Impact of the COVID-19 pandemic in the early-onset colorectal cancer

The COVID19 pandemic has affected the spectrum of cancer care worldwide. Early onset colorectal cancer (EOCRC) is defined as diagnosis below the age of 50. Patients with EOCRC faced multiple challenges during the COVID19 pandemic and in some institutions it jeopardized cancer diagnosis and care delivery. Our study aims to identify the clinicopathological features and outcomes of patients with EOCRC in our Centre during the first wave of the pandemic in comparison with the same period in 2019 and 2021.

Patients with EOCRC visited for the first time at Vall d'Hebron University Hospital in Spain from the 1st March to 31st August of 2019, 2020 and 2021 were included in the analysis. 177 patients with EOCRC were visited for the first time between 2019 and 2021, of which 90 patients met the inclusion criteria (2019: 30 patients, 2020: 29 patients, 2021: 31 patients). Neither differences in frequency nor in stage at diagnosis or at first visit during the given periods were observed. Of note, indication of systemic therapy in the adjuvant or metastatic setting was not altered. Days to treatment initiation and enrollment in clinical trials in this subpopulation was not affected due to the COVID-19 outbreak.

Upfront surgery versus self-expanding metallic stent as bridge to surgery in left-sided colonic cancer obstruction: A multicenter observational study

BACKGROUND

Oncological outcomes of self-expanding metallic stent used as a bridge to surgery in potential curative patients with left-sided colonic cancer obstruction remain unclear. The aim of this study was to investigate perioperative and mid-term oncological outcomes of 2 of the currently most commonly performed treatments in left-sided colonic cancer obstruction.

METHODS

This is a retrospective multicenter study including patients with left-sided colonic cancer obstruction treated with curative intent between 2013 and 2017. The presence of metastasis at diagnosis was an exclusion criterion. The primary outcome was to evaluate the noninferiority, in terms of overall survival, of bridge to surgery strategy compared with emergency colonic resection. The secondary outcomes were perioperative morbimortality, disease free survival, local recurrence, and distant recurrence.

RESULTS

A total of 564 patients were included, 320 in the emergency colonic resection group and 244 in the bridge to surgery group. Twenty-seven patients of the bridge-to-surgery group needed urgent operation. Postoperative morbidity rates were statistically higher in the emergency colonic resection group (odds ratio [95% confidence interval] 0.37 [0.24-0.55], P < .001). There was no difference in 90-day mortality between groups (odds ratio [95% confidence interval] 0.85 [0.36-1.99], P = .702). The median follow-up was 3.80 years (2.29-4.92). The results show the noninferiority of bridge to surgery versus emergency colonic resection in terms of overall survival (hazard ratio [95% confidence interval) 0.78 [0.56-1.07], P = .127). There were no differences in disease free survival, distant recurrence, and local recurrence rates between bridge to surgery and emergency colonic resection groups.

CONCLUSION

Self-expanding metallic stent as bridge to surgery might not lead to a negative impact on the long-term prognosis of the tumor compared with emergency colonic resection in expert hands and selected patients.

The Gut Microbiota Metabolite Succinate Promotes Adipose Tissue Browning in Crohn's Disease

BACKGROUND AND AIMS

Crohn's disease [CD] is associated with complex microbe-host interactions, involving changes in microbial communities, and gut barrier defects, leading to the translocation of microorganisms to surrounding adipose tissue [AT]. We evaluated the presence of beige AT depots in CD and questioned whether succinate and/or bacterial translocation promotes white-to-beige transition in adipocytes.

METHODS

Visceral [VAT] and subcutaneous [SAT] AT biopsies, serum and plasma were obtained from patients with active [n = 21] or inactive [n = 12] CD, and from healthy controls [n = 15]. Adipose-derived stem cells [ASCs] and AT macrophages [ATMs] were isolated from VAT biopsies.

RESULTS

Plasma succinate levels were significantly higher in patients with active CD than in controls and were intermediate in those with inactive disease. Plasma succinate correlated with the inflammatory marker high-sensitivity C-reactive protein. Expression of the succinate receptor SUCNR1 was higher in VAT, ASCs and ATMs from the active CD group than from the inactive or control groups. Succinate treatment of ASCs elevated the expression of several beige AT markers from controls and from patients with inactive disease, including uncoupling protein-1 [UCP1]. Notably, beige AT markers were prominent in ASCs from patients with active CD. Secretome profiling revealed that ASCs from patients with active disease secrete beige AT-related proteins, and co-culture assays showed that bacteria also trigger the white-to-beige switch of ASCs from patients with CD. Finally, AT depots from patients with CD exhibited a conversion from white to beige AT together with high UCP1 expression, which was corroborated by in situ thermal imaging analysis.

