Surgical repair of rectovaginal fistulas: predictors of fistula closure.

INTRODUCTION AND HYPOTHESIS: We report the clinical outcome of surgical repair for rectovaginal fistula (RVF) carried out by one operative team. We also investigate the predictive factors for fistula healing. METHODS: A retrospective cohort of 63 patients underwent local surgical repair of RVF during January 2008 and December 2017 by one operative group. The clinical features of the patients were reviewed. The association between fistula closure and diverse clinical parameters, including operative method, fistula location, prior repair, and diverting stoma, was analyzed. RESULTS: Sixty-three consecutive patients underwent 80 local surgical repairs by our surgical team. Forty-five patients eventually healed after an average of 1.22 procedures. The overall success rate per procedure was 71.2%, whereas the closure rate of the first operation was 55.5% (n = 35). The etiology of the fistula did not impact on the success rate of surgical repair. The history of prior repair predicted a lower success rate on both overall procedure (RR = 0.59, 95% CI 0.41-0.85, p = 0.008) and the first repair in our institution (RR = 0.50, 95% CI 0.31-0.80, p = 0.003). There was no difference in closure rate between the stoma group and the non-stoma group. Nevertheless, among the 15 patients who underwent more than one operation in our center, a diverting stoma seemed to be necessary (10 patients healed in the stoma group and none of the patients healed in the non-stoma group, p = 0.02). CONCLUSIONS: History of prior surgical repair is a risk factor for failure. Diverting stoma did not increase the overall closure rate, but it seemed to be necessary for patients in whom the first operation failed.

Interleukin 22 protects colorectal cancer cells from chemotherapy by activating the STAT3 pathway and inducing autocrine expression of interleukin 8.

Resistance to chemotherapy is the major cause of colorectal cancer (CRC) treatment failure. The cytokine IL-22, which is produced by T cells and NK cells, is associated with tumorigenesis and tumor progression in cancers. However, the role of IL-22 in chemoresistance has not been investigated. We found that IL-22 levels in tumor tissues and peripheral blood were associated with chemoresistance and indicate poor prognosis for patients who received FOLFOX chemotherapy. In CRC cells, IL-22 was able to attenuate the cytotoxic and apoptosis-inducing effects of 5-FU and OXA by activating the STAT3 pathway and subsequently increasing the expression of anti-apoptotic genes. In addition, IL-22 conferred resistance to 5-FU and OXA by inducing IL-8 autocrine expression through STAT3 activation. Our findings identify IL-22 as a novel chemoresistance cytokine and may be a useful prognostic biomarker for CRC patients receiving FOLFOX chemotherapy.

P4HA2 promotes tumor progression and is transcriptionally regulated by SP1 in colorectal cancer.

P4HA2 has been implicated in various malignant tumors; however, its expression and functional role in colorectal cancer (CRC) remain poorly elucidated. This study aims to investigate the involvement of P4HA2 in CRC metastasis and progression, uncovering the underlying mechanisms. In colorectal cancer (CRC), P4HA2 exhibited overexpression, and elevated levels of P4HA2 expression were associated with an unfavorable prognosis. Functional assays demonstrated P4HA2's regulation of cell proliferation, and epithelial-mesenchymal transition (EMT) both in vitro and in vivo. Additionally, the AGO1 expression was correlated with P4HA2, and depletion of AGO1 reversed the proliferation and EMT function induced by P4HA2. Chromatin immunoprecipitation (ChIP) and luciferase assays suggested that the transcription factor SP1 binds to the promoter sequence of P4HA2, activating its expression in CRC. This study unveiled SP1 as a transcriptional regulator of P4HA2 in CRC and AGO1 is a probable target of P4HA2. In conclusion, P4HA2 emerges as a potential prognostic biomarker and promising therapeutic target in colorectal cancer.

'Dumpling suture method' versus traditional suture method of protective loop ileostomy in laparoscopic anterior rectal resection with specimen extraction through stoma incision: a retrospective comparative cohort study.

