Session 2: Extramural vascular invasion and extranodal deposits: should they be treated the same?

Professor Nagtegaal has already highlighted that lymph nodes are probably not responsible for the development of liver metastases. If they are not, then is there another mechanism? Professor Haboubi addresses the question of extranodal deposits - their frequency and their importance in the development of metastatic disease. The experts review the evidence and discuss whether this information will alter treatment decisions and staging systems in the future.

Session 2: What causes liver metastases - lymph nodes or is it something else?

The traditional view of progression of disease in cancer is the sequential spread of tumour to locoregional lymph nodes and then to distant metastases. However, this view may need to be challenged and modern pathology techniques such as immunohistochemistry and tumour profiling can provide us with a greater insight into the pathways and mechanisms of distant spread. Professor Nagtegaal discusses the evidence for reconsidering the current paradigm and reflects on the need for further investigation into mechanisms of distant metastatic spread.

A collaborative review of the current concepts and challenges of anastomotic leaks in colorectal surgery.

The reduction of the incidence, detection and treatment of anastomotic leakage (AL) continues to challenge the colorectal surgical community. AL is not consistently defined and reported in clinical studies, its occurrence is variably reported and its impact on longterm morbidity and health-care resources has received relatively little attention. Controversy continues regarding the best strategies to reduce the risk. Diagnostic tests lack sensitivity and specificity, resulting in delayed diagnosis and increased morbidity. Intra-operative fluorescence angiography has recently been introduced as a means of real-time assessment of anastomotic perfusion and preliminary evidence suggests that it may reduce the rate of AL. In addition, concepts are emerging about the role of the rectal mucosal microbiome in AL and the possible role of new prophylactic therapies. In January 2016 a meeting of expert colorectal surgeons and pathologists was held in London, UK, to identify the ongoing controversies surrounding AL in colorectal surgery. The outcome of the meeting is presented in the form of research challenges that need to be addressed.

Survival following salvage abdominoperineal resection for persistent and recurrent squamous cell carcinoma of the anus: do these disease categories affect survival?

AIM: This study aimed to investigate the results of salvage abdominoperineal excision (APR) in patients with persistent or recurrent squamous cell carcinoma of the anus (SCCA). METHOD: Patients with anal neoplasia were identified from a prospective database. Patients with invasive SCCA with demonstrated failure of chemoradiation therapy (CRT) who underwent salvage APR for one of three disease categories (persistent, < 6 months post-CRT; early recurrent, 6-24 months post-CRT; late recurrent, > 24 months post-CRT) were included. The primary outcome was overall survival after salvage APR. Tumour size, metastatic lymph nodes (LN), circumferential resection margin positivity (CRM) and neurolymphovascular invasion (NLVI) were correlated with the outcome. RESULTS: Thirty-six patients with a median 3-year overall survival of 46% (median follow-up 24 months) underwent salvage APR due to persistent or recurrent SCCA (14 men, mean age 59 years). Eleven (31%) patients were diagnosed with persistent disease, 17 (47%) with early and 8 (22%) with late recurrence. Two-year overall survival of Stage 0/I/II and III/IV disease was 81.5% and 33.74%, respectively (P = 0.022). Overall disease stage was associated with disease categorization (P = 0.009): patients with persistent disease or early recurrence had a significantly higher disease stage than patients with late recurrence (OR = 20.9 and 17.2). Despite apparently improved survival in patients with late disease recurrence on live table analysis, no significant difference was identified in overall survival when stratified by disease category on log-rank test analysis. CONCLUSION: Persistent and recurrent disease does not show any significant difference in survival, but patients with late recurrence may have a better prognosis.

Defining the histopathological changes induced by nonablative radiofrequency treatment of faecal incontinence--a blinded assessment in an animal model.

