Prognostic Significance of Preoperative and Postoperative Evaluation of Combined Tumor Markers for Patients With Colon Cancer

BACKGROUND

The combined value of the tumor markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in patients with colon cancer (CC) is unclear. This study aimed to investigate the role of composite tumor markers in the prognosis of CC.

METHODS

Patients who underwent curative resection of colon adenocarcinoma were enrolled. The tumor marker status before and after the operation was used to divide the patients into groups according to the number of tumor markers with abnormal expression, and recurrence-free survival (RFS) and overall survival (OS) of different groups were compared. The impact of changes in composite tumor markers in the perioperative period on outcomes was further explored.

RESULTS

Ultimately, 531 patients were enrolled in the study. As the number of preoperative and postoperative elevated tumor markers increased, both RFS and OS rates became lower (both P<0.05). Further analysis revealed that the number of elevated tumor markers after resection can significantly affect the outcomes (both P<0.05). In patients with abnormal preoperative tumor markers, normalization of markers after surgery was a protective factor for prognosis (both P<0.05), and patients with postoperative elevated levels of both tumor markers had a 5.5-fold and 6-fold increase in the risk of recurrence and death. In addition, patients with elevated markers after surgery had a high risk of recurrence within 5 years after colectomy.

CONCLUSIONS

Postoperative tumor markers had a better ability to differentiate postoperative outcomes in patients with CC than preoperative tumor markers. Patients whose tumor markers normalized after surgery had a better prognosis.

Unraveling variations and enhancing prediction of successful sphincter-preserving resection for low rectal cancer: A post hoc analysis of the multicenter LASRE randomized clinical trial

BACKGROUND

Accurate prediction of successful sphincter-preserving resection (SSPR) for low rectal cancer enables peer institutions to scrutinize their own performance and potentially avoid unnecessary permanent colostomy. The aim of this study is to evaluate the variation in SSPR and present the first artificial intelligence (AI) models to predict SSPR in low rectal cancer patients.

STUDY DESIGN

This was a retrospective post hoc analysis of a multicenter, noninferiority randomized clinical trial (LASRE, NCT XXXXXX) conducted in 22 tertiary hospitals across China. A total of 604 patients who underwent neoadjuvant chemoradiotherapy (CRT) followed by radical resection of low rectal cancer were included as the study cohort, which was then split into a training set (67%) and a testing set (33%). The primary end point of this post hoc analysis was SSPR, which was defined as meeting all the following criteria: (1) sphincter-preserving resection; (2) complete or nearly complete TME, (3) a clear CRM (distance between margin and tumor of 1 mm or more), and (4) a clear DRM (distance between margin and tumor of 1 mm or more). Seven AI algorithms, namely, support vector machine (SVM), logistic regression (LR), extreme gradient boosting (XGB), light gradient boosting (LGB), decision tree classifier (DTC), random forest (RF) classifier, and multilayer perceptron (MLP), were employed to construct predictive models for SSPR. Evaluation of accuracy in the independent testing set included measures of discrimination, calibration, and clinical applicability.

RESULTS

The SSPR rate for the entire cohort was 71.9% (434/604 patients). Significant variation in the rate of SSPR, ranging from 37.7% to 94.4%, was observed among the hospitals. The optimal set of selected features included tumor distance from the anal verge before and after CRT, the occurrence of clinical T downstaging, post-CRT weight and clinical N stage measured by magnetic resonance imaging. The 7 different AI algorithms were developed and applied to the independent testing set. The LR, LGB, MLP and XGB models showed excellent discrimination with AUROC values of 0.825, 0.819, 0.819 and 0.805, respectively. The DTC, RF and SVM models had acceptable discrimination with AUROC values of 0.797, 0.766 and 0.744, respectively. LR and LGB showed the best discrimination, and all 7 AI models had superior overall net benefits within the range of 0.3-0.8 threshold probabilities. Finally, we developed an online calculator based on the LGB model to facilitate clinical use.

CONCLUSIONS

The rate of SSPR exhibits substantial variation, and the application of AI models has demonstrated the ability to predict SSPR for low rectal cancers with commendable accuracy.

Mesenchymal stem cells derived from adipose tissue and umbilical cord reveal comparable efficacy upon radiation-induced colorectal fibrosis in rats

Chemoradiotherapy (CRT) and radiotherapy (RT) have served as anticancer treatments and neoadjuvant therapies for conquering multimodal rectal cancers including colorectal carcinoma (CRC), yet the concomitant radiation-induced colorectal fibrosis (RICF) has caused chronic toxicity and stenosis in the colorectal mucosa of patients. Mesenchymal stem/stromal cells (MSCs) with unique bidirectional immunoregulation and anti-fibrotic effect have been recognized as splendid sources for regenerative purposes including intestinal diseases. Herein, we are aiming to verify the feasibility and variations of MSC-based cytotherapy for the remission of RICF from the pathological features and the potential impact upon the transcriptomic signatures of RICF rats. For the purpose, we utilized our well-established RICF Sprague-Dawley (SD) rats by radiation for five weeks, and conducted consecutive intraperitoneal injection of two distinct MSCs for treatment, including MSCs derived from adult adipose tissue (AD-MSCs) and perinatal umbilical cord (UC-MSCs). On the one hand, the efficacy of AD-MSCs and UC-MSCs was assessed by diverse indicators, including weight change, pathological detections (e.g., H&E staining, Masson staining, EVG staining, IF staining, and IHC staining), and proinflammatory and fibrotic factor expression. On the other hand, we turned to RNA-sequencing (RNA-SEQ) and multifaceted bioinformatics analyses (e.g., GOBP, Venn Map, KEGG, and GSEA) to compare the impact of AD-MSC and UC-MSC treatment upon the gene expression profiling and genetic variations. RICF rats after consecutive AD-MSC and UC-MSC administration revealed comparable remission in histopathogenic features and significant suppression of diverse proinflammatory and fibrotic factors expression. Meanwhile, RICF rats after both MSC treatment revealed decrease and variations in the alterations in diverse gene expression and somatic mutations compared to RICF rats. Collectively, our data indicated the comparable therapeutic effect of AD-MSCs and UC-MSCs upon RICF in SD rats, together with the conservations in gene expression profiling and the diverse variations in genetic mutations. Our findings indicated the multifaceted impact of MSC infusion for the supervision of RICF both at the therapeutic and transcriptomic levels, which would provide novel references for the further evaluation and development of MSC-based regimens in future.

Fibrosis signature of anastomotic margins for predicting anastomotic stenosis in rectal cancer with neoadjuvant chemoradiotherapy and sphincter-preserving surgery

Background

Radiation-induced colorectal fibrosis (RICF) is a common pathological alteration among patients with rectal cancer undergoing neoadjuvant chemoradiotherapy (nCRT). Anastomotic stenosis (AS) causes symptoms and negatively impacts patients' quality of life and long-term survival. In this study, we aimed to evaluate the fibrosis signature of RICF and develop a nomogram to predict the risk of AS in patients with rectal cancer undergoing nCRT.

Methods

Overall, 335 pairs of proximal and distal margins were collected and randomly assigned at a 7:3 ratio to the training and testing cohorts. The RICF score was established to evaluate the fibrosis signature in the anastomotic margins. A nomogram based on the RICF score for AS was developed and evaluated by using the area under the curve, decision curve analysis, and the DeLong test.

Results

The training cohort included 235 patients (161 males [68.51%]; mean age, 59.61 years) with an occurrence rate of AS of 17.4%, whereas the testing cohort included 100 patients (72 males [72.00%]; mean age, 57.17 years) with an occurrence rate of AS of 11%. The RICF total score of proximal and distal margins was significantly associated with AS (odds ratio, 3.064; 95% confidence interval [CI], 2.200-4.268; P < 0.001). Multivariable analysis revealed that the RICF total score, neoadjuvant radiotherapy, and surgical approach were independent predictors for AS. The nomogram demonstrated good discrimination in the training cohort (area under the receiver-operating characteristic curve, 0.876; 95% CI, 0.816-0.937), with a sensitivity of 68.3% (95% CI, 51.9%-81.9%) and a specificity of 85.5% (95% CI, 78.7%-89.3%). Similar results were observed in the testing cohort.

Conclusions

This study results suggest that the RICF total score of anastomotic margins is an independent predictor for AS. The prediction model developed based on the RICF total score may be useful for individualized AS risk prediction in patients with rectal cancer undergoing nCRT and sphincter-preserving surgery.

Excluding external iliac node irradiation during neoadjuvant radiotherapy decreases lower intestinal toxicity without compromising efficacy in T4b rectal cancer patients with tumours involving the anterior structures

PURPOSE

To explore the impact of excluding the external iliac node (EIN) from the clinical target volume (CTV) during preoperative radiotherapy in T4b rectal cancer with anterior structure invasion.

METHODS

We retrospectively identified 132 patients with T4b rectal cancer involving the anterior structures who received radiotherapy followed by surgery between May 2010 and June 2019. Twenty-nine patients received EIN irradiation (EIN group), and 103 did not (NEIN group). Failure patterns, survival and toxicities were compared between the two groups.

RESULTS

The most common failure was distant metastasis (23.5%). 11 (8.3%) patients developed locoregional recurrence, 10 (9.7%) patients were in the NEIN group, and 1 (3.4%) was in the EIN group (P = 0.34). The EIN region failure was rare (1/132, 0.8%). The locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), overall survival (OS) and progression-free survival (PFS) rates were 96.3% vs. 90.5%, 82.1% vs.73.7%, 75.9% vs. 78.0% and 72.4% vs. 68.3% (all P > 0.05) for the EIN group and NEIN group, respectively. The incidence of grade 3-4 acute toxicity in the lower intestine was significantly higher in the EIN group than in the NEIN group (13.8% vs. 1.9%, P = 0.02). The Dmax, V35 and V45 of the small bowel was decreased in the NEIN group compared to the EIN group.

