Interobserver agreement of radiologists assessing the response of rectal cancers to preoperative chemoradiation using the MRI tumour regression grading (mrTRG).

AIM: To investigate whether the magnetic resonance imaging (MRI) tumour regression grading (mrTRG) scale can be taught effectively resulting in a clinically reasonable interobserver agreement (>0.4; moderate to near perfect agreement). MATERIALS AND METHODS: This study examines the interobserver agreement of mrTRG, between 35 radiologists and a central reviewer. Two workshops were organised for radiologists to assess regression of rectal cancers on MRI staging scans. A range of mrTRGs on 12 patient scans were used for assessment. RESULTS: Kappa agreement ranged from 0.14-0.82 with a median value of 0.57 (95% CI: 0.37-0.77) indicating good overall agreement. Eight (26%) radiologists had very good/near perfect agreement (κ>0.8). Six (19%) radiologists had good agreement (0.8≥κ>0.6) and a further 12 (39%) had moderate agreement (0.6≥κ>0.4). Five (16%) radiologists had a fair agreement (0.4≥κ>0.2) and two had poor agreement (0.2>κ). There was a tendency towards good agreement (skewness: 0.92). In 65.9% and 90% of cases the radiologists were able to correctly highlight good and poor responders, respectively. CONCLUSIONS: The assessment of the response of rectal cancers to chemoradiation therapy may be performed effectively using mrTRG. Radiologists can be taught the mrTRG scale. Even with minimal training, good agreement with the central reviewer along with effective differentiation between good and intermediate/poor responders can be achieved. Focus should be on facilitating the identification of good responders. It is predicted that with more intensive interactive case-based learning a κ>0.8 is likely to be achieved. Testing and retesting is recommended.

The impact of the two-week wait referral pathway on rectal cancer survival.

AIM: The aim of this study was to compare the outcome of patients with rectal cancer referred through the two-week wait (TWW) system with those identified by routine referral pathways (non-TWW). METHOD: A prospective study was carried out of 125 consecutive patients diagnosed with rectal cancer between January 2000 and December 2005 (6 years) in one district general hospital. Data were recorded prospectively in a local clinicopathological registry. The patients were divided into two groups: group 1 (TWW) and group 2 (routine referral pathway). RESULTS: Fifty-two (41%) of the 125 patients were diagnosed through the TWW (group 1). There was no significant difference in patient demographics, including baseline tumour characteristics, between the two groups. There was no difference in preoperative or postoperative T stage between the two groups (P = 0.63). There was no significant difference in circumferential margin positivity (five of 52 in group 1 vs four of 73 in group 2; P = 0.52) or local recurrence rates (P = 0.37). The 5-year all-cause mortality was 49% for group 1 and 52% for group 2 (P = 0.3). The overall disease-free survival was similar in the two groups (1521 days for group 1 vs 1591 days for group 1, P = 0.29). CONCLUSION: Referral under the TWW strategy does not translate into improved survival in rectal cancer.

Do guidelines improve clinical practice? - a national survey on surveillance colonoscopies.

BACKGROUND: Colonoscopic services are increasingly being utilized in surveillance of conditions predisposing to colorectal cancers (CRC). The ACPGBI/BSG guidelines are the most commonly followed recommendations. Numerous retrospective studies have shown poor compliance with them. We conducted a national survey of colonoscopic practitioners investigating attitudes, awareness and implementation of surveillance guidelines. METHOD: A postal questionnaire was sent to a random population of 250 ACPGBI and 200 BSG members. Questions assessed practice as regards colorectal polyp surveillance, family screening and surveillance for past history of CRC. RESULTS: The ACPGBI/BSG guidelines were the most commonly followed recommendations. Only 17.2% of practitioners used the criteria that would ensure accurate implementation of guidelines for colorectal adenoma surveillance. With regards to familial surveillance for CRC, 53.5% respondents assessed familial risk accurately, while 69.3% recommended surveillance incorrectly. A total of 48.8% of ACPGBI members recommended five yearly colonoscopies following curative treatment for CRC. CONCLUSION: This study has revealed the widespread ignorance of guidelines, which will potentially translate into the gross over utilization of colonoscopic resources. Strategies to improve and audit guideline implementation must be integral to guideline formation. Methods to improve accurate guideline implementation need to be explored.

