Local excision versus total mesorectal excision for rectal cancer patients with clinical complete or near-complete response after neoadjuvant chemoradiotherapy.

PURPOSE: Local excision is an effective approach for managing rectal cancer exhibiting substantial regression after neoadjuvant chemoradiotherapy. The purpose of this study is to compare the outcomes between local excision and total mesorectal excision in rectal cancer patients achieving clinical complete or near-complete response after neoadjuvant chemoradiotherapy. METHODS: This is a retrospective cohort study that includes a consecutive series of rectal cancer patients who responded well to neoadjuvant chemoradiotherapy followed by surgery. A total of 180 rectal cancer patients at a single institution during a 12-year period are included. The main outcomes include short-term outcomes, oncological outcomes, and functional outcomes between the two groups. RESULTS: A total of 180 patients were included in the study. Sixty-one (33.9%) received local excision and 119 (66.1%) received total mesorectal excision. The baseline characteristics were generally balanced between the two groups. The local excision group demonstrated a significantly shorter operative time, less blood loss, and shorter hospital stay (p < 0.001). 3-year overall survival rates were 97.5% (95% CI, 0.93-1.00) and 95.5% (95% CI, 0.91-1.00) between the two groups (p = 0.38). The local excision group exhibited significantly higher 3-year local recurrence rates 15.7% (95% CI, 0.74-0.97) vs 4.2% (95% CI, 0.92-1.00) (p = 0.017), yet lower 3-year distant metastasis rates 9.6% (95% CI, 0.82-1.00) vs 12.6% (95% CI, 0.81-0.94) (p = 0.33) and lower 3-year disease-free survival rates 76.8% (95% CI, 0.64-0.92) vs 84.7% (95% CI, 0.78-0.92) (p = 0.56) comparing with the total mesorectal excision group. The local excision group demonstrated significantly better functional outcomes compared with the total mesorectal excision group (p < 0.001). CONCLUSION: Patients who achieve either clinical complete or near-complete response after neoadjuvant chemoradiotherapy are suitable candidates for local excision. The local excision group demonstrated superior short-term and functional outcomes, and the oncological outcomes were not compromised.

Spatial transcriptomic revealed intratumor heterogeneity and cancer stem cell enrichment in colorectal cancer metastasis.

Metastasis is the main cause of mortality in colorectal cancer (CRC) patients. Exploring the mechanisms of metastasis is of great importance in both clinical and fundamental CRC research. CRC is a highly heterogeneous disease with variable therapeutic outcomes of treatment. In this study, we applied spatial transcriptomics (ST) to generate a tissue-wide transcriptome from two primary colorectal cancer tissues and their matched liver metastatic tissues. Spatial RNA information showed intratumoral heterogeneity (ITH) of both primary and metastatic tissues. The comparison of gene expressions across tissues revealed an apparent enrichment of cancer stem cells (CSCs) in metastatic tissues and identified FOXD1 as a novel metastatic CSC marker. Trajectory and pseudo-time analyses revealed distinct evolutionary trajectories and a dedifferentiation-differentiation process during metastasis. CellphoneDB analysis suggested a dominant interaction of CD74-MIF with tumor cells in metastatic tissues. Further analysis confirmed FOXD1 as a maker of CSCs and the predictor of patient survival, especially in metastatic diseases. Our study found ITH of primary and metastatic tissues and provides novel insights into the cellular mechanisms underlying liver metastasis of CRC and foundations for therapeutic strategies for CRC metastasis.

Cu2O-catalyzed cascade phosphinylation/cyclization of 2'-aminochalcones for the synthesis of hemi-indigo derivatives.

A Cu2O-catalyzed cascade phosphinylation/cyclization reaction of 2'-aminochalcones and diphenylphosphine oxides to produce hemi-indigo derivatives has been developed. This strategy facilitates the sequential formation of a C-P bonds and a C-N bond in a single reaction step. Notably, the approach features one-pot operation, an earth-abundant copper catalyst, readily available starting materials, a broad substrate scope and high compatibility with functional groups, providing 33 compounds in acceptable yields.

Palladium-Catalyzed (3 + 2) Annulation of Aromatic Acids by C(sp3)-H Olefination and Decarboxylative Cross-Coupling Reaction.