AIM: Nonablative radiofrequency (RF) sphincter remodelling has been used to treat gastro-oesophageal reflux disease (GERD) and faecal incontinence (FI). Its mechanism of action is unclear. We aimed to investigate the histomorphological and pathophysiological changes to the internal and external anal sphincter (IAS and EAS) following RF remodelling. METHOD: An experimental FI model was created in 12 female pigs: eight underwent RF 6 weeks following induction of FI (FI+RF) and four were untreated (UFI). Four animals served as controls (CG). Two blinded pathologists examined all haematoxylin and eosin and trichrome stained slides. RESULTS: Compared with the UFI group, histological examination of the IAS in the FI+RF group demonstrated an increased smooth muscle (SM)/connective tissue ratio (77.2 vs 68.1%, P < 0.05) and increased collagen I compared with collagen III content (67.2 vs 54.9%, P < 0.001). The RF+FI group exhibited greater SM bundle thickness compared with the UFI group (SM width 486.93 vs 338.59 µm, P < 0.01; height 4384.4 vs 3321.0 µm, P < 0.05). The EAS of the FI+RF animals showed a significantly higher type I/II fibre ratio (33.5 vs 25.2%, P = 0.023) and fibre type I diameter (67.2 vs 59.7 µm, P < 0.001) compared with the UFI group. Post-RF manometry showed higher basal (18.8 vs 0 mmHg, P < 0.001) and squeeze (76.8 vs 12.4 mmHg, P < 0.05) anal pressures. After RF treatment, the number of interstitial cells of Cajal was significantly reduced compared with the UFI and CG groups [0.9 (FI+RF) vs 6.7 (UFI) vs 0.7 (CG) per mm(2) , P < 0.001]. CONCLUSION: In an animal model nonablative RF appeared to induce morphological changes in the IAS and EAS leading to an anatomical state reminiscent of normal sphincter structure.

Abnormalities in collagen composition may contribute to the pathogenesis of hemorrhoids: morphometric analysis.

PURPOSE: While hemorrhoidal disease is common, its etiology remains unclear. It has been postulated that disturbances in collagen lead to reduced connective tissue stability, and in turn to the development of hemorrhoidal disease. We aimed to compare the quality and quantity of collagen in patients with hemorrhoidal disease versus normal controls. METHODS: Specimens from 57 patients with grade III or IV internal hemorrhoids undergoing hemorrhoidectomy between 2006 and 2011 were evaluated. Samples from 20 human cadavers without hemorrhoidal disease served as controls. Quality of collagen was analyzed by collagen I/III ratio, and quantity of collagen was determined by collagen/protein ratio. The study group was subdivided into gender and age subgroups. RESULTS: The male:female ratios in the study and control groups were 30:27 and 10:10, respectively. Median age was significantly less in the study group [46.9 years (range 20-69)] compared to the control group [76 years (range 46-90)] with P < 0.05. Tissues from patients in the study group had significantly lower collagen I/III ratio as compared to the control group (4.4 ± 1.1 vs. 5.5 ± 0.6; P < 0.0001). Nevertheless, despite a trend toward lower collagen/protein ratio in the study group, it did not reach statistical significance (57 ± 42.4 vs. 73 ± 32.5 g/mg; P = 0.167). There was no difference in collagen I/III or collagen/protein ratios among different age groups and genders. CONCLUSIONS: Hemorrhoidal tissues from patients with hemorrhoidal disease appear to have reduced mechanical stability as compared to normal controls.

Inter-observer and intra-observer variability in the diagnosis of dysplasia in patients with inflammatory bowel disease: correlation of pathological and endoscopic findings.

