Transanal mesorectal excision: early outcomes in Australia and New Zealand.

BACKGROUND: Transanal total mesorectal excision (taTME) aims to overcome some of the technical challenges faced when operating on mid and low rectal cancers. Specimen quality has been confirmed previously, but recent concerns have been raised about oncological safety. This multicentre prospective study aimed to evaluate the safety of taTME among early adopters in Australia and New Zealand. METHODS: Data from all consecutive patients who had taTME for rectal cancer from July 2014 to February 2020 at six tertiary referral centres in Australasia were recorded and analysed. RESULTS: A total of 308 patients of median age of 64 years underwent taTME. Some 75.6 per cent of patients were men, and the median BMI was 26.8 kg/m2. The median distance of tumour from anal verge was 7 cm. Neoadjuvant chemoradiotherapy was administered to 57.8 per cent of patients. The anastomotic leak rate was 8.1 per cent and there was no mortality within 30 days of surgery. Pathological examination found a complete mesorectum in 295 patients (95.8 per cent), a near-complete mesorectum in seven patients (2.3 per cent), and an incomplete mesorectum in six patients (1.9 per cent). The circumferential resection margin and distal resection margin was involved in nine patients (2.9 per cent), and two patients (0.6 per cent) respectively. Over a median follow-up of 22 months, the local recurrence rate was 1.9 per cent and median time to local recurrence was 30.5 months. CONCLUSION: This study showed that, with appropriate training and supervision, skilled minimally invasive rectal cancer surgeons can perform taTME with similar pathological and oncological results to open and laparoscopic surgery.

International validation of a risk prediction algorithm for patients with malignant colorectal polyps.

AIM: The optimal management strategy for patients with endoscopically resected malignant colorectal polyps (MCP) has yet to be defined. The aim of this study was to validate a published decision-making tool, termed the Scottish Polyp Cancer Study (SPOCS) algorithm, on a large international population. METHODS: The SPOCS algorithm allocates patients to risk groups based on just two variables: the polyp resection margin and the presence of lymphovascular invasion (LVI). The risk groups are termed low (clear margin, LVI absent), medium (clear margin, LVI present) or high (involved/non-assessable margin). The International Polyp Cancer Collaborative was formed to validate the algorithm on data from Australia, Denmark, UK and New Zealand. RESULTS: In total, 1423 patients were included in the final dataset. 680/1423 (47.8%) underwent surgical resection and 108/680 (15.9%) had residual disease (luminal disease 8.8%, lymph node metastases 8.8%). The SPOCS algorithm classified 602 patients as low risk (in which 1.5% had residual disease), 198 patients as medium risk (in which 7.1% had residual disease) and 484 as high risk (in which 14.5% had residual disease) (P < 0.001, χ2 test). Receiver operating characteristic curve analysis demonstrated good accuracy of the algorithm in predicting residual disease (area under the curve 0.732, 95% CI 0.687-0.778, P < 0.001). When patients were designated as low risk, the negative predictive value was 98.5%. CONCLUSION: The SPOCS algorithm can be used to predict the risk of residual disease in patients with endoscopically resected MCPs. Surgery can be safely avoided in patients who have a clear margin of excision and no evidence of LVI.

Anal squamous intraepithelial lesions: an update and proposed management algorithm.

The term anal squamous intraepithelial lesion (ASIL) is used to describe premalignant change of anal squamous cells that precede the development of squamous cell carcinoma. Pathophysiology is driven by the human papilloma virus (HPV), and progression and regression of ASIL being well described, with 12% of high-grade lesions progressing to invasive cancer within 5 years. Vaccination against HPV is effective for primary prevention. Management consists of identification and treatment of high-grade lesions to prevent progression to squamous cell carcinoma. Management of established ASIL aims to avoid the progression to invasive cancer and maintain fecal continence. A combination of surveillance, excision, ablative, or topical therapies is used to achieve this. The aim of the present study was to review the contemporary evidence about ASIL and to suggest a management algorithm.

