Putrescine Supplementation Limits the Expansion of pks+ Escherichia coli and Tumor Development in the Colon.

Escherichia coli that harbor the polyketide synthase (pks) genomic island produce colibactin and are associated with sporadic colorectal cancer development. Given the considerable prevalence of pks+ bacteria in healthy individuals, we sought to identify strategies to limit the growth and expansion of pks+ E. coli. We found that culture supernatants of the probiotic strain E. coli Nissle 1917 were able to inhibit the growth of the murine pathogenic strain pks+ E. coli NC101 (EcNC101). We performed a nontargeted analysis of the metabolome in supernatants from several E. coli strains and identified putrescine as a potential postbiotic capable of suppressing EcNC101 growth in vitro. The effect of putrescine supplementation was then evaluated in the azoxymethane/dextran sulfate sodium mouse model of colorectal cancer in mice colonized with EcNC101. Putrescine supplementation inhibited the growth of pks+ E. coli, reduced the number and size of colonic tumors, and downmodulated the release of inflammatory cytokines in the colonic lumen. Additionally, putrescine supplementation led to shifts in the composition and function of gut microbiota, characterized by an increase in the Firmicutes/Bacteroidetes ratio and enhanced acetate production. The effect of putrescine was further confirmed in vitro using a pks+ E. coli strain isolated from a patient with colorectal cancer. These results suggest that probiotic-derived metabolites can be used as an alternative to live bacteria in individuals at risk of developing colorectal cancer due to the presence of pks+ bacteria in their colon. SIGNIFICANCE: Putrescine supplementation inhibits the growth of cancer-promoting bacteria in the gut, lowers inflammation, and reduces colon cancer development. The consumption of healthy foods rich in putrescine may be a potential prophylactic approach for individuals at risk of developing colorectal cancer due to the presence of pks+ bacteria in their colon.

Nonoperative management protocol for locally advanced rectal cancer.

AIM: The standard treatment for low rectal cancer is preoperative chemoradiotherapy followed by surgery with low anterior resection with diverting ileostomy or abdominoperineal resection, both of which have significant long-term effects on bowel and sexual function. Due to the high morbidity of surgery, there has been increasing interest in nonoperative management for low rectal cancer. The aim of this work is to conduct a pan-Canadian Phase II trial assessing the safety of nonoperative management for low rectal cancer. METHOD: Patients with Stage II or III low rectal cancer completing chemoradiotherapy according to standard of care at participating centres will be assessed for complete clinical response 8-14 weeks following completion of chemoradiotherapy. Subjects achieving a clinical complete response will undergo active surveillance including endoscopy, imaging and bloodwork at regular intervals for 24 months. The primary outcome will be the rate of local regrowth 2 years after chemoradiotherapy. Nonoperative management will be considered safe (i.e. as effective as surgery to achieve local control) if the rate of local regrowth is ≤30% and surgical salvage is possible for all local regrowths. Secondary outcomes will include disease-free and overall survival. CONCLUSION: The results will be highly clinically relevant, as it is expected that nonoperative management will be safe and lead to widespread adoption of nonoperative management in Canada. This change in practice has the potential to decrease the number of patients requiring surgery and the costs associated with surgery and long-term surgical morbidity.

Modulating Gut Microbiota Prevents Anastomotic Leak to Reduce Local Implantation and Dissemination of Colorectal Cancer Cells after Surgery.