AIM: Colonic epithelial dysplasia is deemed the precursor lesion of cancer arising in inflammatory bowel disease (IBD). It has been suggested that many dysplastic lesions could be endoscopically detected to obtain target biopsies, leading to better yield. However, the clinical impact of a diagnosis of dysplasia may be hampered by a significant degree of histological and endoscopic intra-observer and inter-observer variability. This study aimed to evaluate intra-observer and inter-observer variability in the microscopic diagnosis of dysplasia in IBD and correlate endoscopic and histological findings. METHOD: In total, 158 cases of ulcerative colitis and 14 of Crohn's disease with dysplasia were selected from a pathology database. Slides were blindly reviewed twice by two expert gastrointestinal pathologists. Results of endoscopic examinations were extracted from the reports. The degree of intra-observer and inter-observer variability was determined by kappa statistics. RESULTS: Overall, there was an excellent degree of histopathological inter-observer agreement (κ = 0.786). The lowest level of agreement in the dysplasia group was for indefinite dysplasia (κ = 0.251). Negative and high grade dysplasia diagnosis reached the highest level of agreement with κ values of 0.822 [95% confidence interval (CI) 0.673-0.971] and 1.00 (95% CI 0.850-1.149), respectively. Intra-observer agreement was good and increased during the latter period of the study (κ = 0.734, 95% CI 0.642-0.826). Endoscopic-histological correlation was poor among the negative endoscopies, as up to 43% of cases were diagnosed with at least focal high grade dysplasia. The endoscopic-histological correlation improved when evaluating suspicious endoscopic lesions. CONCLUSION: Dysplasia is reliably diagnosed by expert gastrointestinal pathologists but has poor correlation with an endoscopic diagnosis of dysplasia.

Local excision of T1 and T2 rectal cancer: proceed with caution.

AIM: This study aimed to compare the clinical outcome between local excision (LE) and total mesorectal excision (TME) for early rectal cancer. METHOD: After Institutional Review Board approval, charts of patients with T1 or T2 N0M0 rectal adenocarcinoma treated by curative LE or TME without preoperative radiotherapy from 2004 to 2012 were reviewed. Categorical and continuous variables were compared using chi-square analysis and the ANOVA test. Kaplan-Meier analysis compared survival rates. RESULTS: The study included 153 patients: 79 underwent TME and 74 LE. Postoperative infection was more common after TME (P = 0.009). There was tumour involvement of the margins in 13.5% after LE compared with 0% after TME (P = 0.001). Of the patients treated initially by LE, 13.5% had additional surgery for unfavourable histological findings and 4.1% had residual tumour. Median follow up was 35 (17-96) months. No deaths were recorded in 56 patients with a pT1 lesion. There was no significant difference in local recurrence (P = 0.332) or 3-year disease-free survival (DFS; P = 0.232) between patients having LE or TME. The 68 patients with a T2 lesion had higher local recurrence (P = 0.025) and lower DFS following LE compared with TME (P = 0.044). There was no difference in overall survival (P = 0.351). CONCLUSION: LE of early rectal cancer is associated with higher local recurrence and decreased DFS. These disadvantages are significant for T2 lesions.

Factors influencing circumferential resection margin in rectal cancer.

AIM: Abdominoperineal excision (APR) has been associated with higher circumferential resection margin (CRM) involvement and local recurrence rates than extralevator APR for low rectal cancer. This study aimed to evaluate the CRMs in APR and low anterior resection (LAR) specimens and to identify factors influencing CRM involvement. METHOD: All pathological specimens from consecutive patients with rectal cancer who underwent curative resection at the Cleveland Clinic Florida, from January 2000 to July 2010, were reviewed by two pathologists. Demographics, tumour characteristics, operative data, postoperative pathology and Dworak's tumour regression grade were compared between specimens with positive and negative CRMs. RESULTS: One-hundred and fifty-four patients underwent curative APR (n = 65) or LAR (n = 69). Mean tumour size was 3.6 cm, and mean distance from the dentate line was 5.4 cm. Nine (6.8%) patients had a positive CRM (n = 6 APR, n = 3 LAR), which was associated with tumour size > 5.9 cm (P = 0.002), a distance of ≤ 2.6 cm from the dentate line (P = 0.013), microvascular invasion (P = 0.009), perineural invasion (P < 0.001), number of positive lymph nodes (P = 0.046) and incomplete total mesorectal excision (TME) (P < 0.001). APR specimens were three times more likely than LAR specimens to have an incomplete mesorectum (9.8%vs 2.9%, P = 0.322). CONCLUSIONS: Factors associated with a positive CRM were tumour size > 5.9 cm, a distance of ≤ 2.6 cm from the dentate line, incomplete TME, number of positive nodes and microvascular and perineural invasion. The incidence of a positive CRM was not significantly different between LAR and APR (n = 3 LAR and n = 6 APR).