CONCLUSIONS

Succinate and bacteria trigger white-to-beige AT transition in CD. Understanding the role of beige AT in CD might aid in the development of therapeutic or diagnostic interventions.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on pouchitis in ulcerative colitis. Part 2: Treatment

Pouchitis treatment is a complex entity that requires a close medical and surgical relationship. The elective treatment for acute pouchitis is antibiotics. After a first episode of pouchitis it is recommended prophylaxis therapy with a probiotic mix, nevertheless it is not clear the use of this formulation for preventing a first episode of pouchitis after surgery. First-line treatment for chronic pouchitis is an antibiotic combination. The next step in treatment should be oral budesonide. Selected cases of severe, chronic refractory pouchitis may benefit from biologic agents, and anti-TNF α should be recommended as the first option, leaving the new biologicals for multi-refractory patients. Permanent ileostomy may be an option in severe refractory cases to medical treatment.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on pouchitis in ulcerative colitis. Part 1: Epidemiology, diagnosis and prognosis

Pouchitis is a common complication in ulcerative colitis patients after total proctocolectomy. This is an unspecific inflammation of the ileo-anal pouch, the aetiology of which is not fully known. This inflammation induces the onset of symptoms such as urgency, diarrhoea, rectal bleeding and abdominal pain. Many patients suffering from pouchitis have a lower quality of life. In addition to symptoms, an endoscopy with biopsies is mandatory in order to establish a definite diagnosis. The recommended index to assess its activity is the Pouchitis Disease Activity Index (PDAI), but its modified version (PDAIm) can be used in clinical practice. In accordance with the duration of symptoms, pouchitis can be classified as acute (<4 weeks) or chronic (>4 weeks), and, regarding its course, pouchitis can be infrequent (<4 episodes per year), recurrent (>4 episodes per year) or continuous.

Development and validation of the QUECOMIICAT questionnaire: a tool to assess disease-related knowledge in patients with inflammatory bowel disease

INTRODUCTION

adequate knowledge of inflammatory bowel disease (IBD) is essential for a successful patient-centered management of IBD.

OBJECTIVE

due to the scarcity of up-to-date tools for measuring IBD literacy, this single-center, prospective study aimed to develop and validate a new questionnaire to assess IBD-related knowledge.

MATERIAL AND METHODS

the study included patients followed up at the Crohn-Colitis Care Unit (UACC) at the Hospital Vall d'Hebron (Barcelona, Spain). Patients admitted to the UACC for the first time were subsequently enrolled into a standard IBD educational program. A pilot questionnaire was developed and validated in 92 IBD patients by determining the internal consistency reliability (Cronbach's α test), feasibility, construct validity (correlation with the Crohn's and Colitis Knowledge [CCKNOW] questionnaire and a knowledge visual analog scale [VAS]) and sensitivity (score change before and after a standard IBD educational program). The questionnaire, named "Qüestionari Coneixements Malaltia Inflamatòria Intestinal Catalunya" (IBD-knowledge questionnaire Catalonia) (QUECOMIICAT) was written in Spanish and had 25 items addressing six dimensions: general concepts, clinic, treatment, surgery, habits and social context.

RESULTS

the median (interquartile range) completion time was 15 (10-20) minutes and the floor and ceiling effects were 1.1% and 2.1%, respectively. The Cronbach's α coefficient was α = 0.75. QUECOMIICAT significantly correlated with the VAS (rho = 0.34, p < 0.01) and CCKNOW questionnaires (rho = 0.74, p < 0.01). Patient knowledge significantly increased 24 hours after attending a standard IBD educational program and remained statistically significant one month later (Pearson's test-retest correlation coefficient r = 0.81, p < 0.001).

CONCLUSION

in conclusion, the QUECOMIICAT questionnaire is a new up-to-date tool to assess IBD-related knowledge with good feasibility and validation results for use in the routine clinical practice.

Analysis of Quality Indicators for Colorectal Cancer Surgery in Units Accredited by the Spanish Association of Coloproctology

INTRODUCTION

Currently, there is growing interest in analyzing the results from surgical units and the implementation of quality standards in order to identify good healthcare practices. Due to this fact, the Spanish Association of Coloproctology (AECP) has developed a unit accreditation program that contemplates basic standards. The aim of this article is to evaluate and analyze the specific quality indicators for the surgical treatment of colorectal cancer, established by the program. Data were collected from colorectal units during the accreditation process.

METHODS

We analyzed prospectively collected data from elective colorectal surgeries at 18 Spanish coloproctology units during the period 2013-2017. Three main and four secondary quality indicators were considered. Colon and rectal surgeries were analyzed independently; furthermore, results were compared according to surgical approach.

RESULTS

A total of 3090 patients were included in the analysis. The global anastomotic leak rate was 7.8% (6.6% colon vs 10.6% rectum), while the surgical site infection rate was 12.6% (11.4% colon vs 14.8% rectum). Overall 30-day mortality was 2.3%, and anastomotic leak-related mortality was 10.2%. There were higher surgical site infection and mortality rates in the patients operated by open approach, however there was no difference in the anastomotic leak rate when compared with minimally invasive approaches.

CONCLUSIONS

The evaluation of these results has determined optimal quality indices for the units accredited in the treatment of colorectal cancer. Furthermore, it allows us to establish realistic references in our country, thereby providing a better understanding and comparison of outcomes.