CONCLUSIONS

Exclusion of the EIN from the CTV in T4b rectal cancer with anterior structure invasion could reduce lower intestinal toxicity without compromising oncological outcomes. These results need further evaluation in future studies.

Dysbiosis of gut microbiota and metabolites is associated with radiation-induced colorectal fibrosis and is restored by adipose-derived mesenchymal stem cell therapy

AIMS

This study aimed to investigate the effects of adipose-derived mesenchymal stem cells (ADSCs) on radiation-induced colorectal fibrosis (RICF) along with the associated dysbiosis of gut microbiota and metabolites.

MAIN METHODS

Fecal microbiota were assessed through 16S rRNA gene sequencing, and the fecal metabolome was characterized using liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. The correlation between microbiota and metabolome data was explored.

KEY FINDINGS

ADSC injection demonstrated a significant restoration of radiation-induced intestinal damage in vivo. At the phylum level, irradiated rats exhibited an increase in Bacteroidota and Campilobacterota, and a decrease in Firmicutes and Desulfobacterota, contrasting with the ADSC treatment group. Metabolomic analysis revealed 72 differently expressed metabolites (DEMs) from gas chromatography-mass spectrometry and 284 DEMs from liquid chromatography-mass spectrometry in the radiation group compared to the blank group. In the ADSC treatment group versus the radiation group, 36 DEMs from gas chromatography-mass spectrometry and 341 DEMs from liquid chromatography-mass spectrometry were identified. KEGG enrichment analysis implicated pathways such as steroid hormone biosynthesis, gap junction, primary bile acid biosynthesis, citrate cycle, cAMP signaling pathway, and alanine, aspartate, and glutamate metabolism during RICF progression and after treated with ADSCs. Correlation analysis highlighted the role of ADSCs in modulating the metabolic process of Camelledionol in fecal Bacteroides.

SIGNIFICANCE

These findings underscore the potential of ADSCs in reversing dysbiosis and restoring normal colonic flora in the context of RICF, offering valuable insights for therapeutic interventions targeting radiation-induced complications.

[Advancements in research on para-aortic lymph node dissection in colorectal cancer]

Para-aortic lymph node metastasis from colorectal cancer is relatively rare. Recent studies have shown that curative para-aortic lymph node dissection can lead to similar prognoses as stage III colorectal cancer for selected patients. However, there are still many unresolved debates regarding the appropriate surgical indications, extent of lymph node dissection, and treatment principles for colorectal cancer patients with para-aortic lymph node metastasis. With the continuous improvement of laparoscopic colorectal surgery techniques, the previously complex and high-risk procedure of para-aortic lymph node dissection has now become a safe and feasible approach. However, there are still several challenges that need to be addressed in this field. It is imperative to conduct multicenter clinical studies to demonstrate the survival benefits of this surgical procedure into greater survival benefits. This will help generate more robust evidence in the field of evidence-based medicine.

The prevention of rectovaginal fistula after rectal cancer surgery by packing with laparoscopic dislocated fat flap containing ovarian vascular pedicle anterior to the anastomotic stoma: a parallel group randomized controlled trial protocol

BACKGROUND

Rectovaginal fistula (RVF) is an abnormal channel formed by epithelial tissue between the anterior wall of the rectum and the posterior wall of the vagina, which manifests as vaginal gassing and defecation. It is one of the common complications of female pelvic surgeries. With the increased number of proctectomies for rectal cancer, the number of postoperative rectovaginal fistulas also increases. Once RVF occurs, the failure rate is still high with various treatments available. RVF causes great suffering to women and is still a major problem in treatment. Therefore, it is significant for female rectal cancer patients to prevent RVF after rectal cancer surgery. In this study, we introduce a new method to prevent RVF during rectal cancer radical operation.

METHODS

In this randomized controlled trial (RCT), all operations are performed according to the principle of total mesorectal excision (TME) radical resection in rectal cancer surgery. All eligible participants will be divided into two groups: the experimental group and the control group. Experimental group: the anterior rectal wall of about 1 cm distal to the anastomosis was dislocated. Before the anastomosis of the rectal end, a fat flap (usually left side) containing the ovarian vascular pedicle was dislocated, measured by 10-15 cm in length and 2 cm in width. The fat flap containing the ovarian vascular pedicle was packed and fixed anterior to the anastomotic stoma with fibrin glue.

CONTROL GROUP

surgery will be carried out in accordance with the TME principle. Participants will be compared on several variables, including the incidence of RVF after operation (primary outcomes), the occurrence time of postoperative RVF, the occurrence time of RVF after stoma closure, and other postoperative complications, such as anastomotic leakage, chylous leakage, and intestinal obstruction (secondary outcomes). The follow-up data collection will be conducted according to the follow-up time point, and the baseline data will also be collected for follow-up analysis. By comparing the incidence of rectovaginal leakage between the experimental group and the control group, we aim to explore the feasibility of this method for the prevention of postoperative RVF.

DISCUSSION

This RCT will explore the feasibility of packing with a laparoscopic dislocated fat flap containing an ovarian vascular pedicle anterior to the anastomotic stoma after rectal cancer surgery to prevent RVF.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR) registration ChiCTR2000031449. Registered on June 26, 2019. All items of the WHO Trial registration data set can be found within the protocol.

Primary Surgery Followed by Selective Chemoradiotherapy Versus Preoperative Chemoradiotherapy Followed by Surgery for Locally Advanced Rectal Cancer: A Randomized Clinical Trial

PURPOSE

The aim of this work was to determine whether locally advanced rectal cancer (LARC) with negative mesorectal fascia (MRF) predicted by magnetic resonance imaging (MRI) can be excluded from preoperative radiation therapy treatment.

METHODS AND MATERIALS

This multicenter, open-label, non-inferiority, randomized clinical trial enrolled patients with LARC within 6 to 12 cm from the anal verge and with negative MRI-predicted MRF. Participants were randomized to the intervention group (primary surgery, in which the patients with positive pathologic [CRM] circumferential margins were subjected to chemoradiotherapy [CRT] and those with negative CRM underwent adjuvant chemotherapy according to pathologic staging) or the control group (preoperative CRT, in which all patients underwent subsequent surgery and adjuvant chemotherapy). The primary endpoint was 3-year disease-free survival (DFS).

RESULTS

A total of 275 patients were randomly assigned to the intervention (n = 140) and control (n = 135) groups, in which 33.57% and 28.15% patients were at clinical T4 stage and 85.92% and 80.45% patients were at "bad" or "ugly" risk in the intervention and control groups, respectively. There were 2 patients (1.52%) and 1 patient (0.77%) with positive CRM in the intervention and control groups, respectively (P > .05). The non-adherence rates for the intervention and control groups were 3.6% and 23.7%, respectively. After a median follow-up of 34.6 months (IQR, 18.2-45.7), 43 patients had positive events (28 patients and 15 patients in the intervention and control groups, respectively). There were 6 patients (4.4%) with local recurrence in the intervention group and none in the control group, which led to the termination of the trial. The 3-year DFS rate was 81.82% in the intervention group (95% CI, 78.18%-85.46%) and 85.37% in the control group (95% CI, 81.75%-88.99%), with a difference of -3.55% (95% CI, -3.71% to -3.39%; hazard ratio, 1.76; 95% CI, 0.94-3.30). In the per-protocol data set, the difference between 3-year DFS rates was -5.44% (95% CI, -5.63% to -5.25%; hazard ratio, 2.02; 95% CI, 1.01-4.06).

CONCLUSIONS

Based on the outcomes of this trial, in patients with LARC and MRI-negative MRF, primary surgery could negatively influence their DFS rates. Therefore, primary surgery was an inferior strategy compared with preoperative CRT followed by surgery and cannot be recommended for patients with LARC.

Early recurrence after complete mesocolic excision for right-sided colon cancer with D3 lymphadenectomy: pattern, risk factors, prognostic impact, and individualized follow-up

The definition of early recurrence (ER) for right-sided colon cancer patients after complete mesocolic excision (CME) with D3 lymphadenectomy remains unclear. This study aimed to define the optimal time for ER and clarify risk factors for ER and post-recurrence survival (PRS). A total of 578 right-sided colon cancer patients who underwent CME with D3 lymphadenectomy were included. The minimum p value method was used to evaluate theme optimal time of recurrence-free survival to discriminate between ER and late recurrence (LR). Risk factors for ER were determined by a logistics regression model. The PRS was compared between ER and LR. The optimal time to define ER was 15 months (P = 1.8697E-7). 93 patients developed tumor recurrence, 46 patients had ER (≤15 months) and 47 patients had LR (>15 months). Preoperative serum CA19-9 > 37 U/mL (OR = 3.185, P = 0.001), pathological N+ stage (OR = 3.042, P = 0.027), and lymphovascular invasion (OR = 2.182, P = 0.027) were identified as independent risk factors associated with ER. Age > 75 years (HR = 1.828, P = 0.040), pathological N2 stage (HR = 1.850, P = 0.009), multiple sites of recurrence (HR = 1.680, P = 0.024), and time to recurrence ≤15 months (HR = 2.018, P = 0.043) were significantly associated with worse PRS in patients with recurrence. 15 months was the optimal time to distinguish ER and LR. ER was associated with a poor PRS. Elevated preoperative serum CA19-9 level, pathological N+ stage, and lymphovascular invasion were significantly predictive of ER.

