Treatment Of Colorectal Cancer Research Articles

Hydroxygenkwanin suppresses peritoneal metastasis in colorectal cancer by modulating tumor-associated macrophages polarization

Peritoneal metastasis is an important cause of high mortality and poor prognosis in colorectal cancer (CRC) patients. Therefore, the development of compounds with unique anti-CRC Peritoneal metastasis activities is urgently needed to improve the survival of CRC patients. Hydroxygenkwanin (HGK),a natural flavonoid compound, have been shown to display anti-inflammatory, antioxidant, antitumor, and immunoregulatory effects. Here, we employed CRC peritoneal metastasis mouse model with MC38 cells to examine the antitumor activity of HGK. The result showed that HGK not only inhibited peritoneal metastasis, but also significantly increased the proportion of M1-like macrophages while decreasing the proportion of M2-like macrophages within the tumor microenvironment (TME). Furthermore, we demonstrated that the inhibitory effect of HGK on peritoneal metastasis of CRC depended on macrophages in vitro and in vivo. Moreover, we revealed that HGK promoted the polarization of TAMs into M1-like macrophages and inhibited their polarization into M2-like macrophages in a LPS- or IL-4-induced bone marrow-derived macrophages (BMDMs) model and co-culture system. Finally, we also investigated the regulatory mechanism of HGK on TAMs polarization that HGK may active p-STAT5, p–NF–κB signaling in M1-like macrophages and inhibit p-STAT6, JMJD3, PPARγ expression in M2-like macrophages. Taken together, our findings suggest that HGK is a natural candidate for effective prevention of peritoneal metastasis in colorectal cancer, which provides a potential strategy for clinical treatment of colorectal cancer.

Modified Lichong decoction intervenes in colorectal cancer by modulating the intestinal flora and the Wnt/β-catenin signaling pathway

BackgroundThe pathogenesis and treatment of colorectal cancer (CRC) continue to be areas of ongoing research, especially the benefits of traditional Chinese medicine (TCM) in slowing the progression of CRC. This study was conducted to investigate the effectiveness and mechanism of action of modified Lichong decoction (MLCD) in inhibiting CRC progression.MethodsWe established CRC animal models using azoxymethane/dextran sodium sulfate (AOM/DSS) and administered high, medium, or low doses of MLCD or mesalazine (MS) for 9 weeks to observe MLCD alleviation of CRC. The optimal MLCD dose group was then subjected to metagenomic and RNA sequencing (RNA-seq) to explore the differentially abundant flora and genes in the control, model and MLCD groups. Finally, the mechanism of action was verified using WB, qRT‒PCR, immunohistochemistry and TUNEL staining.ResultsMLCD inhibited the progression of CRC, and the optimal effect was observed at high doses. MLCD regulated the structure and function of the intestinal flora by decreasing the abundance of harmful bacteria and increasing that of beneficial bacteria. The differentially expressed genes were mainly associated with the Wnt/β-catenin pathway and the cell cycle. Molecular biology analysis indicated that MLCD suppressed the Wnt/β-catenin pathway and the epithelial–mesenchymal transition (EMT), inhibited abnormal cell proliferation and promoted intestinal epithelial cell apoptosis.ConclusionMLCD mitigated the abnormal growth of intestinal epithelial cells and promoted apoptosis, thereby inhibiting the progression of CRC. This inhibition was accomplished by modifying the intestinal microbiota and disrupting the Wnt/β-catenin pathway and the EMT. Therefore, MLCD could serve as a potential component of TCM prescriptions for CRC treatment.

Exploring the Relationship Between KRAS, NRAS, and BRAF Mutations and Clinical Characteristics in Iranian Colorectal Cancer Patients.