Pathologic response grade after long-course neoadjuvant chemoradiation does not influence morbidity in locally advanced mid-low rectal cancer resected by laparoscopy

PURPOSE

Patients with locally advanced rectal cancer and pathologic complete response to neoadjuvant chemoradiation therapy have lower rates of recurrence compared to those who do not. However, the influences of the pathologic response on surgical complications and survival remain unclear. This study aimed to investigate the influence of neoadjuvant therapy for rectal cancer on postoperative morbidity and long-term survival.

METHODS

This was a comparative study of consecutive patients who underwent laparoscopic total mesorectal excision for rectal cancer in two European tertiary hospitals between 2004 and 2014. Patients with and without pathologic complete responses were compared in terms of postoperative morbidity, mortality, and survival.

RESULTS

Fifty patients with complete response (ypT0N0) were compared with 141 patients who exhibited non-complete response. No group differences were observed in the postoperative mortality or morbidity rates. The median follow-up time was 57 months (range 1-121). Over this period, 11 (5.8 %) patients, all of whom were in the non-complete response group, exhibited local recurrence. The 5-year overall survival and disease-free survival were significantly better in the complete response group, 92.5 vs. 75.3 % (p = 0.004) and 89 vs. 73.4 % (p = 0.002), respectively.

CONCLUSIONS

Postoperative complication rate after laparoscopic total mesorectal excision is not associated with the pathologic response grade to neoadjuvant chemoradiation therapy.

Effect of hospital caseload on long-term outcome after standardization of rectal cancer surgery in the Spanish Rectal Cancer Project

INTRODUCCIóN: The purpose of this prospective multicentre multilevel study was to investigate the influence of hospital caseload on long-term outcomes following standardization of rectal cancer surgery in the Rectal Cancer Project of the Spanish Society of Surgeons.

METHODS

Data relating to 2910 consecutive patients with rectal cancer treated for cure between March 2006 and March 2010 were recorded in a prospective database. Hospitals were classified according to number of patients treated per year as low-volume, intermediate-volume, or high volume hospitals (12-23, 24-35, or ≥36 procedures per year).

RESULTS

After a median follow-up of 5 years, cumulative rates of local recurrence, metastatic recurrence and overall survival were 6.6 (CI95% 5.6-7.6), 20.3 (CI95% 18.8-21.9) and 73.0 (CI95% 74.7 - 71.3) respectively. In the multilevel regression analysis overall survival was higher for patients treated at hospitals with an annual caseload of 36 or more patients (HR 0,727 [CI95% 0,556-0,951]; P=.02). The risk of local recurrence and metastases were not related to the caseload. Moreover, there was a statistically significant variation in overall survival (median hazard ratio [MHR] 1.184 [CI95% 1.071-1,333]), local recurrence (MHR 1.308 [CI95% 1.010-1.668]) and metastases (MHR 1.300 [CI95% 1.181; 1.476]) between all hospitals.

CONCLUSIONS

Overall survival was higher for patients treated at hospitals with an annual caseload of 36 or more patients. However, local recurrence was not influenced by caseload.

Morbidity after laparoscopic and open rectal cancer surgery: a comparative analysis of morbidity in octogenarians and younger patients

AIM

Although the oncological adequacy of laparoscopic rectal resection (LR) appears equivalent to open resection (OR), its benefit is controversial in the elderly. The aim of this study was to investigate the influence of LR on morbidity and mortality in octogenarians.

METHOD

This was a retrospective analysis of all patients who underwent rectal surgery for cancer between 2003 and 2013 in a teaching hospital. The primary aim of the study was to assess the influence of surgical approach on mortality and morbidity of rectal resection in patients ≥ 80 years old. Regression analysis was performed to control the effect of covariables on the clinical outcome.

RESULTS

Of 408 patients 203 were in the LR group and 205 in the OR group including 303 (74.3%) less than 80 years and 105 (25.7%) over 80 years. The mortality was lower in the LR group compared with the OR group for patients under 80 years (0% vs 4.6%; P = 0.049) and no different in the over 80 group (11.5% vs 9.4%; P = 0.859). In younger patients, the OR group showed longer hospital stay (9 vs 7 days; P < 0.001) and more complications (44.1% vs 29.8%; P = 0.042). Medical complications were more frequent in LR group than OR group octogenarians (40.4% vs 20.8%; P = 0.009) as well as grade C anastomotic leakage (13.8 vs 10.7; P = 0.041).

CONCLUSION

LR for rectal cancer showed clinical advantages in patients under 80 years and was as safe as OR in patients over 80 years, although the advantages of laparoscopic surgery were lost in the elderly group due to a higher rate of medical complications. OR may be an option in elderly patients with important comorbidities.

[Hospital variation in anastomotic leakage after rectal cancer surgery in the Spanish Association of Surgeons project: The contribution of hospital volume]

OBJECTIVE

This multicentre observational study aimed to determine the anastomotic leak rate in the hospitals included in the Rectal Cancer Project of the Spanish Society of Surgeons and examine whether hospital volume may contribute to any variation between hospitals.