Development and validation of a novel radiomics nomogram for prediction of early recurrence in colorectal cancer

BACKGROUND

Early recurrence (ER) is a significant concern following curative resection of advanced colorectal cancer (CRC) and is linked to poor long-term survival. Reliable prediction of ER is challenging, necessitating the development of a novel radiomics-based nomogram for CRC patients.

METHODS

We enrolled 405 patients, with 298 in the training set and 107 in the external test set. Radiomic features were extracted from preoperative venous-phase computed tomography (CT) images. A radiomics signature was created using univariate logistic regression analyses and the least absolute shrinkage and selection operator algorithm. Clinical factors were integrated into the analyses to develop a comprehensive predictive tool in a multivariate logistic regression model, resulting in a radiomics nomogram. Subsequently, the calibration, discrimination, and clinical usefulness of the nomogram were evaluated.

RESULTS

The radiomics signature, consisting of four selected CT features, was significantly associated with ER in both the training and test datasets (P < 0.05). Independent predictors of ER included TNM stage, carcinoembryonic antigen level and differentiation grade were identified. The radiomics nomogram, incorporating all these predictors, exhibited good predictive ability in both the training set with an area under the curve (AUC) of 0.82 (95 % confidence interval (CI), 0.74-0.90) and the test set with an AUC of 0.85 (95 % CI, 0.72-0.99), surpassing the performance of any single candidate factor alone. Furthermore, additional analysis demonstrated that the nomogram was clinically useful.

CONCLUSIONS

We have developed a radiomics-based nomogram that effectively predicts early recurrence in CRC patients, enhancing the potential for timely intervention and improved outcomes.

Transanal local excision versus intersphincteric resection for low rectal cancer with stage ypT0-1ycN0 after neoadjuvant chemoradiotherapy: an inverse probability weighting analysis for oncological and functional outcomes

OBJECTIVES

This study aimed to compare the efficacy of local excision (LE) and intersphincteric resection (ISR) in patients with locally advanced rectal cancer who achieved a significant or complete pathological response following neoadjuvant chemoradiotherapy.

METHODS

We performed a retrospective analysis of data from patients with stage ypT0-1ycN0 low rectal cancer after neoadjuvant chemoradiotherapy who underwent LE or ISR between June 2016 and June 2021. Baseline characteristics, short-term outcomes, long-term oncological outcomes, and functional outcomes, were compared between the two groups. To reduce the selection bias, inverse probability of treatment weighting (IPTW) was performed.

RESULTS

This study included 106 patients (LE group: n = 51, ISR group: n = 55). There were significant differences in baseline characteristics between the two groups (P < 0.05). After IPTW, there were almost no significant differences in baseline data between the two groups. The LE group showed less postoperative complications and better function outcomes compared to the ISR group. The LE group had significantly lower rates of complications (13.7% vs. 36.4%, P = 0.014). There were no significant differences between the two groups in terms of long-term oncological outcomes.

CONCLUSIONS

For patients with locally advanced low rectal cancer achieving significant or complete pathological response after neoadjuvant therapy, both LE and ISR present comparable oncological outcomes. Yet, LE seems to show more advantages in terms of postoperative complications and functional outcomes. These findings offer important insights for surgical decision-making, emphasizing the necessity to consider both oncological and functional outcomes in selecting the optimal surgical approach.

Comparison of survival outcomes and survival prediction in patients with primary colorectal MANEC and primary colorectal SRCC: a population-based propensity-score matching study

PURPOSE

Primary mixed adeno-neuroendocrine carcinoma (MANEC) and primary signet-ring cell cancer (SRCC) are two rare but highly malignant tumors in colorectal cancer. Therefore, we attempted to compare the tumors' survival outcomes, identify risk factors, and ultimately evaluate the prognosis by developing a nomogram.

METHODS

We identified 755 MANEC and 5836 SRCC patients of colorectal cancer. PSM was used to balance the influence of baseline clinical and pathological differences. Kaplan-Meier method was used to compare the prognosis of different pathological grades and AJCC stages. Cox proportional hazards model was used to identify potential prognostic factors for the two groups. Finally, we developed a nomogram and evaluated the feasibility of the model.

RESULTS

After PSM, the median OS and CSS of MANEC patients were significantly better than those of SRCC patients in stage III-IV (P < 0.001) but similar in stage I-II. The median OS and CSS of MANEC patients in each pathological grade were also greater than those of SRCC patients. Patients with MANEC and SRCC who underwent lymph node dissection in more than four areas had longer survival time. MANEC patients benefited from postoperative chemotherapy and radiotherapy; among SRCC patients, those who received preoperative and postoperative comprehensive chemotherapy and radiotherapy had benefits in OS and CSS.

CONCLUSION

Both MANEC and SRCC are often diagnosed in advanced stages, highlighting the importance of early screening. Despite the better prognosis of MANEC compared to SRCC, both types of patients require the formulation of personalized treatment strategies based on different risk factors combined with column charts.

Transverse Coloplasty Pouch versus Straight Coloanal Anastomosis Following Intersphincteric Resection for Low Rectal Cancer: the Functional Benefits May Emerge After Two Years

PURPOSE

This study aimed to compare the oncological and functional outcomes following intersphincteric resection (ISR) with transverse coloplasty pouch (TCP) or straight coloanal anastomosis (SCAA) for low rectal cancer.

METHODS

A single-center retrospective analysis was performed on patients with low rectal cancer who received ISR between January 2016 and June 2021. The primary endpoint was to compare the outcomes of bowel function within 1 year, 1 to 2 years, and 2 years after ileostomy closure in patients undergoing two different bowel reconstruction procedures (TCP or SCAA). The postoperative complications and oncological results were also compared between the two groups.

RESULTS

A total of 235 patients were enrolled in this study (SCAA group: 166; TCP group: 69). There was no significant difference in complications, including grades A-C anastomotic leakage (9.6% vs 15.9%), 3-year local recurrence rates (6.1% vs 3.9%), disease-free survival (82.4%vs 83.8%), or overall survival (94.1% vs 94.7%) between the two groups. Two years after ileostomy closure, 52.7% of patients in the SCAA group were assessed as having major low anterior resection syndrome (LARS), which was significantly higher than the 25.9% of patients in the TCP group (P = 0.014), but no difference was found prior to 2 years. Similar differences were seen in Wexner scores 2 years after surgery (P = 0.032). Additionally, TCP was an independent protective factor for postoperative bowel function as measured by both the LARS (OR, 0.28; 95% CI, 0.10-0.82; p = 0.020) and Wexner scoring (OR, 0.28; 95% CI, 0.09-0.84; p = 0.023).

CONCLUSION

This study suggests that TCP is a safe technique that may decrease bowel dysfunction after ISR for low rectal cancer compared with SCAA 2 years after ileostomy closure.

Construction and validation of stemness-related lncRNA pair signature for predicting prognosis in colorectal cancer

PURPOSE

The purpose of this study was to identify a prognostic signature based on stemness-related differentially expressed lncRNAs in colorectal cancer (CRC) and to investigate their potential as biomarkers for diagnosis, prognosis, and therapeutic targets.

METHODS

Stemness-related genes were collected from the TCGA cohort, and 13 differently expressed stemness-related lncRNAs were identified as prognostic factors for CRC using Kaplan-Meier analysis. A risk model was constructed based on the calculated risk score as a novel independent prognostic factor for CRC patients. The study also investigated the association between the risk model and immune checkpoints and m6A differentiation gene expression. qRT-PCR analysis was performed to validate the expression of differentially expressed stemness-related lncRNAs in CRC cell lines compared to normal colon mucosal cell line.

RESULTS

The low-risk lncRNAs were associated with higher survival in CRC patients (Kaplan-Meier analysis, P < 0.001). The risk model was a significant independent prognostic factor for CRC patients. Type I INF response was statistically significant between low- and high-risk groups. CD44, CD70, PVR, TNFSF4, BTNL2, CD40, these immune checkpoints were expressed differently between two risk groups. There was a significant difference between m6A differentiation gene expression such as METTL3, METTL14, WTAP, RBM15, ZC3H13, YTHDC2, YTHDF2, ALKBH5. qRT-PCR analysis validated that there were five up-regulated and eight down-regulated differently expressed stemness-related lncRNAs in CRC cell lines compared to the normal colon mucosal cell line.

CONCLUSION

This study suggests that the 13 CRC stemness-related lncRNA signature could become a promising and reliable prognostic factor for colorectal cancer. The risk model based on the calculated risk score may have implications for personalized medicine and targeted therapies for CRC patients. The study also suggests that immune checkpoints and m6A differentiation genes may play important roles in the development and progression of CRC.

Lymph node ratio and hematological parameters predict relapse-free survival in patients with high grade rectal neuroendocrine neoplasms after radical resection: a multicenter prognostic study

BACKGROUND

The prognostic nutritional index (PNI), alkaline phosphatase (ALP), and lymph node ratio (LNR) are reportedly related to prognosis. The aim of this study was to elucidate the clinical importance of the LNR and hematological parameters in patients with high grade rectal neuroendocrine neoplasms (HG-RNENs) who were undergoing radical resection.

METHODS

We reviewed the medical records of patients with HG-RNENs from 17 large-scale medical centers in China (January 1, 2010-April 30, 2022). A nomogram was constructed by using a proportional hazard model. Bootstrap method was used to draw calibration plots to validate the reproducibility of the model. Concordance index (C-Index), decision curve analysis (DCA), and time-dependent area under the receiver operating characteristic curve (TD-AUC) analysis were used to compare the prognostic predictive power of the new model with American Joint Committee on Cancer (AJCC) TNM staging and European Neuroendocrine Tumor Society (ENETS) TNM staging.

