Tumour budding as a prognostic biomarker in biopsies and resections of neoadjuvant-treated rectal adenocarcinoma.

BACKGROUND: Tumour budding (TB) is a marker of tumour aggressiveness which, when measured in rectal cancer resection specimens, predicts worse outcomes and response to neoadjuvant therapy. We investigated the utility of TB assessment in the setting of neoadjuvant treatment. METHODS AND RESULTS: A single-centre, retrospective cohort study was conducted. TB was assessed using the hot-spot International Tumour Budding Consortium (ITBCC) method and classified by the revised ITBCC criteria. Haematoxylin and eosin (H&E) and AE1/AE3 cytokeratin (CK) stains for ITB (intratumoural budding) in biopsies with PTB (peritumoural budding) and ITB (intratumoural budding) in resection specimens were compared. Logistic regression assessed budding as predictors of lymph node metastasis (LNM). Cox regression and Kaplan-Meier analyses investigated their utility as a predictor of disease-free (DFS) and overall (OS) survival. A total of 146 patients were included; 91 were male (62.3%). Thirty-seven cases (25.3%) had ITB on H&E and 79 (54.1%) had ITB on CK assessment of biopsy tissue. In univariable analysis, H&E ITB [odds (OR) = 2.709, 95% confidence interval (CI) = 1.261-5.822, P = 0.011] and CK ITB (OR = 2.165, 95% CI = 1.076-4.357, P = 0.030) predicted LNM. Biopsy-assessed H&E ITB (OR = 2.749, 95% CI = 1.258-6.528, P = 0.022) was an independent predictor of LNM. In Kaplan-Meier analysis, ITB identified on biopsy was associated with worse OS (H&E, P = 0.003, CK: P = 0.009) and DFS (H&E, P = 0.012; CK, P = 0.045). In resection specimens, CK PTB was associated with worse OS (P = 0.047), and both CK PTB and ITB with worse DFS (PTB, P = 0.014; ITB: P = 0.019). In multivariable analysis H&E ITB predicted OS (HR = 2.930, 95% CI = 1.261-6.809) and DFS (HR = 2.072, 95% CI = 1.031-4.164). CK PTB grading on resection also independently predicted OS (HR = 3.417, 95% CI = 1.45-8.053, P = 0.005). CONCLUSION: Assessment of TB using H&E and CK may be feasible in rectal cancer biopsy and post-neoadjuvant therapy-treated resection specimens and is associated with LNM and worse survival outcomes. Future management strategies for rectal cancer might be tailored to incorporate these findings.

Relevance of shrinkage versus fragmented response patterns in rectal cancer.

AIMS: Partial response to neoadjuvant chemoradiotherapy (CRT) presents with one of two main response patterns: shrinkage or fragmentation. This study investigated the relevance of these response patterns in rectal cancer, correlation with other response indicators, and outcome. METHODS AND RESULTS: The study included a test (n = 197) and a validation cohort (n = 218) of post-CRT patients with rectal adenocarcinoma not otherwise specified and a partial response. Response patterns were scored by two independent observers using a previously developed three-step flowchart. Tumour regression grading (TRG) was established according to both the College of American Pathologists (CAP) and Dworak classifications. In both cohorts, the predominant response pattern was fragmentation (70% and 74%), and the scoring interobserver agreement was excellent (k = 0.85). Patients with a fragmented pattern presented with significantly higher pathological stage (ypTNM II-IV, 78% versus 35%; P < 0.001), less tumour regression with Dworak (P = 0.004), and CAP TRG (P = 0.005) compared to patients with a shrinkage pattern. As a predictor of prognosis, the shrinkage pattern outperformed the TRG classification and stratified patients better in overall (fragmented pattern, hazard ratio [HR] 2.04, 95% confidence interval [CI] 1.19-3.50, P = 0.008) and disease-free survival (DFS; fragmented pattern, HR 2.50, 95% CI 1.23-5.10, P = 0.011) in the combined cohorts. The multivariable regression analyses revealed pathological stage as the only independent predictor of DFS. CONCLUSIONS: The heterogeneous nature of tumour response following CRT is reflected in fragmentation and shrinkage. In rectal cancer there is a predominance of the fragmented pattern, which is associated with advanced stage and less tumour regression. While not independently associated with survival, these reproducible patterns give insights into the biology of tumour response.

Metformin has anti-inflammatory effects and induces immunometabolic reprogramming via multiple mechanisms in hidradenitis suppurativa.