METHODS

Hospital variation was quantified using a multilevel approach on prospective data derived from the multicentre database of all adenocarcinomas of the rectum operated by an anterior resection at 84 surgical departments from 2006 to 2013. The following variables were included in the analysis; demographics, American Society of Anaesthesiologists classification, use of defunctioning stoma, tumour location and stage, administration of neoadjuvant treatment, and annual volume of elective surgical procedures.

RESULTS

A total of 7231 consecutive patients were included. The rate of anastomotic leak was 10.0%. Stratified by annual surgical volume hospitals varied from 9.9 to 11.3%. In multilevel regression analysis, the risk of anastomotic leak increased in male patients, in patients with tumours located below 12 cm from the anal verge, and advanced tumour stages. However, a defunctioning stoma seemed to prevent this complication. Hospital surgical volume was not associated with anastomotic leak (OR: 0.852, [0.487-1.518]; P=.577). Furthermore, there was a statistically significant variation in anastomotic leak between all departments (MOR: 1.475; [1.321-1.681]; P<0.001).

CONCLUSION

Anastomotic leak varies significantly among hospitals included in the project and this difference cannot be attributed to the annual surgical volume.

Tankyrase Inhibition Blocks Wnt/β-Catenin Pathway and Reverts Resistance to PI3K and AKT Inhibitors in the Treatment of Colorectal Cancer

PURPOSE

Oncogenic mutations in the KRAS/PI3K/AKT pathway are one of the most frequent alterations in cancer. Although PI3K or AKT inhibitors show promising results in clinical trials, drug resistance frequently emerges. We previously revealed Wnt/β-catenin signaling hyperactivation as responsible for such resistance in colorectal cancer. Here we investigate Wnt-mediated resistance in patients treated with PI3K or AKT inhibitors in clinical trials and evaluate the efficacy of a new Wnt/tankyrase inhibitor, NVP-TNKS656, to overcome such resistance.

EXPERIMENTAL DESIGN

Colorectal cancer patient-derived sphere cultures and mouse tumor xenografts were treated with NVP-TNKS656, in combination with PI3K or AKT inhibitors.We analyzed progression-free survival of patients treated with different PI3K/AKT/mTOR inhibitors in correlation with Wnt/β-catenin pathway activation, oncogenic mutations, clinicopathological traits, and gene expression patterns in 40 colorectal cancer baseline tumors.

RESULTS

Combination with NVP-TNKS656 promoted apoptosis in PI3K or AKT inhibitor-resistant cells with high nuclear β-catenin content. High FOXO3A activity conferred sensitivity to NVP-TNKS656 treatment. Thirteen of 40 patients presented high nuclear β-catenin content and progressed earlier upon PI3K/AKT/mTOR inhibition. Nuclear β-catenin levels predicted drug response, whereas clinicopathologic traits, gene expression profiles, or frequent mutations (KRAS, TP53, or PIK3CA) did not.

CONCLUSIONS

High nuclear β-catenin content independently predicts resistance to PI3K and AKT inhibitors. Combined treatment with a Wnt/tankyrase inhibitor reduces nuclear β-catenin, reverts such resistance, and represses tumor growth. FOXO3A content and activity predicts response to Wnt/β-catenin inhibition and together with β-catenin may be predictive biomarkers of drug response providing a rationale to stratify colorectal cancer patients to be treated with PI3K/AKT/mTOR and Wnt/β-catenin inhibitors.

Guidelines for diagnosis, staging and treatment of metastatic colorectal cancer by Grupo Español Multidisciplinar en Cancer Digestivo (GEMCAD)

Abstract 

Advances in the care of patients with metastatic colorectal cancer arise from well-designed clinical trials. In the present document we address specific challenges in the design of clinical trials for metastatic colorectal cancer regarding staging and standard of care according to prognosis, as well as some relevant methodological issues.

Oncological outcome following anastomotic leak in rectal surgery

BACKGROUND

The influence of anastomotic leak on local recurrence and survival remains debated in rectal cancer.

METHODS

This was a multicentre observational study using data from the Spanish Rectal Cancer Project database. Demographics, American Society of Anesthesiologists classification, tumour location, stage, use of defunctioning stoma, administration of neoadjuvant and adjuvant treatment, invasion of circumferential resection margin, quality of mesorectal excision and anastomotic leakage were recorded. Anastomotic leak was defined as an anastomotic event requiring surgical intervention or interventional radiology, including pelvic abscesses without radiological evidence of leakage and early rectovaginal fistulas. Variables associated with oncological outcome were assessed by multivariable Cox regression analysis.

RESULTS

A total of 1181 consecutive patients were included. Rates of anastomotic leak and 30-day postoperative mortality were 9·4 and 2·4 per cent respectively. Data from 1153 patients were analysed after a median follow-up of 5 years. Cumulative rates of local recurrence, overall recurrence, overall survival and cancer-specific survival were 4·9, 19·4, 77·5 and 84·7 per cent respectively. In the multivariable regression analysis, anastomotic leakage was not associated with local recurrence (hazard ratio (HR) 0·80, 95 per cent c.i. 0·28 to 2·26; P = 0·669), overall recurrence (HR 1·14, 0·70 to 1·85; P = 0·606), overall survival (HR 1·10, 0·73 to 1·65; P = 0·648) or cancer-specific survival (HR 1·23, 0·75 to 2·02; P = 0·421).

