Treatment Of Colorectal Cancer Research Articles

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.

Orally available dextran-aspirin nanomedicine modulates gut inflammation and microbiota homeostasis for primary colorectal cancer therapy.

Reversing the aggravated immunosuppression hence overgrowth of colorectal cancer (CRC) caused by the gut inflammation and microbiota dysbiosis is pivotal for effective CRC therapy and metastasis inhibition. However, the low delivery efficiency and severe dose-limiting off-target toxicities caused by unsatisfied drug delivery systems remain the major obstacles in precisely modulating gut inflammation and microbiota in CRC therapy. Herein, a multifunctional oral dextran-aspirin nanomedicine (P3C-Asp) was utilized for oral treatment of primary CRC, as it could release salicylic acid (SA) while scavenging reactive oxygen species (ROS) and held great potential in modulating gut microbiota with prebiotic (dextran). Oral P3C-Asp retained in CRC tissues for over 12 h and significantly increased SA accumulation in CRC tissues over free aspirin (10.8-fold at 24 h). The enhanced SA accumulation and ROS scavenging of P3C-Asp cooperatively induced more potent inflammation relief over free aspirin, characterized as lower level of cyclooxygenase-2 and immunosuppressive cytokines. Remarkably, P3C-Asp promoted the microbiota homeostasis and notably increased the relative abundance of strengthening systemic anti-cancer immune response associated microbiota, especially lactobacillus and Akkermansia to 6.66- and 103- fold over the control group. Additionally, a demonstrable reduction in pathogens associated microbiota (among 96% to 79%) including Bacteroides could be detected. In line with our findings, inflammation relief along with enhanced abundance of lactobacillus was positively correlated with CRC inhibition. In primary CRC model, P3C-Asp achieved 2.1-fold tumor suppression rate over free aspirin, with an overall tumor suppression rate of 85%. Moreover, P3C-Asp cooperated with αPD-L1 further reduced the tumor weight of each mouse and extended the median survival of mice by 29 days over αPD-L1 alone. This study unravels the synergistic effect of gut inflammation and microbiota modulation in primary CRC treatment, and unlocks an unconventional route for immune regulation in TME with oral nanomedicine.

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.

LncRNA GAS6-AS1 contributes to 5-fluorouracil resistance in colorectal cancer by facilitating the binding of PCBP1 with MCM3

5-Fluorouracil (5-FU) resistance has always been a formidable obstacle in the adjuvant treatment of advanced colorectal cancer (CRC). In recent years, long non-coding RNAs have emerged as key regulators in various pathophysiological processes including 5-FU resistance. TRG is a postoperative pathological score of the chemotherapy effectiveness for CRC, of which TRG 0–1 is classified as chemotherapy sensitivity and TRG 3 as chemotherapy resistance. Here, RNA-seq combined with weighted gene correlation network analysis confirmed the close association of GAS6-AS1 with TRG. GAS6-AS1 expression was positively correlated with advanced clinicopathological features and poor prognosis in CRC. GAS6-AS1 increased the 50% inhibiting concentration of 5-FU, enhanced cell proliferation and accelerated G1/S transition, both with and without 5-FU, both in vitro and in vivo. Mechanistically, GAS6-AS1 enhanced the stability of MCM3 mRNA by recruiting PCBP1, consequently increasing MCM3 expression. Furthermore, PCBP1 and MCM3 counteracted the effects of GAS6-AS1 on 5-FU resistance. Notably, the PDX model indicated that combining chemotherapeutic drugs with GAS6-AS1 knockdown yielded superior outcomes in vivo. Together, our findings elucidate that GAS6-AS1 directly binds to PCBP1, enhancing MCM3 expression and thereby promoting 5-FU resistance. GAS6-AS1 may serve as a robust biomarker and potential therapeutic target for combination therapy in CRC.

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.

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 8h 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.

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.

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.

[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.

First-line oxaliplatin-based chemotherapy and nivolumab for metastatic microsatellite-stable colorectal cancer-the randomised METIMMOX trial.