A pilot study of ultrasound guided Durasphere injection in the treatment of faecal incontinence.

AIM: To assess injection of Durasphere under direct endoanal ultrasound guidance as a treatment for faecal incontinence. METHOD: A total of 23 patients with varying degrees of persistent faecal leakage and/or soiling were recruited. Durasphere was injected in the intersphincteric plane under direct ultrasound guidance. All patients were given a general anaesthetic. Patients had ano-rectal physiology, endoanal ultrasound, continence scoring and quality of life measures assessed at 0, 1, 3, 6 and 12 months. RESULTS: A total of 21 patients were followed up for at least 12 months, with two being excluded at the follow-up stage. Friedman two-way analysis of variance of the Cleveland Clinic Score, Faecal Incontinence Quality of Life Score and Diary Response Score demonstrated a significant sustained improvement. There was no significant improvement in number of bowel movements. There was a significant difference in anal squeeze pressure after therapy, but no significant difference in anal resting pressure. Six patients reported no improvement after Durasphere therapy. CONCLUSIONS: Durasphere gave sustained improvements in quality of life and continence scores in this study group. Strict criteria are needed to ascertain suitability for Durasphere therapy.

Prognostic significance of magnetic resonance imaging-detected extramural vascular invasion in rectal cancer.

BACKGROUND: Extramural vascular invasion (EMVI) is a poor prognostic feature in colorectal cancer. The accuracy of magnetic resonance imaging (MRI) in detecting EMVI and predicting relapse-free survival (RFS) was compared retrospectively with the histological reference standard. METHODS: Preoperative magnetic resonance images from patients diagnosed with rectal and sigmoid cancer were reviewed and an MRI-EMVI score (range 0 to 4) was assigned. Comparison was made with histology and clinical outcome. RESULTS: Some 142 patients with a median follow-up of 3.3 (range 0.9-5.7) years were reviewed. Histological EMVI was reported in a quarter of patients. The sensitivity and specificity of MRI detection of EMVI in 94 patients undergoing primary surgery were 62 and 88 per cent respectively. On univariable analysis, RFS at 3 years was 35 per cent for patients with an MRI-EMVI score of 3-4, compared with 74 per cent for those with a score of 0-2 (P < 0.001), similar to values in patients with positive and negative histological EMVI status respectively (34 versus 73.7 per cent; P < 0.001). CONCLUSION: High MRI-EMVI scores may help in predicting disease relapse.

Surveillance colonoscopies for colorectal polyps--too often, too many! An Audit at a Large District General Hospital.

INTRODUCTION: The British society of Gastroenterologists (BSG) have laid down guidelines for surveillance colonoscopies in patients with large bowel adenomatous polyps. However, numerous studies have shown the gross over-utilization of colonoscopic services in their management. We audited our practice of polyp management and looked at guideline compliance amongst patients on our colonoscopic surveillance list. METHOD: All patients undergoing adenoma surveillance and those with newly detected adenomas over a 2-month period were included in the first loop of the audit. Data on the colonoscopic findings, histology and management were retrieved from paper and on-line records. The BSG guidelines were printed, laminated and displayed in the colorectal clinics. Following this, we re-audited (second loop) our practice. In the second part of the study, we randomly retrieved 533/1800 case notes from our colonoscopic waiting list. Amongst those on surveillance for polyps, compliance was ascertained as regards need for procedure and appropriateness of surveillance interval. FINDINGS: Fifty-four patients were included in the first loop and 59 during the second loop of the audit. Guidelines were followed in 16% (4/25, 95% CI: 0.054-0.33) of patients in the first loop and 46.5% (13/28, 95% CI: 0.293-0.642) in the second loop (P = 0.017). Of the patients on our colonoscopic waiting list for adenomatous polyps, 17.7% satisfied guidelines, 23.4% did not require any further surveillance and 58.9% were booked for a procedure earlier than recommended. CONCLUSION: The mere framing of guidelines is insufficient to improve clinical practice. Strategies to improve implementation need to be explored. Audit of individual practice is recommended.