CONCLUSION

Anastomotic leak after low anterior resection did not affect oncological outcomes in these patients.

Multivisceral Resection for Locally Advanced Rectal Cancer: Prognostic Factors Influencing Outcome

AIMS

To assess outcome in patients with locally advanced rectal cancer undergoing multivisceral resection.

METHODS

Retrospective study of 30 consecutive patients (mean age 67.8 years) with primary locally advanced rectal cancer undergoing en bloc multivisceral resection of the organs involved with curative intent between 1998 and 2010. Overall survival, local and distal recurrence, and disease-free survival were analyzed by the Kaplan-Meier method. Risk factors for clinical outcome were obtained using a Cox multivariate model.

RESULTS

Postoperative complications occurred in 76.7% of patients and the in-hospital mortality rate was 10%. The median follow-up was 28.8 months. A total of 19 patients died at follow-up. Of the 11 patients who were alive, 7 were free of disease. In the multivariate analysis, lymph node involvement, stage II, and lymph vascular invasion were significantly associated with survival, and stage III showed a strong trend towards significance. Suture dehiscence (peritonitis and intra-abdominal abscess) showed a significant trend towards a higher local recurrence. Lymph vascular invasion was associated with a higher distant recurrence.

CONCLUSION

Lymph node involvement was associated with worse survival, whereas stage II and absence of lymph vascular invasion were associated with a better survival. Lymph vascular invasion was associated with a higher distant recurrence.

Ultralow anterior resection with mechanical anastomosis in the treatment of distal third rectal cancer

Tumors of the lower third of the rectum are a challenge for the surgeon. Among the various techniques of surgical treatment of these lesions, radical surgery and ultra low anterior anastomosis is one of the therapeutic options. This technique is a defy both in the evaluation of the potential patient as in the surgical technique. Such evaluation and treatment processes must be audited in order to keep proper quality indices both in the oncological as in their functional results. This is only possible when both the multidisciplinary and surgical teams have an adequate and ongoing specialized training and a satisfactory volume of patients treated. Details of this technique, its indications and results are reported in this paper.

Delphi consensus statement: Quality Indicators for Inflammatory Bowel Disease Comprehensive Care Units

BACKGROUND AND AIMS

While it is commonly accepted that Inflammatory bowel disease (IBD) Comprehensive Care Units (ICCUs) facilitate the delivery of quality care to Crohn's disease and ulcerative colitis patients, it remains unclear how an ICCU should be defined or evaluated. The aim of the present study was to develop a comprehensive set of Quality Indicators (QIs) of structure, process, and outcomes for defining and evaluating an ICCU.

METHODS

A Delphi consensus-based approach with a standardized three-step process was used to identify a core set of QIs. The process included an exhaustive search using complementary approaches to identify potential QIs, and two Delphi voting rounds to select the QIs defining the core requirements for an ICCU.

RESULTS

The consensus selected a core set of 56 QIs (12 structure, 20 process and 24 outcome). Structure and process QIs highlighted the need for multidisciplinary management and continuity of care. The minimal IBD team should include an IBD nurse, gastroenterologists, radiologists, surgeons, endoscopists and stoma management specialists. ICCUs should be able to provide both outpatient and inpatient care and admission should not break the continuity of care. Outcome QIs focused on the adequate prophylaxis of disease complication and drug adverse events, the need to monitor appropriateness of treatment and the need to reinforce patient autonomy by providing adequate information and facilitating the patients' participation in their own care.

CONCLUSIONS

The present Delphi consensus identified a set of core QIs that may be useful for evaluating and certifying ICCUs.

A personalized preclinical model to evaluate the metastatic potential of patient-derived colon cancer initiating cells

PURPOSE

Within the aim of advancing precision oncology, we have generated a collection of patient-derived xenografts (PDX) characterized at the molecular level, and a preclinical model of colon cancer metastasis to evaluate drug-response and tumor progression.

EXPERIMENTAL DESIGN

We derived cells from 32 primary colorectal carcinomas and eight liver metastases and generated PDX annotated for their clinical data, gene expression, mutational, and histopathological traits. Six models were injected orthotopically into the cecum wall of NOD-SCID mice in order to evaluate metastasis. Three of them were treated with chemotherapy (oxaliplatin) and three with API2 to target AKT activity. Tumor growth and metastasis progression were analyzed by positron emission tomography (PET).

RESULTS

Patient-derived cells generated tumor xenografts that recapitulated the same histopathological and genetic features as the original patients' carcinomas. We show an 87.5% tumor take rate that is one of the highest described for implanted cells derived from colorectal cancer patients. Cecal injection generated primary carcinomas and distant metastases. Oxaliplatin treatment prevented metastasis and API2 reduced tumor growth as evaluated by PET.

CONCLUSIONS

Our improved protocol for cancer cell engraftment has allowed us to build a rapidly expanding collection of colorectal PDX, annotated for their clinical data, gene expression, mutational, and histopathological statuses. We have also established a mouse model for metastatic colon cancer with patient-derived cells in order to monitor tumor growth, metastasis evolution, and response to treatment by PET. Our PDX models could become the best preclinical approach through which to validate new biomarkers or investigate the metastatic potential and drug-response of individual patients.