A palladium-catalyzed (3 + 2) annulation of 2-methylbenzoic acid with maleimide using Ac-Leu-OH as a powerful ligand has been reported. Through a site-selective γ-C(sp3)-H olefination reaction and a sequential decarboxylative cross-coupling reaction, a five-membered cyclic ring was obtained as the final product. This novel reaction features great site selectivity and reactivity to generate various cyclic products in moderate to good yields.

Synthesis of ß-Hydroxysulfides via Multi-Component Cascade Hydroxysulfenylation of Styrenes with NH4 SCN and Water under Transition-metal-free Conditions.

Transition-mental-free multi-component hydroxysulfenylation of styrenes with NH4 SCN and water to from ß-hydroxysulfides is established. The reaction mechanism proceeded via a domino reaction after a radical addition to 2-phenylimidazo[1,2-a]pyridines. This approach features a wide substrate scope and functional group compatibility, providing 34 compounds in acceptable yields.

The [3 + 2] Cycloaddition Reaction of N-Substituted Pyrrole-2-carboxaldehydes with Arylalkenes under Copper Catalysis: Access to Dihydropyrrolizine Skeletons.

Herein, we found that treating N-substituted pyrrole-2-carboxaldehydes with arylalkenes in DMF in N2 at 120 °C could afford pyrrolidine scaffolds with an up to 85% yield. This approach has several remarkable features, such as atom and step economy, readily accessible raw materials, and easy-to-operate manner, providing a simple and efficient method for constructing complicated bicyclic pyrroles. Additionally, we have successfully synthesized 28 target compounds, which further demonstrates its practicality and wide applicability.

Clinicopathological features and prognosis of synchronous and metachronous colorectal cancer: a retrospective cohort study.

BACKGROUND: To investigate the clinicopathological features and prognosis of synchronous and metachronous multiple primary colorectal cancer. MATERIALS AND METHODS: Patients who underwent operation for synchronous and metachronous colorectal cancer at the colorectal surgery department of Shanghai Changhai Hospital between January 2000 and December 2021 were included. Perioperative indicators were comprehensively compared and included in the survival analyses. RESULTS: In total, 563 patients with synchronous ( n =372) and metachronous ( n =191) colorectal cancer were included. Patients with synchronous colorectal cancer were more likely to have a long onset time, positive carcinoembryonic antigen, advanced TNM stage, large tumor, perineural invasion, p53 high expression, and mismatch repair proficient. Compared with metachronous colorectal cancer, patients with synchronous colorectal cancer showed worse 5-year overall survival (68.6±3.0% vs 81.9±3.5%, P =0.018) and 5-year disease-free survival (61.2±3.1% vs 71.0±3.9%, P =0.022). In the subgroup analysis, segmental resection was an independent risk factor for the long-term outcomes of bilateral synchronous colorectal cancer. CONCLUSIONS: Clinicopathological and molecular features were different between synchronous and metachronous colorectal cancer. Patients with synchronous colorectal cancer showed a worse prognosis than those with metachronous colorectal cancer. Bilateral synchronous colorectal cancer requires extended resection to achieve improved long-term outcomes.

Synthesis of pyrazoles from sulfonyl hydrazone and benzyl acrylate under transition-metal-free conditions.

Pyrazoles as an important class of heterocyclic compounds, are widely found in pharmaceuticals and bioactive natural products. Herein we report a [3 + 2] cycloaddition reaction for the synthesis of a series of pyrazoles, with the yield up to 77%. This approach exhibits many notable features, such as convenient operating conditions, excellent functional group compatibility and readily accessible raw materials, providing an alternative route for the construction of pyrazole derivatives.

Optimal examined lymph node number for accurate staging and long-term survival in rectal cancer: a population-based study.