RESULTS

A total of 85 patients with HG-RNENs were enrolled in this study. In the 45 patients with HG-RNENs who underwent radical resection, PNI ≤ 49.13 (HR: 3.997, 95% CI: 1.379-11.581, P = 0.011), ALP > 100.0 U/L (HR: 3.051, 95% CI: 1.011-9.205, P = 0.048), and LNR > 0.40 (HR: 6.639, 95% CI: 2.224-19.817, P = 0.0007) were independent predictors of relapse-free survival. The calibration plots suggested that the nomogram constructed based on the three aforementioned factors had good reproducibility. The novel nomogram revealed a C-index superior to AJCC TNM staging (0.782 vs 0.712) and ENETS TNM staging (0.782 vs 0.657). Also, the new model performed better compared to AJCC TNM staging and ENETS TNM staging in DCA and TD-AUC analyses.

CONCLUSIONS

LNR, ALP, and PNI were independent prognostic factors in patients with HG-RNENs after radical resection, and the combined indicator had better predictive efficacy compared with AJCC TNM staging and ENETS TNM staging.

Pathways of lymph node metastasis and prognosis after right hemicolectomy for cecal cancer: results from a retrospective single center

BACKGROUND

The recommended operation for cecum cancer (CC) is right hemicolectomy (RH) in some Western countries while the principle of D3 lymphadenectomy in Japan recommends resecting approximately 10 cm from the tumor edge. Therefore, the optimal surgical approach for cecum cancer (CC) remains controversial. We conducted this retrospective study to explore the pattern of lymph node metastasis and better surgical procedures for CC.

METHODS

A total of 224 cecum cancer patients from January 1, 2014, to December 31, 2021, were retrospectively included in the final study. The pattern of lymph node metastasis (LNM) was investigated.

RESULTS

A total of 113 (50.4%, 113/224) patients had pathologically confirmed LNM. The most frequent metastatic site was no. 201 lymph node (46%, 103/224), while 20 (8.9%, 20/224) patients had LNM in no. 202 lymph node, and 8 (3.6%, 8/224) patients had LNM in no. 203 lymph node. Only 1 (0.4%, 1/224) patient had LNM in no. 221 lymph node, four (1.8, 4/224%) patients had LNM in no. 223 lymph node, and no patients had LNM in no. 222 lymph node. LNM in no. 223 lymph node was significantly associated with a poor prognosis. Multivariate analysis indicated that LNM in no. 223 lymph node (HR = 4.59, 95% CI 1.18-17.86, P = 0.028) was the only independent risk factor associated with worse disease-free survival (DFS).

CONCLUSIONS

The LNM in no. 223 lymph node for cecum cancer was rare. Therefore, standard right hemicolectomy excision is too extensive for most CC cases.

[Anatomical classification of and laparoscopic surgery for left-sided colorectal cancer with persistent descending mesocolon]

Objective: To investigate anatomical morphology and classification of persistent descending mesocolon (PDM) in patients with left-sided colorectal cancer, as well as the safety of laparoscopic radical surgery for these patients. Methods: This is a descriptive study of case series. Relevant clinical data of 995 patients with left colon and rectal cancer who had undergone radical surgery in Fujian Medical University Union Hospital from July 2021 to September 2022 were extracted from the colorectal surgery database of our institution and retrospectively analyzed. Twenty-four (2.4%) were identified as PDM and their imaging data and intra-operative videos were reviewed. We determined the distribution and morphology of the descending colon and mesocolon, and evaluated the feasibility and complications of laparoscopic surgery. We classified PDM according to its anatomical characteristics as follows: Type 0: PDM combined with malrotation of the midgut or persistent ascending mesocolon; Type 1: unfixed mesocolon at the junction between transverse and descending colon; Type 2: PDM with descending colon shifted medially (Type 2A) or to the right side (Type 2B) of the abdominal aorta at the level of the origin of the inferior mesentery artery (IMA); and Type 3: the mesocolon of the descending-sigmoid junction unfixed and the descending colon shifted medially and caudally to the origin of IMA. Results: The diagnosis of PDM was determined based on preoperative imaging findings in 9 of the 24 patients (37.5%) with left-sided colorectal cancer, while the remaining diagnoses were made during intraoperative assessment. Among 24 patients, 22 were male and 2 were female. The mean age was (63±9) years. We classified PDM as follows: Type 0 accounted for 4.2% (1/24); Type 1 for 8.3% (2/24); Types 2A and 2B for 37.5% (9/24) and 25.0% (6/24), respectively; and Type 3 accounted for 25.0% (6/24). All patients with PDM had adhesions of the mesocolon that required adhesiolysis. Additionally, 20 (83.3%) of them had adhesions between the mesentery of the ileum and colon. Twelve patients (50.0%) required mobilization of the splenic flexure. The inferior mesenteric artery branches had a common trunk in 14 patients (58.3%). Twenty-four patients underwent D3 surgery without conversion to laparotomy; the origin of the IMA being preserved in 22 (91.7%) of them. Proximal colon ischemia occurred intraoperatively in two patients (8.3%) who had undergone high ligation at the origin of the IMA. One of these patients had a juxta-anal low rectal cancer and underwent intersphincteric abdominoperineal resection because of poor preoperative anal function. Laparoscopic subtotal colectomy was considered necessary for the other patient. The duration of surgery was (260±100) minutes and the median estimated blood loss was 50 (20-200) mL. The median number of No. 253 lymph nodes harvested was 3 (0-20), and one patient (4.2%) had No.253 nodal metastases. The median postoperative hospital stay was 8 (4-23) days, and the incidence of complications 16.7% (4/24). There were no instances of postoperative colon ischemia or necrosis observed. One patient (4.2%) with stage IIA rectal cancer developed Grade B (Clavien-Dindo III) anastomotic leak and underwent elective ileostomy. The other complications were Grade I-II. Conclusions: PDM is frequently associated with mesenteric adhesions. Our proposed classification can assist surgeons in identifying the descending colon and mesocolon during adhesion lysis in laparoscopic surgery. It is crucial to protect the colorectal blood supply at the resection margin to minimize the need for unplanned extended colectomy, the Hartmann procedure, or permanent stomas.

Errate: Silencing Signal Transducer and Activator of Transcription 3 (STAT3) and Use of Anti-Programmed Cell Death-Ligand 1 (PD-L1) Antibody Induces Immune Response and Anti-Tumor Activity

It was brought to our attention by the authors that Figures 5A and 6A contained errors. The correct version of Figures 5A and 6A are provided below. The corrected figures do not change the overall findings of the study. Reference: Jiaxing Wang, Fakun Huang, Caiyun Jiang, Pan Chi. Silencing Signal Transducer and Activator of Transcription 3 (STAT3) and Use of Anti-Programmed Cell Death-Ligand 1 (PD-L1) Antibody Induces Immune Response and Anti-Tumor Activity. Med Sci Monit, 2020; 26: e915854. DOI: 10.12659/MSM.915854.

[Anatomical and histological investigation of the area anterior to the anorectum passing through the levator hiatus]

Objective: To document the anatomical structure of the area anterior to the anorectum passing through the levator hiatus between the levator ani slings bilaterally. Methods: Three male hemipelvises were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. (1) The anatomical assessment was performed in three ways; namely, by abdominal followed by perineal dissection, by examining serial cross-sections, and by examining median sagittal sections. (2) The series was stained with hematoxylin and eosin to enable identification of nerves, vessels, and smooth and striated muscles. Results: (1) It was found that the rectourethralis muscle is closest to the deep transverse perineal muscle where the longitudinal muscle of the rectum extends into the posteroinferior area of the membranous urethra. The communicating branches of the neurovascular bundle (NVB) were identified at the posterior edge of the rectourethralis muscle on both sides. The rectum was found to be fixed to the membranous urethra through the rectourethral muscle, contributing to the anorectal angle of the anterior rectal wall. (2) Serial cross-sections from the anal to the oral side were examined. At the level of the external anal sphincter, the longitudinal muscle of the rectum was found to extend caudally and divide into two muscle bundles on the oral side of the external anal sphincter. One of these muscle bundles angled dorsally and caudally, forming the conjoined longitudinal muscle, which was found to insert into the intersphincteric space (between the internal and external anal sphincters). The other muscle bundle angled ventrally and caudally, filling the gap between the external anal sphincter and the bulbocavernosus muscle, forming the perineal body. At the level of the superficial transverse perineal muscle, this small muscle bundle headed laterally and intertwined with the longitudinal muscle in the region of the perineal body. At the level of the rectourethralis and deep transverse perineal muscle, the external urethral sphincter was found to occupy an almost completely circular space along the membranous part of the urethra. The dorsal part of the external urethral sphincter was found to be thin at the point of attachment of the rectourethralis muscle, the ventral part of the longitudinal muscle of the rectum. We identified a venous plexus from the NVB located close to the oral and ventral side of the deep transverse perineal muscle. Many vascular branches from the NVB were found to be penetrating the longitudinal muscle and the ventral part of rectourethralis muscle at the level of the apex of the prostate. The rectourethral muscle was wrapped ventrally around the membranous urethra and apex of the prostate. The boundary between the longitudinal muscle and prostate gradually became more distinct, being located at the anterior end of the transabdominal dissection plane. (3) Histological examination showed that the dorsal part of the external urethral sphincter (striated muscle) is thin adjacent to the striated muscle fibers from the deep transverse perineal muscle and the NVB dorsally and close by. The rectourethral muscle was found to fill the space created by the internal anal sphincter, deep transverse perineal muscle, and both levator ani muscles. Many tortuous vessels and tiny nerve fibers from the NVB were identified penetrating the muscle fibers of the deep transverse perineal and rectourethral muscles. The structure of the superficial transverse perineal muscle was typical of striated muscle. These findings were reconstructed three-dimensionally. Conclusions: In intersphincteric resection or abdominoperineal resection for very low rectal cancer, the anterior dissection plane behind Denonvilliers' fascia disappears at the level of the apex of the prostate. The prostate and both NVBs should be used as landmarks during transanal dissection of the non-surgical plane. The rectourethralis muscle should be divided near the rectum side unless tumor involvement is suspected. The superficial and deep transverse perineal muscles, as well as their supplied vessels and nerve fibers from the NVB. In addition, the cutting direction should be adjusted according to the anorectal angle to minimize urethral injury.