Compound-Specific Radiocarbon Analysis by Elemental Analyzer-Accelerator Mass Spectrometry: Precision and Limitations.

We examine instrumental and methodological capabilities for microscale (10-50 µg of C) radiocarbon analysis of individual compounds in the context of paleoclimate and paleoceanography applications, for which relatively high-precision measurements are required. An extensive suite of data for 14C-free and modern reference materials processed using different methods and acquired using an elemental-analyzer-accelerator-mass-spectrometry (EA-AMS) instrumental setup at ETH Zurich was compiled to assess the reproducibility of specific isolation procedures. In order to determine the precision, accuracy, and reproducibility of measurements on processed compounds, we explore the results of both reference materials and three classes of compounds (fatty acids, alkenones, and amino acids) extracted from sediment samples. We utilize a MATLAB code developed to systematically evaluate constant-contamination-model parameters, which in turn can be applied to measurements of unknown process samples. This approach is computationally reliable and can be used for any blank assessment of small-size radiocarbon samples. Our results show that a conservative lower estimate of the sample sizes required to produce relatively high-precision 14C data (i.e., with acceptable errors of <5% on final 14C ages) and high reproducibility in old samples (i.e., F14C ≈ 0.1) using current isolation methods are 50 and 30 µg of C for alkenones and fatty acids, respectively. Moreover, when the F14C is >0.5, a precision of 2% can be achieved for alkenone and fatty acid samples containing ≥15 and 10 µg of C, respectively.

Prognostic factors and patterns of failure after surgery for T4 rectal cancer in the beyond total mesorectal excision era.

BACKGROUND: Despite advances in the rates of total mesorectal excision (TME) for rectal cancer surgery, decreased local recurrence rates and increased 5-year survival, there still exists large variation in the quality of treatment received. Up to 30 per cent of rectal cancers are locally advanced at presentation and approximately 5-10 per cent still breach the mesorectal plane and invade adjacent structures despite neoadjuvant therapy. With the evolution of extended resections for rectal cancers beyond the TME plane, proponents advocate that these resections should be performed only in specialist centres. The aim was to assess the prognostic factors and patterns of failure after beyond TME surgery for T4 rectal cancers. METHODS: Data were collected from prospective databases at three high-volume institutions specializing in beyond TME surgery for T4 rectal cancers between 1990 and 2013. The primary outcome measures were overall survival, local recurrence and patterns of first failure. RESULTS: Three hundred and sixty patients were identified. The negative resection margin (R0) rate was 82·8 per cent (298 patients) and the local recurrence rate was 12·5 per cent (45 patients). The type of surgical procedure (Hartmann's: hazard ratio (HR) 4·49, 95 per cent c.i. 1·99 to 10·14; P = 0·002) and lymphovascular invasion (HR 2·02, 1·08 to 3·77; P = 0·032) were independent predictors of local recurrence. The 5-year overall survival rate for all patients was 61 (95 per cent c.i. 55 to 67) per cent. The 5-year cumulative incidence of first failure was 8 per cent for local recurrence, 6 per cent for local and distant disease, and 18 per cent for distant disease. CONCLUSION: This study has demonstrated that a coordinated approach in specialist centres for beyond TME surgery can offer good oncological and long-term survival in patients with T4 rectal cancers.

