Prolonged interval to surgery following neoadjuvant chemoradiotherapy in locally advanced rectal cancer: A meta-analysis of randomized controlled trials.

BACKGROUND: Long-course neoadjuvant chemoradiotherapy (NCRT), followed by surgery after an interval of 6-8 weeks, represents standard of care for patients with locally advanced rectal cancer (LARC). Increasing this interval may improve rates of complete pathological response (pCR) and tumour downstaging. We performed a meta-analysis comparing standard (SI, within 8 weeks) versus longer (LI, after 8 weeks) interval from NCRT to surgery. METHODS: PubMed, Embase, and Cochrane databases were searched up to 31 August 2022. Randomized controlled trials (RCTs) comparing SI with LI after NCRT for LARC were included. The primary endpoint was pCR rate. Secondary endpoints included rates of R0 resection, circumferential resection margin positivity (+CRM), TME completeness, lymph node yield (LNY), operative duration, tumour downstaging (TD), sphincter preservation, mortality, postoperative complications, surgical site infection (SSI) and anastomotic leak (AL). Random effects models were used to calculate pooled effect size estimates. RESULTS: Four RCTs encompassing 867 patients were included. There were 539 males (62.1%). LI was associated with a higher pCR rate (OR 0.61, 95%CI â€‹= â€‹0.39-0.95, p â€‹= â€‹0.03), and more TD (OR 0.60, 95%CI â€‹= â€‹0.37-0.97, p â€‹= â€‹0.04) compared to SI. However, there was no difference in rates of R0 resection (p â€‹= â€‹0.87), +CRM (p â€‹= â€‹0.66), sphincter preservation (p â€‹= â€‹0.26), incomplete TME (p â€‹= â€‹0.49), LNY (p â€‹= â€‹0.55), SSI (p â€‹= â€‹0.33), AL (p â€‹= â€‹0.20), operative duration (p â€‹= â€‹0.07), mortality (p â€‹= â€‹0.89) or any surgical complication (p â€‹= â€‹0.91). CONCLUSIONS: A LI to surgery after NCRT for LARC increases pCR and TD rates. Local recurrence or survival were not assessed due to unavailable data. We recommend deferring TME until after an interval of 8 weeks following completion of NCRT.

Mucinous and non-mucinous colorectal cancers show differential expression of chemotherapy metabolism and resistance genes.

Previous research has identified differences in mutation frequency in genes implicated in chemotherapy resistance between mucinous and non-mucinous colorectal cancers (CRC). We hypothesized that outcomes in mucinous and non-mucinous CRC may be influenced by expression of genes responsible for chemotherapy resistance. Gene expression data from primary tumor samples were extracted from The Cancer Genome Atlas PanCancer Atlas. The distribution of clinical, pathological, and gene expression variables was compared between 74 mucinous and 521 non-mucinous CRCs. Predictors of overall survival (OS) were assessed in a multivariate analysis. Kaplan-Meier curves were constructed to compare survival according to gene expression using the log rank test. The median expression of 5-FU-related genes TYMS, TYMP, and DYPD was significantly higher in mucinous CRC compared to non-mucinous CRC (p < 0.001, p = 0.003, p < 0.001, respectively). The median expression of oxaliplatin-related genes ATP7B and SRPK1 was significantly reduced in mucinous versus non-mucinous CRC (p = 0.004, p = 0.007, respectively). At multivariate analysis, age (odds ratio (OR) = 0.96, p < 0.001), node positive disease (OR = 0.49, p = 0.005), and metastatic disease (OR = 0.32, p < 0.001) remained significant negative predictors of OS, while high SRPK1 remained a significant positive predictor of OS (OR = 1.59, p = 0.037). Subgroup analysis of rectal cancers demonstrated high SRPK1 expression was associated with significantly longer OS compared to low SRPK1 expression (p = 0.011). This study highlights that the molecular differences in mucinous CRC and non-mucinous CRC extend to chemotherapy resistance gene expression. SRPK1 gene expression was associated with OS, with a prognostic role identified in rectal cancers.

The utility of preoperative radiological evaluation of early rectal neoplasia: a systematic review and meta-analysis.