A meta-analysis assessing the survival implications of subclassifying T3 rectal tumours.

AIM: Although T3 tumour subclassifications have been linked to prognosis, its mandatory adoption in histopathological reports has not been incorporated. This article focusses on the survival outcomes in patients with T3 rectal cancer according to extramural spread beyond the muscularis propria. METHODS: A systematic review of all studies up to January 2016, without language restriction, was identified from MEDLINE, Cochrane Controlled Trials Register (1960-2016) and Embase (1991-2016). All studies reporting on survival and T3 tumours with a defined cut-off of 5 mm ± 1 mm tumour invasion beyond the muscularis propria for rectal cancers were included. Hazard ratios were extracted directly from the studies or from survival curves using the technique described by Parmar. Quality assessment was performed using the Newcastle-Ottawa scale. RESULTS: Tumours with invasion more than 5 ± 1 mm from the muscularis propria had statistically significantly worse overall survival (natural log of the hazard ratio [lnHR]: 1.40 [1.06, 2.04], p < 0.001) and there was no statistically significant heterogeneity (χ2 = 1.541, df = 3, p = 0.673, I2 = 0). There was statistically significantly worse disease-free survival in more invasive tumours (lnHR: 1.49 [1.19, 2.00], p < 0.001) and cancer specific survival (lnHR: 1.22 [0.917, 1.838], p < 0.001). Overall survival in patients who had preoperative therapy was higher in patients with less invasion beyond the muscularis propria [p < 0.01]. CONCLUSIONS: Subclassifying all T3 rectal tumours according to the depth of spread with a cut-off of 5±1 mm beyond the muscularis propria is prognostically relevant for overall survival, disease-free survival and cancer-specific survival irrespective of the nodal status; therefore, subclassifying T3 tumours should be a reporting requirement in histopathology reports.

An audit comparing the reporting of staging MRI scans for rectal cancer with the London Cancer Alliance (LCA) guidelines.

BACKGROUND: This article focuses on the audit and assessment of clinical practice before and after introduction of MRI reporting guidelines. Standardised proforma based reporting may improve quality of MRI reports. Uptake of the use may be facilitated by endorsement from regional and national cancer organisations. METHODS: This audit was divided into 2 phases. MRI reports issued between April 2014 and June 2014 were included in the first part of our audit. Phase II included MRI reports issued between April 2015 and June 2015. RESULTS: 14 out of 15 hospitals that report MRI scans in the LCA responded to our audit proposal. The completion rate of key MRI metrics/metrics was better in proforma compared to prose reports both before (98% vs 73%; p < 0.05) and after introduction of the guidelines (98% vs 71%; p < 0.05). There was an approximate doubling of proforma reporting after the introduction of guidelines and workshop interventions (39% vs 65%; p < 0.05). Evaluation of locally advanced cancers (tumours extending to or beyond the circumferential resection margin) for beyond TME surgery was reported in 3% of prose reports vs. 42% in proformas. CONCLUSIONS: Incorporation of standardised reporting in official guidelines improved the uptake of proforma based reporting. Proforma based reporting captured more MRI reportable items compared to prose summaries, before and after the implementation of guidelines. MRI reporting of advanced cancers for beyond TME surgery falls short of acceptable standards but is more detailed in proforma based reports. Further work to improve completion especially in beyond TME reporting is required.

Systematic review: adipose tissue, obesity and gastrointestinal diseases.