ANTECEDENTES: A pesar de las mejoras en los porcentajes de extirpación total del mesorrecto (total mesorectal excision, TME) en la cirugía de cáncer de recto, la disminución de los porcentajes de recidiva local y el aumento de la supervivencia a 5 años, todavía existe una gran variabilidad en la calidad del tratamiento recibido. Hasta el 30% de los cánceres de recto están localmente avanzados en el momento del diagnóstico y aproximadamente el 5-10% sobrepasarán el plano mesorrectal e invadirán las estructuras adyacentes a pesar del tratamiento neoadyuvante. Con la evolución de las resecciones ampliadas para los cánceres de recto que sobrepasan el plano de la TME, los defensores recomiendan que estas resecciones solo se realicen en centros especializados. El objetivo fue evaluar los factores pronósticos y los patrones de recidiva después de la cirugía ampliada más allá de la TME para los cánceres de recto T4. MÉTODOS: Los datos se recogieron a partir de bases de datos prospectivas de tres instituciones de alto volumen especializadas en resecciones ampliadas más allá de la TME para el cáncer de recto T4 entre 1990 y 2013. Los criterios de valoración principal fueron la supervivencia global, la recidiva local y los patrones de la primera recidiva. RESULTADOS: Se identificaron 360 pacientes. El margen de resección fue negativo (R0) en el 82,8% (n = 298) y el porcentaje de recidiva local fue de 12,5% (n = 45). El tipo de cirugía realizada (Hartmann: cociente de riesgos instantáneos, hazard ratio, HR 4,49; i.c. del 95%: 1,99-10,14; P = 0,002) y la invasión linfovascular (HR 2,02; i.c. del 95%: 1,08-3,77; P = 0,032) fueron factores predictivos independientes de recidiva local. La supervivencia global a 5 años para todos los pacientes fue del 61% (i.c. del 95%: 55-67). La incidencia acumulada a los 5 años de la primera recidiva fue de 8% para la recidiva local, 6% para la recidiva local y a distancia, y 18% para la recidiva a distancia. CONCLUSIÓN: Este estudio demuestra que un abordaje coordinado en centros especializados para cirugía más allá de la TME puede ofrecer una buena supervivencia oncológica y a largo plazo en pacientes con cáncer de recto T4.

Activation of old carbon by erosion of coastal and subsea permafrost in Arctic Siberia.

The future trajectory of greenhouse gas concentrations depends on interactions between climate and the biogeosphere. Thawing of Arctic permafrost could release significant amounts of carbon into the atmosphere in this century. Ancient Ice Complex deposits outcropping along the ~7,000-kilometre-long coastline of the East Siberian Arctic Shelf (ESAS), and associated shallow subsea permafrost, are two large pools of permafrost carbon, yet their vulnerabilities towards thawing and decomposition are largely unknown. Recent Arctic warming is stronger than has been predicted by several degrees, and is particularly pronounced over the coastal ESAS region. There is thus a pressing need to improve our understanding of the links between permafrost carbon and climate in this relatively inaccessible region. Here we show that extensive release of carbon from these Ice Complex deposits dominates (57 ± 2 per cent) the sedimentary carbon budget of the ESAS, the world's largest continental shelf, overwhelming the marine and topsoil terrestrial components. Inverse modelling of the dual-carbon isotope composition of organic carbon accumulating in ESAS surface sediments, using Monte Carlo simulations to account for uncertainties, suggests that 44 ± 10 teragrams of old carbon is activated annually from Ice Complex permafrost, an order of magnitude more than has been suggested by previous studies. We estimate that about two-thirds (66 ± 16 per cent) of this old carbon escapes to the atmosphere as carbon dioxide, with the remainder being re-buried in shelf sediments. Thermal collapse and erosion of these carbon-rich Pleistocene coastline and seafloor deposits may accelerate with Arctic amplification of climate warming.

Meta-analysis of prophylactic mesh to prevent parastomal hernia.