PURPOSE: Anastomotic leak (AL) is a major complication in colorectal cancer surgery and consists of the leakage of intestinal content through a poorly healed colonic wound. Colorectal cancer recurrence after surgery is a major determinant of survival. We hypothesize that AL may allow cancer cells to escape the gut and lead to cancer recurrence and that improving anastomotic healing may prevent local implantation and metastatic dissemination of cancer cells. EXPERIMENTAL DESIGN: We investigated the association between AL and postoperative outcomes in patients with colorectal cancer. Using mouse models of poor anastomotic healing, we assessed the processes of local implantation and dissemination of cancer cells. The effect of dietary supplementation with inulin and 5-aminosalicylate (5-ASA), which activate PPAR-γ in the gut, on local anastomotic tumors was assessed in mice undergoing colonic surgery. Inulin and 5-ASA were also assessed in a mouse model of liver metastasis. RESULTS: Patients experiencing AL displayed lower overall and oncologic survival than non-AL patients. Poor anastomotic healing in mice led to larger anastomotic and peritoneal tumors. The microbiota of patients with AL displays a lower capacity to activate the antineoplastic PPAR-γ in the gut. Modulation of gut microbiota using dietary inulin and 5-ASA reinforced the gut barrier and prevented anastomotic tumors and metastatic spread in mice. CONCLUSIONS: Our findings reinforce the hypothesis that preventing AL is paramount to improving oncologic outcomes after colorectal cancer surgery. Furthermore, they pave the way toward dietary targeting of PPAR-γ as a novel way to enhance healing and diminish cancer recurrence.

Safety and clinical efficacy of EUS-guided pelvic abscess drainage.

Background and Objectives: EUS is a potential alternative for the drainage of abscesses. The aim of this study was to determine if EUS-guided pelvic abscess drainage is technically feasible, safe, and a valid option for abscess resolution. Methods: We conducted a retrospective review from 2002 to 2020 at a single quaternary institution. EUS-guided pelvic abscess drainage via the transrectal route was performed in all patients with or without drain/stent placement. Technical and clinical success of EUS-guided pelvic abscess drainage was analyzed. Descriptive analyses and Fisher exact test were performed. Results: Sixty consecutive patients were included in the study (53.5% male; mean age, 53.8 ± 17.9 years). Pelvic abscesses occurred mainly postoperatively (33 cases; 60.0%) and from complicated diverticulitis (14 cases; 23.3%). Mean diameter was 6.5 ± 2.4 cm (80% unilocular). Drainage was performed with EUS-guided stent placement (double-pigtail plastic or lumen-apposing metal) in 74.5% of cases and with aspiration alone for the remainder. Technical success occurred in 58 cases (97%). Of those with long-term follow-up after EUS-guided pelvic abscess drainage (n = 55; 91.7%), complete abscess resolution occurred in 72.7% of all cases. Recurrence occurred in 8 cases (14.5%) and persisted in 7 patients (12.5%), 7 of which were successfully retreated with EUS-guided pelvic abscess drainage. Accounting for these successful reinterventions, the overall rate of abscess resolution was 85.5%. Abscess resolution rate improved with drain placement (83%). Accounting for 7 repeat EUS-guided pelvic abscess drainages, overall abscess resolution improved. Two deaths occurred (3.4%) because of sepsis from failed source control in patients who had previously failed medical, radiological, and surgical treatment. Conclusions: EUS-guided pelvic abscess drainage is technically feasible, safe, and an effective alternative to radiological or open surgical drainage. It also offers favorable clinical outcomes in different clinical situations.

Gut microbiota influence anastomotic healing in colorectal cancer surgery through modulation of mucosal proinflammatory cytokines.

OBJECTIVE: Colorectal cancer (CRC) is the third most diagnosed cancer, and requires surgical resection and reconnection, or anastomosis, of the remaining bowel to re-establish intestinal continuity. Anastomotic leak (AL) is a major complication that increases mortality and cancer recurrence. Our objective is to assess the causal role of gut microbiota in anastomotic healing. DESIGN: The causal role of gut microbiota was assessed in a murine AL model receiving faecal microbiota transplantation (FMT) from patients with CRC collected before surgery and who later developed or not, AL. Anastomotic healing and gut barrier integrity were assessed after surgery. Bacterial candidates implicated in anastomotic healing were identified using 16S rRNA gene sequencing and were isolated from faecal samples to be tested both in vitro and in vivo. RESULTS: Mice receiving FMT from patients that developed AL displayed poor anastomotic healing. Profiling of gut microbiota of patients and mice after FMT revealed correlations between healing parameters and the relative abundance of Alistipes onderdonkii and Parabacteroides goldsteinii. Oral supplementation with A. onderdonkii resulted in a higher rate of leaks in mice, while gavage with P. goldsteinii improved healing by exerting an anti-inflammatory effect. Patients with AL and mice receiving FMT from AL patients presented upregulation of mucosal MIP-1α, MIP-2, MCP-1 and IL-17A/F before surgery. Retrospective analysis revealed that patients with AL present higher circulating neutrophil and monocyte counts before surgery. CONCLUSION: Gut microbiota plays an important role in surgical colonic healing in patients with CRC. The impact of these findings may extend to a vast array of invasive gastrointestinal procedures.