BACKGROUND: Obesity is increasingly being recognized as a risk factor for a number of benign and malignant gastrointestinal conditions. However, literature on the underlying pathophysiological mechanisms is sparse and ambiguous. Insulin resistance is the most widely accepted link between obesity and disease, particularly colorectal cancer. The recognition that intra-abdominal fat is immunologically active sheds new light not only on the pathogenesis of obesity-related gastrointestinal conditions, but also on inflammatory conditions such as Crohn's disease. AIM: To describe the biology of adipose tissue, its impact on the immune system and explores the possible underlying mechanisms linking obesity to gastrointestinal diseases. It also looks at the role of mesenteric fat in determining severity and course of Crohn's disease. METHODS: Relevant English-language literature and abstracts cited on MEDLINE database were reviewed. RESULTS: Our recent finding of an association between obesity and subclinical bowel inflammation suggests that, apart from promoting generalized immune activation, fat also evokes local immune responses. We propose that the proinflammatory milieu promoted by obesity could underlie many of these associations and that the mechanism implicating insulin resistance may merely represent an epiphenomenon. In Crohn's disease, on the other hand, intra-abdominal fat may provide a protective mechanism. CONCLUSION: The potential of adipose tissue as a therapeutic target is vast and needs exploration.

Predictive poor prognostic factors in colonic carcinoma.

INTRODUCTION: Five-year survival in rectal cancer has been steadily improving since the introduction of neoadjuvant chemoradiation and total mesorectal excision surgery. In contrast, 5-year survival rates and management of colonic carcinoma remain relatively unchanged. This study aims to identify poor prognostic factors in colonic cancer patients that could potentially be predicted pre-operatively to identify a subset of patients amenable to neoadjuvant treatment strategies. METHODS: Database compilation of all operable rectal and colonic cancer patients presenting to a single district general hospital over 5 years. Data were documented on presentation and site of tumour, TNM staging, differentiation and extramural venous invasion. RESULTS: There was no significant difference in 4-year survival between rectal (57.5%) and right (57%) or left sided (52.5%) colonic cancers (p=0.4689). On multivariate analysis, N2-stage, T4-stage and emergency presentation were identified as independent prognostic factors. On univariate analysis, in addition to the above factors, presence of venous invasion (p=0.001) and poor differentiation (p=0.0003) of tumour also predicted for poor 5-year survival. CONCLUSION: T4-stage and N2-stage and extramural venous invasion are poor prognostic factors that could be identified pre-operatively with suitably accurate imaging. Such patients could then be considered for a pre-operative treatment strategy.

Correlation of plasma and serum vascular endothelial growth factor levels with platelet count in colorectal cancer: clinical evidence of platelet scavenging?

Most studies measuring circulating vascular endothelial growth factor (VEGF) have sampled serum rather than plasma. There has been much debate whether the collection of sera (which causes the activation of platelets and VEGF release) is a true reflection of tumor angiogenic activity or whether platelets act as scavengers of VEGF. Addressing this issue, we measured serum and plasma VEGF, before and after colorectal resection, with reference to platelet counts. Serum and plasma samples were collected from 116 colorectal cancer (CRC) and 116 control patients. Ninety CRC and 32 benign resections were performed. Both plasma and serum VEGF were significantly higher in CRC patients (18.5 and 327 pg/ml, respectively) compared with controls (9.0 and 151.5 pg/ml, respectively; P < 0.0001). Paired serum and plasma VEGF measurements correlated in both CRC (r = 0.56) and control patients (r = 0.73; P < 0.0001). Serum and plasma VEGF levels correlated with platelet count in CRC patients (r = 0.58 and 0.44, respectively) but not in controls. Plasma and serum VEGF levels, and VEGF concentration per platelet, increased with advancing disease stage. The correlation of serum and plasma VEGF with platelet counts in CRC but not in benign disease may be attributable to the scavenging of VEGF from the tumor source by platelets, with plasma levels reflecting free circulating VEGF in equilibrium with platelet levels. VEGF levels in citrated plasma are low and lie close to the limits of ELISA sensitivity. We recommend that a standardized measurement of serum VEGF--normalized by the patient's platelet count to give a value of serum VEGF per platelet--be adopted.

