CT and 3-T MRI accurately identify T3c disease in colon cancer, which strongly predicts disease-free survival.

AIM: To compare the preoperative staging accuracy of computed tomography (CT) and 3-T magnetic resonance imaging (MRI) in colon cancer, and to investigate the prognostic significance of identified risk factors. MATERIALS AND METHODS: Fifty-eight patients undergoing primary resection of their colon cancer were prospectively recruited, with 53 patients included for final analysis. Accuracy of CT and MRI were compared for two readers, using postoperative histology as the reference standard. Patients were followed-up for a median of 39 months. Risk factors were compared by modality and reader in terms of metachronous metastases and disease-free survival (DFS), stratified for adjuvant chemotherapy. RESULTS: Accuracy for the identification of T3c+ disease was non-significantly greater on MRI (75% and 79%) than CT (70% and 77%). Differences in the accuracy of MRI and CT for identification of T3+ disease (MRI 75% and 57%, CT 72% and 66%) and N+ disease (MRI 62% and 63%, CT 62% and 56%) were also non-significant. Identification of extramural venous invasion (EMVI+) disease was significantly greater on MRI (75% and 75%) than CT (79% and 54%) for one reader (p=0.029). T3c+ disease at histopathology was the only risk factor that demonstrated a significant difference in rate of metachronous metastases (odds ratio [OR] 8.6, p=0.0044) and DFS stratified for adjuvant therapy (OR=4, p=0.048). CONCLUSION: T3c or greater disease is the strongest risk factor for predicting DFS in colon cancer, and is accurately identified on imaging. T3c+ disease may therefore be the best imaging entry criteria for trials of neoadjuvant treatment.

The results of local excision with or without postoperative adjuvant chemoradiotherapy for early rectal cancer among patients choosing to avoid radical surgery.

AIM: The study aimed to establish the oncological outcome of patients who opted for close surveillance with or without adjuvant chemoradiotherapy rather than radical surgery after local excision (LE) of early rectal cancer. METHOD: The Royal Marsden Hospital Rectal Cancer database was used to identify rectal cancer patients treated by primary LE from 2006 to 2015. All patients were entered in an intensive surveillance programme. RESULTS: Twenty-eight of 34 analysed patients had a high or very high risk of residual disease predicted by adverse histopathological features for which the recommendation had been radical surgery. Eighteen (52%) of the 34 had received radiotherapy following LE. Three-year disease-free survival for the 34 patients was 85% (95% CI 78.8%-91.2%) and overall survival was 100%. Twenty-two of 24 patients with a low tumour which would have required total rectal excision have so far avoided radical surgery and remain disease free at a median follow-up of 3.2 years. CONCLUSION: The findings suggest that with modern MRI and clinical surveillance radical surgery can be avoided in patients following initial LE of a histopathologically defined high risk early rectal cancer. These findings are comparable with those obtained after major radical resection and warrant further prospective investigation as a treatment arm in larger prospective trials.

Adjuvant chemotherapy may improve disease-free survival in patients with rectal cancer positive for MRI-detected extramural venous invasion following chemoradiation.

AIM: MRI-detected extramural venous invasion (mrEMVI) is a poor prognostic factor in rectal cancer. Preoperative chemoradiotherapy (CRT) can cause regression in the severity of EMVI and subsequently improve survival whereas mrEMVI persisting after CRT confers an increased risk of recurrence. The effect of adjuvant chemotherapy (AC) following CRT on survival in rectal cancer remains unclear. The aim of this study was to determine whether there is a survival advantage for AC given to patients with mrEMVI persisting after CRT. METHOD: A prospective analysis was conducted of consecutive patients with locally advanced rectal cancer between 2006 and 2013. All patients underwent CRT followed by surgery. AC was given to selected patients based on the presence of specific 'high-risk' features. Comparison was made between patients offered AC with observation alone. The primary outcome was 3-year disease-free survival (DFS). RESULTS: Of 631 patients, 227 (36.0%) demonstrated persistent mrEMVI following CRT. Patients were grouped on the basis of AC or observation and were matched for age, performance status and final histopathological staging. Three-year DFS in the AC group was 74.6% compared with 53.7% in the observation only group. AC had a survival benefit on multivariate analysis (hazard ratio 0.458; 95% CI: 0.271-0.775, P = 0.004). CONCLUSION: Patients with persistent mrEMVI following CRT who receive AC may have a decreased risk of recurrence and an improved 3-year DFS compared with patients not receiving AC, irrespective of age and performance status.

Colorectal cancer in younger patients - a single centre analysis.