Prevalence of pks + bacteria and enterotoxigenic Bacteroides fragilis in patients with colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most diagnosed cancer and the second most common cause of cancer deaths worldwide. CRC patients present with an increase in pathogens in their gut microbiota, such as polyketide synthase-positive bacteria (pks +) and enterotoxigenic Bacteroides fragilis (ETBF). The pks + Escherichia coli promotes carcinogenesis and facilitates CRC progression through the production of colibactin, a genotoxin that induces double-strand DNA breaks (DSBs). ETBF is a procarcinogenic bacterium producing the B. fragilis toxin (bft) that promotes colorectal carcinogenesis by modulating the mucosal immune response and inducing epithelial cell changes. METHODS: Fecal samples were collected from healthy controls (N = 62) and CRC patients (N = 94) from the province of Québec (Canada), and a bacterial DNA extraction was performed. Fecal DNA samples were then examined for the presence of the pks island gene and bft using conventional qualitative PCR. RESULTS: We found that a high proportion of healthy controls are colonized by pks + bacteria (42%) and that these levels were similar in CRC patients (46%). bft was detected in 21% of healthy controls and 32% of CRC patients, while double colonization by both pks + bacteria and ETBF occurred in 8% of the healthy controls and 13% of the CRC patients. Most importantly, we found that early-onset CRC (< 50 years) patients were significantly less colonized with pks + bacteria (20%) compared to late-onset CRC patients (52%). CONCLUSIONS: Healthy controls had similar levels of pks + bacteria and ETBF colonization as CRC patients, and their elevated levels may place both groups at greater risk of developing CRC. Colonization with pks + bacteria was less prevalent in early-compared to late-onset CRC.

[Access to donor human milk in Switzerland and CHUV's first human milk bank in Romandy : issues and perspectives]. / Pédiatrie - Accès au lait de donneuses en Suisse et création de la première banque de lait maternel romande au CHUV : enjeux et perspectives.

Mother's own milk (MOM) is ideal for infant growth and health. When MOM is unavailable, donor human milk (DHM), rather than infant formula, is recommended for at-risk, preterm or sick neonates (NN), in view of its protective effects. Human milk banks (HMB) collect, secure, process and distribute DHM. In Switzerland, there is insufficient and unequal access to DHM in the absence of a national policy framework. With the support of the State of Vaud, the CHUV and the Interregional Blood Transfusion of the Swiss Red Cross will open the first HMB in Romandy in 2022. This HMB offers an innovative system in Switzerland, based on complementary expertise, in order to guarantee the quality and safety of DHM and to support the promotion of breastfeeding and human milk donation.

Le lait maternel (LM) est idéal pour la croissance et la santé des nourrissons. En l'absence de LM, le lait de donneuses (LD) est préférable au lait artificiel pour les nouveau-nés (NN) à risques, prématurés ou présentant certaines pathologies, au vu de ses effets protecteurs. Les banques de lait (BL) collectent, sécurisent, traitent et distribuent le LD. Il existe en Suisse une insuffisance et une inégalité d'accès au LD, faute de cadre national. Avec le soutien de l'État de Vaud, le CHUV et la Transfusion interrégionale de la Croix-Rouge suisse ouvriront en 2022 la première BL romande. Cette BL propose un système novateur en Suisse, fondé sur une complémentarité d'expertises, afin d'optimiser la qualité et la sécurité du LD et de soutenir la promotion de l'allaitement et du don.