The use of molecular markers as a method to predict the response to neoadjuvant therapy for advanced stage rectal adenocarcinoma.

AIM: The response to combined neoadjuvant therapy for advanced stage rectal adenocarcinoma is predictive of outcome. In addition to both clinical and pathological features, the expression of a variety of molecules may provide another method of identifying tumour responsiveness to pre-operative therapy. The aim of this study was to evaluate several markers in the apoptotic pathway as well as expression of Cox-2 and vascular endothelial growth factor (VEGF) to determine their ability to predict response to neoadjuvant therapy. METHOD: In total, 152 patients with advanced rectal adenocarcinoma were treated with neoadjuvant therapy followed by resection. Paraffin-embedded sections obtained before and after therapy were assessed by immunohistochemical staining for Cox-2, VEGF, p53, p21, p27, Bax, BCL-2 and apoptosis protease-activating factor 1 (APAF-1). These stains were correlated with tumour regression grade, complete pathological response and T-downstaging of the surgical specimen. Clinical and pathological data were also collected. Data were analysed using the χ2 and Spearman's correlation tests. RESULTS: Pathological complete response was seen in 24.5% of patients. Amongst the apoptosis-associated markers, only APAF-1 expression was found to be significantly associated with tumour regression grade (P<0.001), complete pathological response (P<0.031) and T-downstaging (P<0.004). On multivariate analysis, APAF-1 expression was found to be independently associated with good tumour regression grade. In contrast, overexpression of Cox-2 and VEGF in pretreatment biopsies was related to less tumour regression (P<0.003) and less likelihood of T-downstaging (P<0.03). CONCLUSION: Immunohistochemical evaluation of initial biopsy specimens of rectal cancer with APAF-1, Cox-2 and VEGF may predict tumour response to neoadjuvant therapy in patients with advanced rectal adenocarcinoma. Those with an expected limited response may be considered for other investigational neoadjuvant protocols.

Granulomas in Crohn's disease: does progression through the bowel layers affect presentation or predict recurrence?

AIM: The aim of the study was to correlate the presence and pattern of distribution of granulomas in resected specimens to clinical characteristics and outcome in patients undergoing surgery for Crohn's disease. METHOD: Patients with Crohn's disease who underwent surgical resection between 2001 and 2007 were identified. Pathology slides were reviewed for the presence, number and location of granulomas in four representative slides from each specimen. RESULTS: Two-hundred and seven patients were identified. At a mean follow up of 14 months, 39 patients had a recurrence, 22 (57%) of whom underwent reoperation. Ninety-four (45%) patients had granulomas present in the surgical specimen. Patients with granulomas were younger (P<0.001), had a lower preoperative body mass index (P=0.037), were more likely to be female (P=0.017) and were more likely to have extra-intestinal manifestations (P=0.026) or perianal disease (P=0.012). Sites of disease and procedures performed were similar in both groups. Disease recurrence and reoperative rates were similar in both groups, as were length of stay and morbidity rates. The average number of granulomas present in each sampled pathology slide was 7.2, and there was no correlation between number of granulomas and disease severity. No link was found between the depth of involvement of the granulomas and fistulizing or stricturing disease. CONCLUSION: Granulomas were associated with increased extra-intestinal manifestations and perianal disease, a lower body mass index and younger or female patients. There was no correlation between the presence of granulomas and disease progression or recurrence rates during the short follow-up period of this study.

The correlation between tumour regression grade and lymph node status after chemoradiation in rectal cancer.