BACKGROUND: Although the recommended minimal examined lymph node (ELN) number in rectal cancer (RC) is 12, this standard remains controversial because of insufficient evidence. We aimed to refine this definition by quantifying the relationship between ELN number, stage migration and long-term survival in RC. METHODS: Data from a Chinese multi-institutional registry (2009-2018) and the Surveillance, Epidemiology, and End Results (SEER) database (2008-2017) on stages I-III resected RC were analysed to determine the relationship between ELN count, stage migration, and overall survival (OS) using multivariable models. The series of odds ratios (ORs) for negative-to-positive node stage migration and hazard ratios (HRs) for survival with more ELNs were fitted using a Locally Weighted Scatterplot Smoothing (LOWESS) smoother, and structural breakpoints were determined using the Chow test. The relationship between ELN and survival was evaluated on a continuous scale using restricted cubic splines (RCS). RESULTS: The distribution of ELN count between the Chinese registry ( n =7694) and SEER database ( n =21 332) was similar. With increasing ELN count, both cohorts exhibited significant proportional increases from node-negative to node-positive disease (SEER, OR, 1.012, P <0.001; Chinese registry, OR, 1.016, P =0.014) and serial improvements in OS (SEER: HR, 0.982; Chinese registry: HR, 0.975; both P <0.001) after controlling for confounders. Cut-point analysis showed an optimal threshold ELN count of 15, which was validated in the two cohorts, with the ability to properly discriminate probabilities of survival. CONCLUSIONS: A higher ELN count is associated with more precise nodal staging and better survival. Our results robustly conclude that 15 ELNs are the optimal cut-off point for evaluating the quality of lymph node examination and stratification of prognosis.

C-H Borylation of Benzophenones Using Hydrazone as the Traceless Directing Group.

C-H borylation is one of the powerful C-H bond functionalization reactions. In this context, a metal-free C-H borylation of benzophenones using hydrazone as the traceless directing group has been reported. The dibromoboron intermediates can be obtained in excellent yields, and the corresponding arylboronic esters are generated in moderate to excellent yields. Furthermore, the borylated compounds can be transformed in a one-pot method, avoiding the loss of overall yield caused by the separation of the arylboronic esters.

Palladium-Catalyzed Tandem Diolefination Reaction of Benzaldehyde Enabled by a Remote Directing Group.

A tandem diolefination reaction of benzaldehyde has been developed via Pd-catalyzed ß-C(sp2)-H olefination of the benzene ring and tandem C(sp2)-H olefination of acrylate. 2-((Aminooxy)methyl)benzonitrile was involved with the benzaldehyde substrate as a remote directing group to realize the C-H bond activation. The control experiments proved that the presence of a remote cyano group is essential for this novel diolefination reaction.

Single-cell sequencing technology in colorectal cancer: a new technology to disclose the tumor heterogeneity and target precise treatment.

Colorectal Cancer (CRC) is one of the most common gastrointestinal tumors, and its high tumor heterogeneity makes traditional sequencing methods incapable of obtaining information about the heterogeneity of individual cancer cells in CRC. Therefore, single-cell sequencing technology can be applied to better analyze the differences in genetic and protein information between cells, to obtain genomic sequence information of single cells, and to more thoroughly analyze the cellular characteristics and interactions in the CRC microenvironment. This will provide a more comprehensive understanding of colorectal cancer development and metastasis and indicate the treatment plan and prognosis. In this study, we review the application of single-cell sequencing to analyze the tumor microenvironment of CRC, explore the mechanisms involved in CRC metastasis and progression, and provide a reference for potential treatment options.

DSTN Hypomethylation Promotes Radiotherapy Resistance of Rectal Cancer by Activating the Wnt/ß-Catenin Signaling Pathway.