AIM: The diagnostic role for preoperative imaging of clinically benign rectal adenomas is unclear. The objective of this systematic review and meta-analysis was to examine the diagnostic accuracy of preoperative imaging in distinguishing benign adenomas from rectal cancer. METHOD: A systematic search was performed for all studies published that correlated staging of clinically benign rectal adenomas with endorectal ultrasound (ERUS) or MRI and histology. Imaging was compared with postoperative histology and data on the numbers of true positives, false positives, true negatives and false negatives were extracted. Summary estimates of sensitivity and specificity with 95% CIs were calculated using a bivariate random effects model. The QUADAS2 tool was used to determine the methodological quality of included studies. RESULTS: Eleven studies describing 1511 patients were retrieved. A total of 1134 patients underwent local excision and 377 had a formal proctectomy. A benign rectal adenoma was diagnosed in 840 and 214 had a T1 rectal cancer. For confirming benign adenomas, the pooled sensitivity of ERUS was 0.81 (95% CI 0.69-0.89) and specificity was 0.85 (95% CI 0.68-0.93). For detecting occult T1 tumours, the pooled sensitivity of ERUS was 0.50 (95% CI 0.33-0.66) and specificity was 0.89 (95% CI 0.82-0.94). Quantitative analysis of MRI could not be performed due to insufficient studies. CONCLUSION: This study demonstrates the limited accuracy of preoperative ERUS in distinguishing benign adenomas from T1 rectal cancer. Preoperative imaging must be interpreted with caution to prevent over-staging and unnecessary proctectomy. We propose that clinically benign lesions may undergo local excision, with subsequent management based on final histology.

Meta-analysis of the molecular associations of mucinous colorectal cancer.

BACKGROUND: Mucinous differentiation occurs in 5-15 per cent of colorectal adenocarcinomas. This subtype of colorectal cancer responds poorly to chemoradiotherapy and has a worse prognosis. The genetic aetiology underpinning this cancer subtype lacks consensus. The aim of this study was to use meta-analytical techniques to clarify the molecular associations of mucinous colorectal cancer. METHODS: This study adhered to MOOSE guidelines. Databases were searched for studies comparing KRAS, BRAF, microsatellite instability (MSI), CpG island methylator phenotype (CIMP), p53 and p27 status between patients with mucinous and non-mucinous colorectal adenocarcinoma. A random-effects model was used for analysis. RESULTS: Data from 46 studies describing 17 746 patients were included. Mucinous colorectal adenocarcinoma was associated positively with KRAS (odds ratio (OR) 1·46, 95 per cent c.i. 1·08 to 2·00, P = 0·014) and BRAF (OR 3·49, 2·50 to 4·87; P < 0·001) mutation, MSI (OR 3·98, 3·30 to 4·79; P < 0·001) and CIMP (OR 3·56, 2·85 to 4·43; P < 0·001), and negatively with altered p53 expression (OR 0·46, 0·31 to 0·67; P < 0·001). CONCLUSION: The genetic origins of mucinous colorectal adenocarcinoma are predominantly associated with BRAF, MSI and CIMP pathways. This pattern of molecular alterations may in part explain the resistance to standard chemotherapy regimens seen in mucinous adenocarcinoma.

Trends in the treatment of rectal prolapse: a population analysis.

PURPOSE: Rectal prolapse is a common condition, with conflicting opinions on optimal surgical management. Existing literature is predominantly composed of case series, with a dearth of evidence demonstrating current, real-world practice. This study investigated recent national trends in management of rectal prolapse in the Republic of Ireland (ROI). METHODS: This population analysis used a national database to identify patients admitted in the ROI primarily for the management of rectal prolapse, as defined by the International Classification of Diseases, 10th Revision (ICD-10). Demographics, procedures, comorbidities, and outcomes were obtained for patients admitted from 2005 to 2015 inclusive. RESULTS: There were 2648 admissions with a primary diagnosis of rectal prolapse; 39.3% underwent surgical correction. The majority were treated with either a perineal resection (47.2%) or an abdominal rectopexy ± resection (45.1%). The population-adjusted rate of operative intervention increased over the study period, from 25 to 42 per million (p < 0.001), with no change in the mean age of patients over time (p = 0.229). The application of a laparoscopic approach increased over time (p = 0.001). Patients undergoing an abdominal rectopexy were younger than those undergoing a perineal procedure (64.1 ± 17.3 versus 75.2 ± 15.5 years, p < 0.001) despite having a similar Charlson Comorbidity Index (p = 0.097). The mortality rate for elective repair was 0.2%. CONCLUSIONS: Despite the popularization of ventral mesh rectopexy over the study period, perineal resection Delorme's procedure remains the most common procedure employed for the correction of rectal prolapse in the ROI, with specific approach determined by age.