OBJECTIVE: To determine the correlation between tumour response to preoperative RCTX and lymph node status, an established parameter of clinical outcome. METHOD: After IRB approval, 86 consecutive rectal cancer patients who received preoperative RCTX were identified. Fifty seven were males. Mean age 62 years. Preoperative staging by ultrasound was available in 60 patients. Radiotherapy consisted of (40-60 g) and chemotherapy of 5-FU infusion (1500 mg/m(2) week), assessed using Dworak's system. RESULTS: Tumour response according to Tumor regression grade (TRG) were: TRG 0: 8 (9.3%); TRG 1: 15 (17.4%); TRG 2: 14 (16.2%); TRG 3: 31 (36%); TRG 4: 18 (20%). Eighteen patients had tumour stage 0 (20.9%); while 8 (9.2%), 28 (32.1%), 30 (34.5%) and three had tumours stages 1, 2, 3 and 4 respectively. Evaluation of nodal status revealed no involvement in 65 patients (N0), and positive nodes in 21 (14 N1, 7 N2). Response to RCTX was significantly associated with node stage, hence individuals without node involvement (N0) had 66% of positive tumour response (TRG 4), while individuals with node metastasis had less response to RCTX (TRG 0, 1 and 2) 35% N1 and 14% for N2 (P = 0.007). Node status was independently associated to poor response to preoperative RCTX, even after adjusting for tumour stage, age and gender (OR 0.02, 95% CI 0.0009-0.67). CONCLUSION: Tumour shrinkage by preoperative RCTX appears to correlate with lymph node metastasis suggesting that neoadjuvant RCTX may have a positive impact in overall patient survival.

Gender-specific effects of endogenous testosterone: female alpha-estrogen receptor-deficient C57Bl/6J mice develop glomerulosclerosis.

Young female mice on a C57Bl/6J (B6) background are considered glomerulosclerosis (GS)-resistant but aging B6 mice develop mild GS. Estrogen deficiency accelerates while estrogen replacement retards GS in young sclerosis-prone oligosyndactyly mutant mice on an ROP background. To explore the effects of sex hormones on glomerular structure and function in the context of gender and genetic background, we studied mice in which the estrogen-receptor (ER) genes alpha- or -beta were deleted (alpha- or betaER knockout (KO)) and crossed into the B6 background. We also studied ovariectomized (Ovx) B6 mice given testosterone. Male and female betaERKO and male alphaERKO mice had no glomerular dysfunction at 9 months of age; however, alphaERKO female mice displayed albuminuria and GS. Ovx prevented glomerular dysfunction in alphaERKO female mice by eliminating endogenous testosterone production while exogenous testosterone induced GS in Ovx B6 mice. Androgen receptor (AR) expression and function was found in microdissected glomeruli and cultured mesangial cells. Testosterone compared to placebo increased both AR expression and TGF-beta1 mRNA levels in glomeruli isolated from female B6 mice. Estrogen deficiency had no deleterious effects on the glomeruli in B6 mice. Our study shows that genetic traits strongly influence the GS-promoting effects of estrogen deficiency while testosterone induces GS in a gender-specific manner.

Combined AGE inhibition and ACEi decreases the progression of established diabetic nephropathy in B6 db/db mice.

The accumulation of advanced glycation end products (AGE) is a key factor in diabetic nephropathy (DN). Pyridoxamine inhibits AGE formation and protects against type I DN. Herein we tested: (1) whether C57BL6 db/db mice as a model of established type II DN resembled patients treated with drugs which inhibit angiotensin II action; (2) whether pyridoxamine was effective as a single therapy; and (3) whether pyridoxamine would add to the benefit of angiotensin-converting enzyme inhibition (ACEi) by enalapril. In first set of experiments mice were treated with ACEi (benazepril) and an angiotensin II receptor blocker (valsartan) combination for 16 weeks after the onset of diabetes. In second group, mice with established DN were treated with pyridoxamine for 8 weeks. In a third set, mice with established DN were treated with pyridoxamine and enalapril combination for 16 weeks. Benazepril and valsartan combination partially prevented the development and progression of DN. Pyridoxamine treatment, as single therapy, decreased the progression of albuminuria and glomerular lesions. The combination of pyridoxamine with enalapril reduced both mortality and the progression of DN. In conclusion, (1) C57 BL6 db/db mice are a model of progressive type II DN; (2) The combination of pyridoxamine with enalapril decreased progression of type 2 DN and overall mortality. Thus, pyridoxamine could be a valuable adjunct to the current treatment of established type II DN.