BACKGROUND: Rates of parastomal hernia following stoma formation remain high. Previous systematic reviews suggested that prophylactic mesh reduces the rate of parastomal hernia; however, a larger trial has recently called this into question. The aim was to determine whether mesh placed at the time of primary stoma creation prevents parastomal hernia. METHODS: The Cochrane Central Register of Controlled Trials, MEDLINE, Embase and CINAHL were searched using medical subject headings for parastomal hernia, mesh and prevention. Reference lists of identified studies, clinicaltrials.gov and the WHO International Clinical Trials Registry were also searched. All randomized clinical trials were included. Two authors extracted data from each study independently using a purpose-designed sheet. Risk of bias was assessed by a tool based on that developed by Cochrane. RESULTS: Ten randomized trials were identified among 150 studies screened. In total 649 patients were included in the analysis (324 received mesh). Overall the rates of parastomal hernia were 53 of 324 (16·4 per cent) in the mesh group and 119 of 325 (36·6 per cent) in the non-mesh group (odds ratio 0·24, 95 per cent c.i. 0·12 to 0·50; P < 0·001). Mesh reduced the rate of parastomal hernia repair by 65 (95 per cent c.i. 28 to 85) per cent (P = 0·02). There were no differences in rates of parastomal infection, stomal stenosis or necrosis. Mesh type and position, and study quality did not have an independent effect on this relationship. CONCLUSION: Mesh placed prophylactically at the time of stoma creation reduced the rate of parastomal hernia, without an increase in mesh-related complications.

Population-based study demonstrating an increase in colorectal cancer in young patients.

BACKGROUND: New Zealand has among the highest rates of colorectal cancer in the world and is an unscreened population. The aim of this study was to determine the trends in incidence and tumour location in the New Zealand population before the introduction of national colorectal cancer screening. METHODS: Data were obtained from the national cancer registry and linked to population data from 1995 to 2012. Incidence rates for colorectal cancer by sex, age (less than 50 years, 50-79 years, 80 years or more) and location (proximal colon, distal colon and rectum) were assessed by linear regression. RESULTS: Among patients aged under 50 years, the incidence of distal colonic cancer in men increased by 14 per cent per decade (incidence rate ratio (IRR 1·14), 95 per cent c.i. 1·00 to 1·30; P = 0·042); the incidence of rectal cancer in men increased by 18 per cent (IRR 1·18, 1·06 to 1·32; P = 0·002) and that in women by 13 per cent (IRR 1·13, 1·02 to 1·26; P = 0·023). In those aged 50-79 years, there was a reduction in incidence per decade of proximal, distal and rectal cancers in both sexes. In the group aged 80 years and over, proximal cancer incidence per decade increased by 19 per cent in women (IRR 1·19, 1·13 to 1·26; P < 0·001) and by 25 per cent in men (IRR 1·25, 1·18 to 1·32; P < 0·001); among women, the incidence of distal colonic cancer decreased by 8 per cent (IRR 0·92, 0·86 to 0·98); P = 0·012), as did that of rectal cancer (IRR 0·92, 0·86 to 0·97; P = 0·005). CONCLUSION: The increasing incidence of rectal cancer among younger patients needs to be considered when implementing screening strategies.

The long-term outcome of anti-TNF alpha therapy in perianal Crohn's disease.

BACKGROUND: The aim of the present study was to evaluate the long-term outcomes of anti-tumour necrosis factor alpha therapy in perianal Crohn's disease and identify factors predicting response to treatment. METHODS: Data from hospital clinical records and coding databases were retrospectively reviewed from a tertiary care hospital in Christchurch, New Zealand. The study included 75 adult patients with perianal Crohn's disease commenced on anti-tumour necrosis factor alpha therapy from January 2000 to December 2012. Response to treatment was determined from records relating to clinical evaluation, magnetic resonance imaging follow-up and whether further surgical intervention was required. RESULTS: 73% (55) of all patients and 38 of the 57 (67%) patients with perianal fistulas responded to anti-tumour necrosis factor alpha therapy. Patients with complex fistulas were less likely to improve as compared to patients without fistulising disease. Five of the 57 (13%) patients with perianal fistulas demonstrated complete healing on clinical evaluation; however, magnetic resonance imaging confirmed complete healing in only two. Patients that had taken antibiotics and those that had previously required abscess drainage were less likely to respond to treatment [relative risk (RR) = 0.707 and 0.615, respectively; p = 0.03, p = 0.0001]. Responders were less likely to require follow-up surgery (RR = 0.658, p = 0.014) including ileostomy or proctectomy. CONCLUSIONS: Although anti-tumour necrosis factor alpha tends to improve symptoms of perianal Crohn's disease, in the long term, it rarely achieves complete healing. Perianal fistulising disease, a history of perianal abscess and antibiotic treatment are predictors of poor response to therapy.