Safety and efficacy of left atrial appendage occlusion with the ACP or Watchman device guided by intracardiac echocardiography from the left atrium.

BACKGROUND: There is a paucity of randomized data regarding the safety and efficacy of the use of intracardiac echocardiography (ICE) from the left atrium (LA) to guide left atrial appendage occlusion (LAAO) procedures under local anesthesia using either of the available devices. HYPOTHESIS: The aim of this study was to compare the efficacy and safety of ICE from the LA with transesophageal echocardiography (TEE) for guidance during transcatheter LAAO procedures. METHODS: Single-center, cohort study of patients undergoing LAAO with the Amplatzer Cardiac Plug or Watchman device. Procedures were guided by ICE from the LA with local anesthesia (n = 175) or TEE under general anesthesia (n = 49). Efficacy outcomes were procedural success and peri-device leaks 6 weeks after LAAO. The safety outcome was a composite of procedure-related complications. RESULTS: Procedural success was similar between groups: 100% in the TEE-guided group, and 98% in the ICE-guided group. Procedure-related complications such as death, embolism, migration, or major vascular complications occurred similarly between groups (p = 0.590). The rate and degree of peri-device leaks or presence of a thrombus on the device did not differ between groups on follow-up CT. Turnover time in the catheter laboratory and use of contrast agent were reduced with ICE. CONCLUSIONS: ICE in the left atrium to guide LAAO procedures appears to be as effective and safe as TEE. There was no increase in procedure-related complications, whatever the device used. ICE resulted in similar procedural success while decreasing procedure time and requiring only local anesthesia.

Left Atrial Remodeling and Brain Natriuretic Peptide Levels Variation after Left Atrial Appendage Occlusion.

BACKGROUND: Few data are available about brain natriuretic peptide (BNP) variation and left atrial remodeling after the left atrial appendage occlusion (LAAO) technique. METHODS: Prospective study included all consecutive patients successfully implanted with an LAAO device. Contrast-enhanced cardiac computed tomography (CT) was performed before and 6 weeks after the procedure with reverse left atrial remodeling defined by an increase in LA volume >10%, together with blood sampling obtained before, 48 h after device implantation and at the first visit after discharge (30-45 days) for BNP measurement. RESULTS: Among the 43 patients implanted with a complete dataset, mean end-diastolic LA volume was 139 ± 64 mL and 141 ± 62 mL at baseline and during follow-up (45 ± 15 days), respectively, showing no statistical difference (p = 0.45). No thrombus was seen on the atrial side of the device. Peridevice leaks (defined as presence of dye in the LAA beyond the device) were observed in 17 patients (40%) but were trivial or mild. Reverse atrial remodeling (RAR) at 6 weeks was observed in six patients (14%). Despite no difference in BNP levels on admission, median BNP levels at 48 h were slightly increased in RAR patients when compared with controls. During FU, BNP levels were strictly identical in both groups. These results were not modified even when each RAR case was matched with two controls on age, LVEF, creatinine levels and ACE inhibitors treatment to avoid potential confounders. CONCLUSION: Our study showed that despite the fact that the LAAO technique can induce left atrial remodeling measured by a CT scan, it does not seem to impact BNP levels on the follow-up. The results need to be transposed to clinical outcomes of this expanding population in future studies.

Improvement of colonic healing and surgical recovery with perioperative supplementation of inulin and galacto-oligosaccharides.