Effects of radiotherapy on different histopathological types of rectal carcinoma.

BACKGROUND: Down staging by pre-operative chemoradiotherapy is currently considered part of the standard therapeutic approach to rectal carcinoma. The aim of this study was to assess the response to chemoradiotherapy of different histopathological types of rectal carcinoma with emphasis on the mucinous variant. METHOD: Between 1997 and 2002, 71 patients who received pre-operative chemoradiotherapy followed by surgery for rectal carcinoma were enrolled in the study. Staging of the rectal carcinoma was performed according to transrectal ultrasound findings (TN score) prior to the chemoradiotherapy. The chemoradiotherapy was followed by radical resection with mesorectal excision. All surgical specimens were examined by a single pathologist (MB). Pathological TN staging was assessed and tumour regression was graded according to a standard method (TRG1, complete response - TRG5 no response). Tumours were classified as mucinous or nonmucinous according to pre- and post-operative biopsy and specimen histopathological types. TN score change and TRG differences between groups were assessed. RESULTS: Tumour regression was seen after chemoradiotherapy in 94.4% of the patients, while in 5.6% of the patients no response was found. The change in TN score and TRG were correlated. Higher TRG was associated with a smaller decrease in TN staging. TRG was significantly lower in the nonmucinous compared to the mucinous group and the decrease in TN grade was significantly larger in the nonmucinous group. CONCLUSION: Mucinous carcinoma was associated with a lower response to pre-operative chemo-radiotherapy in this group of rectal carcinoma patients. Further studies are needed to determine its prognostic value.

Anatomic extent of colitis and disease severity are not predictors of pouchitis after restorative proctocolectomy for mucosal ulcerative colitis.

BACKGROUND: Pouchitis is a common complication following restorative proctocolectomy with ileal pouch anal anastomosis (RPC-IPAA) for mucosal ulcerative colitis (MUC). The aim of this study was to determine if perioperative anatomic extent and severity of disease are predictors of pouchitis. METHODS: All consecutive patients who underwent RPC-IPAA for MUC between 1988 and 2002 were retrospectively studied. Pouchitis was classified as acute, recurrent or refractory. Colectomy specimen slides were histopathologically evaluated by a single blinded pathologist (MB), who assessed extent and severity of disease. RESULTS: Of 112 patients assessed, 70 (62.5%) had some form of pouchitis at a median follow-up of 38 months (range, 1-204 months). No association was found between the extent or severity of disease and subsequent development of acute or chronic pouchitis. A positive correlation was found between the histopathologic score and the occurrence of clinical pouchitis (p=0.014). The presence of colonic metaplasia in the pouch biopsy was significantly correlated with a histopathologic diagnosis of pouchitis (p<0.0001, r=-0.449). CONCLUSIONS: Following RPC for MUC, the extent and severity of disease do not predict the subsequent development of pouchitis.

Laparoscopic resection of ectopic pancreas in the gastric antrum: case report and literature review.

We report a case of ectopic pancreas tissue in the gastric wall that was removed using a minimally invasive approach. The patient was a 46-year-old obese woman who presented with fatigue, weakness, abdominal discomfort, and guaiac-positive stools. Laboratory analysis showed iron deficiency anemia. Preoperative endoscopy revealed a submucosal lesion in the gastric antrum. Intraoperative upper endoscopy clearly located the lesion at the antrum. The lesion was marked with India ink, allowing it to be identified easily at laparoscopy. A laparoscopic wedge resection of the gastric antrum was performed. The patient had an uneventful recovery. We believe that this is a valid treatment option for this benign condition.