Cohort study of mesenteric panniculitis and its relationship to malignancy.

BACKGROUND: Mesenteric panniculitis (MP) is a rare condition that historically has been associated with the presence of malignancy. Paraneoplastic phenomena in general regress with cure and in most cases with treatment of the cancer. This study was undertaken to determine whether MP regressed with cancer treatment and cure. METHODS: This was a retrospective review of a database of all patients with MP confirmed on CT between 2003 and August 2015 at Christchurch Hospital. Patients were categorized as having malignant or non-malignant disease, and follow-up scans were assessed for remission of MP. Patients with malignancy were further categorized as having malignancy cured or not cured. RESULTS: A total of 308 patients were identified with possible MP; 135 were excluded as radiological appearances were not typical of MP (43 patients) or there was no follow-up CT (92). Of 173 patients (131 men) included, 75 (43·4 per cent) were diagnosed with malignancy. Follow-up imaging showed that 33 patients (19·1 per cent) had remission of MP, whereas 140 (80·9 per cent) had no remission. There was no difference in the rates of MP remission in the malignancy versus no malignancy groups (P = 1·000), or between groups in which malignancy was cured or not cured (P = 0·572). Nor was there any difference in the rates of MP remission in malignancy cured versus no malignancy groups (P = 0·524). CONCLUSION: MP does not behave like a paraneoplastic phenomenon. The association with malignancy is most likely an epiphenomenon of the many CT images acquired for staging of cancer.

Translating colorectal cancer genetics into clinically useful biomarkers.

Colorectal cancer (CRC) is a major health problem worldwide accounting for over a million deaths annually. While many patients with Stage II and III CRC can be cured with combinations of surgery, radiotherapy and chemotherapy, this is morbid costly treatment and a significant proportion will suffer recurrence and eventually die of CRC. Increased understanding of the molecular pathogenesis of CRC has the potential to identify high risk patients and target therapy more appropriately. Despite increased understanding of the molecular events underlying CRC development, established molecular techniques have only produced a limited number of biomarkers suitable for use in routine clinical practice to predict risk, prognosis and response to treatment. Recent rapid technological developments, however, have made genomic sequencing of CRC more economical and efficient, creating potential for the discovery of genetic biomarkers that have greater diagnostic, prognostic and therapeutic capabilities for the management of CRC. This paper reviews the current understanding of the molecular pathogenesis of CRC, and summarizes molecular biomarkers that surgeons will encounter in current clinical use as well as those under development in clinical and preclinical trials. New molecular technologies are reviewed together with their potential impact on the understanding of the molecular pathogenesis of CRC and their potential clinical utility in classification, diagnosis, prognosis and targeting of therapy.

Progress in the management of retrorectal tumours.

AIM: Tumours in the retrorectal space are rare and pathologically heterogeneous. The roles of imaging and preoperative biopsy, nonoperative management and the indications for surgical resection are controversial. This study investigated a series of retrorectal tumours treated in a single institution with the aim of producing a modern improved management algorithm. METHOD: A retrospective analysis was conducted of the management of all retrorectal lesions identified between 1998 and 2013 from a radiology database search. Patient demographics, presenting symptoms, imaging, biopsy, management and the results were recorded. Descriptive statistics were used and Kaplan-Meier survival analysis was performed. RESULTS: Sixty-nine patients with a confirmed retrorectal tumour were identified. The median age was 50 (36-67 interquartile range) and 42 (56%) were female. Twenty (29%) of the tumours were malignant: 4 of 41 cystic lesions were malignant (12.9%) vs. 16 of 28 solid (or heterogeneous) lesions (57.1%) (P < 0.0001). Imaging demonstrated a 95% sensitivity and 64% specificity for differentiating benign from malignant tumours. Magnetic resonance imaging (MRI) was significantly better at distinguishing between benign and malignant tumours than computed tomography (94% vs. 64%, P = 0.03). Percutaneous biopsy was performed in 16 patients and only 27 underwent resection. There was no evidence of local recurrence associated with biopsy. Solid lesions were associated with a nonsignificant decreased overall survival (P = 0.348). CONCLUSION: This study demonstrated that MRI should be the investigation of choice for retrorectal lesions. Biopsy of solid lesions is safe and useful for guiding neoadjuvant and surgical therapy. Cystic lesions without suspicious radiological features can be followed by serial imaging without resection.