Patients with colorectal cancer can benefit from anti-EGFR (epidermal growth factor receptor) therapy. However, this therapy is not effective for treating colorectal cancers with constitutive activating mutations in the KRAS, NRAS, and BRAF genes. Molecular analysis of tumor tissue frequently informs treatment decisions for colorectal cancer. This study aims to identify KRAS, NRAS, and BRAF mutations in Iranian patients diagnosed with colorectal cancer and to assess the prevalence of these mutations relative to the tumor differentiation stage within these populations. From April 2018 to December 2022, 2000 specimens from patients with colorectal cancer were collected. Data on sex, age, and tumor differentiation stage were recorded for all samples. For mutation detection, the KRAS and NRAS exons (2, 3, and 4) were amplified using the Diatech kit, and a specific primer was used to amplify BRAF exon 15. Pyrosequencing was then performed. Analysis of samples revealed that 1105 specimens (55.3%) contained mutations in at least one of the screened genes. Among the genes studied, the highest occurrence was the KRAS mutation at 47.4%, followed by NRAS at 5.3% and BRAF at 2.7%. Most KRAS mutations were found in exon 2 (89.7%), with the G12D mutation being the most prevalent at 32% of cases. There was a significant difference in the rate of KRAS mutations in women (52.5%) compared to men (43.5%) (P = 0.02). For NRAS, the majority mutations were observed in exon 3 (76.2%), with the Q61H mutation being the most prevalent at 28.5% of cases. There were no significant associations between the clinicopathological parameters and mutations. The study's findings indicate a rising frequency of mutations in these genes in Iran, highlighting the need to screening mutations in the main exons of all three genes for effective colorectal cancer treatment strategies.

Oxaliplatin-induced Acute Neurotoxicity Recovers Between Repeat Infusion Cycles: An Axonal Excitability Repeated Multiple Measurements Study.

Oxaliplatin, a platinum-based chemotherapy used in the treatment of colorectal cancer, induces acute neurotoxicity following infusion. The aim of this study was to establish whether alterations in axonal excitability develop progressively with higher cumulative doses and whether there is a recovery in motor axons after each cycle of treatment. Twenty consecutive patients with a colorectal cancer diagnosis, referred from the Oncology Department of Aretaieion Hospital of Athens, were enrolled in this study between October 2018 and May 2019. None of the participants had diabetes, alcohol abuse, known neuropathy or were previously treated with another neo-adjuvant therapy. Threshold Tracking techniques and Qtrac software were used for assessing axonal excitability in motor axons. Excitability recordings were undertaken before and immediately after the end of oxaliplatin infusion. Statistically significant changes were found (p<0.01) in axonal excitability (relative refractory period, refractoriness at 2 ms and 2.5 ms, sub-excitability and super-excitability) before and after oxaliplatin infusion. No statistically significant changes (p>0.05) were found in threshold electrotonus and strength-duration parameters before and after oxaliplatin infusion. We also did not find statistically significant differences (p>0.05) between means of excitability parameters before infusion at each cycle. Our study confirms oxaliplatin-induced acute neurotoxicity following infusion and suggests that motor axons recover between repeat infusion cycles.

A dual gene combination therapy approach by KRAS-G12V gene editing and SLC25A22 gene silencing for KRAS-mutant colorectal cancer

KRAS gene is mutated in 40% of colorectal cancers (CRC), which induces malignant proliferation by regulating cellular nutrient metabolism and biosynthesis. It has been found that malignant proliferation of KRAS-mutant colorectal cancer relies on the upregulation of SLC25A22 protein expression, suggesting that inhibition the expression of both KRAS and SLC25A22 is a potential CRC therapeutics. Stably knocking down the oncogenic KRAS-G12V gene can achieve long-term gene therapy effects, while transient downregulation of SLC25A22, a normal functional gene most of the time, is preferred to kill tumor cells and minimize the side impact on normal cells. Here, two lipid nanoparticles (LNP) were designed to encapsulate KRAS-G12V CRISPR/Cas9 gene editing plasmids (pKRAS-LNPs) and SLC25A22 siRNA (siSLC-LNPs), respectively. Therapeutic effects of both nanoparticles alone and in combination on KRAS-G12V mutant colorectal cancer cells in vitro were first examined. The result showed that delivery of pKRAS-LNPs or siSLC-LNPs alone could effectively achieve KRAS-G12V gene editing or SLC25A22 gene silencing and inhibit tumor cell proliferation, while co-delivery of both LNPs could achieve stronger inhibition of tumor cell proliferation by inducing stronger apoptosis. Furthermore, we found that co-delivery of pKRAS-LNPs and siSLC-LNPs induced stronger apoptosis and cell proliferation inhibition compared to pKRAS&siSLC-LNPs that were constructed by pre-mixing pKRAS and siSLC and then encapsulating them. Finally, we validated that co-delivery of pKRAS-LNPs and siSLC-LNPs can achieve KRAS-G12V colorectal cancer treatment in vivo with a tumor inhibition rate of 61.15%. In summary, the delivery vectors constructed for nucleic acids targeting KRAS and SLC25A22 achieved therapeutic targeting of KRAS-G12V colorectal cancer in vitro and in vivo.