Debate surrounds the nature of colorectal cancers in younger patients and whether they are more likely to present with aggressive disease. Pearson's correlation coefficient was used to examine whether a relationship exists between age and variables such as family history, mucinous tumours, metastases and final pathology. 41 patients under the age of 45 were diagnosed and operated for colorectal cancer between September 1998 and December 2010 in our centre. Nineteen patients were under the mean age of 35 years. There was no correlation between younger patients and metastatic disease (r= -0.129, p=0.440) or family history (r= -0.258, p=0.123). There was no correlation between age and Dukes staging (r= -0.052, p=0.756), tumour stage (r= -0.110, p=0.516), nodal status (r= -0.053, p=0.751), mucinous tumours (r=0.104, p=0.569) and cell differentiation (r= 0.046, p=0.787). Overall mortality was 26% and of those who survived 10% have metastatic disease. Median survival was 26 months after surgery. Younger patients under 45 appear to be a homogenous group in relation to colorectal tumour characteristics. Further longitudinal studies to examine the differences between this group and older people are needed.

Perfusion CT to assess angiogenesis in colon cancer: technical limitations and practical challenges.

OBJECTIVE: Perfusion CT may have the potential to quantify the degree of angiogenesis of solid tumours in vivo. This study aims to identify the practical and technical challenges inherent to the technique, and evaluate its feasibility in colorectal tumours. METHODS: 51 patients from 2 institutions prospectively underwent a single perfusion CT on 2 different multidetector scanners. The patients were advised to breath-hold as long as possible, followed by shallow breathing, and were given intravenous buscopan to reduce movement. Numerous steps were explored to identify the challenges. RESULTS: 43 patients successfully completed the perfusion CT as per protocol. Inability to detect the tumour (n=3), misplacement of dynamic sequence co-ordinates (n=2), failure of contrast injection (n=2) and displacement of tumour (n=1) were the reasons for failure. In 14 cases excessive respiratory motion displaced the tumour out of the scanning field along the temporal sequence, leading to erroneous data capture. In nine patients, minor displacements of the tumour were corrected by repositioning the region of interest (ROI) to its original position after reviewing each dynamic sequence slice. In 20 patients the tumour was stable, and data captured from the ROI were representative, and could have been analysed by commercially available Body Tumor Perfusion 3.0® software (GE Healthcare, Waukesha, WI). Hence all data were manually analysed by MATLAB® processing software (MathWorks, Cambridge, UK). CONCLUSION: Perfusion CT in tumours susceptible to motion during acquisition makes accurate data capture challenging and requires meticulous attention to detail. Motion correction software is essential if perfusion CT is to be used routinely in colorectal cancer.

Preoperative MRI sphincter morphology and anal manometry: can they be markers of functional outcome following anterior resection for rectal cancer?

AIM: Good functional outcome following anterior resection (AR) for rectal cancer is an important clinical goal, but its prediction has proven difficult. Assessments such as anal manometry have been advocated as a potential tool but functional anatomy as depicted on MRI has not been investigated. This study looked at whether sphincter complex measurements recorded from preoperative staging MRIs and preoperative anal manometry have any correlation with functional outcome. METHOD: Consecutive patients with rectal adenocarcinoma underwent preoperative manometric assessment and MRI staging. MRIs were assessed with regard to anorectal angle, puborectalis thickness, canal length and external and internal anal sphincter thickness. Functional outcome was categorized into three groups according to the number of adverse postoperative symptoms (frequency, urgency, leakage, diarrhoea, use of pads, use of antidiarrhoeal medication): 0, 1 and ≥ 2. This was evaluated 1 year following surgery and 6 months following stoma reversal where applicable. Univariate analysis of an ordinal regression model was performed with significance at the 5% level. RESULTS: Thirty patients were assessed. No single preoperative manometric parameter proved significant (P > 0.05). Only puborectalis thickness showed a significant (P = 0.01) relationship with the number of adverse symptoms suffered postoperatively. On receiver operating characteristics analysis, a cut-off value of 3.5 mm gave an optimal sensitivity of 0.5 (95% CI, 0.17-0.83) and specificity of 0.86 (95% CI, 0.64-0.96). CONCLUSIONS: Measurements of the puborectalis thickness on preoperative staging MRIs for rectal cancer may help predict functional outcome following AR. Prospective assessment of larger numbers with a fully validated continence score are required to evaluate these findings further.

Accuracy of radiological staging in identifying high-risk colon cancer patients suitable for neoadjuvant chemotherapy: a multicentre experience.