BACKGROUND: Targeting immunometabolism has shown promise in treating autoimmune and inflammatory conditions. Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease involving painful lesions in apocrine gland-bearing skin. Therapeutic options for HS are limited and often ineffective; thus, there is a pressing need for improved treatments. To date, metabolic dysregulation has not been investigated in HS. As HS is highly inflammatory, we hypothesized that energy metabolism is dysregulated in these patients. Metformin, an antidiabetic drug, which is known to impact on cellular metabolic and signalling pathways, has been shown to have anti-inflammatory effects in cancer and arthritis. While metformin is not licensed for use in HS, patients with HS taking metformin show improved clinical symptoms. OBJECTIVE: To assess the effect and mechanism of action of metformin in HS. METHODS: To assess the effect of metformin in vivo, we compared the immune and metabolic profiles of peripheral blood mononuclear cells (PBMCs) of patients with HS taking metformin vs. those not taking metformin. To examine the effect of metformin treatment ex vivo, we employed a skin explant model on skin biopsies from patients with HS not taking metformin, which we cultured with metformin overnight. We used enzyme-linked immunosorbent assays, multiplex cytokine assays and quantitative real-time polymerase chain reaction (RT-PCR) to measure inflammatory markers, and Seahorse flux technology and quantitative RT-PCR to assess glucose metabolism. RESULTS: We showed that metabolic pathways are dysregulated in the PBMCs of patients with HS vs. healthy individuals. In metformin-treated patients, these metabolic pathways were restored and their PBMCs had reduced inflammatory markers following long-term metformin treatment. In the skin explant model, we found that overnight culture with metformin reduced inflammatory cytokines and chemokines and glycolytic genes in lesions and tracts of patients with HS. Using in vitro assays, we found that metformin may induce these changes via the NLR family pyrin domain containing 3 (NLRP3) inflammasome and the AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) pathway, which is linked to glycolysis and protein synthesis. CONCLUSIONS: Our study provides insight into the mechanisms of action of metformin in HS. The anti-inflammatory effects of metformin support its use as a therapeutic agent in HS, while its effects on immunometabolism suggest that targeting metabolism is a promising therapeutic option in inflammatory diseases, including HS.

Targeting the NLRP3 inflammasome reduces inflammation in hidradenitis suppurativa skin.

BACKGROUND: Treatment for the debilitating disease hidradenitis suppurativa (HS) is inadequate in many patients. Despite an incidence of approximately 1%, HS is often under-recognized and underdiagnosed, and is associated with a high morbidity and poor quality of life. OBJECTIVES: To gain a better understanding of the pathogenesis of HS, in order to design new therapeutic strategies. METHODS: We employed single-cell RNA sequencing to analyse gene expression in immune cells isolated from involved HS skin vs. healthy skin. Flow cytometry was used to quantify the absolute numbers of the main immune populations. The secretion of inflammatory mediators from skin explant cultures was measured using multiplex and enzyme-linked immunosorbent assays. RESULTS: Single-cell RNA sequencing analysis identified a significant enrichment in the frequency of plasma cells, T helper (Th) 17 cells and dendritic cell subsets in HS skin, and the immune transcriptome was distinct and more heterogeneous than healthy skin. Flow cytometry revealed significantly increased numbers of T cells, B cells, neutrophils, dermal macrophages and dendritic cells in HS skin. Genes and pathways associated with Th17 cells, interleukin (IL)-17, IL-1ß and the NLRP3 inflammasome were enhanced in HS skin, particularly in samples with a high inflammatory load. Inflammasome constituent genes principally mapped to Langerhans cells and a subpopulation of dendritic cells. The secretome of HS skin explants contained significantly increased concentrations of inflammatory mediators, including IL-1ß and IL-17A, and culture with an NLRP3 inflammasome inhibitor significantly reduced the secretion of these, as well as other, key mediators of inflammation. CONCLUSIONS: These data provide a rationale for targeting the NLRP3 inflammasome in HS using small-molecule inhibitors that are currently being tested for other indications.

Segmental versus extended colectomy for tumours of the transverse colon: a systematic review and meta-analysis.

