancer, upfront surgery followed by adjuvant chemotherapy in patients deemed at risk of cancer recurrence is the current standard of care. A significant proportion of patients with non-metastatic colon cancer harbor a deficient mismatch repair (dMMR)/microsatellite instability-high (MSI-H) signature in tumors, which predicts a deep and durable response to immune checkpoint inhibitors (ICI) in a large proportion of such patients. This opens an opportunity for organ preservation in colon cancer in select circumstances. Herein, we describe a patient with locally advanced dMMR/MSI-H colon cancer who could not undergo standard colon surgery but achieved complete remission following treatment with ICI.

A possible theranostic approach of chitosan-coated iron oxide nanoparticles against human colorectal carcinoma (HCT-116) cell line

Iron oxides have become increasingly popular for their use as a diagnostic and therapeutic tool in oncology. This study aimed to improve pharmacological valuable of Fe₃O₄, which may be use to diagnosis colorectal cancers (CRC). Here, we have developed chitosan (CS) coated Fe₃O₄ through a cost-effective procedure. First, we determined the characterization of OA-C-Fe₃O₄ by FTIR, UV–Vis spectra, and TEM. Then, we evaluated the photodynamic therapeutic (PDT) activity of OA-C-Fe₃O₄ in human colorectal carcinoma cell lines (HCT 116). Current results revealed that the light-induced enhanced reactive oxygen species (ROS) activity of the nanoparticles (NPs) and caused cell death via the activity of caspase 9/3. The in vitro magnetic resonance imaging (MRI) experiments in (HCT 116) and human embryonic kidney cells (HEK 293) illustrated that nanohybrid is an effective MRI contrasting agents for the diagnosis of colorectal cancer.

Clinical implication of adjuvant chemotherapy according to mismatch repair status in patients with intermediate-risk stage II colon cancer

Background

The present study evaluated the clinical implications of adjuvant chemotherapy according to the mismatch repair (MMR) status and clinicopathologic features of patients with intermediate- and high-risk stage II colon cancer (CC).

Methods

This study retrospectively reviewed 5,774 patients who were diagnosed with CC and underwent curative surgical resection at Kyungpook National University Chilgok Hospital. The patients were enrolled according to the following criteria: (1) pathologically diagnosed with primary CC; (2) stage II CC classified based on the 7th edition of the American Joint Committee on Cancer staging system; (3) intermediate- and high-risk features; and (4) available test results for MMR status. A total of 286 patients met these criteria and were included in the study.

Results

Among the 286 patients, 54 (18.9%) were identified as microsatellite instability-high (MSI-H) or deficient MMR (dMMR). Although all the patients identified as MSI-H/dMMR showed better survival outcomes, T4 tumors and adjuvant chemotherapy were identified as independent prognostic factors for survival. For the intermediate-risk patients identified as MSI-low (MSI-L)/microsatellite stable (MSS) or proficient MMR (pMMR), adjuvant chemotherapy exhibited a significantly better disease-free survival (DFS) but had no impact on overall survival (OS). Oxaliplatin-containing regimens showed no association with DFS or OS. Adjuvant chemotherapy was not associated with DFS in intermediate-risk patients identified as MSI-H/dMMR.

Conclusion

The current study found that the use of adjuvant chemotherapy was correlated with better DFS in MSI-L/MSS or pMMR intermediate-risk stage II CC patients.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis treatment and follow-up of patients with localised colon cancer

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of localised colon cancer was published in 2020. It was decided by both the ESMO and the Japanese Society of Medical Oncology (JSMO) to convene a special virtual guidelines meeting in March 2021 to adapt the ESMO 2020 guidelines to take into account the ethnic differences associated with the treatment of localised colon cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with localised colon cancer representing the oncological societies of Japan (JSMO), China (CSCO), India (ISMPO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug availability and reimbursement situations in the different Asian countries.

A narrative review of genetic factors affecting fluoropyrimidine toxicity

OBJECTIVE

Our objective is to document progress in developing personalized therapy with fluoropyrimidine drugs (FPs) to improve outcomes for cancer patients and to identify areas requiring further investigation.