Predictors of outcome in palliative colonic stent placement for malignant obstruction.

BACKGROUND: Emergency surgery for large bowel obstruction carries significant morbidity and mortality. After initially promising results, concerns have been raised over complication rates for self-expandable metal stents (SEMS) in both the palliative and bridge-to-surgery settings. This article documents the technique used at the authors' institution, and reports on success and complication rates, as well as identifying predictors of endoscopic reintervention or surgical treatment. METHODS: Data were collected for a prospective cohort of consecutive patients undergoing attempted colonoscopic SEMS insertion at a single institution between 1998 and 2013. Multivariable logistic models were fitted to assess possible predictors of endoscopic reintervention and surgical treatment. RESULTS: Palliative SEMS insertion was attempted in 146 patients. Primary colorectal cancer was the most common cause of obstruction (95.2 per cent). The majority of patients (77.4 per cent) were treated in an acute setting, with a high technical success rate of 97.3 per cent. The perforation rate was 4.8 per cent and the 30-day procedural mortality rate 2.7 per cent. No predictors of early complications were identified, although patients with metastases and those who received chemotherapy were more likely to have late complications. Some 30.8 per cent of patients required at least one further intervention, with 11.0 per cent of the cohort requiring a stoma. Endoscopic reintervention was largely successful. CONCLUSION: SEMS offer a valid alternative to operative intervention in the palliative management of malignant large bowel obstruction. Patients receiving chemotherapy are more likely to receive endoscopic reintervention, which is largely successful.

Clinical and genetic risk factors for perianal Crohn's disease in a population-based cohort.

OBJECTIVES: Perianal Crohn's disease (CD) affects around one-quarter of CD patients and represents a distinct disease phenotype. The objective of this study was to investigate a large population-based cohort of inflammatory bowel disease (IBD) patients to identify clinical and genetic risk factors for perianal CD. METHODS: Data were collected in the Canterbury IBD database, estimated to include 91% of all patients with IBD in Canterbury, New Zealand. Genotyping was performed for selected loci previously demonstrated to be associated with CD. Patients with perianal disease were then compared with both CD patients without perianal disease and healthy controls to assess the presence of potential phenotypic, environmental, and genetic risk factors. RESULTS: Of the 715 CD patients in the database, 190 (26.5%) had perianal disease. In all, 507 patients with genotype data available were analyzed. Perianal disease was associated with younger age at diagnosis (P < 0.0001), complicated intestinal disease (P < 0.0001), and ileal disease location (P = 0.002). There was no association with gender, ethnicity, smoking, or breast feeding. Genotype analysis revealed an association with the neutrophil cytosolic factor 4 (NCF4) gene compared with both non-perianal CD patients (odds ratio (OR): 1.47; 95% confidence interval (CI): 1.08-1.99) and healthy controls (OR: 1.47; 95% CI: 1.10-1.95). There was no association identified with other genes, including IBD5 (OR: 0.91; 95% CI: 0.69-1.20), tumor necrosis factor α (OR: 1.04; 95% CI: 0.56-1.85), and IRGM (immunity-related guanosine triphosphatase protein type M) (OR: 1.21; 95% CI: 0.80-1.82). CONCLUSIONS: This study suggests that younger age at diagnosis, complicated disease behavior, and ileal disease location are risk factors for perianal CD. In addition, this paper represents the first report of an association of the NCF4 gene with perianal disease.

The process and outcomes of a nurse-led colorectal cancer follow-up clinic.