AIM: There is no consensus on the appropriate extent of oncological resection for tumours of the transverse colon. Concerns regarding tumour factors such as pattern of lymph node spread and technical factors such as anastomotic perfusion lead to a variety of procedures being performed. METHODS: A comprehensive search for published studies examining outcomes following segmental versus extended colectomy for transverse colon tumours was performed adhering to PRISMA (Preferred Reporting Items in Systematic Reviews and Meta-analyses) guidelines. Random effects methods were used to combine data. RESULTS: Seven comparative series examining outcomes in 3395 patients were identified. Segmental colectomy results in shorter operating times (mean difference 15.80 min, 95% CI -20.98 to -10.62, P < 0.001) and less ileus (OR 0.52, 95% CI 0.33-0.81, P = 0.004). There was no difference in length of hospital stay (mean difference 1.53 days, 95% CI -3.79 to 0.73, P = 0.18). Extended colectomy results in a lower rate of anastomotic leak (OR 0.62, 95% CI 0.40-0.97, P = 0.04). There are fewer nodes retrieved in segmental colectomy (mean difference 7.60 nodes, 95% CI -9.60 to -5.61, P < 0.001) but no difference in disease recurrence (OR 0.88, 95% CI 0.59-1.34, P = 0.56) or overall survival (OR 0.98, 95% CI 0.68-1.4, P = 0.9). CONCLUSIONS: Available data are limited due to a lack of randomized controlled trials. However, based on current evidence, segmental resection for transverse colon tumours is associated with less ileus but lower lymph node yields and higher anastomotic leak rates. Length of stay is similar. Oncological outcomes are equivalent.

A case-control study examining the association of smad7 and TLR single nucleotide polymorphisms on the risk of colorectal cancer in ulcerative colitis.

AIM: Ulcerative colitis (UC) is characterized by chronic mucosal inflammation and an increased risk of colorectal cancer. smad7, TLR2 and TLR4 modulate intestinal inflammation and their polymorphisms affect the risk of development of sporadic colorectal cancer. The aim of the current study was to examine the association between single nucleotide polymorphisms (SNPs) in smad7, TLR2 and TLR4 and the development of colorectal cancer in patients with UC. METHOD: DNA was extracted from formalin-fixed, paraffin-embedded tissue from 90 patients with UC who had undergone panproctocolectomy between 1985 and 2013 (30 with UC-associated colorectal cancer and 60 control UC patients). Control cases were matched 2:1 for age at diagnosis of colitis, duration of disease and gender. Genotyping was performed for the smad7 rs4464148, rs11874392, rs12953717 and rs4939827 SNPs, the TLR2 rs5743704 and rs5743708 SNPs and the TLR4 rs4986790 and rs4986791 SNPs. RESULTS: Sixty three of the 90 patients (70%) were men and the mean age at diagnosis of UC was 38.6 ± 1.6 years. The mean time to the diagnosis of UC-associated colorectal cancer was 13.5 ± 1.9 years. The 5-year recurrence-free and cancer-specific survival rates were 76% and 88%, respectively. All eight SNPs were in Hardy-Weinberg equilibrium. None of the eight SNPs assessed in smad7, TLR2 or TLR4 were associated with the development of UC-associated colorectal cancer at an allelic or genotypic level. CONCLUSIONS: These data do not support an association between polymorphisms in smad7, TLR2 or TLR4 and the development of UC-associated colorectal cancer.

Conflicting Guidelines: A Systematic Review on the Proper Interval for Colorectal Cancer Treatment.

BACKGROUND: Timely treatment for colorectal cancer (CRC) is a quality indicator in oncological care. However, patients with CRC might benefit more from preoperative optimization rather than rapid treatment initiation. The objectives of this study are (1) to determine the definition of the CRC treatment interval, (2) to study international recommendations regarding this interval and (3) to study whether length of the interval is associated with outcome. METHODS: We performed a systematic search of the literature in June 2020 through MEDLINE, EMBASE and Cochrane databases, complemented with a web search and a survey among colorectal surgeons worldwide. Full-text papers including subjects with CRC and a description of the treatment interval were included. RESULTS: Definition of the treatment interval varies widely in published studies, especially due to different starting points of the interval. Date of diagnosis is often used as start of the interval, determined with date of pathological confirmation. The end of the interval is rather consistently determined with date of initiation of any primary treatment. Recommendations on the timeline of the treatment interval range between and within countries from two weeks between decision to treat and surgery, to treatment within seven weeks after pathological diagnosis. Finally, there is no decisive evidence that a longer treatment interval is associated with worse outcome. CONCLUSIONS: The interval from diagnosis to treatment for CRC treatment could be used for prehabilitation to benefit patient recovery. It may be that this strategy is more beneficial than urgently proceeding with treatment.