BACKGROUND AND AIMS: Anastomotic leak (AL) is a major complication in colorectal surgery. Recent evidence suggests that the gut microbiota may affect healing and may cause or prevent AL. Butyrate is a beneficial short-chain fatty acid (SCFA) that is produced as a result of bacterial fermentation of dietary oligosaccharides and has been described as beneficial in the maintenance of colonic health. To assess the impact of oligosaccharides on colonic anastomotic healing in mice, we propose to modulate the microbiota with oligosaccharides to increase butyrate production via enhancement of butyrate-producing bacteria and, consequently, improve anastomotic healing in mice. METHODS: Animal experiments were conducted in mice that were subjected to diets supplemented with inulin, galacto-oligosaccharides (GOS) or cellulose, as a control, for two weeks before undergoing a surgical colonic anastomosis. Macroscopic and histological assessment of the anastomosis was performed. Extent of epithelial proliferation was assessed by Ki-67 immunohistochemistry. Gelatin zymography was used to evaluate the extent of matrix metalloproteinase (MMP) hydrolytic activity. RESULTS: Inulin and GOS diets were associated with increased butyrate production and better anastomotic healing. Histological analysis revealed an enhanced mucosal continuity, and this was associated with an increased re-epithelialization of the wound as determined by increased epithelial proliferation. Collagen concentration in peri-anastomotic tissue was higher with inulin and GOS diets and MMP activity, a marker of collagen degradation, was lower with both oligosaccharides. Inulin and GOS diets were further associated with lower bacterial translocation. CONCLUSIONS: Dietary supplementation with inulin and GOS may improve anastomotic healing and reinforce the gut barrier in mice.

High-grade neuroendocrine small-cell carcinoma of the anal canal: Long-term remission with chemoradiotherapy.

Primary small-cell carcinoma of the anal canal is an exceedingly rare tumor with a poor prognosis even when aggressive therapy is initiated. We present the case of a 53-year-old male patient who presented with chronic anal pain. Examination under general anesthesia revealed the presence of a mass in the anal canal. A biopsy was performed, and histopathological examination showed a high-grade neuroendocrine small-cell carcinoma. Assessment with endoscopic ultrasound showed an invasion of the internal anal sphincter. The patient was treated with a chemoradiotherapy (CRT) regimen consisting of cisplatin and etoposide, combined to radiotherapy. The patient achieved long-term remission with CRT. This is one of the first reports in the literature of a case of a high-grade neuroendocrine small-cell carcinoma of the anal canal where long-term remission was achieved with non-surgical management of a tumor invading the anal sphincter. This favorable evolution with CRT suggests that remission could still be achieved with anal small-cell carcinomas. More cases are however required to validate this approach. RELEVANCE FOR PATIENTS: This case presentation suggests that long-term remission can still be achieved using CRT and without an extensive surgical resection in patients with small-cell carcinoma of the anal canal.

The role of butyrate in surgical and oncological outcomes in colorectal cancer.

Butyrate is a short-chain fatty acid produced by colonic gut bacteria as a result of fermentation of dietary fibers. In the colon, butyrate is a major energy substrate and contributes to the nutritional support and proliferation of a healthy mucosa. It also promotes the intestinal barrier function by enhancing mucus production and tight junctions. In addition to its pro-proliferative effect in healthy colonocytes, butyrate inhibits the proliferation of cancer cells. The antineoplastic effect of butyrate is associated with the inhibitory effect of butyrate on histone deacetylase (HDAC) enzymes, which promote carcinogenesis. Due to the metabolic shift of cancer cells toward glycolysis, unused butyrate accumulates and inhibits procarcinogenic HDACs. In addition, recent studies suggest that butyrate may improve the healing of colonic tissue after surgery in animal models, specifically at the site of reconnection of colonic ends, anastomosis, after surgical resection. Here, we review current evidence on the impact of butyrate on epithelial integrity and colorectal cancer and present current knowledge on data that support its potential applications in surgical practice.

Crohn's Disease after Proctocolectomy and IPAA for Ulcerative Colitis.