BACKGROUND

FPs including 5-fluorouracil (5-FU), are among the most widely used drugs for treating colorectal cancer (CRC) and other gastrointestinal (GI) malignancies. While FPs confer a survival benefit for CRC patients, serious systemic toxicities, including neutropenia, occur in ~30% of patients with lethality in 0.5-1% of patients. While serious systemic toxicities may occur in any patient, patients with polymorphisms in DPYD, which encodes the rate-limiting enzyme for pyrimidine degradation are at very high risk. Other genetic factors affecting risk for 5-FU toxicity, including miR-27a, are under investigation.

METHODS

Literature used to inform the text of this article was selected from PubMed.gov from the National Library of Medicine while regulatory documents were identified via Google search.

CONCLUSIONS

Clinical studies to date have validated four DPYD polymorphisms (DPYD*2A, DPYD*13, c.2846A>T, HapB3) associated with serious toxicities in patients treated with 5-FU. Genetic screening for these is being implemented in the Netherlands and the UK and has been shown to be a cost-effective way to improve outcomes. Factors other than DPYD polymorphisms (e.g., miR-27a, TYMS, ENOSF1, p53) also affect 5-FU toxicity. Functional testing for deficient pyrimidine catabolism {defined as [U] >16 ng/mL or [UH2]:[U] <10} is being implemented in France and has demonstrated utility in identifying patients with elevated risk for 5-FU toxicity. Therapeutic drug monitoring (TDM) from plasma levels of 5-FU during first cycle treatment also is being used to improve outcomes and pharmacokinetic-based dosing is being used to increase the percent of patients within optimal area under the curve (AUC) (18-28 mg*h/L) values. Patients maintained in the optimal AUC range experienced significantly reduced systemic toxicities. As understanding the genetic basis for increased risk of 5-FU toxicity becomes more refined, the development of functional-based methods to optimize treatment is likely to become more widespread.

Advantages and Challenges of Using ctDNA NGS to Assess the Presence of Minimal Residual Disease (MRD) in Solid Tumors

The ability to detect minimal residual disease (MRD) after a curative-intent surgery or treatment is of paramount importance, because it offers the possibility to help guide the clinical decisions related adjuvant therapy. Thus, the earlier MRD is detected, the earlier potentially beneficial treatment can be proposed to patients who might need it. Liquid biopsies, and in particular the next-generation sequencing of circulating tumor DNA (ctDNA) in the blood, have been the focus of an increasing amount of research in the past years. The ctDNA detection at advanced cancer stages is practicable for several solid tumors, and complements molecular information on acquired therapy resistance. In the context of MRD, it is by definition more challenging to detect ctDNA, but it is technically achievable and provides information on treatment response and probability of relapse significantly earlier than standard imaging methods. The clinical benefit of implementing this new technique in the routine is being tested in interventional clinical trials at the moment. We propose here an update of the current use of ctDNA detection by NGS as a tool to assess the presence of MRD and improve adjuvant treatment of solid tumors. We also discuss the main limitations and medium-term perspectives of this process in the clinic.

Polymeric Nanoparticles for Mitochondria Targeting Mediated Robust Cancer Therapy

Despite all sorts of innovations in medical researches over the past decades, cancer remains a major threat to human health. Mitochondria are essential organelles in eukaryotic cells, and their dysfunctions contribute to numerous diseases including cancers. Mitochondria-targeted cancer therapy, which specifically delivers drugs into the mitochondria, is a promising strategy for enhancing anticancer treatment efficiency. However, owing to their special double-layered membrane system and highly negative potentials, mitochondria remain a challenging target for therapeutic agents to reach and access. Polymeric nanoparticles exceed in cancer therapy ascribed to their unique features including ideal biocompatibility, readily design and synthesis, as well as flexible ligand decoration. Significant efforts have been put forward to develop mitochondria-targeted polymeric nanoparticles. In this review, we focused on the smart design of polymeric nanosystems for mitochondria targeting and summarized the current applications in improving cancer therapy.