Fixation versus no fixation in laparoscopic totally extraperitoneal repair of primary inguinal hernia-a systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: The necessity of mesh fixation in laparoscopic totally extraperitoneal (TEP) inguinal hernia repair remains controversial. We performed a systematic review and meta-analysis to compare the effectiveness of mesh fixation versus no fixation in laparoscopic TEP repair for primary inguinal hernia. MATERIALS AND METHODS: PubMed, EMBASE, and Cochrane databases were searched for relevant articles from January 1992 until May 2020. All trials that compared fixation versus no fixation in TEP repairs for inguinal herniae were included. Recurrent and femoral herniae were excluded from the current analysis. The primary outcome measure was recurrence while secondary outcomes included postoperative pain at 24 h, mean operative time, urinary retention, and seroma rates. Random effects models were used to calculate pooled effect size estimates. Sensitivity analyses were also carried out. RESULTS: Eight randomized controlled trials were included capturing 557 patients and 715 inguinal herniae. On random effects analysis, there were no significant differences between fixation and no fixation with respect to recurrence (RD 0.00, 95% CI = - 0.01 to 0.01, p = 1.00), operative time (MD 1.58 min, 95% CI = - 0.22 to 3.37, p = 0.09), seroma (OR = 0.70, 95% CI = 0.28 to 1.74, p = 0.44), or urinary retention (RD 0.09, 95% CI = - 0.18 to 0.36, p = 0.53). However, fixation was associated with more pain at 24 h (MD 0.93, 95% CI = 0.20 to 1.66, p = 0.01). CONCLUSIONS: Mesh fixation in laparoscopic TEP repair for primary inguinal herniae is associated with increased postoperative pain at 24 h but similar recurrence, seroma, and urinary retention. Therefore, it may be omitted.

Altered distribution and increased IL-17 production by mucosal-associated invariant T cells in adult and childhood obesity.

Mucosal-associated invariant T (MAIT) cells are innate MHC-unrestricted cells that regulate inflammatory responses through the rapid production of cytokines. In this article, we show that circulating MAIT cells are depleted in obese adults, and depletion is associated with diabetic status. Circulating MAIT cells more frequently produced IL-17 upon stimulation ex vivo, a cytokine implicated in insulin resistance. MAIT cells were enriched in adipose tissue (AT) compared with blood. AT MAIT cells, but not circulating MAIT cells, were capable of producing IL-10. In AT from obese subjects, MAIT cells were depleted, were less likely to produce IL-10, and more frequently produced IL-17. Finally, we show that IL-17(+) MAIT cells are also increased in childhood obesity, and altered MAIT cell frequencies in obese children are positively associated with insulin resistance. These data indicate that MAIT cells are enriched in human AT and display an IL-17(+) phenotype in both obese adults and children, correlating with levels of insulin resistance. The alterations in MAIT cells may be contributing to obesity-related sterile inflammation and insulin resistance.

Changing the Rules of the Game: How Do We Measure Success in Social Media?

Ours will be the generation proud to say we shifted the sands of educational deserts by open access and proliferation, seeding of data sharing, and watering grassroots research in resource-compromised environments. Universal "social" media is defining features of modern professional life that provide powerful modes of knowledge acquisition/sharing to that end. Altmetric and other measurements stratify academic communications according to this alternate, online media presence (not academic penetrance). Are they meaningless, self-absorbed integers, or reliable yardsticks of scientific and educational prowess? Far beyond this trite, patronizing question from the minds of outdated, terrified technophobes, the real impact of "social" media is not narcissistic solipsism. Instant dissemination of contemporary surgical controversies on a truly global level drives improved (or at least reflective) health care for all. While a numerical assignment of value according to views, "likes," impressions, or "retweets" may seem meaningless to cynical, established academics, the impetus for universal improvement is self-evident. Electronic data and opinion sharing may not balance the inequity between low- and high-income countries, but it keeps it in perspective. The best way to shift desert sands is to blow on them constantly.

Differential protein abundance of a basolateral MCT1 transporter in the human gastrointestinal tract.