Longitudinal associations of diurnal rest-activity rhythms with fatigue, insomnia, and health-related quality of life in survivors of colorectal cancer up to 5 years post-treatment

BackgroundThere is a growing population of survivors of colorectal cancer (CRC). Fatigue and insomnia are common symptoms after CRC, negatively influencing health-related quality of life (HRQoL). Besides increasing physical activity and decreasing sedentary behavior, the timing and patterns of physical activity and rest over the 24-h day (i.e. diurnal rest-activity rhythms) could also play a role in alleviating these symptoms and improving HRQoL. We investigated longitudinal associations of the diurnal rest-activity rhythm (RAR) with fatigue, insomnia, and HRQoL in survivors of CRC.MethodsIn a prospective cohort study among survivors of stage I-III CRC, 5 repeated measurements were performed from 6 weeks up to 5 years post-treatment. Parameters of RAR, including mesor, amplitude, acrophase, circadian quotient, dichotomy index, and 24-h autocorrelation coefficient, were assessed by a custom MATLAB program using data from tri-axial accelerometers worn on the upper thigh for 7 consecutive days. Fatigue, insomnia, and HRQoL were measured by validated questionnaires. Confounder-adjusted linear mixed models were applied to analyze longitudinal associations of RAR with fatigue, insomnia, and HRQoL from 6 weeks until 5 years post-treatment. Additionally, intra-individual and inter-individual associations over time were separated.ResultsData were available from 289 survivors of CRC. All RAR parameters except for 24-h autocorrelation increased from 6 weeks to 6 months post-treatment, after which they remained relatively stable. A higher mesor, amplitude, circadian quotient, dichotomy index, and 24-h autocorrelation were statistically significantly associated with less fatigue and better HRQoL over time. A higher amplitude and circadian quotient were associated with lower insomnia. Most of these associations appeared driven by both within-person changes over time and between-person differences in RAR parameters. No significant associations were observed for acrophase.ConclusionsIn the first five years after CRC treatment, adhering to a generally more active (mesor) and consistent (24-h autocorrelation) RAR, with a pronounced peak activity (amplitude) and a marked difference between daytime and nighttime activity (dichotomy index) was found to be associated with lower fatigue, lower insomnia, and a better HRQoL. Future intervention studies are needed to investigate if restoring RAR among survivors of CRC could help to alleviate symptoms of fatigue and insomnia while enhancing their HRQoL.Trial registrationEnCoRe study NL6904 (https://www.onderzoekmetmensen.nl/).

Metabolic Rewiring in Cancer: Small Molecule Inhibitors in Colorectal Cancer Therapy.

Alterations in cellular metabolism, such as dysregulation in glycolysis, lipid metabolism, and glutaminolysis in response to hypoxic and low-nutrient conditions within the tumor microenvironment, are well-recognized hallmarks of cancer. Therefore, understanding the interplay between aerobic glycolysis, lipid metabolism, and glutaminolysis is crucial for developing effective metabolism-based therapies for cancer, particularly in the context of colorectal cancer (CRC). In this regard, the present review explores the complex field of metabolic reprogramming in tumorigenesis and progression, providing insights into the current landscape of small molecule inhibitors targeting tumorigenic metabolic pathways and their implications for CRC treatment.