AIM: A pilot study was undertaken to determine the accuracy of computed tomography (CT) staging in identifying patients with high-risk colon cancers who would be considered as candidates for a neoadjuvant therapy trial (FOxTROT) and those at low risk (T1/T2) who would be excluded. METHOD: Participating radiologists from 19 centres attended workshops for standardization of image interpretation according to previously defined prognostic criteria: good prognosis tumours, including, T1/T2; intermediate prognosis, T3 < 5 mm tumour invasion beyond the muscularis propria (MP); and poor prognosis tumours, including T3 with tumour extension ≥ 5 mm beyond the MP or T4. The CT findings were compared with histopathology as the reference standard. RESULTS: Of 94 patients with radiological and pathological data, 71% were categorized by CT as having a poor prognosis. The sensitivity and specificity of CT in identifying these tumours were 87% (95% CI, 74-94) and 49% (95% CI, 33-65). Sensitivity and specificity for tumour infiltration beyond the MP (T3/T4 vs T1/T2) were 95% (95% CI, 87-98) and 50% (95% CI, 22-77), respectively. Including all CT-staged T3 and T4 patients in the trial would have increased the proportion eligible for entry to 89% (n = 84) without affecting the false-positive rate of 7%. Some 20% of T3/T4 patients would have been ineligible for FOxTROT because of synchronous metastases. CONCLUSION: In a multicentre setting, CT scanning identified high-risk (T3/4) colon cancers with minimal overstaging of T1/T2 tumours, thus establishing the feasibility of radiologically guided neoadjuvant chemotherapy.

One millimetre is the safe cut-off for magnetic resonance imaging prediction of surgical margin status in rectal cancer.

BACKGROUND: A pathologically involved margin in rectal cancer is defined as tumour within 1 mm of the surgical resection margin. There is no standard definition of a predicted safe margin on magnetic resonance imaging (MRI). The aim of this study was to assess which cut-off (1, 2 or 5 mm) was the best predictor of local recurrence based on preoperative MRI assessment of the circumferential resection margin (CRM). METHODS: Data were collected prospectively on the distance between the tumour and mesorectal fascia for patients with documented radiological margin status in the MERCURY study. Positive margin and local recurrence rates were compared for MRI distances from the tumour to the mesorectal fascia of 1 mm or less, more than 1 mm up to 2 mm, more than 2 mm up to 5 mm, and more than 5 mm. The Cox proportional hazard regression method was used to determine the effect of level of margin involvement on time to local recurrence. RESULTS: Univariable analysis showed that, relative to a distance measured by MRI of more than 5 mm, the hazard ratio (HR) for local recurrence was 3·90 (95 per cent confidence interval 1·99 to 7·63; P < 0·001) for a margin of 1 mm or less, 0·81 (0·36 to 1·85; P = 0·620) for a margin of more than 1 mm up to 2 mm, and 0·33 (0·10 to 1·08; P = 0·067) for a margin greater than 2 mm up to 5 mm. Multivariable analysis of the effect of MRI distance to the mesorectal fascia and preoperative treatment on local recurrence showed that a margin of 1 mm or less remained significant regardless of preoperative treatment (HR 3·72, 1·43 to 9·71; P = 0·007). CONCLUSION: For preoperative staging of rectal cancer, the best cut-off distance for predicting CRM involvement using MRI is 1 mm. Using a cut-off greater than this does not appear to identify patients at higher risk of local recurrence.

Successful treatment of pulmonary aspergillosis in a cat.

A 7-year-old, spayed female Domestic Longhair cat was evaluated for a 6-week history of coughing. Thoracic radiography revealed a pleural effusion. Thoracic ultrasound revealed a pleural effusion and a focal lung mass. The cat underwent exploratory thoracotomy and a total left pneumonectomy was performed. Histopathology and cultures revealed fungal pneumonia and pyothorax caused by Aspergillus fumigatus. Abdominal ultrasound, repeat thoracic radiography, urinalysis with culture, and retroviral screening failed to detect evidence of systemic disease. The cat's poorly regulated diabetes mellitus is suspected to be the predisposing factor allowing a fungal pulmonary infection to become established. At 18 months after surgery the cat was still disease-free. To our knowledge this is the first reported case of successful treatment of pulmonary aspergillosis in the cat.

Small intestinal ganglioneuromatosis in a dog.