Bacterially derived short chain fatty acids (SCFAs), such as butyrate, are vital in maintaining the symbiotic relationship that exists between humans and their gastrointestinal microbial populations. A key step in this process is the transport of SCFAs across colonic epithelial cells via MCT1 transporters. This study investigated MCT1 protein abundance in various human intestinal tissues. Initial RT-PCR analysis confirmed the expected MCT1 RNA expression pattern of colon > small intestine > stomach. Using surgical resection samples, immunoblot analysis detected higher abundance of a 45 kDa MCT1 protein in colonic tissue compared to ileum tissue (P < 0.001, N = 4, unpaired t-test). Importantly, MCT1 abundance was found to be significantly lower in sigmoid colon compared to ascending colon (P < 0.01, N = 8-11, ANOVA). Finally, immunolocalization studies confirmed MCT1 to be abundant in the basolateral membranes of surface epithelial cells of the ascending, transverse, and descending colon, but significantly less prevalent in the sigmoid colon (P < 0.05, N = 5-21, ANOVA). In conclusion, these data confirm that basolateral MCT1 protein abundance is correlated to levels of bacterially derived SCFAs along the human gastrointestinal tract. These findings highlight the importance of precise tissue location in studies comparing colonic MCT1 abundance between normal and diseased states.

Risk factors for surgical site infection following colorectal resection: a multi-institutional study.

INTRODUCTION: Surgical site infection (SSI) is an infection occurring in an incisional wound within 30 days of surgery and significantly affects patients undergoing colorectal surgery. This study examined a multi-institutional dataset to determine risk factors for SSI following colorectal resection. METHODS: Data on 386 patients who underwent colorectal resection in three institutions were accrued. Patients were identified using a prospective SSI database and hospital records. Data are presented as median (interquartile range), and logistic regression analysis was used to identify risk factors. RESULTS: Patients (21.5%) developed a postoperative SSI. The median time to the development of SSI was 7 days (5-10). Of all infections, 67.5% were superficial, 22.9% were deep and 9.6% were organ space. In univariate analysis, an ASA grade of II (RR 0.6, CI 0.3-0.9, P = 0.019), having an elective procedure (RR 0.4, CI 0.2-0.6, P < 0.001), using a laparoscopic approach (RR 0.5, CI 0.3-0.9, P = 0.019), having a daytime procedure (RR 0.3, CI 0.1-0.7, P = 0.006) and having a clean/contaminated wound (RR 0.4, CI 0.2-0.7, P = 0.001) were associated with reduced risk of SSI. In multivariate analysis, an ASA grade of IV (RR 3.9, CI 1.1-13.7, P = 0.034), a procedure duration over 3 h (RR 4.3, CI 2.3-8.2, P < 0.001) and undergoing a panproctocolectomy (RR 6.5, CI 1.0-40.9, P = 0.044) were independent risk factors for SSI. Those who developed an SSI had a longer duration of inpatient stay (22 days [16-31] vs 15 days [10-26], P < 0.001). CONCLUSIONS: Patients who develop an SSI have a longer duration of inpatient stay. Independent risk factors for SSI following colorectal resection include being ASA grade IV, having a procedure duration over 3 h, and undergoing a panproctocolectomy.

Transanal endoscopic microsurgery versus standard transanal excision for the removal of rectal neoplasms: a systematic review and meta-analysis.

BACKGROUND: Transanal endoscopic microsurgery is the intraluminal excision of rectal lesions with the use of instrumentation to maintain a stable pneumorectum, enabling a magnified view of the target lesion. Despite suggested benefits over traditional transanal excision, there is no consensus on which technique is superior. OBJECTIVE: The aim of the current study is to use meta-analytical techniques to compare transanal endoscopic microsurgery with transanal excision. DATA SOURCES: A comprehensive literature search of PubMed, Embase, and The Cochrane Library was performed. STUDY SELECTION: All studies comparing transanal endoscopic microsurgery with transanal excision were included. INTERVENTIONS: Transanal endoscopic microsurgery was compared with transanal excision by using random-effects methods to combine data. Data are presented as ORs with 95% CIs. MAIN OUTCOME MEASURES: The main outcomes measured were postoperative complication rate, negative microscopic margin rate, specimen fragmentation rate, and lesion recurrence. RESULTS: Six comparative series comparing outcomes following 927 local excisions were identified. There was no difference between techniques in postoperative complication rate (OR, 1.018; 95% CI, 0.658-1.575; p = 0.937). Transanal endoscopic microsurgery had a higher rate of negative microscopic margins in comparison with transanal excision (OR, 5.281; 95% CI, 3.201-8.712; p < 0.001). Transanal endoscopic microsurgery had a reduced rate of specimen fragmentation (OR, 0.096; 95% CI, 0.044-0.209; p < 0.001) and lesion recurrence (OR, 0.248; 95% CI, 0.154-0.401; p < 0.001) compared with transanal excision. There was no across-study heterogeneity for any end point. LIMITATIONS: Most studies were retrospectively designed, and there were variations in patient populations and duration of follow-up. CONCLUSIONS: Available data are limited because of a lack of randomized controlled trials. However, based on current evidence, transanal endoscopic microsurgery is oncologically superior to transanal excision for the excision of rectal neoplasms.