BACKGROUND: A diverting loop ileostomy (DLI) is performed in laparoscopic anterior rectal resection (LAR) surgery at high risk of anastomotic fistula. Minimally invasive surgery promotes postoperative recovery and cosmetics. To reduce abdominal trauma, specimen extraction through stoma incision (EXSI) is usually performed to avoid auxiliary abdominal incision with enlarged stomal incision. The traditional suture method (TSM) reduces the incision size by suturing the ends of the enlarged incision, leading to peristomal incisions and a higher risk of stomal complications. The study aimed to introduce the dumpling suture method (DSM) of PLI and compare this new method with TSM. MATERIALS AND METHODS: The authors propose a novel stoma suture technique, which utilized a method of skin folding suture to reduce the enlarged incision size. A retrospective analysis was conducted on 71 consecutive patients with rectal cancer who underwent LAR-DLI with EXSI, and the intraoperative details and postoperative outcomes of the two groups were measured. RESULTS: The DSM group showed a lower stomal complication rate (10.3 vs. 35.7%, P=0.016) than that of the TSM group. The scores of DET (Discoloration, Erosion, Tissue overgrowth), stomal pain, quality of life were all significantly lower in DSM group than in TSM group. In multivariate analysis, DSM was an independent protective factor for stoma-related complications. Operative time, time to first flatus, defecation and eat, nonstomal related postoperative complications were similar in both groups. CONCLUSION: DSM utilizes a method of skin folding suture to reduce the enlarged incision size, which is safe and effective in reducing the incidence of peristomal skin infections and stomal complications. This procedure offers a novel suturing approach for loop ileostomy with enlarged incision, effectively reducing the postoperative trauma and incidence of stomal complications.

Metabolic pathway-based molecular subtyping of colon cancer reveals clinical immunotherapy potential and prognosis.

PURPOSE: Colon cancer presents challenges to clinical diagnosis and management due to its high heterogeneity. For more efficient and convenient diagnosis and treatment of colon cancer, we are committed to characterizing the molecular features of colon cancer by pioneering a classification system based on metabolic pathways. METHODS: Based on the 113 metabolic pathways and genes collected in the previous stage, we scored and filtered the metabolic pathways of each sample in the training set by ssGSEA, and obtained 16 metabolic pathways related to colon cancer recurrence. In consistent clustering of training set samples with recurrence-related metabolic pathway scores, we identified two robust molecular subtypes of colon cancer (MC1 and MC2). Furthermore, we performed multi-angle analysis on the survival differences of subtypes, metabolic characteristics, clinical characteristics, functional enrichment, immune infiltration, differences with other subtypes, stemness indices, TIDE prediction, and drug sensitivity, and finally constructed colon cancer prognostic model. RESULTS: The results showed that the MC1 subtype had a poor prognosis based on higher immune activity and immune checkpoint gene expression. The MC2 subtype is associated with high metabolic activity and low expression of immune checkpoint genes and a better prognosis. The MC2 subtype was more responsive to PD-L1 immunotherapy than the MC1 subclass. However, we did not observe significant differences in tumor mutational burden between the two. CONCLUSION: Two molecular subtypes of colon cancer based on metabolic pathways have distinct immune signatures. Constructing prognostic models based on subtype differential genes provides valuable reference for personalized therapy targeting unique tumor metabolic signatures.

Incidence, prevention, risk factors, and prediction of venous thromboembolism in Chinese patients after colorectal cancer surgery: a prospective, multicenter cohort study.