A 6-week-old Staffordshire Bull Terrier cross was presented with a 4-week history of vomiting and small bowel diarrhoea. Abdominal ultrasound showed thickening of the distal jejunum and ileum. The dog underwent two exploratory laparotomies, during which grossly abnormal sections of intestine were resected. The patient developed septic peritonitis 48 h after the second surgery, caused by dehiscence of an intestinal anastomosis, and was euthanased. All intestinal tissue samples were examined histopathologically and a diagnosis of gastrointestinal ganglioneuromatosis was made. Intestinal ganglioneuromatosis is rare and this case represents a novel occurrence in the small intestine of a dog.

Proforma-based reporting in rectal cancer.

The improvements in outcomes associate with the use of preoperative therapy rather than postoperative treatment means that clinical teams are increasingly reliant on imaging to identify high-risk features of disease to determine treatment plans. For many solid tumours, including rectal cancer, validated techniques have emerged in identifying prognostic factors pre-operatively. In the MERCURY study, a standardised scanning technique and the use of reporting proformas enabled consistently accurate assessment and documentation of the prognostic factors. This is now an essential tool to enable our clinical colleagues to make treatment decisions. In this review, we describe the proforma-based reporting tool that enables a systematic approach to the interpretation of the magnetic resonance images, thereby enabling all the clinically relevant features to be adequately assessed.

Diagnostic precision of CT in local staging of colon cancers: a meta-analysis.

AIM: To determine the accuracy of computed tomography (CT) in detecting disease with invasion beyond the muscularis propria (MP) and malignant lymph nodes. MATERIALS AND METHODS: A literature search of Ovid, Embase, the Cochrane database, and Medline using Pubmed, Google Scholar and Vivisimo search engines was performed to identify studies reporting on the accuracy of CT to predict the staging of colonic tumours. Publication bias was demonstrated by Funnel plots. The sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated using a bivariate random effects model and hierarchical summary operating curves (HSROC) were generated. RESULTS: Nineteen studies fulfilled all the necessary inclusion criteria. The pooled sensitivity, specificity, DOR for detection of tumour invasion were 86% (95% CI: 78-92%); 78% (95% CI: 71-84%); 22.4 (95% CI: 11.9-42.4). Similarly, the values for nodal detection were 70% (95% CI: 63-73%); 78% (95% CI: 73-82%); 8.1(95% CI: 4.7-14.1). In the subgroup analysis, the best results were obtained in studies utilizing multidetector CT (MDCT). CONCLUSION: Preoperative staging CT accurately distinguishes between tumours confined to the bowel wall and those invading beyond the MP; however, it is significantly poorer at identifying nodal status. MDCT provides the best results.

Accuracy of multidetector computed tomography in identifying poor prognostic factors in colonic cancer.

BACKGROUND: Recent neoadjuvant strategies for high-risk colonic tumours have renewed interest in accurate preoperative staging. The aim of this study was to validate prospectively the accuracy of multidetector computed tomography (MDCT) in stratifying patients into good and poor prognostic groups in a multicentre setting. METHODS: Staging MDCT scans of 84 patients with colonic cancer were reviewed by two independent radiologists and stratified into low-risk (T1/T2 and T3 with extramural tumour depth (EMD) of less than 5 mm) and high-risk (T3 with EMD of at least 5 mm and T4) tumours. Nodal status and extramural venous invasion (EMVI) were also assessed. RESULTS: The accuracy, sensitivity, specificity and positive predictive value of stratification by CT compared with histological examination was 74 (95 per cent confidence interval 64 to 82), 78 (65 to 87), 67 (49 to 81) and 81 (68 to 89) per cent respectively. Accuracy for detecting malignant lymph nodes and EMVI was 58 and 70 per cent respectively. The agreement for predicting prognostic stratification was moderate (kappa = 0.54). CONCLUSION: As the ability of CT to identify node status is poor, the depth of tumour invasion beyond the muscularis propria is the most accurate way to identify patients with a poor prognosis who may be suitable for neoadjuvant treatment.

Seroma formation and method of mesh fixation in laparoscopic ventral hernia repair--highlights of a case series.