Multicenter Evaluation of Rectal cancer ReImaging pOst Neoadjuvant (MERRION) Therapy.

OBJECTIVE: The aim of this study was to evaluate the utility of reimaging rectal cancer post-CRT (chemoradiotherapy) with magnetic resonance (MR) imaging of the pelvis for local staging and computed tomography of thorax, abdomen, and pelvis (CT TAP) to identify distant metastases. BACKGROUND: The success of neoadjuvant CRT for locally advanced rectal cancer has changed an already complex management algorithm. There is no consensus whether patients should be restaged before surgery. METHODS: Data from 5 institutions with prospectively maintained databases including patients who received neoadjuvant CRT for locally advanced rectal cancer were acquired. Only patients who had been staged pre- and post-CRT with MR imaging and CT TAP were included. MR findings were correlated with histopathological stage using weighted κ (kappa) statistics to test agreement, where a κ value of less than 0.5 was deemed unacceptable. RESULTS: A total of 285 patients fulfilled the criteria for the study; 84% had American Joint Committee for Cancer stage 3 disease pre-CRT, and the remainder had stage 2 disease. Fourteen patients did not proceed to surgery post-CRT-2 were observed as "complete responders," and the remainder either had unresectable disease or were unfit for surgery. MR imaging could not predict T stage (κ = 0.212) or nodal involvement (κ = 0.336). Most pertinently, MR imaging was unable to detect a complete pathological response (κ = 0.021), nor could it discriminate T4 disease (κ = 0.445). CT TAP restaging altered management in 6.7% of patients, who had metastatic disease. CONCLUSIONS: MR reimaging using standard protocols is of limited value in determining surgical approaches; a better modality of local restaging is required.

Strategies to improve clinical research in surgery through international collaboration.

More than 235 million patients undergo surgery every year worldwide, but less than 1% are enrolled in surgical clinical trials--few of which are international collaborations. Several levels of action are needed to improve this situation. International research collaborations in surgery between developed and developing countries could encourage capacity building and quality improvement, and mutually enhance care for patients with surgical disorders. Low-income and middle-income countries increasingly report much the same range of surgical diseases as do high-income countries (eg, cancer, cardiovascular disease, and the surgical sequelae of metabolic syndrome); collaboration is therefore of mutual interest. Large multinational trials that cross cultures and levels of socioeconomic development might have faster results and wider applicability than do single-country trials. Surgeons educated in research methods, and aided by research networks and trial centres, are needed to foster these international collaborations. Barriers to collaboration could be overcome by adoption of global strategies for regulation, health insurance, ethical approval, and indemnity coverage for doctors.

Prognostic significance of tumor budding in rectal cancer biopsies before neoadjuvant therapy.

Tumor budding is an increasingly important prognostic feature for pathologists to recognize. The aim of this study was to correlate intra-tumoral budding in pre-treatment rectal cancer biopsies with pathological response to neoadjuvant chemoradiotherapy and with long-term outcome. Data from a prospectively maintained database were acquired from patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy. Pre-treatment rectal biopsies were retrospectively reviewed for evidence of intra-tumoral budding. Multivariate logistic regression was used to identify factors contributing to cancer-specific death, expressed as hazard ratios with 95% confidence intervals. Of the 185 patients with locally advanced rectal cancer, 89 patients met the eligibility criteria, of whom 18 (20%) exhibited budding in a pre-treatment tumor biopsy. Intra-tumoral budding predicted a poor pathological response to neoadjuvant chemoradiotherapy (higher ypT stage, P=0.032; lymph node involvement, P=0.018; lymphovascular invasion, P=0.004; and residual poorly differentiated tumors, P=0.005). No patient with intra-tumoral budding exhibited a tumor regression grade 1 or complete pathological response, providing a 100% specificity and positive predictive value for non-response to neoadjuvant chemoradiotherapy. Intra-tumoral budding was associated with a lower disease-free 5-year survival rate (33 vs 78%, P<0.001), cancer-specific 5-year survival rate (61 vs 87%, P=0.021) and predicted cancer-specific death (hazard ratio 3.51, 95% confidence interval 1.03-11.93, P=0.040). Intra-tumoral budding at diagnosis of rectal cancer identifies those who will poorly respond to neoadjuvant chemoradiotherapy and those with a poor prognosis.