Human SMC2 protein, a core subunit of human condensin complex, is a novel transcriptional target of the WNT signaling pathway and a new therapeutic target

Human SMC2 is part of the condensin complex, which is responsible for tightly packaging replicated genomic DNA prior to segregation into daughter cells. Engagement of the WNT signaling pathway is known to have a mitogenic effect on cells, but relatively little is known about WNT interaction with mitotic structural organizer proteins. In this work, we described the novel transcriptional regulation of SMC2 protein by direct binding of the β-catenin·TCF4 transcription factor to the SMC2 promoter. Furthermore, we identified the precise region in the SMC2 promoter that is required for β-catenin-mediated promoter activation. Finally, we explored the functional significance of down-regulating SMC2 protein in vivo. Treatment of WNT-activated intestinal tumor cells with SMC2 siRNA significantly reduced cell proliferation in nude mice, compared with untreated controls (p = 0.02). Therefore, we propose that WNT signaling can directly activate SMC2 transcription as a key player in the mitotic cell division machinery. Furthermore, SMC2 represents a new target for oncological therapeutic intervention.

Use of a prosthetic mesh to prevent parastomal hernia during laparoscopic abdominoperineal resection: a randomized controlled trial

PURPOSE

Prevention of parastomal hernia represents an important aim when a permanent stoma is necessary. The objective of this work is to assess whether implantation of a prophylactic prosthetic mesh during laparoscopic abdominoperineal resection contributed to reduce the incidence of parastomal hernia.

METHODS

Rectal cancer patients undergoing elective laparoscopic abdominoperineal resection with permanent colostomy were randomized to placement of a large-pore lightweight mesh in the intraperitoneal/onlay position by the laparoscopic approach (study group) or to the control group (no mesh). Parastomal hernia was defined radiologically by a CT scan performed after 12 months of surgery. The usefulness of subcutaneous fat thickness measured by CT to discriminate patients at risk of parastomal hernia was assessed by ROC curve analysis.

RESULTS

Thirty-six patients were randomized, 19 to the mesh group and 17 to the control group. Parastomal hernia was detected in 50 % of patients in the mesh group and in 93.8 % of patients in the control group (P = 0.008). The AUC for thickness of the subcutaneous abdominal was 0.819 (P = 0.004) and the optimal threshold 23 mm. Subcutaneous fat thickness ≥23 mm was a significant predictor of parastomal hernia (odds ratio 15.7, P = 0.010), whereas insertion of a mesh was a protective factor (odds ratio 0.06, P = 0.031).

CONCLUSIONS

Use of prophylactic large-pore lightweight mesh in the intraperitoneal/onlay position by a purely laparoscopic approach reduced the incidence of parastomal hernia formation. Subcutaneous fat thickness ≥23 mm measured by CT was an independent predictor of parastomal hernia.

Brush border myosin Ia has tumor suppressor activity in the intestine

The loss of the epithelial architecture and cell polarity/differentiation is known to be important during the tumorigenic process. Here we demonstrate that the brush border protein Myosin Ia (MYO1A) is important for polarization and differentiation of colon cancer cells and is frequently inactivated in colorectal tumors by genetic and epigenetic mechanisms. MYO1A frame-shift mutations were observed in 32% (37 of 116) of the colorectal tumors with microsatellite instability analyzed, and evidence of promoter methylation was observed in a significant proportion of colon cancer cell lines and primary colorectal tumors. The loss of polarization/differentiation resulting from MYO1A inactivation is associated with higher tumor growth in soft agar and in a xenograft model. In addition, the progression of genetically and carcinogen-initiated intestinal tumors was significantly accelerated in Myo1a knockout mice compared with Myo1a wild-type animals. Moreover, MYO1A tumor expression was found to be an independent prognostic factor for colorectal cancer patients. Patients with low MYO1A tumor protein levels had significantly shorter disease-free and overall survival compared with patients with high tumoral MYO1A (logrank test P = 0.004 and P = 0.009, respectively). The median time-to-disease recurrence in patients with low MYO1A was 1 y, compared with >9 y in the group of patients with high MYO1A. These results identify MYO1A as a unique tumor-suppressor gene in colorectal cancer and demonstrate that the loss of structural brush border proteins involved in cell polarity are important for tumor development.

Multivisceral resection for colon cancer: analysis of prognostic factors

BACKGROUND/AIMS

To assess outcome of multivisceral resection in colon cancer patients and to identify predictors of survival.

METHODS

One hundred and thirteen consecutive patients with primary locally advanced colon cancer infiltrating adjacent organs undergoing multivisceral resection between 1998 and 2007 were reviewed. Overall survival and disease-free survival were analyzed by the Kaplan-Meier method. The relative risk for clinical outcome was obtained using a Cox multivariate model.