C-reactive protein as a predictor of anastomotic leak in the first week after anterior resection for rectal cancer.

AIM: Anastomotic leak (AL) after anterior resection results in increased morbidity, mortality and local recurrence. The aim of this study was to assess the ability of C-reactive protein (CRP) to predict AL in the first week after anterior resection for rectal cancer. METHOD: A retrospective review of a prospectively maintained database that included all patients undergoing anterior resection between January 2008 and December 2013 was performed. The ability of CRP to predict AL was assessed using area under the receiver-operating characteristics (AUC) curves. The severity of AL was defined using the International Study Group of Rectal Cancer (ISREC) grading system. RESULTS: Two-hundred and eleven patients were included in the study. Statistically significant differences in mean CRP values were found between those with and without an AL on postoperative days 5, 6 and 7. A CRP value of 132 mg/l on postoperative day 5 had an AUC of 0.75, corresponding to a sensitivity of 70%, a specificity of 76.6%, a positive predictive value of 16.3% and a negative predictive value of 97.5%. Multivariable analysis found that a CRP of > 132 mg/l on postoperative day 5 was the only statistically significant patient factor that was linked to an increased risk of AL (HR = 8.023, 95% CI: 1.936-33.238, P = 0.004). CONCLUSION: Early detection of AL may minimize postoperative complications. CRP is a useful negative predictive test for the development of AL following anterior resection.

Endolaparoscopic removal of colonic polyps.

AIM: A proportion of colonic polyps is not amenable to exclusively colonoscopic removal due to their location, size or tortuosity of the colon. A combined laparoscopic/colonoscopic polypectomy or endolaparoscopic polypectomy (ELP) is an alternative to formal segmental resection. We present our experience of ELP. METHOD: This is a retrospective review of a consecutive series of patients who underwent ELP for preoperatively diagnosed benign polyps between 2010 and 2013. Data are presented as median (interquartile range, IQR). RESULTS: Thirty patients commenced ELP. Eighteen were male and the median (IQR) age was 65.4 (61.6-73.5) years. Of 30 attempted cases, 22 (73%) underwent successful ELP surgery. Patients in whom combined ELP surgery was unsuccessful were converted to laparoscopic colectomy (one) or colonic mobilization and colotomy (seven). The median operation time for successful ELP was 105 (75-125) min. The complication rate was 13.3% and the median length of stay was 2.0 (1.0-3.0) days for successful ELP compared with 5.5 (3.5-6.8) days for converted patients (P = 0.014). The median polyp size was 14 (10-22) mm; eight (26.7%) had high-grade dysplasia with two cases of invasive cancer identified. CONCLUSION: A combined endoscopic-laparoscopic approach provides an alternative to segmental resection for treating challenging colonic polyps. This approach appears to be safe and effective and should be offered to selected patients with benign colonic polyps.

The prognostic value of tumour regression grade following neoadjuvant chemoradiation therapy for rectal cancer.