Tetramethylpyrazine inhibits proliferation of colon cancer cells in vitro

BACKGROUND

Colon cancer is one of the most common malignancies worldwide, and chemotherapy is a widely used strategy in colon cancer clinical therapy. However, chemotherapy resistance is a major cause of disease recurrence and progression in colon cancer, and thus novel drugs for treatment are urgently needed. Tetramethylpyrazine (TMP), a component of the traditional Chinese medicine Chuanxiong Hort, has been proven to exhibit a beneficial effect in tumors.

AIM

To investigate the potential anticancer activity of TMP in colon cancer and its underlying mechanisms.

METHODS

Colon cancer cells were incubated with different concentrations of TMP. Cell viability was evaluated by crystal violet staining assay and cell counting kit-8 assay, and cell apoptosis and cell cycle were assessed by flow cytometry.

RESULTS

TMP significantly inhibited the proliferation of colon cancer cells in a dose- and time-dependent manner. In addition, flow cytometry revealed that TMP induced cell cycle arrest at the G0/G1 phase. TMP treatment caused early stage apoptosis in SW480 cells, whereas it caused late stage apoptosis in HCT116 cells.

CONCLUSION

Our studies demonstrated that TMP inhibits the proliferation of colon cancer cells in a dose- and time-dependent manner by inducing apoptosis and arresting the cell cycle at the G0/G1 phase. Our findings suggest that TMP might serve as a potential novel therapeutic drug in the treatment of human colon cancer.

Whether early stage pancreatic ductal adenocarcinoma patients could benefit from the post-operation chemotherapy regimens: a SEER-based propensity score matching study

To investigate whether chemotherapy could prolong the postoperative survival time in patients with early stages pancreatic ductal adenocarcinoma (PDAC). A total of 5280 stage ⅠA -ⅡB PDAC patients diagnosed from 2010 to 2015 were selected from surveillance，epidemiology，and end results (SEER) database. Propensity score matching (PSM) analysis was adopted to reduce the baseline differences between the groups. Univariate survival analysis was conducted with the Kaplan-Meier method. Multivariate survival analysis was performed with the Cox proportional hazards model. Univariate and multivariate survival analyses showed that age, differentiation, stage, chemotherapy were independent risk factors for the survival of PDAC patients. After PSM, it is found that adjuvant chemotherapy could prolong the median overall survival time (mOS) for stage ⅠB, ⅡA and ⅡB patients. However, for stage ⅠA patients, there were no significant differences in 3-year survival rate and mOS between patients with chemotherapy (=283) and without chemotherapy (=229) (57.4% vs 55.6%, vs all >0.05). Further analyses show that among 101 patients with well differentiated PDAC and 294 patients with moderately differentiated PDAC, there were no significant differences in survival rate and mOS between patients with and without chemotherapy (all >0.05). Among 117 patients with low-differentiated + undifferentiated PDAC, 3-year survival rate and mOS in patients with chemotherapy were significantly better than those without chemotherapy (48.5% vs 34.1%, vs all <0.05). Chemotherapy regimen used currently is not beneficial for patients with moderately and well differentiated stage ⅠA PDAC, but it is an independent prognostic factor for low-differentiated + undifferentiated PDAC patients.

Minimal Residual Disease Detection using a Plasma-only Circulating Tumor DNA Assay in Patients with Colorectal Cancer

PURPOSE

Detection of persistent circulating tumor DNA (ctDNA) after curative-intent surgery can identify patients with minimal residual disease (MRD) who will ultimately recur. Most ctDNA MRD assays require tumor sequencing to identify tumor-derived mutations to facilitate ctDNA detection, requiring tumor and blood. We evaluated a plasma-only ctDNA assay integrating genomic and epigenomic cancer signatures to enable tumor-uninformed MRD detection.

EXPERIMENTAL DESIGN

A total of 252 prospective serial plasma specimens from 103 patients with colorectal cancer undergoing curative-intent surgery were analyzed and correlated with recurrence.