INTRODUCTION: Laparoscopic ventral hernia repair (LVHR) is gaining popularity amongst minimally invasive surgeons, promising shorter lengths of hospital stay and decreased morbidity compared to conventional open repair. We aim to report our experience of LVHR performed at a single institution and analyse morbidity to improve outcome. METHODS: A retrospective analysis using a prospectively collected database and patient re-cords was performed on all patients that underwent LVHR. Patient demographics, morbidity and mortality were recorded. Patients with recurrences underwent further analysis. RESULTS: There were a total of 55 laparoscopic ventral hernia operations performed on 50 patients. 24 (48%) were male, and the median BMI was 31 (range 20-41). The median operating time was 50 mins (range 30-120), the median length of stay (LOS) was one day (range 1-14) and the median follow-up period was 14 months (range 3-31). Operative complications occurred in two (3.6%) patients. Minor morbidity occurred in 12 (21.8%) patients. Eight (14.5%) patients developed seromas within the residual hernia sac post-operatively. There were six recurrences following LVHR in five patients. At re-operation, all recurrences appeared to be due to mesh detachment. CONCLUSION: LVHR is safe and the results are comparable to published series. We are encouraged by a shorter LOS and operative time compared to most published data. Post-operative se-roma formation is common. If there is a suspicion of recurrence, these should all be imaged appropriately to avoid unnecessary operative intervention. A higher BMI is an independent risk factor for recurrence in LVHR. Consideration should be given to using transfascial sutures or other fixation methods to improve recurrence rates in this difficult patient group.

(R)-3-hydroxyhexan-2-one is a major pheromone component of Anelaphus inflaticollis (Coleoptera: Cerambycidae).

We report the identification and field bioassays of a major component of the male-produced aggregation pheromone of Anelaphus inflaticollis Chemsak, an uncommon desert cerambycine beetle. Male A. inflaticollis produced a sex-specific blend of components that included (R)-3-hydroxyhexan-2-one, (S)-2-hydroxyhexan-3-one, 2,3-hexanedione, and (2R,3R)- and (2R,3S)-2,3-hexanediols. Field trials with baited bucket traps determined that the reconstructed synthetic pheromone blend and (R)-3-hydroxyhexan-2-one alone attracted adult A. inflaticollis of both sexes, with significantly more beetles being attracted to the blend. We conclude that (R)-3-hydroxyhexan-2-one is a major pheromone component of A. inflaticollis, and our results suggest that one or more of the minor components may further increase attraction of conspecifics. Scanning electron microscopy showed that male A. inflaticollis have pores on the prothorax that are consistent in structure with sex-specific pheromone gland pores in related species. Males also displayed stereotyped calling behavior similar to that observed in other cerambycine species. This study represents the first report of volatile pheromones for a cerambycine species in the tribe Elaphidiini.

CT staging of colon cancer.

Computer tomography (CT) has been the principal investigation in the staging of colon cancers. The information obtained with routine CT has been limited to identifying the site of the tumour, size of the tumour, infiltration into surrounding structures and metastatic spread. The Foxtrot trial National Cancer Research Institute (NCRI) has been specifically designed to evaluate the efficacy of neoadjuvant treatment in colon cancers by using preoperative chemotherapy with or without an anti-Epidermal Growth Factor Receptor (EGFR) monoclonal antibody to improve outcome in high-risk operable colon cancer. Patients are selected based on their staging CT examination. The criteria for poor prognosis are T4 and T3 tumours with more than 5mm extramural depth. Thus the success of the trial would depend upon the confidence of the radiologist to identify the patients that would receive the neoadjuvant treatment. The aim of this review is to explain the process of identifying high-risk features seen on the staging CT images. This will help to identify a cohort of patients that could truly benefit from neoadjuvant strategies.

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.

Permethrin toxicity in cats: a retrospective study of 20 cases.

OBJECTIVE: Permethrin is a synthetic pyrethroid widely used in flea control products for small animals. Accidental toxicity can occur with off-label usage, and cats are particularly susceptible. METHODS: Retrospective study of 20 cases of permethrin toxicity in cats treated at an emergency clinic in Brisbane, Queensland from October 2004 to June 2005. RESULTS: The diagnosis of permethrin toxicity was made on the basis of a history of exposure and characteristic clinical signs, including seizures, muscle fasciculations, and tremors. Decontamination and appropriate seizure or muscle fasciculation control were the basis of treatment. The outcome was good after rapid intervention and 19 of the 20 cats were successfully treated, with the only death occurring in a kitten for which treatment was delayed for 24 h. No long-term complications were reported by the cats' owners at 4-month follow-up after discharge from hospital. CONCLUSIONS: Owner education, together with more appropriate product labelling, may help eliminate this problem in the future.

Successful treatment of disseminated cutaneous phaeohyphomycosis in a dog.

A 7-year-old castrated male Whippet developed deep ulcerative skin lesions whilst receiving immunosuppressive doses of prednisolone and cyclosporine for the treatment of immune-mediated haemolytic anaemia. The lesions were determined to be a phaeohyphomycosis, caused by Curvularia lunata. The dog was treated with a combination of systemic antifungals and weaning off immunosuppressants and made a complete recovery. To the authors' knowledge, this is the first case report of the successful treatment of disseminated cutaneous phaeohyphomycosis in a dog.