AIM: To date, there is no uniform consensus on whether tumour regression grade (TRG) is predictive of outcome in rectal cancer. Furthermore, the lack of standardization of TRG grading is a major source of variability in published studies. The aim of this study was to evaluate the prognostic impact of TRG in a cohort of patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy (CRT). In addition to the Mandard TRG, we utilized four TRG systems modified from the Mandard TRG system and applied them to the cohort to assess which TRG system is most informative. METHOD: One-hundred and fifty-three patients with a T3/T4 and/or a node-positive rectal cancer underwent neoadjuvant 5-fluorouracil-based CRT followed by surgical resection. RESULTS: Thirty-six (23.5%) patients achieving complete pathological response (ypCR) had a 5-year disease-free survival (DFS) rate of 100% compared with a DFS rate of 74% for 117 (76.5%) patients without ypCR (P = 0.003). The Royal College of Pathologists (RCPath) TRG best condenses the Mandard five-point TRG by stratifying patients into three groups with distinct 5-year DFS rates of 100%, 86% and 67%, respectively (P = 0.001). In multivariate analysis, pathological nodal status and circumferential resection margin (CRM) status, but not TRG, remained significant predictors of DFS (P = 0.002, P = 0.035 and P = 0.310, respectively). CONCLUSION: Our findings support the notion that ypCR status, nodal status after neoadjuvant CRT and CRM status, but not TRG, are predictors of long-term survival in patients with locally advanced rectal cancer.

Vertical rectus abdominis myocutaneous flap and quality of life following abdominoperineal excision for rectal cancer: a multi-institutional study.

BACKGROUND: To obtain a clear surgical margin, abdominoperineal excision (APE) for rectal cancer frequently leaves a large perineal defect surrounded by irradiated tissue. A vertical rectus abdominis myocutaneous (VRAM) flap may facilitate healing of this wound. The current study aims to determine the effect of VRAM flap perineal reconstruction following APE on patient quality of life (QOL). METHODS: This is a retrospective cohort study from a prospectively collected database. Data on QOL were assessed via telephone questionnaire using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-C30, EORTC QLQ-C29 and the Cleveland Clinic QOL questionnaires. RESULTS: Twenty-seven patients underwent primary perineal closure, and 12 patients underwent a VRAM flap perineal reconstruction. The mean duration of follow-up was 16.8 months. Overall, there was no significant difference in the Cleveland Clinic QOL score between groups (VRAM vs. no VRAM: 0.7 ± 0.2 vs. 0.7 ± 0.2, p 0.735). Patients in the VRAM group had lower levels of fatigue (5.5 ± 9.9 vs. 23.6 ± 19.2, p 0.004). Patients in the VRAM group had reduced sore skin scores around the stoma site (11.0 ± 16.2 vs. 31.8 ± 31.1, p 0.036). VRAM flap was associated with an increased incidence of abdominal wall hernia (VRAM vs. no VRAM: 25 % vs. 0 %, p 0.024). CONCLUSIONS: This study is limited by its non-randomized retrospective design and relatively small sample size. A significant difference in patient QOL was not demonstrated between VRAM flap and primary perineal closure after APE for rectal cancer. Further studies in this area are warranted.

Length of stay following elective surgery--can we improve efficiency?

Increasing emergency admissions place significant demands on limited hospital resources. We assessed national practices and resources for initiatives to reduce length of stay (LOS) and thereby improve efficiency of resource utilisation. Consultant members of the Irish Association of Coloproctology received a questionnaire seeking information about available initiatives aimed at reducing LOS. 20 out of 32 (62.5%) consultants responded to the questionnaire. Pre-assessment clinics for day surgery were available to 18(90%). Only 13 (65%) had access to pre-assessment clinics for patients requiring longer admissions. 11 (55%) could admit major cases on the day of surgery. Only 9 (45%) surgeons could guarantee immediate re-admission of patients discharged from hospital if needed. There was a divergence of opinion regarding the acceptable average LOS and percentage suitable for day surgery for a variety of common surgical procedures. This study highlights a number of key areas in which certain well-established initiatives could improve efficiency.

Implementation and usefulness of single-access laparoscopic segmental and total colectomy.