[Clinical application and standardized implementation of intersphincteric resection]

Intersphincteric resection (ISR) is the ultimate sphincter-preserving surgical technique for low rectal cancer. To promote the standardized implementation of ISR, this review discusses the important issues regarding the clinical application of ISR with reference to the latest Chinese expert consensus on ISR. In terms of ISR-related pelvic anatomy of the rectum/anal canal, hiatal ligament is not identical with the anococcygeal ligament. At the level where the rectourethralis muscle continuously extends to the posteroinferior area of the membranous urethra from the rectum, the neurovascular bundle is identified between the posterior edge of rectourethralis muscle and the anterior edge of the longitudinal muscle of the rectum. This knowledge is crucial to detect the anterior dissection plane during ISR at the levator hiatus level. The indication criteria for ISR included: (1) stage I early low rectal cancer; (2) stage II-III low rectal cancer undergoing neoadjuvant treatment, and supra-anal tumors and juxta-anal tumors of stage ycT3NxM0, or intra-anal tumors of stage ycT2NxM0. However, signet ring cell carcinoma, mucinous adenocarcinoma and undifferentiated carcinoma should be contraindicated to ISR. For locally advanced low rectal cancer (especially anteriorly located tumor), neoadjuvant treatment should be carried out in a standardized manner. However, it should be recognized that neoadjuvant chemoradiotherapy was a risk factor for poor anal function after ISR. For surgical approaches for ISR, including transanal, transabdominal, and transanal transabdominal approaches, the choice should be based on oncological safety and functional consequences. While ensuring the negative margin, maximal preservation of rectal walls and anal canal contributs to better postoperative anorectal function. Careful attention must be paid to complications regarding ISR, with special focus on the anastomotic complications. The incidence of low anterior resection syndrome (LARS) was higher than 40%. However, this issue is often neglected by clinicians. Thus, management and rehabilitation strategies for LARS with longer follow-ups were required.

Combining chemotherapy and tislelizumab with preoperative split-course hypofraction radiotherapy for locally advanced rectal cancer: study protocol of a prospective, single-arm, phase II trial

INTRODUCTION

Short-course radiotherapy (SCRT) with systemic therapy has the potential to further improve the long-term efficacy in patients with locally advanced rectal cancer (LARC). To maximise the benefits of neoadjuvant therapy for improved prognosis, it is important to determine the optimal mix of chemotherapy, immunotherapy and SCRT.

METHODS AND ANALYSIS

Fifty treatment-naïve patients with operable LARC (T3-4 and/or N+) will be recruited. Patients will be synchronously treated with capecitabine plus oxaliplatin (CAPOX) chemotherapy, tislelizumab and preoperative split-course hypofraction radiotherapy (SCHR) (5×7 Gy) before surgery. Chemotherapy for CAPOX starts on day 1 of every 21-day cycle: on day 1, oxaliplatin 130 mg/m² will be injected intravenously. On days 1-14, capecitabine 1000 mg/m² was ingested two times a day. Simultaneously, tocilizumab 200 mg will be given intravenously on the first day of every 21-day cycle. A single 7 Gy SCHR treatment (day 7 of each 21-day cycle) will be delivered five times during the seventh day of treatment. The primary endpoint will be pathological complete response. The secondary outcomes will be the 3-year disease-free survival, local recurrence rate, overall survival, sphincter-sparing surgery rate, R0 resection rate, predictive biomarkers and quality of life.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of Xiehe Affiliated Hospital of Fujian Medical University (XAHFMU) (No. 2021YF025-01). Results from our study will be disseminated in international peer-reviewed journals. All study procedures were developed in order to assure data protection and confidentiality.

TRIAL REGISTRATION NUMBER

NCT05176964.

Impact of glucocorticoids on the efficacy of neoadjuvant chemoradiotherapy and survival of patients with locally advanced rectal cancer: a retrospective study

BACKGROUND

Preclinical studies suggest that glucocorticoids (GCs) promote the proliferation and development of colorectal cancer. Because GCs are broadly prescribed for treatment-related adverse events in patients with locally advanced rectal cancer (LARC) receiving neoadjuvant chemoradiotherapy (NCRT), it's essential to assess the effect of GCs on clinical outcomes.

METHODS

LARC cases treated with NCRT followed by surgery were assessed retrospectively. Evaluation of the relationship between GCs use (GCs vs. non-GCs) and neoadjuvant rectal (NAR) score (as a three-level categorical dependent variable) was performed using multivariable multinomial logistic regression (MLR). We also examined the relationship between the accumulated dose of GCs and NAR using multivariate MLR. Survival analysis of disease-free survival (DFS) and overall survival (OS) was performed using the Kaplan-Meier method. Multivariate Cox regression was used to assess confounding factors that could influence OS and DFS.

RESULTS

This retrospective cohort study included 790 patients with newly diagnosed non-metastatic LARC (T3-4/N + M0) who received NCRT followed by surgery between January 2012 and April 2017. The end of the follow-up period was May 11, 2022. Among the 790 patients with LARC, 342 (43.2%) received GCs treatment and 448 (56.8%) did not during the NCRT-to-surgery period. GCs medication was significantly different between mid-NAR (8-16) and low-NAR (< 8) (odds ratio [OR], 0.615; 95% CI, 0.420-0.901; P = 0.013), and the high-NAR (> 16) and low-NAR (0.563; 0.352-0.900; 0.016). Patients exposed to GCs, had a decreased 5-year OS (GCs vs. non-GCs = 80.01% (95% CI, 75.87%-84.37%) vs. 85.30% (82.06%-88.67%), P = 0.023) and poorer 5-year DFS (73.99% (69.45%-78.82%) vs. 78.7% (75.14%-82.78%), P = 0.045). The accumulated dose of GCs was an independent risk factor for OS (hazard ratio [HR], 1.007 [1.001-1.014], 0.036) and DFS (1.010 [1.004-1.017], 0.001).

CONCLUSIONS AND RELEVANCE

Our study revealed that GCs were associated with reduced efficacy of NCRT and worse clinical outcomes in patients with LARC during the NCRT-to-surgery period.

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.

The impact of prophylactic oophorectomy on the survival for postmenopausal patients with pT4a colorectal cancer

PURPOSE

This study aimed to evaluate the prognostic effect of prophylactic oophorectomy (PO) in postmenopausal patients with pT4 colorectal cancers (CRC) in terms of overall survival (OS), disease-free survival (DFS), and peritoneal metastasis.

METHODS

The data of postmenopausal female patients with pT4 CRC undergoing surgical resection between 2000 and 2019 were analyzed. Kaplan-Meier analysis was used to evaluate survival outcomes between patients treated with and without PO. Risk factors for DFS and peritoneal metastasis were evaluated using Cox regression analysis. p-values <0.05 were considered statistically significant.

RESULTS

Totally, 176 (34.3%) patients received PO. There was no significant difference in estimated blood loss, rates of postoperative complications, and hospitalization between the PO and non-PO groups. The 5-year OS and DFS rates were similar in the two groups (47.9% vs. 54.1%, p = 0.278; 53.5% vs. 50.5%, p = 0.161, respectively). In the subgroup analysis of patients with peritoneal metastasis, the median survival was significantly longer for the PO group compared with the non-PO group (14 vs. 11 months, p < 0.001).

CONCLUSION

Undertaking PO in pT4 CRC female patients did not confer a survival benefit. Indication of PO even for advanced CRC patients should require caution. It has potential survival benefit only when the patients developed metachronous peritoneal metastases.

Minimally invasive para-aortic lymph node dissection in left-sided colonic and rectal cancer: experience based on a high-volume centre

AIM

There is no established consensus on the optimal surgical approach to para-aortic lymph node (PALN) dissection in patients with colorectal cancer. This study aimed to demonstrate the technical and oncological safety of minimally invasive PALN dissection for left-sided colonic and rectal cancer patients with clinically suspected infrarenal PALN metastasis.

METHOD

One hundered and one patients who underwent primary tumour resection and minimally invasive (laparoscopic n = 92, robotic n = 9) PALN dissection for left-sided colonic and rectal cancer were included. Logistic regression analysis was used to identify risk factors for PALN metastasis. Survival outcomes were evaluated using the Kaplan-Meier (log-rank) method.

RESULTS

Para-aortic lymph node metastasis was pathologically confirmed in 23 patients (22.8%). Postoperative complications occurred in 22 patients (21.8%). Pathological N2 stage (OR = 9.337, p = 0.003) and inferior mesenteric artery LN metastasis (OR = 7.499, p = 0.009) were independently associated with PALN metastasis. The median follow-up time was 32 months (range 3-92 months). In all patients, the 5-year overall survival (OS) and progression-free survival (PFS) rates were 76.1% and 69.5%, respectively. The 5-year OS and PFS rates in patients with PALN metastasis were 49.8% and 47.5%, respectively. Patients with PALN metastasis had lower 5-year OS (p = 0.023) and PFS rates (p = 0.035) than those without PALN metastasis.

CONCLUSION

Minimally invasive PALN dissection had acceptable postoperative complications and may be oncologically beneficial in selected patients with clinically suspicious PALN metastasis.