A Contemporary Review on the Critical Role of Nonsteroidal Anti-inflammatory Agents in Colorectal Cancer Therapy.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) are widely recognized as effective pain relievers and function by inhibiting the cyclooxygenase enzyme (COXs). Moreover, they have been found to participate in various cellular processes through different signaling pathways, such as WNT, MAPK, NF-KB, and PI3K/AKT/mTOR. This makes them potential candidates for chemoprevention of several malignancies, particularly colorectal cancer (CRC). However, the use of NSAIDs in cancer prevention and treatment is a complex issue due to their adverse effects and gastrointestinal toxicity. Therefore, it is crucial to explore combination therapies that can minimize side effects while maximizing synergistic effects with other agents and to evaluate the success rate of such approaches in both pre-clinical and clinical studies. In this review, we aim to provide an overview of the effects of NSAIDs in the prevention and treatment of CRC. We will focus on elucidating the possible mechanisms of action of these drugs, the signaling pathways involved in CRC, and the potential synergistic effects when combined with other therapeutic agents.

Sequencing considerations in the third-line treatment of metastatic colorectal cancer.

Numerous advances in the standard of care for metastatic colorectal cancer (mCRC), including the approval of several new treatments indicated for treatment in the third line or later (3L+), have been made, yet data and appropriate guidance on the optimal sequencing and treatment strategies for these lines of therapy are lacking. Four treatments-regorafenib, trifluridine/tipiracil alone or with bevacizumab, and fruquintinib-are FDA-approved and recommended by the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for the treatment of mCRC in the 3L+. When considering sequencing of treatment options for patients in the 3L+, the goal of treatment is to improve survival, but also maintain quality of life, a goal that requires consideration of relative efficacy and cumulative toxicity such as persistent myelosuppression.

VIC Regimen (Vemurafenib/Irinotecan/Cetuximab) Versus Bevacizumab Plus Chemotherapy as First-Line Treatment for BRAF V600E-Mutated Unresectable or Metastatic Colorectal Cancer in Asian Patients: A Prospective Cohort Study

VIC Regimen (Vemurafenib/Irinotecan/Cetuximab) Versus Bevacizumab Plus Chemotherapy as First-Line Treatment for BRAF V600E-Mutated Unresectable or Metastatic Colorectal Cancer in Asian Patients: A Prospective Cohort Study

A decade of progress: advances in the third-line treatment of patients with metastatic colorectal cancer.

The treatment of metastatic colorectal cancer (mCRC) remains challenging. There has been substantial progress in understanding the molecular pathology of the disease that has led to meaningful advancements in treatment options with varying mechanisms of action, although treatment remains costly. Cytotoxic therapies, which are typically combined with targeted therapies, remain the mainstay of first- and second-line treatment for mCRC. While also relevant in earlier lines of therapy, molecular testing has become increasingly important to guide therapy across lines of therapy, for which treatment options are limited. A paucity of data exists in establishing clinical criteria for optimizing the sequencing of therapies in the third line and beyond. A customized approach should consider the efficacy of the therapy balanced with the patient's goals. Sequencing criteria should include a consideration for exposing patients to as many different modes of therapy as possible while preserving quality of life, avoiding serious toxicities, and accounting for the potential impact of cumulative toxicities from prior therapies.

Nanoliposomes Encapsulated Rapamycin/Resveratrol to Induce Apoptosis and Ferroptosis for Enhanced Colorectal Cancer Therapy

Objectives: Monotherapy is often ineffective for treating colorectal cancer. In this study, we developed PEG-modified liposomes loaded with rapamycin (Rapa) and resveratrol (Res) (Rapa/Res liposomes, or RRL) to investigate their therapeutic potential in colorectal cancer.Methods: RRL were constructed using the reversed-phase evaporation method. We assessed the cytotoxicity, apoptosis, and ferroptotic effects of RRL on HCT116 colorectal cancer cells. The anti-tumor efficacy of RRL was evaluated in HCT116 xenograft mice.Results: RRL had a particle size of 86.67 ± 1.10 nm and a zeta potential of -33.13 ± 0.49 mV. The coloaded formulation demonstrated satisfactory performance both in vitro and in vivo, resulting in increased cytotoxicity to HCT116 colorectal cancer cells and significant suppression of HCT116 xenografts tumor growth. Mechanically, RRL significantly increased the apoptosis rate of HCT116 cells, induced ROS accumulation in tumor cells, and effectively downregulated the expression of the ferroptosis-associated proteins GPX4 and SLC7A11, demonstrating its superior efficacy compared to that of Rapa liposomes (Rapa/Lps) or Res liposomes (Res/Lps) alone.Conclusion: Coloading Rapa and Res into liposomes to promote apoptosis and ferroptosis in tumor cells represents a promising strategy for the treatment of colorectal cancer.

