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.

Robotic intersphincteric resection for low rectal cancer: a cumulative sum analysis for the learning curve.

PURPOSE: This study aimed to assess the learning curve of robot-assisted intersphincteric resection for low rectal cancer. METHODS: We retrospectively analyzed the clinical data of 89 patients who underwent robot-assisted intersphincteric resection. All surgeries were performed by the same group of surgeons at our institution between June 2016 and April 2021. The learning curve was evaluated using a cumulative sum analysis and the best-fit curve. The different stages of the learning curve were compared based on patient characteristics and short-term clinical outcomes to evaluate their impact on clinical efficacy. RESULTS: The minimum number of cases required to overcome the learning curve was 47. The learning curve was divided into the learning improvement and proficiency stages. Significant differences were observed in the operation time and the number of lymph nodes between the two stages (P < 0.05), whereas no significant differences were found in intraoperative blood loss, first postoperative exhaust time, postoperative complications, 3-year progression-free survival, overall survival, and local recurrence-free survival (P > 0.05). CONCLUSION: Robotic-assisted intersphincteric resection for low rectal cancer exhibits a learning curve that can be divided into two stages: namely, learning improvement and proficiency. Achieving proficiency requires a minimum of 47 surgical cases.

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.

Safety and efficacy of indocyanine green fluorescence imaging-guided laparoscopic para-aortic lymphadenectomy for left-sided colorectal cancer:A preliminary case-matched study.

AIM: This study is aimed to explore the safety and feasibility of indocyanine green (ICG) fluorescence imaging guidance in laparoscopic para-aortic lymph node (PALN) dissection for left-sided colorectal cancer (CRC) patients with clinically suspected PALN metastasis. METHOD: A total of 151 patients who underwent primary tumor resection and laparoscopic PALN dissection for left-sided CRC were included, with 20 patients in the ICG group and 131 patients in the non-ICG group. The surgical outcomes, postoperative complications, and pathological results, such as the number of harvested and metastatic lymph nodes were compared between groups after propensity score matching. RESULTS: Following propensity score matching, the ICG group had 20 patients, and the non-ICG group had 53 patients, and the two groups were similar in baseline characteristics. No significant differences were observed in overall intraoperative and postoperative complications between groups, except for chylous leakage, where the ICG group had a longer time to a normal diet. The number of harvested pericolic/perirectal and intermediate lymph nodes were comparable between the two groups, while the ICG group had a significantly higher number of total harvested lymph nodes (39 [14-78] vs. 29 [11-70], P = 0.001), inferior mesenteric artery lymph nodes (IMALN, 6 [0-17] vs. 3 [0-11], P = 0.006), and PALNs (9 [3-29] vs. 5 [1-37], P = 0.001). CONCLUSION: ICG fluorescence imaging could increase the retrieval of IMALN, PALN, and total lymph nodes, and potentially improve the completeness of laparoscopic PALN dissection in patients with left-sided CRC.

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.

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.

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.

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.

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.

Natural History and Histopathology of Expanding Cysts and Hematomas After Stereotactic Radiosurgery for Arteriovenous Malformations of the Brain: A Case Series.

BACKGROUND: We reviewed the clinical course and histopathologic findings for cases involving the formation of expanding cysts and/or hematomas after gamma knife surgery (GKS) for arteriovenous malformations (AVMs). METHODS: We report a single-center retrospective review of 18 patients who presented with cyst and/or hematoma expansion after GKS for AVMs between 1993 and 2023. Expanding cysts and hematomas were defined as well-demarcated cavities filled with fluid or well-marginated heterogenous hematomas presenting with expansion proximal to or in the location of the original AVM, respectively. Patient demographics, AVM characteristics, history of interventions and surgeries, and imaging and histopathologic features of expanding cysts and hematomas were collected for analysis. RESULTS: Among 1072 AVM patients treated using GKS, 18 presented with expanding cysts or hematomas during a total follow-up period of 16,757 patient-years (0.11 case/100 persons/patient-year). The time to cyst or hematoma identification was 4-13 years after initial GKS, with a mean duration of 8.6 years. Among the patients examined, 7 (38.9%) presented mainly with hematoma, 10 (55.6%) presented mainly with cysts, and 1 presented with approximately equal components of both. Among the 18 patients, 13 (72.2%) underwent craniotomy to treat cyst or hematoma expansion. All the specimens had similar histopathologic characteristics, including organizing hematoma with fresh and old hemorrhage, fibrinoid necrosis of the vessels, gliosis of normal brain tissue, infiltration of hemosiderin-laden histiocytes, and extravascular protein leakage. CONCLUSIONS: Our findings suggest that the formation of these 2 complications can be attributed to a common mechanism involving radiation-induced vascular damage in brain tissue adjacent to the AVM and subsequent chronic inflammation and capillary dilatation.

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.

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.

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.

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.

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.