BACKGROUND: Venous thromboembolism (VTE) is a common and serious complication after colorectal cancer (CRC) surgery. Few large-sample studies have reported VTE incidence and management status after CRC surgery in China. This study aimed to investigate the incidence and prevention of VTE in Chinese patients after CRC surgery, identify risk factors for developing VTE, and construct a new scoring system for clinical decision-making and care planning. METHODS: Participants were recruited from 46 centers in 17 provinces in China. Patients were followed up for 1 month postoperatively. The study period was from May 2021 to May 2022. The Caprini score risk stratification and VTE prevention and incidence were recorded. The predictors of the occurrence of VTE after surgery were identified by multivariate logistic regression analysis, and a prediction model (CRC-VTE score) was developed. RESULTS: A total of 1836 patients were analyzed. The postoperative Caprini scores ranged from 1 to 16 points, with a median of 6 points. Of these, 10.1% were classified as low risk (0-2 points), 7.4% as moderate risk (3-4 points), and 82.5% as high risk (≥5 points). Among these patients, 1210 (65.9%) received pharmacological prophylaxis, and 1061 (57.8%) received mechanical prophylaxis. The incidence of short-term VTE events after CRC surgery was 11.2% (95% CI 9.8-12.7), including deep venous thrombosis (DVT) (11.0%, 95% CI 9.6-12.5) and pulmonary embolism (PE) (0.2%, 95% CI 0-0.5). Multifactorial analysis showed that age (≥70 years), history of varicose veins in the lower extremities, cardiac insufficiency, female sex, preoperative bowel obstruction, preoperative bloody/tarry stool, and anesthesia time at least 180 min were independent risk factors for postoperative VTE. The CRC-VTE model was developed from these seven factors and had good VTE predictive performance ( C -statistic 0.72, 95% CI 0.68-0.76). CONCLUSIONS: This study provided a national perspective on the incidence and prevention of VTE after CRC surgery in China. The study offers guidance for VTE prevention in patients after CRC surgery. A practical CRC-VTE risk predictive model was proposed.

Nuclear TEAD4 with SIX1 Overexpression is an Independent Prognostic Marker in the Stage I-III Colorectal Cancer.

INTRODUCTION: Stage I-III colorectal cancer patients are under risk of tumor recurrence and metachronous metastasis after radical surgery. An increased expression of transcription factor TEAD4 is associated with epithelial-mesenchymal transition, metastasis and poor prognosis in colorectal cancer. However, the mechanistic role of TEAD4 in driving colon cancer progression and its prognostic value in early stage of CRC remains unclear. METHODS: In this study, the regulation, function and prognostic significance of TEAD4 and its new direct target gene SIX1 in CRC progression were evaluated using human tissues, molecular and cell biology. RESULTS: We show that TEAD4 directly upregulates the expression of SIX1 at transcriptional level in CRC cells, establishing that SIX1 is a new direct target gene of TEAD4. TEAD4 promotes EMT and cell migration of CRC cells, while SIX1 knockdown attenuates this effect and SIX1 overexpression enhances this effect, indicating that SIX1 mediates the function of TEAD4 in promoting cell migration in CRC cells. Clinically, nuclear TEAD4, overexpression of SIX1 and nuclear TEAD4 with SIX1 overexpression predict poor prognosis in CRC patients. DISCUSSION: Our study identifies TEAD4-SIX1-CDH1 form a novel signaling axis, which contributes to CRC progression, and its aberrant expression and activation predicts poor prognostic for CRC patients in stage I-III.

Lysyl oxidase: A colorectal cancer biomarker of lung and hepatic metastasis.

BACKGROUND: Colorectal cancer (CRC) is a common and lethal disease in which distant metastasis remains the primary cause of death. Paradoxical roles of LOX have been reported in CRC, and the intracellular function of LOX has also recently been determined. Correlations of LOX expression and its intracellular localization with clinicopathological features in CRC patients remain largely unknown. The aim of the present study was to explore the potential roles of LOX in CRC. METHODS: LOX messenger RNA expression was assayed by quantitative PCR in eight paired normal mucosa and tumor tissues. Immunohistochemistry was conducted using tissue arrays to investigate LOX expression in 201 CRC patients. Regulation of LOX by YAP and TEAD4 was explored by YAP or TEAD4 short hairpin RNA interference in a LoVo cell line. RESULTS: LOX messenger RNA expression was elevated in some CRC specimens, and LOX nuclear localization was detected in CRC tumor tissues. LOX nuclear localization was found to correlate with lung/hepatic metastasis, elevated serum carcinoembryonic antigen concentration, and mucinous tumor type (P < 0.05). Nuclear LOX expression was found to be associated with poor overall and disease-free survival (P < 0.05), and postoperative lung/hepatic metastasis (P < 0.05). Knockdown of YAP or TEAD4 induced downregulation of LOX expression. CONCLUSIONS: LOX nuclear localization was significantly associated with poor survival in patients with CRC. Nuclear LOX expression was correlated with synchronous or postoperative lung/hepatic metastasis. LOX may prove to be a potential target gene of YAP and TEAD4.