Unanticipated pathological clearance in two cases of clinical T4b dMMR/MSI-h advanced colorectal cancer: the potential of immune checkpoint inhibitors despite positive positron-emission tomography results.

The standard treatment for colorectal cancer consists of surgery and chemotherapy, which can be combined to improve outcomes. Immune checkpoint inhibitors (ICI) are a significant advancement in the standard treatment of metastatic, unresectable colorectal cancer with deficient mismatch repair (dMMR). However, limited data are available about the use of ICI in the neoadjuvant and conversion settings. Here, we present two cases treated with ICI. Case 1: A 75-year-old male with a large, borderline resectable rectal cancer diagnosed as cT4bN1bM0 who underwent neoadjuvant chemotherapy, followed by combination ICI consisting of ipilimumab and nivolumab. After four courses of ICI, the tumor significantly shrank, but positron emission tomography still showed a positive result and R0 resection was performed. Pathological analysis revealed no residual cancer cells. The patient has been monitored without adjuvant chemotherapy, and no recurrences have occurred after one year. Case 2: A 60-year-old male with locally advanced sigmoid colon cancer who received neoadjuvant treatment with pembrolizumab. The tumor partially shrank after three courses, and continued pembrolizumab monotherapy resulted in further tumor shrinkage which still showed positive positron emission tomography. Curative sigmoidectomy with partial resection of the ileum and bladder was performed, and the pathological outcome was pCR. There was no viable tumor in the specimen. The patient has been monitored without adjuvant chemotherapy for six months, and no recurrence has been observed. The present study reports two cases, including a large, borderline resectable rectal cancer after failure of chemotherapy followed by combination treatment with nivolumab and ipilimumab and one case of sigmoid colon cancer after pembrolizumab treatment, which resulted in pathological complete response. However, it remains unknown whether ICI therapy can replace surgery or diminish the optimal extent of resection, or whether adjuvant chemotherapy is needed after surgery in the case of achieving pCR after ICI therapy. Overall, this case report suggests that ICI before colorectal surgery can be effective and potentially a 'watch-and-wait" strategy could be used for cases in which ICI is effective.

Changes in clinical guidelines for the treatment of colorectal cancer in 2024

Aim. The ensuring that changes to clinical guidelines can be discussed more widely before they are formally introduced into clinical practice.Materials and methods. A brief review of the literature and rationale for each proposed major change in the treatment section is presented. The refusal to carry out preoperative radiation therapy for cancer of the upper ampullary rectum, the narrowing of indications for preoperative radiation therapy for cancer of the mid-ampullary rectum, as well as the expansion of indications for total non-adjuvant chemotherapy for rectal cancer with damage to the circular resection margin are discussed. Changes to the drug treatment section are discussed.Results. This article presents planned changes to clinical guidelines for the treatment of non-metastatic colorectal cancer in 2024. The most significant alterations concerned neoadjuvant treatment of rectal cancer and adjuvant treatment of colon cancer. A new algorithm was proposed for choosing rectal cancer neoadjuvant therapy, considering individual treatment decisions.Conclusion. A consensus was achieved concerning the necessity to expand indications for neoadjuvant rectal cancer chemotherapy, but only in patients with good functional status. The most benefit can be achieved in patients, for whom complete clinical response is the aim of the treatment and in patients with positive circumferential resection margin.

Screening, awareness and challenges for colorectal cancer treatment in Saudi Arabia: an update

Colorectal cancer (CRC) is the second most common cancer in the world. In Saudi Arabia, CRC is the most common cancer in males and the third most common in females, and its incidence rate is rising as the country continues to develop. However, the country does not have a national CRC screening program for CRC. This review aims to review recent studies that have attempted to address and rectify this issue and discern the most notable and prevalent barriers. Despite these efforts, guidelines are still lacking. Two prospective studies have been conducted in recent years, one of which was a national pilot screening program conducted by the Ministry of Health (MOH). While both had a similar number of participants, the colonoscopy rate for patients with a positive fecal immunochemical test (FIT) in the MOH program was only 20% compared to 75.8% in the Al-Kharj program. Awareness of the Saudi population regarding CRC and its screening appears to be insufficient. The most common barriers to patients' willingness to undergo screening were embarrassment, fear, and pain. Barriers to physicians are mostly related to factors outside their hands, such as lack of equipment and time. We conclude that efforts should be made to establish a national screening program and improve awareness of the population and physicians.