MRI diagnose post-operative anastomotic leak in patients with rectal cancer: preliminary experience

BACKGROUND

Anastomotic leakage (AL) is one of the most serious postoperative complications after colorectal anastomosis. This study aims to evaluate the feasibility and diagnostic accuracy of magnetic resonance imaging (MRI) in the early detection of AL in patients with clinically suspected AL after rectal anterior resection.

METHODS

This was a prospective study including patients who underwent anterior resection and postoperative MRI examination. AL was diagnosed by comprehensive indictors, which were mainly confirmed by clinical signs, symptoms, and retrograde contrast enema (RCE) radiography. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of diagnosing AL with MRI were calculated.

RESULTS

In total, 347 patients received anterior resection for rectal cancer, and 28 patients were suspected to have AL. Finally, 23 patients were included and received MRI examination. The median time interval from surgery to MRI was 10 days (3-21 days). The median distance from anastomosis to anal verge was 4.0 cm (2.0-10 cm), and 11 patients underwent diverted ileostomy. Eighteen patients had an anastomotic leak, including one patient who had a pelvic abscess and five patients who had no evidence of AL in the MRI examination. The overall sensitivity and specificity were 94.4% (95% CI 70.6% to 99.7%) and 80% (95% CI 29.8% to 98.9%), respectively. The PPV was 0.94 (95% CI 0.71 to 0.99) and the NPV was 0.80 (95% CI 0.29 to 0.99). For patients who had anastomosis less than 5 cm, the diagnostic accuracy of MRI was 93.7% (15/16). T2-weighted imaging with fat suppression can effectively reveal the leak track.

CONCLUSIONS

The accuracy of plain MRI examination in diagnosing AL was favorable for patients with a suspected AL. T2-weighted imaging with fat suppression was the best imaging modality to diagnose AL. A multicenter prospective study with more samples is needed to further determine the safety and feasibility of MRI in the diagnosis of AL.

Development and validation of artificial intelligence models for preoperative prediction of inferior mesenteric artery lymph nodes metastasis in left colon and rectal cancer

BACKGROUND

Dissection of lymph nodes at the roots of the inferior mesenteric artery (IMAN) should be offered only to selected patients at a major risk of developing IMAN involvement. The aim of this study is to present the first artificial intelligence (AI) models to predict IMAN metastasis risk in the left colon and rectal cancer patients.

METHODS

A total of 2891 patients with descending colon including splenic flexure, sigmoid colon and rectal cancer undergoing major primary surgery and IMAN dissection were included as a study cohort, which was then split into a training set (67%) and a testing set (33%). Feature selection was conducted using the least absolute shrinkage and selection operator (LASSO) regression model. Seven AI algorithms, namely Support Vector Machine (SVM), Logistic Regression (LR), Extreme Gradient Boosting (XGB), Light Gradient Boosting (LGB), Decision Tree Classifier (DTC), Random Forest (RF) classifier, and Multilayer Perceptron (MLP), as well as traditional multivariate LR model were employed to construct predictive models. The optimal hyperparameters were determined with 5 fold cross-validation. The predictive performance of models and the expert surgeon was assessed and compared in the testing set independently.

RESULTS

The IMAN involvement incidence was 4.6%. The optimal set of features selected by LASSO included 10 characteristics: neoadjuvant treatment, age, synchronous liver metastasis, synchronous lung metastasis, signet ring adenocarcinoma, neural invasion, lymphovascular invasion, CA199, endoscopic obstruction, T stage evaluated by MRI. The most accurate model derived from MLP showed excellent prediction power with area under the receiver operating characteristic curve (AUROC) of 0.873 and produced 81.0% recognition sensitivity and 82.5% specificity in the testing set independently. In contrast, the judgment of IMAN metastasis by expert surgeon yield rather imprecise and unreliable results with a significantly lower AUROC of 0.509. Additionally, the proposed MLP had the highest net benefits and the largest reduction of unnecessary IMAN dissection without the cost of additional involved IMAN missed.

CONCLUSION

MLP model was able to maintain its prediction accuracy in the testing set better than other models and expert surgeons. Our MLP model could be used to help identify IMA nodal metastasis and to select candidates for individual IMAN dissection.

Monoclonal gammopathy of undetermined significance (MGUS) characterized by refractory lower gastrointestinal postoperative bleeding with coagulopathy

Bleeding is a common complication after lower gastrointestinal surgery, and cases due to coagulation dysfunction are rare. The current authors encountered a 54-year-old Chinese man with refractory bleeding after endoscopic rectal polypectomy, and multiple endoscopic and surgical interventions failed to control that bleeding. An APTT mixing test could not be corrected and there was no evidence of autoimmune-related disease, so the presence of nonspecific antibodies was considered. After empiric therapy with a cyclophosphamide and glucocorticoid, APTT was corrected and gastrointestinal bleeding stopped. Based on laboratory results and therapeutic results, the patient was ultimately diagnosed with prolonged APTT induced by monoclonal gammopathy of undetermined significance (MGUS). MGUS and coagulopathy characterized by a prolonged APTT has rarely been reported. Here, studies noting elevated monoclonal immunoglobulins and coagulopathy have been reviewed. If a prolonged APTT of undetermined significance cannot be corrected with an APTT mixing test and if autoimmune-related factors are excluded, then plasma cell-related diseases such as MGUS need to be considered.

Morphology of the anterior mesorectum: a new predictor for local recurrence in patients with rectal cancer

BACKGROUND

Pre-operative assessment with high-resolution magnetic resonance imaging (MRI) is useful for assessing the risk of local recurrence (LR) and survival in rectal cancer. However, few studies have explored the clinical importance of the morphology of the anterior mesorectum, especially in patients with anterior cancer. Hence, the study aimed to investigate the impact of the morphology of the anterior mesorectum on LR in patients with primary rectal cancer.

METHODS

A retrospective study was performed on 176 patients who underwent neoadjuvant treatment and curative-intent surgery. Patients were divided into two groups according to the morphology of the anterior mesorectum on sagittal MRI: (1) linear type: the anterior mesorectum was thin and linear; and (2) triangular type: the anterior mesorectum was thick and had a unique triangular shape. Clinicopathological and LR data were compared between patients with linear type anterior mesorectal morphology and patients with triangular type anterior mesorectal morphology.

RESULTS

Morphometric analysis showed that 90 (51.1%) patients had linear type anterior mesorectal morphology, while 86 (48.9%) had triangular type anterior mesorectal morphology. Compared to triangular type anterior mesorectal morphology, linear type anterior mesorectal morphology was more common in females and was associated with a higher risk of circumferential resection margin involvement measured by MRI (35.6% [32/90] vs . 16.3% [14/86], P   =  0.004) and a higher 5-year LR rate (12.2% vs . 3.5%, P   =  0.030). In addition, the combination of linear type anterior mesorectal morphology and anterior tumors was confirmed as an independent risk factor for LR (odds ratio = 4.283, P  = 0.014).

CONCLUSIONS

The classification established in this study was a simple way to describe morphological characteristics of the anterior mesorectum. The combination of linear type anterior mesorectal morphology and anterior tumors was an independent risk factor for LR and may act as a tool to assist with LR risk stratification and treatment selection.

The global, regional, and national early-onset colorectal cancer burden and trends from 1990 to 2019: results from the Global Burden of Disease Study 2019

PURPOSE

The incidence of early-onset colorectal cancer (EO-CRC), which occurs in people under age 50, has been increasing annually. The aim of this study was to provide an up-to-date estimate of the global EO-CRC burden.

METHODS

We used Global Burden of Disease Study data and methodologies to describe changes in the EO-CRC burden from 1990 to 2019, including incidence, prevalence, mortality, and disability-adjusted life years (DALYs). The driving factors for cancer burden variation were further analyzed using decomposition analysis. Frontier analysis was used to visually demonstrate the potential for burden reduction in each country or region based on their development levels.

RESULTS

The global EO-CRC incidence more than doubled, increasing from 95,737 (95% uncertainty interval (UI): 90,838-101.042) /100,000 in 1990 to 226,782 (95% UI: 207,495-248,604) /100,000 in 2019. Additionally, related deaths increased from 50,997 (95% UI: 47,692-54,410) /100,000 to 87,014 (95% UI: 80,259-94,339) /100,000, and DALYs increased from 256,1842 (95% UI: 239,4962-2,735,823) /100,000 to 4,297,573 (95% UI: 3,965,485-4,650,790) /100,000. Regarding age-standardized rates, incidence and prevalence increased significantly, while mortality and DALYs rate were basically unchanged. Decomposition analysis showed a significant increase in DALYs in the middle sociodemographic index (SDI) quintile region, in which aging and population growth played a major driving role. Frontier analysis showed that countries or regions with a higher SDI quintile tend to have greater improvement potential.

CONCLUSION

The current EO-CRC burden was found to be the greatest in the high-middle SDI quintile region and East Asia, which may need to adjust screening guidelines accordingly and introduce more effective interventions.

The endorectal incision level of transanal total mesorectal excision (taTME): An emphasis on the distance from the anterior vs. posterior mesorectal ends to the anal verge

BACKGROUND

There is no intraluminal guidance to ensure complete inclusion of the mesorectum in transanal total mesorectal excision (taTME). This study aimed to assess the distance difference between the anterior and posterior mesorectal terminal ends and the anal verge as a potential risk for residual mesorectum after resection.

METHODS

Forty-four surgical specimens of extra-levator abdominoperineal excision (ELAPE) and 28 mid-sagittal cadaveric specimens were included to this study. The distance between the mesorectum terminal end (T) and the endoluminal landmarks (dentate line (D)/anal verge (A)) was measured and compared between men and women. Furthermore, 66 MRI images from The Cancer Imaging Archive (TCIA) were used to validate the same concept in a non-Asian population.