Prognostic value of IRF-2 expression in colorectal cancer.

Interferon regulatory factor 2 (IRF-2) is known to play a pivotal role in the development and progression of several malignancies. As a crucial member of interferon regulatory factor family, the association between the expression of IRF-2 and clinical prognostic significance has not been fully explored in colorectal cancer (CRC). The purpose of our study was to investigate the expression profile of IRF-2 in CRC and to examine its association with clinical features. The expression levels of IRF-2 in 18 paired CRC and non-cancerous colorectal tissues were measured by quantitative real-time PCR (qRT-PCR) and those in 4 paired samples by Western blotting. The results showed a significant increase in IRF-2 mRNA expression and protein expression in CRC tissues compared to those in paired normal tissues. Besides, high expression of IRF-2 was significantly associated with distant metastasis (P = 0.041) and preoperative serum CEA level (P = 0.045). Kaplan-Meier survival analysis showed that patients with high expression of IRF-2 had a significantly worse overall survival than those with low expression of IRF-2 (P = 0.006). Further multivariate analysis indicated that IRF-2 and TNM stage were independent prognostic factors for overall survival in patients with CRC. Our study primarily suggests IRF-2 as a potential prognostic biomarker in CRC.

Therapeutic Evaluation of Biofeedback Therapy in the Treatment of Anterior Resection Syndrome After Sphincter-Saving Surgery for Rectal Cancer.

BACKGROUND: Anterior resection syndrome (ARS) is common after sphincter-saving surgery for rectal cancer. It includes changes in the frequency and urgency of bowel movements and fecal incontinence. The therapeutic efficacy of biofeedback on ARS is unclear. We sought to evaluate the effectiveness of biofeedback therapy in patients with ARS after anterior resection for rectal cancer and to investigate the associated factors for therapeutic success. PATIENTS AND METHODS: The study was designed as a retrospective review of the data from 61 patients with ARS collected from a prospectively maintained institutional cancer database. Therapeutic efficacy was evaluated using anorectal manometry, the number of bowel movements daily, and fecal incontinence scoring systems (Vaizey and/or Wexner scores). Changes of > 15% in the Vaizey and/or Wexner scores were considered to indicate effectiveness. Stepwise logistic regression models were performed to evaluate whether the associated factors influenced therapeutic efficacy. RESULTS: The parameters of anorectal manometry in patients with rectal cancer were significantly lower than those in control group (P < .01). After biofeedback therapy, significant improvements were observed in the incontinence scale scores (P < .001), number of bowel movements (P < .001), and anorectal manometry data (maximum resting pressure, P < .001; maximum squeeze pressure, P = .001; and rectal capacity, P = .015). In contrast, no significant difference in the rectal initial sensation threshold was observed (P = .089). Patients with fecal incontinence as the primary symptom experienced significant improvements in all variables (P < .01), except for the rectal initial sensation threshold (P = .125). Age at surgery, current smoking status, diabetes, treatment cycles, laparoscopic surgery, interval from surgery to biofeedback therapy, and the use of radiation therapy were closely associated with therapeutic success. On multivariate analysis, current smoking status (odds ratio [OR], 0.09; 95% confidence interval [CI], 0.01-0.87), number of biofeedback therapy cycles (OR, 0.01; 95% CI, 0.00-0.06), and laparoscopic surgery (OR, 11.53; 95% CI, 1.17-113.61) were factors contributing to biofeedback therapeutic success. CONCLUSION: Biofeedback therapy can improve the anal function of patients after restorative resection for rectal cancer.