VEGF-A, VEGF-C, and VEGF-D in colorectal cancer progression.

We aimed to assess the relationship of the angiogenic cytokines VEGF-A, VEGF-C, and VEGF-D and their receptors VEGFR-2 and VEGFR-3 in the adenoma-carcinoma sequence and in metastatic spread of colorectal cancer (CRC). mRNA expression levels were measured using semi-quantitative reverse transcription polymerase chain reaction in 70 CRC (35 with paired mucosae) and 20 adenomatous polyps. Immunohistochemistry and ELISA assessed protein expression. VEGF-D mRNA expression was significantly lower in both polyps and CRCs compared with normal mucosa (P=.0002 and.002, respectively), whereas VEGF-A and VEGF-C were significantly raised in CRCs (P=.006 and.004, respectively), but not polyps (P=.22 and P=.5, respectively). Receptor expression was similar in tumor tissue and normal mucosae. Tumors with lymph node metastases had significantly higher levels of VEGF-A compared with non-metastatic tumors (P=.043). There was no association between VEGF-C or VEGF-D and lymphatic spread. The decrease in VEGF-D occurring in polyps and carcinomas may allow the higher levels of VEGF-A and VEGF-C to bind more readily to the VEGF receptors, and produce the angiogenic switch required for tumor growth. Increased expression of VEGF-A within CRCs was associated with lymphatic metastases, and therefore, this member of the VEGF family may be the most important in determining metastatic spread.

Plasma basic fibroblast growth factor levels in colorectal cancer: a clinically useful assay?

Angiogenic cytokines in the plasma and serum of cancer patients may serve as 'surrogate' markers of tumour neoangiogenesis. Serum VEGF correlates with disease stage in colorectal cancer (CRC), but the role of bFGF in CRC is uncertain. This study aimed to assess plasma bFGF levels in CRC patients before treatment, during chemoradiotherapy and at one-year follow-up. Plasma samples were taken from 124 CRC patients, 26 polyp patients and 55 controls, and bFGF levels were measured by ELISA. 19 patients underwent pre-operative chemoradiotherapy. One-year follow-up samples were available from 48 disease-free patients and 18 patients with progressive disease. There were no detectable differences between plasma bFGF levels in polyp, Dukes' A or B patients (4.55, 5.77, 4.25 pg/ml, respectively), but there was a significant increase in metastatic CRC patients [Dukes' C and D (7.42 and 6.6 pg/ml; P = 0.004 and 0.048, respectively)], relative to median control levels of 4.14 pg/ml. At follow-up, there was a significant fall in plasma bFGF levels in disease-free patients (pre-op 6.09 and follow-up 3.45 pg/ml, P = 0.0004), but a non-significant rise in 18 patients with progressive disease (pre-treatment 5.90 and follow-up 9.99 pg/ml, P = 0.33). Pre-treatment plasma bFGF in patients receiving chemo-radiotherapy was similar in those with responsive and non-responsive tumours. There were no detectable changes in plasma bFGF through the adenoma-carcinoma sequence or patient groups with non-metastatic cancers. Elevated plasma bFGF was, however, associated with metastatic spread. The significant fall in bFGF in disease-free patients following therapy suggests that bFGF may be useful in clinical practice.

Adjuvant intraoperative photodynamic therapy for colorectal carcinoma: a clinical study.

The local recurrence rate of colorectal carcinoma after surgery is unacceptable in most series, and adjuvant therapies have made only a small impact on this. There is experimental evidence that adjuvant intraoperative photodynamic therapy (AIOPDT) may be effective. AIOPDT involves systematically photosensitizing the patient preoperatively with a drug (HpD) which relatively localizes to tumour and is activated using visible light. At operation the resected tumour bed is illuminated with a predetermined uniform light energy density to eradicate microscopic tumour deposits left at the lateral resection margin. We have previously investigated technical and biological factors leading to this clinical trial. Seventeen patients have received AIOPDT in a potentially effective dose, and safety and technical matters have been investigated. Cutaneous phototoxicity occurred in 3 patients. Three patients had anastomotic breakdown, none considered attributable to PDT. The intraoperative technique was a practical option. AIOPDT carried a low patient morbidity and should be investigated in prospective clinical trials to determine if local recurrence rates can be decreased.