BACKGROUND: Proctocolectomy with IPAA is considered curative for ulcerative colitis. However, signs of Crohn's disease can develop postoperatively in some cases. OBJECTIVE: Our aim was to document the postoperative diagnosis of Crohn's disease, to identify potential preoperative predictive factors, and to review the evolution of patients on treatment. DESIGN: This is a retrospective cohort study. SETTINGS: This study was conducted at a tertiary care center in Montreal, Canada. PATIENTS: A total of 301 patients underwent an IPAA for ulcerative colitis between 1985 and 2014. MAIN OUTCOME MEASURES: The primary outcome was the cumulative incidence of the postoperative diagnosis of Crohn's disease. RESULTS: During a median follow-up of 68 months, Crohn's disease was diagnosed at a median time of 77 months (8-270) in 38 patients (12.6%). The cumulative incidence of Crohn's disease was 7.5% at 5 years postoperatively and gradually increased to 17.7% and 33.0% at 10 and 20 years. The following predictive factors for Crohn's disease were observed on univariate analysis: current tobacco smoking at surgery (HR 3.56 (95% CI, 1.54-8.22)), suspicion of indeterminate colitis (HR 3.50 (95% CI, 1.69-7.24)), presence of mouth ulcers before surgery (HR 2.16 (95% CI, 1.03-4.53)), and age at diagnosis of ulcerative colitis (HR 0.94 (95% CI, 0.90-0.97)). Suspicion of indeterminate colitis (HR 3.18 (95% CI 1.46-6.93); p = 0.004) and age at diagnosis (HR 0.95 (95% CI, 0.91-0.99); p = 0.018) remained statistically significant on multivariate analysis. Postoperative inflammatory disease was controlled by medical therapy in most patients. Removal of the pouch was necessary in 16% of patients with Crohn's disease. LIMITATIONS: This was a retrospective single-center study. CONCLUSIONS: Diagnosis of Crohn's disease can occur at a distance from surgery with an increasing cumulative incidence over time. Preoperative predictive factors are few and should not determine candidacy for surgery. Therapeutic options are identical to those available for treatment of typical Crohn's disease and allow a favorable evolution in most patients. See Video Abstract at http://links.lww.com/DCR/B372. BROTE DE CROHN DESPUS DE UNA PROCTOCOLECTOMA CON ANASTOMOSIS DE RESERVORIO LEOANAL EN CASOS DE COLITIS ULCEROSA: ANTECEDENTES:La proctocolectomía con reservorio ileo-anal se considera curativa para la colitis ulcerosa. Sin embargo, signos de enfermedad de Crohn pueden desarrollarse después de la operación en algunos casos.OBJETIVO:Nuestro objetivo fue documentar el diagnóstico postoperatorio de la enfermedad de Crohn, identificar posibles factores predictivos preoperatorios y revisar la evolución de los pacientes con tratamiento.DISEÑO:Estudio retrospectivo de cohortes.AJUSTES:Centro de atención terciaria en Montreal, Canadá.PACIENTES:301 pacientes portadores de un reservorio íleo-anal realizados por colitis ulcerosa entre 1985 y 2014.PRINCIPALES MEDIDAS DE RESULTADO:Acumulación de la incidencia en el diagnóstico postoperatorio de enfermedad de Crohn.RESULTADOS:Durante una media de 68 meses de seguimiento, la enfermedad de Crohn fué diagnosticada en un tiempo medio de 77 meses (8-270) en 38 pacientes (12,6%). La acumulación de incidencia de la enfermedad de Crohn fue del 7,5% a los 5 años después de la operación y aumentó gradualmente a 17,7 y 33,0% a los 10 y 20 años. Los siguientes factores predictivos para la enfermedad de Crohn se observaron en el análisis univariado: tabaquismo activo al momento de la cirugía (cociente de riesgo (HR) 3.56 (intervalo de confianza del 95% (IC) 1.54-8.22)), sospecha de colitis indeterminada (HR 3.50 (IC del 95% 1.69-7.24)), presencia de úlceras en la boca antes de la cirugía (HR 2.16 (IC 95% 1.03-4.53)) y edad al diagnóstico de colitis ulcerosa (HR 0.94 (IC 95% 0.90-0.97)). La sospecha de colitis indeterminada (HR 3.18 (IC 95% 1.46-6.93), p = 0.004) y la edad al momento del diagnóstico (HR 0.95 (IC 95% 0.91-0.99), p = 0.018) permanecieron estadísticamente significativos en el análisis multivariado. La reacción inflamatoria intestinal postoperatoria fue controlada con tratamiento médico en la mayoría de los pacientes. El retiro del reservorio íleo-anal fue necesario en 16% de los pacientes con enfermedad de Crohn.LIMITACIONES:Estudio retrospectivo de centro único.CONCLUSIONES:El diagnóstico de la enfermedad de Crohn puede ocurrir a distancia de la cirugía con la acumulación de incidencia creciente con el tiempo. Los factores predictivos preo-peratorios son pocos y no pueden determinar la candidatura para la cirugía. Las opciones terapéuticas son idénticas a las disponibles para el tratamiento de la enfermedad de Crohn típica y permiten una evolución favorable en la mayoría de los pacientes. Consulte Video Resumen en http://links.lww.com/DCR/B372. (Traducción-Dr. Xavier Delgadillo).