RESULTS

The median follow-up was 74.9 months. Fifty-two patients had sigmoid tumors and 48 involvement of the small intestine. Complications occurred in 54 patients. The diagnosis was conventional adenocarcinoma in 94 patients. R0 resection was achieved in 96 patients (85%). Eighty-three patients received postoperative adjuvant therapy. The operative mortality was 7.1% (8 patients). Sixty-seven patients died at follow-up. Of the 46 patients who were alive, 38 were free of disease. In 73 patients with pT4a disease, 42 patients died (57.5%) and of the 31 survivors, recurrence was documented in 6. Hematochezia and adjuvant chemotherapy were independent factors of favorable outcome and grade G3 and tumor stage III-IV of poor survival.

CONCLUSION

Hematochezia and adjuvant chemotherapy were associated with a better survival, and poorly differentiated tumors and stage IV disease with a poor survival.

Aprataxin tumor levels predict response of colorectal cancer patients to irinotecan-based treatment

PURPOSE

Irinotecan (CPT11) treatment significantly improves the survival of colorectal cancer patients and is routinely used for the treatment of these patients, alone or in combination with other agents. However, only 20% to 30% of patients show an objective response to irinotecan, and there is great need for new molecular markers capable of identifying the subset of patients who are unlikely to respond.

EXPERIMENTAL DESIGN

Here we used microarray analysis of a panel of 30 colorectal cancer cell lines and immunohistochemistry to identify and validate a new biomarker of response to irinotecan.

RESULTS

A good correlation was observed between irinotecan sensitivity and the expression of aprataxin (APTX), a histidine triad domain superfamily protein involved in DNA repair. Moreover, using an isogenic in vitro system deficient in APTX, we show that aprataxin directly regulates the cellular sensitivity to camptothecin, suggesting that it could be used to predict patient response to irinotecan. We constructed a tissue microarray containing duplicate tumor samples from 135 patients that received irinotecan for the treatment of advanced colorectal cancer. Immunohistochemical assessment of the tumor levels of aprataxin showed a significant association with treatment response and patient survival. Patients with low aprataxin had longer progression-free (9.2 versus 5.5 months; P = 0.03) and overall survival (36.7 versus 19.0 months; P = 0.008) than patients with high tumor aprataxin. No associations were found between coding APTX variants and aprataxin levels or camptothecin sensitivity.

CONCLUSIONS

These results show that aprataxin tumor levels can be used to identify patients with low probability of response to irinotecan-based therapy who are ideal candidates to receive treatment with alternative agents in an attempt to improve patient survival.

[Risk of venous thromboembolic disease in general surgery]

Despite preventive efforts, venous thromboembolic disease (VTED) is still a major problem for surgeons due to its frequency and the morbidity, mortality and enormous resource consumption caused by this entity. However, the most important feature of VTED is that it is one of the most easily preventable complications and causes of death. To take appropriate prophylactic decisions (indication, method, initiation, duration, etc.), familiarity with the epidemiology of VTED in general surgery and some of its most significant populations (oncologic, laparoscopic, bariatric, ambulatory and short-stay) is essential. These factors must also be known to determine the distinct risk factors in these settings with a view to stratifying preoperative risk.

EPHB4 and survival of colorectal cancer patients

The family of receptor tyrosine kinases EPH and their Ephrin ligands regulate cell proliferation, migration, and attachment. An important role in colorectal carcinogenesis is emerging for some of its members. In this study, we evaluate the role of EPHB4 in colorectal cancer and its value as a prognostic marker. EPHB4 levels were assessed by immunohistochemical staining of tissue microarrays of 137 colorectal tumors and aberrant hypermethylation of the EPHB4 promoter was investigated using methylation-specific PCR. We found that EPHB4 expression is frequently reduced or lost in colorectal tumors. Patients with low EPHB4 tumor levels had significantly shorter survival than patients in the high EPHB4 group (median survival, 1.8 and >9 years, respectively; P < 0.01, log-rank test), and this finding was validated using an independent set of 125 tumor samples. In addition, we show that EPHB4 promoter hypermethylation is a common mechanism of EPHB4 inactivation. Moreover, reintroduction of EPHB4 resulted in a significant reduction in the clonogenic potential of EPHB4-deficient cells, whereas abrogation of EPHB4 in cells with high levels of this receptor lead to a significant increase in clonogenicity. In summary, we identified EPHB4 as a useful prognostic marker for colorectal cancer. In addition, we provide mechanistic evidence showing that promoter methylation regulates EPHB4 transcription and functional evidence that EPHB4 can regulate the long-term clonogenic potential of colorectal tumor cells, revealing EPHB4 as a potential new tumor suppressor gene in colorectal cancer.

High EPHB2 mutation rate in gastric but not endometrial tumors with microsatellite instability

The EPH/EFN family of receptor tyrosine kinases regulates cell adhesion and migration and has an important role in controlling cell positioning in the normal intestinal epithelium. Inactivation of EPHB2 has recently been shown to accelerate tumorigenesis in the colon and rectum, and we have previously demonstrated frequent frameshift mutations (41%) in an A9 coding microsatellite repeat in exon 17 of EPHB2 in colorectal tumors with microsatellite instability (MSI). In this study, we extended these analyses to extracolonic MSI cancers, and found frameshift EPHB2 mutations in 39% (25/64) of gastric tumors and 14% (8/56) of endometrial tumors. Regression analysis of these EPHB2 mutation data on the basis of our previously proposed statistical model identified EPHB2 as a selective target of frameshift mutations in MSI gastric cancers but not in MSI endometrial carcinomas. These results suggest a functional role for EPHB2 in gastric tumor progression, and emphasize the differences between the tumorigenic processes in MSI gastrointestinal and endometrial cancer.