Accurate measurement of surface areas of anatomical structures by computer-assisted triangulation of computed tomography images.

There is a need for accurate surface area measurement of internal irregular anatomical structures in order to define light dosimetry in adjunctive intraoperative photodynamic therapy (AIOPDT). No satisfactory preoperative method exists of measuring this parameter. We have investigated whether computer-assisted triangulation of serial sections generated by computed tomography (CT) scanning can give an accurate assessment of the surface area of the walls of the true pelvis after anterior resection and before colorectal anastomosis. We have shown that the technique of paper density tessellation is an acceptable method of measuring the surface areas of phantom objects, with a maximum error of 0.5%, and is used as the gold standard. Computer-assisted triangulation of CT images of standard geometric objects and accurately-constructed pelvic phantoms gives a surface area assessment with a maximum error of 2.5% compared with the gold standard. The CT images of 20 patients' pelves have been analysed by computer-assisted triangulation and this shows that the surface area of the walls varies from 143 cm2 to 392 cm2. Simple step-like analysis of images and approximation to geometric shapes with subsequent calculation give unacceptably high errors. The surface area of an internal, rigid, irregular surface area for illumination in AIOPDT can be accurately measured preoperatively by computer-assisted triangulation of CT images.

Délorme's operation for rectal prolapse.

Between 1981 and 1988 inclusive, 22 patients with full-thickness rectal prolapse presenting to two surgeons in this hospital were treated using the Délorme operation. There was no mortality and morbidity was minimal. Twenty-one patients (95.5%) were cured of prolapse and 19 patients (86.4%) had normal anal sphincter function after the operation.

The role of colonoscopy in coloproctological practice.

Colonoscopy has completely changed the practice of colorectal surgery. It has both diagnostic and therapeutic roles. In diagnosis, it allows direct visualization of the colon and taking of tissue biopsies for histology. The commonest therapeutic manoeuvre is polypectomy for bleeding. Colonoscopy is safe and, where facilities exist, it should be used as first-line investigation of colorectal disorders.

Accuracy of CT prediction of poor prognostic features in colonic cancer.

Whilst imaging of poor prognostic features in rectal cancers has assisted pre-operative treatment stratification, such features have yet to be evaluated in colonic cancers. This study aims to develop criteria for identifying poor prognostic features in colonic tumours and assess the accuracy of CT prediction against histopathology. Criteria were developed for predicting T-stage and N-stage, the presence of extramural vascular invasion and involvement of the retroperitoneal surgical margin (RSM). These criteria were tested on 33 patients with colonic cancer who underwent pre-operative high-resolution CT of their tumour. Two radiologists (Obs 1 and Obs 2) identified independently these poor prognostic features and the results were compared with the final histopathological results. Histological agreement and interobserver variation were calculated using the kappa test. Accuracy of CT prediction of tumour extension beyond muscularis propria was 82% (Obs 1) and 70% (Obs 2). Correct prediction of RSM involvement was 76% (95% confidence interval (CI): 57.8-88.9%) and 79% (95%CI: 61.1-91%) for Obs1 and Obs 2, respectively, with significant agreement between observers (kappa = 0.455, p = 0.050). Prognosis was correctly predicted using CT in 82% (95%CI: 61.5-81.2%) (Obs1) and 85% (95%CI: 68.1-94.9%) (Obs2) with moderate agreement (kappa = 0.459, kappa = 0.527, respectively) with histology. In conclusion, CT has potential as the imaging modality of choice in the pre-operative prediction of poor prognostic features in colonic cancers and could play a role in future treatment stratification.