Optimizing treatment sequencing of chemotherapy for patients with rectal cancer: The KIR randomized phase II trial.

BACKGROUND: Randomized studies have shown low compliance to adjuvant chemotherapy in rectal cancer patients receiving preoperative chemotherapy and external beam radiation (CT/EBRT) with total mesorectal excision. We hypothesize that giving neoadjuvant CT before local treatment would improve CT compliance. METHODS: Between 2010-2017, 180 patients were randomized (2:1) to either Arm A (AA) with FOLFOX x6 cycles prior to high dose rate brachytherapy (HDRBT) and surgery plus adjuvant FOLFOX x6 cycles, or Arm B (AB), with neoadjuvant HDRBT with surgery and adjuvant FOLFOX x12 cycles. The primary endpoint was CT compliance to ≥85% of full-dose CT for the first six cycles. Secondary endpoints were ypT0N0, five-year disease free survival (DFS), local control and overall survival (OS). RESULTS: Patients were randomized to either AA (n = 120, median age (MA) 62 years) or AB (n = 60, MA 63 years). 175/180 patients completed HDRBT as planned (97.2%). In AA, two patients expired during CT; three patients post-randomization received short course EBRT because of progression under CT (n = 2, AA) or personal preference (n = 1, AB). ypT0N0 was 31% in AA and 28% in AB (p = 0.7). CT Compliance was 80% in AA and 53% in AB (p = 0.0002). Acute G3/G4 toxicity was 35.8% in AA and 27.6% in AB (p = 0.23). With a median follow-up of 48.5 months (IQR 33-72), the five-year DFS was 72.3% with AA and 68.3% with AB (p = 0.74), the five-year OS 83.8% for AA and 82.2% for AB (p = 0.53), and the five-year local recurrence was 6.3% for AA and 5.8% for AB (p = 0.71). CONCLUSION: We confirmed improved compliance to neoadjuvant CT in this study. Although there is no statistical difference in ypT0N0 rate, local recurrence, and DFS between the two arms, a trend towards favourable oncological outcomes is observed.

Transcriptomic Analysis and High-dimensional Phenotypic Mapping of Mononuclear Phagocytes in Mesenteric Lymph Nodes Reveal Differences Between Ulcerative Colitis and Crohn's Disease.