We evaluated first-line treatment of metastatic microsatellite-stable colorectal cancer with short-course oxaliplatin-based chemotherapy alternating with immune checkpoint blockade. Patients were randomly assigned to chemotherapy (the FLOX regimen; control group) or alternating two cycles each of FLOX and nivolumab (experimental group). Radiographic response assessment was done every eight weeks with progression-free survival (PFS) as the primary endpoint. Cox proportional-hazards regression models estimated associations between PFS and relevant variables. A post hoc analysis explored C-reactive protein as signal of responsiveness to immune checkpoint blockade. Eighty patients were randomised and 38 in each group received treatment. PFS was comparable-control group: median 9.2 months (95% confidence interval (CI), 6.3-12.7); experimental group: median 9.2 months (95% CI, 4.5-15.0). The adjusted Cox model revealed that experimental-group subjects aged ≥60 had significantly lowered progression risk (p = 0.021) with hazard ratio 0.17 (95% CI, 0.04-0.76). Experimental-group patients with C-reactive protein <5.0 mg/L when starting nivolumab (n = 17) reached median PFS 15.8 months (95% CI, 7.8-23.7). One-sixth of experimental-group cases (all KRAS/BRAF-mutant) achieved complete response. The investigational regimen did not improve the primary outcome for the intention-to-treat population but might benefit small subgroups of patients with previously untreated, metastatic microsatellite-stable colorectal cancer. ClinicalTrials.gov number, NCT03388190 (02/01/2018).

[Reassessment of practice of Chinese surgeons since introduction of the watch and wait strategy after neoadjuvant therapy for rectal cancer].

Objective: To investigate perspectives and changes in treatment selection by Chinese surgeons since introduction of the watch-and-wait approach after neoadjuvant therapy for rectal cancer. Methods: A cross-sectional survey was conducted using a questionnaire distributed through the "Wenjuanxing" online survey platform. The survey focused on the recognition and practices of Chinese surgeons regarding the strategy of watch-and-wait after neoadjuvant therapy for rectal cancer and was disseminated within the China Watch-and-Wait Database (CWWD) WeChat group. This group targets surgeons of deputy chief physician level and above in surgical, radiotherapy, or internal medicine departments of nationally accredited tumor-specialist or comprehensive hospitals (at provincial or municipal levels) who are involved in colorectal cancer diagnosis and treatment. From 13 to 16 December 2023, 321 questionnaires were sent with questionnaire links in the CWWD WeChat group. The questionnaires comprised 32 questions encompassing: (1) basic physician characteristics (including surgical volume); (2) assessment methods and criteria for clinical complete response (cCR); (3) patients eligible for watch-and-wait; (4) neoadjuvant therapies and other measures for achieving cCR; (5) willingness to implement watch-and-wait and factors influencing that willingness; (6) risks and monitoring of watch-and-wait; (7) subsequent treatment and follow-up post watch-and-wait; (8) suggestions for development of the CWWD. Descriptive statistics were employed for data analysis, with intergroup comparisons conducted using the χ2 or Fisher's exact probability tests. Results: The response rate was 31.5%, comprising 101 responses from the 321 individuals in the WeChat group. Respondents comprised 101 physicians from 70 centers across 23 provinces, municipalities, and autonomous regions nationwide, 85.1% (86/101) of whom represented provincial tertiary hospitals. Among the respondents, 87.1% (88/101) had implemented the watch-and-wait strategy. The approval rate (65.6%, 21/32) and proportion of patients often informed (68.8%, 22/32) were both significantly higher for doctors in oncology hospitals than for those in general hospitals (27.7%, 18/65; 32.4%, 22/68) (χ2=12.83, P<0.001; χ2=11.70, P=0.001, respectively). The most used methods for diagnosing cCR were digital rectal examination (90.1%, 91/101), colonoscopy (91.1%, 92/101), and rectal T2-weighted magnetic resonance imaging (86.1%, 87/101). Criteria used to identify cCR comprised absence of a palpable mass on digital rectal examination (87.1%, 88/101), flat white scars or new capillaries on colonoscopy (77.2%, 78/101), absence of evident tumor signals on rectal T2-weighted sequences or T2WI low signals or signals equivalent to the intestinal wall (83.2%, 84/101), and absence of tumor hyperintensity on diffusion-weighted imaging with no corresponding hypointensity on apparent diffusion coefficient maps (66.3%, 67/101). As for selection of neoadjuvant regimen and assessment of cCR, 57.4% (58/101) of physicians preferred a long course of radiotherapy with or without induction and/or consolidation capecitabine + oxaliplatin, whereas 25.7% (26/101) preferred immunotherapy in combination with chemotherapy and concurrent radiotherapy. Most (96.0%, 97/101) physicians believed that the primary lesion should be assessed ≤12 weeks after completion of radiotherapy. Patients were frequently informed about the possibility of achieving cCR after neoadjuvant therapy and the strategy of watch-and-wait by 43.6% (44/101) of the responding physicians and 38.6% (39/101) preferred watch-and-wait for patients who achieved cCR or near cCR after neoadjuvant therapy for rectal cancer. Capability for multiple follow-up evaluations (70.3%, 71/101) was a crucial factor influencing physicians' choice of watch-and-wait after cCR. The proportion who patients who did not achieve cCR and underwent surgical treatment was lower in provincial tertiary hospitals (74.2%, 23/31) than in provincial general hospitals (94.5%, 52/55) and municipal hospitals (12/15); these differences are statistically significant (χ2=7.43, P=0.020). The difference between local recurrence and local regrowth was understood by 88.1% (89/101) of respondents and 87.2% (88/101) agreed with monitoring every 3 months for 5 years. An increase in local excision or puncture rates to reduce organ resections in patients with pCR was proposed by 64.4% (65/101) of respondents. Conclusion: Compared with the results of a previous survey, Chinese surgeons' awareness of the watch-and-wait concept has improved significantly. Oncologists in oncology hospitals are more aware of the concept of watch-and-wait.