RESULTS

The mesorectal terminal end was found to be aligned along with the levator hiatus. From the midsagittal view, the ELAPE specimens showed that the distance between T and A anteriorly was significantly longer than the same distance posteriorly (34.74±7.79mm vs 23.74±4.24mm, P<0.001). Similarly, the distance measured in the cadaveric specimens was significantly longer anteriorly than posteriorly (P<0.001). The validation cohort of non-Asian MRI image has confirmed the same (56.68±14.17mm vs. 38.18 ±10.42mm, P<0.001(. There was no significant difference between men and women.

CONCLUSIONS

Because of the remarkable distance difference between the anterior and posterior mesorectal terminal ends away from the anal verge, the taTME proctectomy level may not meet the required mesorectal end. Thus, if TME is planned, aligning the proctectomy level around the levator hiatus would be the best place that can ensure complete TME.

The "terminal line": a novel sign for the identification of distal mesorectum end during TME for rectal cancer

Background

Although the clinical importance of complete, intact total mesorectal excision (TME) is the widely accepted standard for decreasing local recurrence of rectal cancer, the residual mesorectum still represents a significant component of resection margin involvement. This study aimed to use a visible intraoperative sign to detect the distal mesorectal end to ensure complete inclusion of the mesorectum and avoid unnecessary over-dissection.

Methods

The distal mesorectum end was investigated retrospectively through a review of 124 operative videos at the Union Hospital of Fujian Medical University (Fujian, China) and Cleveland Clinic (Ohio, USA) by two independent surgeons who were blinded to each other. Furthermore, 28 cadavers and 44 post-operative specimens were prospectively examined by hematoxylin and eosin (H&E) staining and Masson's staining to validate and confirm the findings of the retrospective part. Univariate and multivariate analyses were carried out to detect the independent factors that can affect the visualization of the distal mesorectal end.

Results

The terminal line (TL) is the distal mesorectal end of the transabdominal and transanal TME (taTME) and appears as a remarkable pearly white fascial structure extending posteriorly from 2 to 10 o'clock. Histopathological examination revealed that the fascia propria of the rectum merges with the presacral fascia at the TL, beyond which the mesorectum ends, with no further downward extension. In the retrospective observation, the TL was seen in 56.6% of transabdominal TME and 56.0% of taTME operations. Surgical approach and tumor distance from the anal verge were the independent variables that directly influenced the detection of the TL (P = 0.03 and P = 0.01).

Conclusion

The TL is a visible sign where the transabdominal TME should end and the taTME should begin. Recognition of the mesorectal end may impact the certainty of complete mesorectum inclusion. Further clinical trials are needed to confirm the preliminary findings.

Short-term Outcomes of Laparoscopy-Assisted vs Open Surgery for Patients With Low Rectal Cancer: The LASRE Randomized Clinical Trial

Importance

The efficacy of laparoscopic vs open surgery for patients with low rectal cancer has not been established.

Objective

To compare the short-term efficacy of laparoscopic surgery vs open surgery for treatment of low rectal cancer.

Design, Setting, and Participants

This multicenter, noninferiority randomized clinical trial was conducted in 22 tertiary hospitals across China. Patients scheduled for curative-intent resection of low rectal cancer were randomized at a 2:1 ratio to undergo laparoscopic or open surgery. Between November 2013 and June 2018, 1070 patients were randomized to laparoscopic (n = 712) or open (n = 358) surgery. The planned follow-up was 5 years. Data analysis was performed from April 2021 to March 2022.

Interventions

Eligible patients were randomized to receive either laparoscopic or open surgery.

Main Outcomes and Measures

The short-term outcomes included pathologic outcomes, surgical outcomes, postoperative recovery, and 30-day postoperative complications and mortality.

Results

A total of 1039 patients (685 in laparoscopic and 354 in open surgery) were included in the modified intention-to-treat analysis (median [range] age, 57 [20-75] years; 620 men [59.7%]; clinical TNM stage II/III disease in 659 patients). The rate of complete mesorectal excision was 85.3% (521 of 685) in the laparoscopic group vs 85.8% (266 of 354) in the open group (difference, -0.5%; 95% CI, -5.1% to 4.5%; P = .78). The rate of negative circumferential and distal resection margins was 98.2% (673 of 685) vs 99.7% (353 of 354) (difference, -1.5%; 95% CI, -2.8% to 0.0%; P = .09) and 99.4% (681 of 685) vs 100% (354 of 354) (difference, -0.6%; 95% CI, -1.5% to 0.5%; P = .36), respectively. The median number of retrieved lymph nodes was 13.0 vs 12.0 (difference, 1.0; 95% CI, 0.1-1.9; P = .39). The laparoscopic group had a higher rate of sphincter preservation (491 of 685 [71.7%] vs 230 of 354 [65.0%]; difference, 6.7%; 95% CI, 0.8%-12.8%; P = .03) and shorter duration of hospitalization (8.0 vs 9.0 days; difference, -1.0; 95% CI, -1.7 to -0.3; P = .008). There was no significant difference in postoperative complications rate between the 2 groups (89 of 685 [13.0%] vs 61 of 354 [17.2%]; difference, -4.2%; 95% CI, -9.1% to -0.3%; P = .07). No patient died within 30 days.

Conclusions and Relevance

In this randomized clinical trial of patients with low rectal cancer, laparoscopic surgery performed by experienced surgeons was shown to provide pathologic outcomes comparable to open surgery, with a higher sphincter preservation rate and favorable postoperative recovery.

Trial Registration

ClinicalTrials.gov Identifier: NCT01899547.

PD-1 blockage combined with vaccine therapy can facilitate immune infiltration in tumor microenvironment of Lynch syndrome colon cancer

Background: Lynch syndrome is a genetic disease resulting from mismatch repair gene mutation. Vaccine therapy can enhance the immunogenicity of Lynch syndrome and improve the therapeutic efficacy of immunotherapy. However, there is no approved Lynch syndrome vaccine coming onto the market.

Methods: Herein, we used gene knockdown method to construct Lynch syndrome cell model, paving way for us to develop Lynch syndrome tumor lysate vaccine. Then the isograft technique was employed for constructing the tumor-bearing mouse model of Lynch syndrome. And this isograft model was treated with PD-1 monoclonal antibody and tumor vaccine, respectively. Flow cytometry was used for detecting the proportion of immune cells and immunosuppressive cells, and ELISA was used for detecting the contents of chemokines and cytokines in the blood circulation system and tumor tissues of mice. Finally, IHC was used to detect the effects of tumor vaccines as well as PD-1 antibody on tumor tissue proliferation and angiogenesis.

Results: The results demonstrated that tumor vaccine could prolong the overall survival of mice, and improve the disease-free survival rate of mice. The vaccine could increase the proportion of inflammatory cells and decrease the proportion of anti-inflammatory cells in the blood circulation system of mice. In addition, tumor vaccine could also improve inflammatory infiltration in the tumor microenvironment and reduce the proportion of immunosuppressive cells. The results of IHC showed that tumor vaccine could inhibit angiogenesis and tumor cell proliferation in mouse tumor tissues.

Conclusion: In colon cancer associated with Lynch syndrome, tumor vaccine can hinder the growth of tumor cells, and assist immunotherapy whose therapeutic effect on this kind of cancer is thus enhanced.

[Historical evolution and ultimate goal of minimally invasive surgery for colorectal cancer]

Minimally invasive colorectal surgery has been an entity for just over 30 years. Compared with traditional open surgery, minimally invasive surgery has the advantages of less trauma, more delicate operation and faster postoperative recovery. At present, minimally invasive surgery for colorectal tumor shows a diversified trend in terms of surgical approach, surgical platform or surgical methods. Besides, standardized comprehensive treatment and immunotherapy have had far-reaching impacts on the development of minimally invasive surgery. The diagnosis and treatment of perioperative complications is still another important topic in the research of minimally invasive surgery in the future. In addition to the short-term outcomes, the most important thing that patients truly require and emphasize is the permanence of the curative effect, that is, long-term survival and good defecation, urination and sexual function. Thus, permanence is the ultimate goal of minimally invasive surgery. To achieve this, we should strive to correct improper treatment methods, rationally select applicable groups of emerging surgical approaches and surgical platforms, pay more attention to comprehensive tumor diagnosis and treatment, and prudently carry out new technology research on the basis of the basic concept of patient safety.

Clinical implication of the advanced lung cancer inflammation index in patients with right-sided colon cancer after complete mesocolic excision: a propensity score-matched analysis

Background

This study aimed to assess the clinical implications of the advanced lung cancer inflammation index (ALI) in patients with right-sided colon cancer (RCC) after complete mesocolic excision (CME).

Methods

A total of 441 patients with RCC who underwent CME were included. The optimal cut-off value for the ALI was determined using the X-tile software. Logistic and Cox regression analyses were used to identify risk factors for postoperative complications and long-term outcomes. Predictive nomograms for overall survival (OS) and disease-free survival (DFS) were constructed after propensity score matching (PSM), and their performance was assessed using the net reclassification improvement index (NRI), integrated discrimination improvement index (IDI), and time-dependent receiver operating characteristic (time-ROC) curve analysis.

Results

The optimal preoperative ALI cut-off value was 36.3. After PSM, ASA classification 3/4, operative duration, and a low ALI were independently associated with postoperative complications in the multivariate analysis (all P<0.05). Cox regression analysis revealed that an age >60 years, a carbohydrate antigen 19-9 (CA19-9) level >37 U/mL, pathological N+ stage, and a low ALI were independently correlated with OS (all P<0.05). A CA19-9 level >37 U/mL, pathological N+ stage, lymphovascular invasion, and a low ALI were independent predictors of DFS (all P<0.05). Predictive nomograms for OS and DFS were constructed using PSM. Furthermore, a nomogram combined with the ALI was consistently superior to a non-ALI nomogram or the pathological tumor-node-metastasis classification based on the NRI, IDI, and time-ROC curve analysis after PSM (all P<0.05).