Loss of nuclear localization of TET2 in colorectal cancer.

5-Hydroxymethylcytosine (5hmC) is lost in multiple human cancers, including colorectal cancer (CRC). Decreased ten-eleven translocation 1 (TET1) messenger RNA (mRNA), but not other two TET family members, has been observed in the colorectal cancer and is crucial for colorectal cancer initiation. Here, we show that nuclear localization of TET2 was lost in a significant portion of CRC tissues, in association with metastasis. In CRC cells, nuclear expression of TET2 were absent but not TET3. Nuclear export inhibitor can increase the 5hmC level in CRC cells, probably through regulating TET2. Our results indicate a new mechanism of TET2 dysregulation in colorectal cancer.

CCX-CKR expression in colorectal cancer and patient survival.

Colorectal cancer is one of the most common malignant cancers, with bad prognosis when distal metastasis occurs. The current study aimed to investigate the potential value of using CCX-CKR expression for the prognosis of colorectal cancer patients. The results showed that CCX-CKR expression was a negative predictor of cancer metastasis, and that it was positively correlated to the patients’ survival rate. Finally, we found that CCX-CKR expression in vitro could modulate cellular migration and invasion abilities, potentially via the regulation of other chemotactic factors/receptors.

Survival benefits of metformin for colorectal cancer patients with diabetes: a systematic review and meta-analysis.

BACKGROUND: Several studies suggest that metformin has the potential effect of reducing cancer risk. However, its survival benefit in patients with colorectal cancer (CRC) and diabetes is unknown. The aim of our study is to address the effect of metformin on outcomes for CRC based on a systematic review and meta-analysis. METHODS AND FINDINGS: We searched EMBASE and MEDLINE databases from inception through August, 2013, using search terms related to metformin, diabetes, colorectal cancer, and prognostic outcome. The outcome measures were hazard ratios (HRs) with 95% CIs comparing CRC survival in diabetic patients using metformin and without using metformin. The primary end points were overall survival (OS) and CRC specific survival (CS). A total of six cohort studies including 2,461 patients met full eligibility criteria. The pooled HR favoring metformin users was 0.56 for OS (95% CI, 0.41 to 0.77) and 0.66 for CRC-specific survival (95% CI, 0.50 to 0.87). Thus metformin therapy reduced the risk of all cause of death by 44% and the risk of CRC specific death by 34% in CRC patients compared to those in non-users. However, evidence of heterogeneity and possible publication bias was noted for OS. CONCLUSIONS: Patients with CRC and diabetes treated with metformin appear to have an improved survival outcome. Prospective study should be warranted to examine the association between metformin exposure intensity as well as some other confounding variables and survival outcome in diabetic CRC patients.

Procalcitonin in abdominal exudate to predict prolonged postoperative ileus following colorectal carcinoma surgery.

BACKGROUND: Prolonged postoperative ileus (PPOI) is a common problem after major abdominal surgery and can cause postoperative morbidity, extended hospitalization, as well as increased health care costs. AIM: To investigate whether the levels of cytokines from abdominal exudate are predictive for early diagnosis of PPOI after colorectal surgery. METHODS: One hundred patients who had undergone elective resection for carcinoma of the sigmoid or rectum were recruited. The abdominal exudate was obtained from a drain tube after surgery to examine the levels of C-reactive protein (CRP), procalcitonin (PCT), and tumor necrosis factor alpha (TNF-α). The relationship between cytokine levels on postoperative day 1, 3 and 5 and the occurrence of PPOI was analyzed. RESULTS: Eight patients developed PPOI, which was diagnosed on postoperative day 10-15. PCT levels on postoperative day 1 and 3 were not significantly different between the 8 patients who developed PPOI and the 92 patients without PPOI. In contrast, PCT levels on day 5 were significantly higher in patients who developed PPOI than in patients without PPOI. The levels of CRP and TNF-α were irregular from day 1 to 5, and were not significantly different. CONCLUSIONS: Increased PCT levels in abdominal exudate may predict PPOI in the early period following colorectal surgery.