Training in optical diagnosis in community hospitals is associated with improved recognition and treatment of T1 CRC: a prospective multicenter intervention study (OPTICAL II).

Recognition of T1 colorectal cancer (CRC) is difficult, with sensitivities of 35-60% in Western countries. We evaluated the real-life effects of the implementation of the OPTICAL model, a recently developed structured and validated prediction model, in Dutch community hospitals. In this prospective multicenter study, 383 endoscopists from 40 hospitals were invited to follow an e-learning on the OPTICAL-model, to increase sensitivity for detecting T1CRC in non-pedunculated polyps. Next, real-life recognition of T1CRC was evaluated in 25 hospitals. Endoscopic and pathologic reports of T1CRCs detected during the next year were collected retrospectively while endoscopists were unaware of this evaluation. Sensitivity for recognition of T1CRC, R0 resection rate, and treatment modality were compared for trained vs. untrained endoscopists and for recognised vs. unrecognised T1CRCs. Within 1 year after the e-learning 251 endoscopists detected 528 non-pedunculated T1CRCs, 118 (47%) of the endoscopist were trained. T1CRCs had a median size of 20mm and were mainly located in the distal colorectum (66%). Trained endoscopists recognised T1CRCs more frequently than untrained endoscopists (sensitivity 74% vs. 62%; mixed model analysis OR 2.90; 95%CI 1.54-5.45. A higher rate of R0 resection was seen for T1CRCs detected by trained endoscopists (69% vs. 56%, OR 1.73; 95%CI 1.03-2.91). Training in optical recognition of T1CRCs in community hospitals was associated with an increase in sensitivity for T1CRCs. Recognition led to a higher rate of en bloc local excision, resulting in higher R0-resection rates. This may be an important step towards more organ-preserving strategies.

Genetic and microbial determinants of azoxymethane-induced colorectal tumor susceptibility in Collaborative Cross mice and their implication in human cancer

ABSTRACT The insights into interactions between host genetics and gut microbiome (GM) in colorectal tumor susceptibility (CTS) remains lacking. We used Collaborative Cross mouse population model to identify genetic and microbial determinants of Azoxymethane-induced CTS. We identified 4417 CTS-associated single nucleotide polymorphisms (SNPs) containing 334 genes that were transcriptionally altered in human colorectal cancers (CRCs) and consistently clustered independent human CRC cohorts into two subgroups with different prognosis. We discovered a set of genera in early-life associated with CTS and defined a 16-genus signature that accurately predicted CTS, the majority of which were correlated with human CRCs. We identified 547 SNPs associated with abundances of these genera. Mediation analysis revealed GM as mediators partially exerting the effect of SNP UNC3869242 within Duox2 on CTS. Intestine cell-specific depletion of Duox2 altered GM composition and contribution of Duox2 depletion to CTS was significantly influenced by GM. Our findings provide potential novel targets for personalized CRC prevention and treatment.