AIM: Single-access laparoscopic surgery is a recent vogue in the field of minimally invasive colorectal surgery. While selected series have indicated feasibility, we prospectively examined its usefulness for resectional surgery in routine practice. METHOD: All patients undergoing laparoscopic colorectal resection over a 12-month period were considered for a single-access approach by a single surgical team in a university hospital. This utilized a 'glove' port via a 3-5 cm periumbilical or stomal site incision, with standard rigid laparoscopic instruments then being used. RESULTS: Of 76 planned laparoscopic colorectal resections, 35 (47%) were performed by this single-incision laparoscopic modality without disruption of theatre list efficiency or surgical training obligations. The mean (range) age and body mass index of these 25 consecutive right-sided resections, eight total colectomies (seven urgent operations) and two anterior resections was 58 (22-82) years and 23.9 (18.6-36.2) kg/m(2) , respectively. The modal postoperative day of discharge was 4. For right-sided resections, the mean (range) postoperative stay in those undergoing surgery for benign disease was 4.0 days, while for those undergoing operation for neoplasia (n=18, mean age 71 years) it was 5.8 days and the average lymph node harvest was 13. Use of the glove port reduced trocar cost by 58% (€60/£53) by allowing the use of trocar sleeves alone without obturators. CONCLUSION: Single-incision laparoscopic surgery is an effective option for abdominal surgery and seems especially suited for laparoscopic-assisted right-sided colonic resections. The glove port technique facilitates procedural frequency and familiarity and proves economically favourable.

A review of major trauma admissions to a tertiary adult referral hospital over a ten year period: fewer patients, similar survival.

BACKGROUND: Trauma is an important cause for presentation to the emergency department, representing a significant number of emergency surgical admissions. Societal changes result in alterations in the epidemiology of trauma. OBJECTIVES: This study aimed to review patients admitted to a tertiary referral hospital as a result of traumatic injuries, assessing for changes in admission epidemiology. METHODS: Trauma admissions over two year-long periods a decade apart were reviewed. The Trauma Audit and Research Network (TARN) audit system identified admissions and transfers between June 2006 and May 2007. The Hospital In-Patient Enquiry (HIPE) system identified those fulfilling TARN criteria a decade earlier. Comparative analysis was performed on the dataset. RESULTS: There were 367 trauma admissions between June 2006 and May 2007: 88 road traffic accidents (RTAs), 201 falls and 77 other injuries, with 627 admissions a decade earlier: 286 RTAs, 247 falls and 94 others. Males comprised 72% and 69% of RTA admissions in both periods respectively. Firearm-related injuries increased significantly (p = 0.015). Neurosurgical transfers decreased from 256 to 150 with a slight increase in unadjusted overall mortality from 8.5% to 10.9%. Admissions of patients aged less than 19 reduced from 150 to 59 (p = 0.0031) with a similar trend in those aged between 20 and 29 years from 149 to 78. CONCLUSION: Admissions resulting from RTAs and of patients aged under 30 reduced significantly, however, young males remain the most affected sub-group. Firearm injuries increased significantly, a worrying trend in view of the severity of injury sustained by these victims.

Centralisation of rectal cancer care has improved patient survival in the republic of Ireland.

BACKGROUND: Centralisation of rectal cancer surgery to designated centres was a key objective of the Irish national cancer control program. A national audit of rectal cancer surgery indicated centralisation was associated with improved early surgical outcomes. This study aimed to determine the impact of implementation of the national cancer strategy on survival from rectal cancer. MATERIALS AND METHODS: Data were collected from the National Cancer Registry of Ireland to include all patients with Stage I-III rectal cancer undergoing rectal cancer surgery with curative intent between 2003 and 2012. Five-year overall survival and cancer-specific survival was compared between patients in the pre-centralisation (2003-2007) and post-centralisation period (2008-2012) and between patients receiving surgery in designated cancer centres and non-cancer centres. RESULTS: The proportion of rectal cancer surgery performed in a designated cancer centre increased from 42% during 2003-2007 to 58% during 2008-2012. Five-year overall survival increased from 66.1% in 2003-2007 to 73.5% in 2008-2012 (p < 0.001). Five-year cancer-specific survival increased from 75.3% in 2003-2007 to 81.9% in 2008-2012 (p < 0.001). Surgery in a cancer centre and surgery post-centralisation were significantly associated with overall and cancer specific survival using Cox proportional hazards regression. CONCLUSION: Survival following resection of rectal cancer was significantly improved following implementation of a national cancer strategy incorporating centralisation of rectal cancer surgery.