BACKGROUND AND AIMS: Crohn's disease [CD] and ulcerative colitis [UC] are distinct forms of inflammatory bowel disease. Heterogeneity of HLA-DR+SIRPα + mononuclear phagocytes [MNPs], including macrophages [MΦ], monocyte-derived [Mono] cells, and dendritic cells [DCs], was reported in gut tissue but not yet investigated in mesenteric lymph nodes [MLNs] of IBD patients. We here compared the phenotype, function, and molecular profile of HLA-DR+SIRPα + MNPs in CD and UC MLNs. METHODS: Cell distribution, morphology, immune function, and transcriptomic [bulk RNAseq] and high-dimensional protein expression profiles [CyTOF] of HLA-DR+SIRPα + MNPs were examined in MLNs of UC [n = 14], CD [n = 35], and non-IBD [n = 12] patients. RESULTS: Elevated frequencies of CD14+CD64+CD163+ [Mono/MΦ-like] MNPs displaying monocyte/MΦ morphology and phagocytic function were a distinct feature of UC MLNs. In CD, the proportion of CD14-CD64-CD163- [DC-like] cells was augmented relative to Mono/MΦ-like cells; DC-like cells drove naïve T cell proliferation, Th1 polarisation, and Th17 TCM plasticity. Gene expression profile corroborated the nature of DC-like cells, best represented by BTLA, SERPINF, IGJ and, of Mono/MΦ-like cells, defined by CD163, MARCO, MAFB, CD300E, S100A9 expression. CyTOF analysis showed that CD123+ plasmacytoid cells predominated over conventional DCs in DC-like cells. Four CD163+ clusters were revealed in Mono/MΦ-like cells, two of which were enriched in MARCO-CD68dimHLA-DRdim monocyte-like cells and MARCOhiCD68hiHLA-DRhi Mɸ, whose proportion increased in UC relative to CD. CONCLUSIONS: Defining the landscape of MNPs in MLNs provided evidence for expansion of CD163+ Mono/MΦ-like cells in UC only, highlighting a distinction between UC and CD, and thus the potential contribution of monocyte-like cells in driving colitis.

Image Guided Adaptive Endorectal Brachytherapy in the Nonoperative Management of Patients With Rectal Cancer.

PURPOSE: Organ preservation or nonoperative management of rectal cancer is of growing interest. Image guided adaptive endorectal brachytherapy is a radiation dose escalation modality: we explored its role in elderly patients unfit for surgery and patients refusing surgery. METHODS AND MATERIALS: In this registry study, patients with rectal cancer who were ineligible for surgery received 40 Gy in 16 fractions of pelvic external beam radiation therapy. They subsequently received 3 weekly image guided adaptive brachytherapy boosts of 10 Gy to the residual tumor, for a total of 30 Gy in 3 fractions. Complete clinical response (cCR) and local control were the primary endpoints. RESULTS: 94 patients were included; the median age was 81.1 years. With a median follow-up of 1.9 years, the proportion of cCR was 86.2%, the tumor regrowth proportion was 13.6%, and the cumulative incidence of local relapse was 2.7% at 1 year and 16.8% at 2 years. When considering responders and nonresponders, the 2-year local control was 71.5%. The overall survival at 2 years was 63.6%. Acute rectal grade 1 to 2 toxicity included all patients: 12.8% of patients had late bleeding requiring iron replacement, blood transfusions, or argon plasma therapy. CONCLUSIONS: Results of this registry study, evaluating radiation dose escalation for elderly medically unfit patients with unselected tumors, reveal that a high proportion of patients achieved cCR with a manageable toxicity profile. This technology will likely contribute to the challenging nonoperative management paradigm of rectal cancer.

Current evidence on the relation between gut microbiota and intestinal anastomotic leak in colorectal surgery.

BACKGROUND: Anastomotic leak (AL) is a major complication in colorectal surgery. It worsens morbidity, mortality and oncological outcomes in colorectal cancer. Some evidence suggests a potential effect of the intestinal microbiome on wound healing. This review aims to provide a comprehensive review on historical and current evidence regarding the relation between the gastrointestinal microbiota and AL in colorectal surgery, and the potential microbiota-modifying effect of some perioperative commonly used measures. DATA SOURCES: A comprehensive search was conducted in Pubmed, Medline and Embase for historical and current clinical and animal studies addressing perioperative intestinal microbiota evaluation, intestinal healing and AL. CONCLUSIONS: Evidence on microbes' role in AL is mainly derived from animal experiments. The microbiota's composition and implications are poorly understood in surgical patients. Elaborate microbiota sequencing is required in colorectal surgery to identify potentially beneficial microbial profiles that could lead to specific perioperative microbiome-altering measures and improve surgical and oncological outcomes.