Resveratrol triggers autophagy-related apoptosis to inhibit the progression of colorectal cancer via inhibition of FOXQ1.

Colorectal cancer (CRC) is a significant health problem with elevated mortality rates, prompting intense exploration of its complex molecular mechanisms and innovative therapeutic avenues. Resveratrol (RSV), recognised for its anticancer effects through SIRT1 activation, is a promising candidate for CRC treatment. This study focuses on elucidating RSV's role in CRC progression, particularly its effect on autophagy-related apoptosis. Using bioinformatics, protein imprinting and immunohistochemistry, we established a direct correlation between FOXQ1 and adverse CRC prognosis. Comprehensive in vitro experiments confirmed RSV's ability to promote autophagy-related apoptosis in CRC cells. Plasmids for SIRT1 modulation were used to investigate underlying mechanisms. Molecular docking, glutathione-S-transferase pull-down experiments and immunoprecipitation highlighted RSV's direct activation of SIRT1, resulting in the inhibition of FOXQ1 expression. Downstream interventions identified ATG16L as a crucial autophagic target. In vivo and in vitro studies validated RSV's potential for CRC therapy through the SIRT1/FOXQ1/ATG16L pathway. This study establishes RSV's capacity to enhance autophagy-related cell apoptosis in CRC, positioning RSV as a prospective therapeutic agent for CRC within the SIRT1/FOXQ1/ATG16L pathway.

Baicalein triggers ferroptosis in colorectal cancer cells via blocking the JAK2/STAT3/GPX4 axis.

Colorectal cancer (CRC) is a prevalent form of gastrointestinal malignancy with challenges in chemotherapy resistance and side effects. Effective and low toxic drugs for CRC treatment are urgently needed. Ferroptosis is a novel mode of cell death, which has garnered attention for its therapeutic potential against cancer. Baicalein (5, 6, 7-trihydroxyflavone) is the primary flavone extracted from the dried roots of Scutellaria baicalensis that exhibits anticancer effects against several malignancies including CRC. In this study, we investigated whether baicalein induced ferroptosis in CRC cells. We showed that baicalein (1-64 μM) dose-dependently inhibited the viability of human CRC lines HCT116 and DLD1. Co-treatment with the ferroptosis inhibitor liproxstatin-1 (1 μM) significantly mitigated baicalein-induced CRC cell death, whereas autophagy inhibitor chloroquine (25 μM), necroptosis inhibitor necrostatin-1 (10 μM), or pan-caspase inhibitor Z-VAD-FMK (10 μM) did not rescue baicalein-induced CRC cell death. RNA-seq analysis confirmed that the inhibitory effect ofbaicalein on CRC cells isassociated with ferroptosis induction. We revealed that baicalein (7.5-30 μM) dose-dependently decreased the expression levels of GPX4, key regulator of ferroptosis, in HCT116 and DLD1 cells by blocking janus kinase 2 (JAK2)/STAT3 signaling pathway via direct interaction with JAK2, ultimately leading to ferroptosis in CRC cells. In a CRC xenograft mouse model, administration of baicalein (10, 20 mg/kg, i.g., every two days for two weeks) dose-dependently inhibited the tumor growth with significant ferroptosis induced by inhibiting the JAK2/STAT3/GPX4 axis in tumor tissue. This study demonstrates that ferroptosis contributes to baicalein-induced anti-CRC activity through blockade of the JAK2/STAT3/GPX4 signaling pathway, which provides evidence for the therapeutic application of baicalein against CRC.