Quality of colonoscopy performance among gastroenterology and surgical trainees: a need for common training standards for all trainees?

BACKGROUND AND STUDY AIM: Cecal intubation and polyp detection rates are objective measures of colonoscopy performance. Minimum cecal intubation rates greater than 90% have been endorsed by the American Society for Gastrointestinal Endoscopy (ASGE) and the Joint Advisory Group (JAG) UK. Performance data for medical and surgical trainee endoscopists are limited, and we used endoscopy quality parameters to compare these two groups. METHODS: Retrospective review of all single-endoscopist colonoscopies done by gastroenterology and surgical trainees ("registrars," equivalent to fellows, postgraduate year 5) with more than two years' endoscopy experience, in 2006 and 2007 at a single academic medical center. Completion rates and polyp detection rates for endoscopists performing more than 50 colonoscopies during the study period were audited. Colonoscopy withdrawal time was prospectively observed in a representative subset of 140 patients. RESULTS: Among 3079 audited single-endoscopist colonoscopies, seven gastroenterology trainees performed 1998 procedures and six surgery trainees performed 1081. The crude completion rate was 82%, 84% for gastroenterology trainees and 78% for surgery trainees (P < 0.0001). Adjusted for poor bowel preparation quality and obstructing lesions, the completion rate was 89%; 93% for gastroenterology trainees, and 84% for surgical trainees (P < 0.0001). The polyp detection rate was 19% overall, with 21% and 14% for gastroenterology and surgical trainees, respectively (P < 0.0001). The adenoma detection rate in patients over 50 was 12%; gastroenterology trainees 14% and surgical trainees 9% (P = 0.0065). In the prospectively audited procedures, median withdrawal time was greater in the gastroenterology trainee group and polyp detection rates correlated closely with withdrawal time (r = 0.99). CONCLUSION: The observed disparity in endoscopic performance between surgical and gastroenterology trainees suggests the need for a combined or unitary approach to endoscopy training for specialist medical and surgical trainees.

Novel use of an air-filled breast prosthesis to allow radiotherapy to recurrent colonic cancer.

AIM: The authors present the novel and successful use of an air-filled breast prosthesis for extra pelvic exclusion of small bowel to facilitate adjuvant radiotherapy following resection of recurrent adenocarcinoma of the ascending bowel. The therapeutic use of radiotherapy in colon cancer can cause acute or chronic radiation enteropathy. Mobile small bowel can be sequestered in 'dead space' or by adhesions exposing it to adjuvant radiotherapy. A variety of pelvic partitioning methods have been described to exclude bowel from radiation fields using both native and prosthetic materials. METHOD: In this case a 68 year old presented with ascending colon adenocarcinoma invading the peritoneum and underwent en bloc peritoneal resection. Thirty-seven months later surveillance CT identified a local recurrence. Subsequent resection resulted in a large iliacus muscle defect which would sequester small bowel loops thus exposing the patient to radiation enteropathy. The lateral position of the defect precluded the use of traditional pelvic partitioning methods which would be unlikely to remain in place long enough to allow radiotherapy. A lightweight air-filled breast prosthesis (Allergan 133 FV 750 cms) secured in place with an omentoplasty was used to fill the defect. RESULTS: Following well tolerated radiotherapy the prosthesis was deflated under ultrasound guidance and removed via a 7-cm transverse incision above the right iliac crest. The patient is disease free 18 months later with no evidence of treatment related morbidity. CONCLUSION: The use of a malleable air-filled prosthesis for pelvic partitioning allows specific tailoring of the prosthesis size and shape for individual patient defects. It is also lightweight enough to be secured in place using an omentoplasty to prevent movement related prosthesis migration. In the absence of adequate omentum a mesh sling may be considered to allow fixation. In this case the anatomy of the prosthesis position allowed for its removal without the need for repeat laparotomy. Pre-operative deflation of the air-filled prosthesis under ultrasound guidance also reduces the size of the incision required for removal. This technique may be valuable to prevent collateral small bowel irradiation following resection of renal or retroperitoneal malignancy.