Conclusion

The ALI was an effective indicator for predicting short- and long-term outcomes in patients with RCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02712-0.

A LASSO-based survival prediction model for patients with synchronous colorectal carcinomas based on SEER

Background

The nomogram for postoperative prediction of overall survival (OS) in patients’ synchronous colorectal carcinomas (SCC) was developed and validated by least absolute shrinkage and selection operator (LASSO)-based Cox regression.

Methods

The data was obtained from the SEER database of patients diagnosed with colorectal cancer (CRC) more than one time between 2004 and 2013. Patients who had CRC more than 3 times or multiple metachronous primary carcinomas were excluded. The cut-off points for the continuous variable were identified by the K-adaptive partitioning algorithm and x-tile software. Using LASSO-based Cox regression, a model for predicting the OS of SCC was built, internally and externally validated, and measured through a calibration curve, C-index, Akaike information criterion (AIC), Bayesian information criterion (BIC), net reclassification improvement (NRI), integrated discrimination improvement (IDI), time-dependent receiver operating characteristic (timeROC), time-dependent area under curve (timeAUC), and decision curve analysis (DCA), and results compared to the model developed by the Cox regression.

Results

Patients with SCC were found to be older, more often men, and likely to have a depth of invasion by T3. In addition, there were no significant differences between the model developed by LASSO-based Cox regression and the Cox regression in the C-index (0.712 and 0.710), AIC (33,420 and 33,431), BIC (4.49), IDI (0.002), NRI (–0.009), timeROC, and DCA. Besides, the model developed by LASSO-based Cox regression was found to perform better than the Cox regression in the timeAUC. Moreover, the model developed by LASSO-based Cox regression showed good C-index (0.712, 0.637, and 0.651), AIC (33,420, 34,043, and 33,994), BIC (1,178.76 and 1,098.57), IDI (–0.072 and –0.064), NRI (0.525 and 0.466), timeROC, timeAUC and had a larger net benefit compared to both the first time TNM staging and the combination of two times TNM staging.

Conclusions

This present study indicates that a close follow-up of older patients, male, and T3 should be made. Compared with the traditional Cox regression model, LASSO-based Cox regression decreases the variables of the model, avoids overfitting and collinearity and has clinical significance.

Preoperative chemoradiotherapy with capecitabine and triweekly oxaliplatin versus capecitabine monotherapy for locally advanced rectal cancer: a propensity-score matched study

Background

Distant metastasis has been the main failure pattern for locoregionally advanced rectal cancer (LARC) patients, and intensified neoadjuvant chemotherapy has become a popular research topic. The present study aimed to compare the survival outcomes, acute toxicities and surgical complications in LARC patients who received preoperative chemoradiotherapy with triweekly oxaliplatin and capecitabine (triweekly XELOX) or capecitabine.

Methods: Between 2007 and 2017, patients with clinically staged II-III rectal cancer who were treated with preoperative chemoradiotherapy using either triweekly XELOX (oxaliplatin 130 mg/m² plus capecitabine 825 mg/m²) or capecitabine were included. Variables potentially influencing chemotherapy treatment selection were used to generate propensity scores (PS). The association between chemotherapy regimens and survival endpoints, including distant metastasis-free survival (DMFS), overall survival (OS) and disease-free survival (DFS), were evaluated and adjusted with PS. The acute toxicities and surgical complications were also compared.

Results

A total of 810 patients were included in the analysis; 277 (34.2%) patients received triweekly XELOX, and 533 (65.8%) received capecitabine. The pathological complete response (pCR) rates were 20.2 and 19.9% (P = 0.912) for the groups treated with triweekly XELOX and capecitabine, respectively. The 5-year DMFS, OS and DFS with triweekly XELOX versus capecitabine were 75.6% vs. 77.6% (P = 0.555), 79.2% vs. 83.3% (P = 0.101), and 69.9% vs. 73.7% (P = 0.283), respectively. Triweekly XELOX was not associated with an increased risk of severe toxicity during chemoradiotherapy, but it increased the risk of postoperative complications compared to capecitabine. After PS adjustment, the differences between the two groups remained insignificant in pCR rate, survival outcomes, and acute toxicities, and the difference in surgical complications disappeared.

Conclusions

Triweekly XELOX or capecitabine concurrent with neoadjuvant radiotherapy leads to similar long-term survival outcomes, acute toxicities and surgical complications in LARC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09855-z.

[Delayed gastric emptying after surgery for transverse colon cancer: diagnosis, management and prevention]

Delayed gastric emptying is a syndrome of gastric motility disorder with slow gastric emptying as the main sign, provided that mechanical factors such as intestinal obstruction and anastomotic stricture are excluded. The incidence of delayed gastric emptying after colon cancer surgery is 1.4%, mainly after transverse colon cancer surgery. Most of the studies on delayed gastric emptying are case reports, lacking systematic studies. The diagnoses and treatments can be draw on the experience of delayed gastric emptying after pancreatic surgery. Our retrospective study indicated that the incidence of delayed gastric emptying after surgery for transverse colon cancer was 4.0%, higher than that for other colon cancer. Patients who underwent gastrocolic ligament lymph node dissection were at higher risk than those who did not (3.6% vs. 0.8%). Gastrocolic ligament lymph node dissection and stress are causative factors for delayed gastric emptying after surgery for transverse colon cancer. We add the gastrografin test upon the diagnostic criteria of the International Study Group for Pancreatic Surgery, which is simple and practical. Nasogastric tube decompression, enteral nutrition combined with parenteral nutrition, glucocorticoids, and prokinetic agents can cure most patients with postoperative delayed gastric emptying. All the patients with postoperative delayed gastric emptying were cured in our studies. Strict indications for gastrocolic ligament lymph node dissection (patients with cT3-4 and cN+) may decrease the occurrence of delayed gastric emptying after surgery for transverse colon cancer.

[Anatomical observation and clinical significance of the prostatic part of neurovascular bundle in total mesorectal excision]

Objective: To observe the anatomical architecture of the prostatic part of the neurovascular bundle (NVB) in total mesorectal excision (TME). Methods: A descriptive cohort study and an anatomical observation study were carried out. A total of 38 male patients with rectal cancer who underwent TME in the Department of Colorectal Surgery at the affiliated Union hospital of Fujian Medical University between November 2013 and March 2015 were included. A total of 4 hemipelvis were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. The following outcomes were observed: 1) the clinical significance of bleeding of the prostatic part of NVB: surgical videos were reviewed and the incidence of bleeding was recorded. The urogenital function was assessed using the International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF) score. The correlation between prostatic part bleeding and postoperative urogenital function was evaluated. 2) anatomical observation: the vessels, nerve fibers, as well as their surrounding fatty tissue from the prostatic part were treated as a whole, namely, the fat pad of the prostatic part. The anatomical architecture of the prostatic part in the surgical videos was reviewed and interpreted with the cadaveric findings. Categorical variables were compared between groups using a Fisher exact probability. while continuous variables with skewed distribution were compared between groups using the Mann-Whiteny U test. Results: The median age of the included 38 patients was 57 years (range, 31-75), and the median tumor distance to the anal verge was 6 cm (range, 1-8). Of them, a total number of 21 (55.3%) patients had bleeding of the prostatic part of NVB (bleeding group), while the rest had not (17 cases, 44.7%, non-bleeding group). 1) the clinical significance of bleeding of the prostatic part of NVB. The urinary function significantly decreased in patients in the bleeding group according to IPSS score after the 3rd month and the 6rd month of the surgery [7 (0-16) vs. 2 (0-3), Z=-1.787, P=0.088; 2 (0-15) vs. 0 (0-2), Z=-2.270, P=0.028]. There was no difference regarding the IPSS score between the two groups after 1 year of the surgery (P>0.05). With a total of 23 patients with normal preoperative sexual activity included, 87.5% (7/8) of patients in the non-bleeding group can expect to return to their preoperative baseline, this incidence was significantly higher than that of only 40% (6/15) in the bleeding group (P=0.029). 2) anatomical observation: for cadaveric observation, the prostatic part of NVB was located in the narrow triangular space composed of anterolateral walls of the rectum, the posterolateral surface of the prostate and the medial surface of the levator ani musculature. The tiny vascular branches and nerve fibers from the prostatic part were hard to identify. The cavernosal nerves cannot reliably be distinguished from the neural supply to the prostate, rectum and levator ani. In the cross-section of levels of prostatic base and mid-prostate in cadaveric hemipelvis specimens, the boundary of the prostatic part fat pad was partly overlapped and merged with the boundary of the mesorectum. Intraoperative observation showed that the areas of overlap referred to the rectal branches from the prostatic part piercing the proper fascia to supply the mesorectum, which carried the largest tension and high risk of bleeding during circumferential dissection toward the perirectal plane. The ultrasonic scalpel was required to pre-coagulate the rectal branches at the point close to the proper fascia of the rectum to prevent bleeding. In the cross-section of the prostatic apex level, the prostatic part approached ventrally and its boundary was away from the boundary of the mesorectum. Conclusions: NVB prostatic part injury is one of the causes of urogenital dysfunction after TME. The nerve fibers from the prostatic part were tiny, and its functional zones cannot be distinguished during operation. Therein, the fat pad of the prostatic part should be protected as a whole. Understanding the morphology of the fat pad of the prostatic part provides invaluable surgical guidance to dissect this critical area. When dissecting around the anterolateral rectal wall, appropriate anti-traction tension should be maintained and the rectal branches from the prostatic part should be coagulated with an ultrasonic scalpel to prevent bleeding.