PURPOSE: Although surgical resection combined with neoadjuvant radiation therapy can reduce the local recurrence rate of rectal cancer, not all patients benefit from neoadjuvant radiation therapy. Therefore, screening for patients with rectal cancer who are sensitive or resistant to radiation therapy has great clinical significance. METHODS AND MATERIALS: Patients with rectal cancer were selected according to postoperative tumor regression grade, and tumor samples were taken for detection. Differential genes between radiation-resistant and radiation-sensitive tissues were screened and validated by Illumina Infinium MethylationEPIC BeadChip, proteomics, Agena MassARRAY methylation, reverse transcription quantitative real-time polymerase chain reaction, and immunohistochemistry. In vitro and in vivo functional experiments verified the role of DSTN. Protein coimmunoprecipitation, western blot, and immunofluorescence were used to investigate the mechanisms of DSTN-related radiation resistance. RESULTS: DSTN was found to be highly expressed (P < .05) and hypomethylated (P < .01) in rectal cancer tissues resistant to neoadjuvant radiation therapy. Follow-up data confirmed that patients with high expression of DSTN in neoadjuvant radiation therapy-resistant rectal cancer tissues had shorter disease-free survival (P < .05). DSTN expression increased after methyltransferase inhibitor inhibition of DNA methylation in colorectal cancer cells (P < .05). In vitro and in vivo experiments showed that knockdown of DSTN promoted the sensitivity of colorectal cancer cells to radiation therapy, and overexpression of DSTN promoted the resistance of colorectal cancer cells to radiation (P < .05). The Wnt/ß-catenin signaling pathway was activated in colorectal cancer cells overexpressing DSTN. ß-catenin was highly expressed in radiation therapy-resistant tissues, and there was a linear correlation between the expression of DSTN and ß-catenin (P < .0001). Further studies showed that DSTN can bind to ß-catenin and increase its stability. CONCLUSIONS: The degree of DNA methylation and the expression level of DSTN can be used as biomarkers to predict the sensitivity of neoadjuvant radiation therapy for rectal cancer. DSTN and ß-catenin are also expected to become a reference for the selection of neoadjuvant radiation therapy.

An easy-to-use artificial intelligence preoperative lymph node metastasis predictor (LN-MASTER) in rectal cancer based on a privacy-preserving computing platform: multicenter retrospective cohort study.

BACKGROUND: Although the surgical treatment strategy for rectal cancer (RC) is usually based on the preoperative diagnosis of lymph node metastasis (LNM), the accurate diagnosis of LNM has been a clinical challenge. In this study, we developed machine learning (ML) models to predict the LNM status before surgery based on a privacy-preserving computing platform (PPCP) and created a web tool to help clinicians with treatment-based decision-making in RC patients. PATIENTS AND METHODS: A total of 6578 RC patients were enrolled in this study. ML models, including logistic regression, support vector machine, extreme gradient boosting (XGB), and random forest, were used to establish the prediction models. The areas under the receiver operating characteristic curves (AUCs) were calculated to compare the accuracy of the ML models with the US guidelines and clinical diagnosis of LNM. Last, model establishment and validation were performed in the PPCP without the exchange of raw data among different institutions. RESULTS: LNM was detected in 1006 (35.3%), 252 (35.3%), 581 (32.9%), and 342 (27.4%) RC patients in the training, test, and external validation sets 1 and 2, respectively. The XGB model identified the optimal model with an AUC of 0.84 [95% confidence interval (CI), 0.83-0.86] compared with the logistic regression model (AUC, 0.76; 95% CI, 0.74-0.78), random forest model (AUC, 0.82; 95% CI, 0.81-0.84), and support vector machine model (AUC, 0.79; 95% CI, 0.78-0.81). Furthermore, the XGB model showed higher accuracy than the predictive factors of the US guidelines and clinical diagnosis. The predictive XGB model was embedded in a web tool (named LN-MASTER) to predict the LNM status for RC. CONCLUSION: The proposed easy-to-use model showed good performance for LNM prediction, and the web tool can help clinicians make treatment-based decisions for patients with RC. Furthermore, PPCP enables state-of-the-art model development despite the limited local data availability.

Erratum: miR-365a-3p regulates ADAM10-JAK-STAT signaling to suppress the growth and metastasis of colorectal cancer cells: Erratum.

[This corrects the article DOI: 10.7150/jca.42731.].

Tandem C-C/C-N Bond Formation via Rh(III)-Catalyzed α-Fluoroalkenylation and Sequential Annulation of 2-Arylquinazolinones and gem-Difluorostyrenes.

An efficient method of Rh(III)-catalyzed coupling reaction between 2-arylquinazolinones and gem-difluorostyrenes has been developed. In this work, two diverse structures of monofluoroalkenes and isoindolo[1,2-b]quinazolin-10(12H)-one derivatives were respectively synthesized by controlling the amount of additives (Ca(OH)2 and AgNTf2) to achieve controlled stepwise breaking of the C-F bonds of gem-difluorostyrenes. This reaction has the characteristics of a wide range of substrates and good functional group tolerance. Meanwhile, several control experiments were conducted and a plausible mechanism was proposed.