Colonoscopy and computerized tomography scan are not sufficient to localize right-sided colonic lesions accurately.

AIM: Accurate preoperative localization of colonic lesions is critical especially in laparoscopic colectomy where tactile localization is absent particularly in screen-detected tumours. The study aimed to evaluate the accuracy of colonoscopy and double-contrast computerized tomography (CT) scan to localize lesions treated by right hemicolectomy. METHOD: A retrospective chart review was performed of patients treated by right hemicolectomy under the colorectal service between July 2003 and October 2006. Preoperative tumour location determined by CT scan and colonoscopy was compared with the intra-operative and histopathological findings. RESULTS: Out of 101 patients, 73 (73%) were for adenoma or cancer, with a final diagnosis of adenocarcinoma in 59 (58%). Preoperative localization was inaccurate in 29% of lesions using both CT and colonoscopy. In the transverse colon, colonoscopy alone was only 37.5% accurate, increasing to 62.5% when information from the CT scan was added. CONCLUSION: Preoperative localization of right-sided colon cancers using colonoscopy and CT scanning is unreliable in at least 29% of cases. Inaccurate localization of transverse colon tumours risks inadequate lymphadenectomy with an adverse cancer outcome. Preoperative abdominal CT scan improves accuracy but endoscopic tattoo localization should be employed routinely especially in patients undergoing laparoscopic resection.

Microsatellite instability and response to neoadjuvant chemoradiotherapy in rectal cancer: A systematic review and meta-analysis.

BACKGROUND: Response to neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer is variable. Identification of biomarkers to predict response is desirable in order to provide prognostic information and targeted therapy. Several studies have investigated microsatellite instability (MSI) as a predictor of response to CRT with contradictory results. This study aims to clarify the effect of MSI status on response to CRT in locally advanced rectal cancer through systematic review and meta-analysis. METHODS: A systematic search of PubMed, Embase and Cochrane databases was performed for all studies relating to MSI and response to CRT in rectal cancer using the search algorithm (Microsatellite Instability) AND (Chemoradiotherapy) AND (Rectal Cancer). From each included study the number of patients with MSI tumors and Microsatellite Stable (MSS) tumors and the numbers achieving pathological complete response (pCR) were recorded. Pooled outcome measures were determined using a random effects model and the odds ratio estimated with variance and 95% confidence interval. RESULTS: Nine published studies were identified reporting data on MSI and its effect on outcome after CRT for locally advanced rectal cancer. Five studies describing 5,877 patients included data on MSI and the number of patients achieving pCR. There was no significant association between MSI and pCR (MSI Vs MSS: 10.1% Vs 6.6%, OR 1.38, 95% CI: 0.7-2.72, p = 0.35). CONCLUSION: This meta-analysis concludes that there appears to be no significant difference in pCR rate following CRT in patients with MSI versus MSS rectal tumors.

Iliopsoas abscess: a re-emerging clinical entity not to be forgotten.

Iliopsoas abscesses are relatively rare clinical entities. They present with subtle and non-specific symptoms and as a result the diagnosis is often delayed, leading to significant morbidity and mortality. With an increasing number of immunocompromised patients in the population the prevalence of this condition is set to rise. Therefore, early diagnosis and appropriate management remain a challenge for clinicians. We present three patients with iliopsoas abscesses, two of which were primary and one of which was secondary to Crohn's disease. The average age of patients was 59 years and both patients with primary psoas abscesses were male. All presented with non-specific symptoms. Psoas sign was present in only one patient. CT confirmed the diagnosis in all cases. Treatment consisted of appropriate antibiotic cover and associated percutaneous drainage. The psoas abscess that was secondary to underlying Crohn's disease was subsequently treated with surgical excision of the affected segment of bowel and lavage of the abscess cavity. A high index of suspicion is required to ensure the accurate and early diagnosis of this rare clinical entity. Abdominal CT scanning remains the gold standard for diagnosis. Management is with appropriate antibiotics and adequate drainage. This can be achieved by either percutaneous or surgical drainage. Such treatment can reduce the overall morbidity and mortality of this condition.