RESULTS

Of 103 patients, 84 [stage I (9.5%), II (23.8%), III (47.6%), IV (19%)] had evaluable plasma drawn after completion of definitive therapy, defined as surgery only (n = 39) or completion of adjuvant therapy (n = 45). In "landmark" plasma drawn 1-month (median, 31.5 days) after definitive therapy and >1 year follow-up, 15 patients had detectable ctDNA, and all 15 recurred [positive predictive value (PPV), 100%; HR, 11.28 (P < 0.0001)]. Of 49 patients without detectable ctDNA at the landmark timepoint, 12 (24.5%) recurred. Landmark recurrence sensitivity and specificity were 55.6% and 100%. Incorporating serial longitudinal and surveillance (drawn within 4 months of recurrence) samples, sensitivity improved to 69% and 91%. Integrating epigenomic signatures increased sensitivity by 25%-36% versus genomic alterations alone. Notably, standard serum carcinoembryonic antigen levels did not predict recurrence [HR, 1.84 (P = 0.18); PPV = 53.9%].

CONCLUSIONS

Plasma-only MRD detection demonstrated favorable sensitivity and specificity for recurrence, comparable with tumor-informed approaches. Integrating analysis of epigenomic and genomic alterations enhanced sensitivity. These findings support the potential clinical utility of plasma-only ctDNA MRD detection.

PD-L1 as a Prognostic Factor in Early-Stage Colon Carcinoma within the Immunohistochemical Molecular Subtype Classification

BACKGROUND

There is a patent need to better characterize early-stage colorectal cancer (CRC) patients. PD-1 ligand (PD-L1) expression has been proposed as a prognostic factor but yields mixed results in different settings. The Consensus Molecular Subtype (CMS) classification has yet to be integrated into clinical practice. We sought to evaluate the prognostic value of PD-L1 expression overall and within CMS in early-stage colon cancer patients, in the hope of assisting treatment choice in this setting.

METHODS

Tissue-microarrays were constructed from tumor samples of 162 stage II/III CRC patients. They underwent automatic immunohistochemical staining for PD-L1 and the proposed CMS panel. Primary endpoints were overall survival (OS) and disease-free survival (DFS).

RESULTS

PD-L1 expression was significantly and independently associated with better prognosis (HR = 0.46 (0.26-0.82), p = 0.009) and was mostly seen in immune cells of the tumor-related stroma. CMS4 five-folds the risk of mortalitycompared with CMS1 (HR = 5.58 (1.36, 22.0), p = 0.034). In the subgroup CMS2/CMS3 analysis, PD-L1 expression significantly differentiated individuals with better OS (p = 0.004) and DFS (p < 0.001).

CONCLUSIONS

Our study suggests that PD-L1 expression is an independent prognostic factor in patients with stage II/III colon cancer. Additionally, it successfully differentiates patients with better prognosis in the CMS2/CMS3 group and may prove significant for the clinical relevance of the CMS classification.

The Promise of Circulating Tumor DNA (ctDNA) in the Management of Early-Stage Colon Cancer: A Critical Review

The current standard treatment for patients with early-stage colon cancer consists of surgical resection, followed by adjuvant therapy in a select group of patients deemed at risk of cancer recurrence. The decision to administer adjuvant therapy, intended to eradicate the clinically inapparent minimal residual disease (MRD) to achieve a cure, is guided by clinicopathologic characteristics of the tumor. However, the risk stratification based on clinicopathologic characteristics is imprecise and results in under or overtreatment in a substantial number of patients. Emerging research indicates that the circulating tumor DNA (ctDNA), a fraction of cell-free DNA (cfDNA) in the bloodstream that originates from the neoplastic cells and carry tumor-specific genomic alterations, is a promising surrogate marker of MRD. Several recent studies suggest that ctDNA-guided risk stratification for adjuvant therapy outperforms existing clinicopathologic prognostic indicators. Preliminary data also indicate that, aside from being a prognostic indicator, ctDNA can inform on the efficacy of adjuvant therapy, which is the underlying scientific rationale for several ongoing clinical trials evaluating ctDNA-guided therapy escalation or de-escalation. Furthermore, serial monitoring of ctDNA after completion of definitive therapy can potentially detect cancer recurrence much earlier than conventional surveillance methods that may provide a critical window of opportunity for additional curative-intent therapeutic interventions. This article presents a critical overview of published studies that evaluated the clinical utility of ctDNA in the management of patients with early-stage colon cancer, and discusses the potential of ctDNA to transform the adjuvant therapy strategies.