Trends of sphincter-preserving surgeries for low lying rectal cancer: A 20-year experience in China.

Background: Over the last 2 decades, patients with low rectal cancer have had better outcomes from improvements in surgical techniques in sphincter preservation. We aimed to quantify the trends in sphincter-preserving surgeries for low rectal cancer over 20 years in a top tertiary hospital in China. Methods: Between 1999 and 2021, a cohort of patients with primary malignant rectal tumor ≤5cm from the anal verge and who received elective surgeries at Changhai Hospital, Shanghai, China, was identified. Data were extracted from electronic medical records. A Joinpoint Regression Model was used to analyze trends in surgical procedures by average annual percentage change (AAPC). Adjusted Cox proportional hazards regression model was used to assess overall survival. Results: Among a total of 4,172 patients during the study period, 3,111 (74.6%) underwent a sphincter-preserving surgery and 1,061 (25.4%) received APR. Sphincter-preserving surgery increased 3.6% per year (95%CI, 2.3-4.9). Low anterior resection was the most performed procedure (86.3%) and maintained a steady trend, while intersphincteric resection increased 49.4% annually (95%CI, 19.5-86.7) after initiation. Laparoscopic techniques increased 15.1% per year (95%CI, 8.4-43.4) after initiation. Sphincter-preserving surgery increased annually for tumors ≤2cm, 2-≤3cm and 3-≤4cm from the anal verge (AAPC 7.1, 4.5-9.8; 4.7, 3.1-6.3; 2.7, 1.7-3.6, respectively). Furthermore, patients with sphincter-preserving surgery had a better overall survival than abdominoperineal resection (APR) patients (adjusted HR 0.78, 95% CI, 0.65-0.93, p=.01). Conclusions: Utilization of sphincter-preserving surgeries increased significantly over the last 20 years. Patients with low rectal cancer who underwent sphincter preservation had better survival than similar patients who underwent APR.

Measurement of distal intramural spread and the optimal distal resection by naked eyes after neoadjuvant radiation for rectal cancers.

BACKGROUND: The safe distance between the intraoperative resection line and the visible margin of the distal rectal tumor after preoperative radiotherapy is unclear. We aimed to investigate the furthest tumor intramural spread distance in fresh tissue to determine a safe distal intraoperative resection margin length. METHODS: Twenty rectal cancer specimens were collected after preoperative radiotherapy. Tumor intramural spread distances were defined as the distance between the tumor's visible and microscopic margins. Visible tumor margins in fresh specimens were identified during the operation and were labeled with 5 - 0 sutures under the naked eye at the distal 5, 6, and 7 o'clock directions of visible margins immediately after removal of the tumor. After fixation with formalin, the sutures were injected with nanocarbon particles. Longitudinal tissues were collected along three labels and stained with hematoxylin and eosin. The spread distance after formalin fixation was measured between the furthest intramural spread of tumor cells and the nanocarbon under a microscope. A positive intramural spread distance indicated that the furthest tumor cell was distal to the nanocarbon, and a negative value indicated that the tumor cell was proximal to the nanocarbon. The tumor intramural spread distance in fresh tissue during the operation was 1.75 times the tumor intramural spread distance after formalin fixation according to the literature. RESULTS: At the distal 5, 6, and 7 o'clock direction, seven (35%), five (25%), and six (30%) patients, respectively, had distal tumor cell intramural spread distance > 0 mm. The mean and 95% confidence interval of tumor cell intramural spread distance in fresh tissue during operation was - 0.3 (95%CI - 4.0 ~ 3.4) mm, - 0.9 (95%CI - 3.4 ~ 1.7) mm, and - 0.4 (95%CI - 3.5 ~ 2.8) mm, respectively. The maximal intraoperative intramural spread distances in fresh tissue were 8.8, 7, and 7 mm, respectively. CONCLUSIONS: The intraoperative distance between the distal resection line and the visible margin of the rectal tumor after radiotherapy should not be less than 1 cm to ensure oncological safety.