Preclinical evaluation of AGTR1-Targeting molecular probe for colorectal cancer imaging in orthotopic and liver metastasis mouse models

Despite advancements in colorectal cancer (CRC) treatment, the prognosis remains unfavorable for patients with distant liver metastasis. Fluorescence molecular imaging with specific probes is increasingly used to guide CRC surgical resection in real-time and treatment planning. Here, we demonstrate the targeted imaging capacity of an MPA-PEG4-N3-Ang II probe labeled with near-infrared (NIR) fluorescent dye targeting the angiotensin II (Ang II) type 1 receptor (AGTR1) that is significantly upregulated in CRC. MPA-PEG4-N3-Ang II was highly selective and specific to in vitro tumor cells and in vivo tumors in a mouse CRC xenograft model. The favorable ex vivo imaging and in vivo biodistribution of MPA-PEG4-N3-Ang II afforded tumor-specific accumulation with low background and >10 contrast tumor-to-colorectal values in multiple subcutaneous CRC models at 8 h following injection. Biodistribution analysis confirmed the probe's high uptake in HT29 and HCT116 orthotopic and liver metastatic models of CRC with signal-to-noise ratio (SNR) values of tumor-to-colorectal and -liver fluorescence of 5.8 ± 0.6, 5.3 ± 0.7, and 2.7 ± 0.5, 2.6 ± 0.5, respectively, enabling high-contrast intraoperative tumor visualization for surgical navigation. Given its rapid tumor targeting, precise tumor boundary delineation, durable tumor retention and docking study, MPA-PEG4-N3-Ang II is a promising high-contrast imaging agent for the clinical detection of CRC.

Organ preservation in locally advanced colorectal cancer with microsatellite instability-high after immunotherapy

Neoadjuvant immunotherapy has achieved exciting efficacy with high clinical complete response (cCR) and pathologic complete response (pCR) rates and durable long-term effects. PD-1 checkpoint blockade-based immunotherapy has been highly successful in microsatellite instability high (MSI-H)/mismatch repair deficiency (dMMR) colorectal cancer and has been recommended as the first-line treatment for metastatic colorectal cancer by domestic and international guidelines. Several studies have shown that immunotherapy can be a potentially curable treatment for MSI-H rectal cancer and has even shown promise in organ preservation in colon cancer. In this study, we first clarified the feasibility of the watch-and-wait strategy after PD-1 checkpoint blockade treatment by indirect and direct evidence. Then from the assessment tools (including digital rectal examination, endoscopy, radiology, and lymph node assessment), the viable assessment methods of cCR for immunotherapy and related difficulties are proposed. Finally, the medication choices of immunotherapy, the treatment regimen, and the follow-up strategy are further discussed. We hope that neoadjuvant immunotherapy could be appropriately applied in MSI-H/dMMR colorectal cancer so that more patients can achieve organ preservation.

Monitoring ctDNA RAS Mutational Status in Metastatic Colorectal Cancer: A Trial Protocol of RAS-trace and RAS-trace-2 Studies.

Spatial and temporal heterogeneities of RAS and other molecular genes should be considered in the treatment of metastatic colorectal cancer (mCRC) treated with anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs); acquired RAS mutation is sometimes observed at disease progression of treatment with the anti-EGFR mAb. At the same time, discrepancy of RAS status from tissues and circulating tumor DNA (ctDNA) in the same patient is sometimes observed. Based on this, we commenced two observational studies to clarify these heterogeneities of RAS and BRAF in mCRC, using next generation sequencing from liquid biopsy. RAS-trace study is an observational study to monitor ctDNA RAS/BRAF/PIK3CA status every 4-12 weeks using the Plasma-SeqSensei™ CRC RUO Kit (Sysmex Inostics GmbH) in mCRC with RAS/BRAF wild-type (wt) on tumor tissue. The primary endpoint was the time to the acquired RAS mutations. A total of 42 patients has been accrued. RAS-trace-2 study is also an observational study aimed at comparing the efficacy of the anti-EGFR mAb in ctDNA RAS/BRAF wt with ctDNA RAS or BRAF mutant mCRC patients, whose RAS/BRAF are wt in tumor tissue. The primary endpoint was progression-free survival in patients with ctDNA RAS/BRAF wt and RAS or BRAF mutant. A total of 240 patients will be accrued over 2 years. These trials will help us understanding the clinical significance of spatial and temporal heterogeneities of RAS, BRAF and other genes, while optimizing the anti-EGFR mAb treatment strategies in mCRC.