BRAF screening as a low-cost effective strategy for simplifying HNPCC genetic testing

BACKGROUND

According to the international criteria for hereditary non-polyposis colorectal cancer (HNPCC) diagnostics, cancer patients with a family history or early onset of colorectal tumours showing high microsatellite instability (MSI-H) should receive genetic counselling and be offered testing for germline mutations in DNA repair genes, mainly MLH1 and MSH2. Recently, an oncogenic V600E hotspot mutation within BRAF, a kinase encoding gene from the RAS/RAF/MAPK pathway, has been found to be associated with sporadic MSI-H colon cancer, but its association with HNPCC remains to be further clarified.

METHODS

BRAF-V600E mutations were analysed by automatic sequencing in colorectal cancers from 206 sporadic cases with MSI-H and 111 HNPCC cases with known germline mutations in MLH1 and MSH2. In addition, 45 HNPCC cases showing abnormal immunostaining for MSH2 were also analysed.

RESULTS

The BRAF-V600E hotspot mutation was found in 40% (82/206) of the sporadic MSI-H tumours analysed but in none of the 111 tested HNPCC tumours or in the 45 cases showing abnormal MSH2 immunostaining.

CONCLUSIONS

Detection of the V600E mutation in a colorectal MSI-H tumour argues against the presence of a germline mutation in either the MLH1 or MSH2 gene. Therefore, screening of these mismatch repair (MMR) genes can be avoided in cases positive for V600E if no other significant evidence, such as fulfilment of the strict Amsterdam criteria, suggests MMR associated HNPCC. In this context, mutation analysis of the BRAF hotspot is a reliable, fast, and low cost strategy which simplifies genetic testing for HNPCC.

Increased mucosal tumour necrosis factor alpha production in Crohn's disease can be downregulated ex vivo by probiotic bacteria

BACKGROUND AND AIMS

Tumour necrosis factor alpha (TNF-alpha) plays a key role in the pathogenesis of intestinal inflammation in Crohn's disease. The effect of bacteria on TNF-alpha release by intestinal mucosa was investigated.

METHODS

Ileal specimens were obtained at surgery from 10 patients with Crohn's disease (ileal stricture) and five disease controls undergoing right hemicolectomy (caecal cancer). Mucosal explants from each specimen were cultured for 24 hours with either non-pathogenic Escherichia coli, Lactobacillus casei DN-114001, L bulgaricus LB10, or L crispatus (each study contained blank wells with no bacteria). Tissue and bacterial viability was confirmed by lactate dehydrogenase (LDH) release and culture. Concentrations of TNF-alpha were measured in supernatants and the phenotype of the intestinal lymphocytes was analysed by flow cytometry.

RESULTS

Coculture of mucosa with bacteria did not modify LDH release. Release of TNF-alpha by inflamed Crohn's disease mucosa was significantly reduced by coculture with L casei or L bulgaricus; changes induced by L crispatus or E coli were not significant. The effect of L casei and L bulgaricus was not prevented by protease inhibitors. Coculture with L casei and L bulgaricus reduced the number of CD4 cells as well as TNF-alpha expression among intraepithelial lymphocytes from Crohn's disease mucosa. None of the bacteria induced changes in non-inflamed mucosa.

CONCLUSIONS

Probiotics interact with immunocompetent cells using the mucosal interface and modulate locally the production of proinflammatory cytokines.

Somatic mutations in the DNA damage-response genes ATR and CHK1 in sporadic stomach tumors with microsatellite instability

Maintenance of genomic stability depends on the appropriate cellular responses to DNA damage and the integrity of the DNA repair systems. We analyzed stomach tumors with microsatellite instability (MSI) for frameshift mutations in several potential targets of the mutator phenotype involved in DNA damage-response pathways, such as the ataxia telangiectasia mutated protein-related protein (ATR)-CHK1-Cdc25c pathway, and DNA repair. High frequency of mutations was found within ATR [5 (21%) of 23], MED1 [10 (43%) of 23], hMSH3 [13 (56%) of 23], and hMSH6 [10 (43%) of 23] genes. Also, a low frequency of mutations within the CHK1 gene was detected in 9% (2 of 23) of tumors. No mutations of hMLH3, ATM, BRCA1, or NBS1 genes were detected. These results confirm ATR, MED1, and CHK1 as targets of the mutator pathway in stomach tumorigenesis, and also suggest a potential role of MED1 increasing, together with hMSH3 and hMSH6, the genomic instability in the mutator pathway as a secondary mutator. Furthermore, these results suggest that the inhibition of the ATR-CHK1 DNA damage-response pathway might be involved in the tumorigenesis of gastric cancer with microsatellite instability.