AIM: Evidence suggests that follow-up after colorectal cancer improves survival. Colorectal cancer is so common that patient follow-up can overwhelm a service, affecting the ability to see new referrals and reassess patients seen previously who have new symptoms. In order to cope with this demand a nurse-led follow-up service was started in 2004. We aimed to review the results of a nurse-led colorectal cancer follow-up clinic. METHOD: Between 1 December 2004 and 31 January 2011, patients who underwent resection for colorectal cancer were followed up by a nurse specialist according to a protocol determined by the colorectal surgeons in the unit. All patient details were recorded prospectively in a purpose designed database. RESULTS: Nine hundred and fifty patients were followed up over 7 years. Some 368 patients were discharged from the follow-up programme, 474 patients remain actively involved in the programme and 108 patients died. Of the patients discharged from the follow-up scheme 269 (73%) were discharged to their general practitioner free of disease after 5 years. Of the 108 who patients died, 98 were as a result of colorectal cancer. Twenty patients (2.1%) were identified with local (peri-anastomotic) disease recurrence and 93 patients (9.8%) were found to have developed distant metastatic disease. Of these, 65 patients (6.8%) were referred for palliative care and 28 (2.9%) had surgery for focal metastatic disease of whom 18 were still alive at the time of this analysis. CONCLUSION: This paper shows that a nurse-led clinic for colorectal cancer follow-up can achieve satisfactory results with detection rates of recurrent or metastatic disease comparable to consultant follow-up. A nurse-led clinic provides the benefits of follow-up without overwhelming the consultant colorectal surgical clinic practice.

Pulmonary staging in colorectal cancer: a review.

AIM: Assessment of the chest in colorectal cancer (CRC) staging is variable. The aim of this review was to look at different chest staging strategies and determine which has the greatest efficacy. METHOD: A review of studies assessing chest staging modalities for patients with CRC was performed. Modalities included chest X-ray (CXR), CT and positron emission tomography (PET). RESULTS: The majority of data consisted of case series. Two studies identified a low pick-up rate for CXR as a staging tool. Five studies showed increased detection rates of pulmonary metastases for chest CT vs CXR and abdominal CT. The clinical benefit of the increased detection rates was not clear. The incidence of indeterminate lung lesions (ILL) on staging chest CT varied from 4 to 42%. The majority (≥ 70%) of ILLs did not have any clinical significance. On CT scans, the incidence of pulmonary metastases in patients with rectal cancer ranged from 10 to 18% and in patients with colon cancer the incidence of pulmonary metastases ranged from 5-6%. The incidence of synchronous liver and pulmonary metastases compared with the overall incidence of pulmonary metastases ranged from 45 to 70%. There was no evidence reporting the superiority of PET/CT vs CT for the detection of pulmonary metastases or characterization of ILL. CONCLUSION: Studies show that chest CT scanning increases the detection rates for ILL and pulmonary metastases. The clinical benefit of the increased detection rates is not clear. There is a paucity of data assessing the optimal chest staging strategy for patients presenting with CRC.

Routine colonoscopy following acute uncomplicated diverticulitis.

BACKGROUND: The evidence supporting current recommendations that the colon should be evaluated following an initial episode of acute diverticulitis is poor. The aim of this study was to clarify whether acute uncomplicated diverticulitis is a valid indication for subsequent colonoscopy/computed tomography (CT) colonography. METHODS: This was a retrospective longitudinal study of patients with an initial presentation of acute uncomplicated diverticulitis on the basis of CT criteria, at a single institution between January 2004 and December 2008. RESULTS: A radiological diagnosis of acute uncomplicated diverticulitis was made in 292 patients. Some 205 patients underwent subsequent colonic evaluation or had undergone colonoscopy/CT colonography within the preceding 2 years. Colorectal polyps were present in 50 patients (24·4 per cent). Twenty patients (9·8 per cent) had hyperplastic polyps and 19 (9·3 per cent) had adenomas. Eleven patients (5·4 per cent) had advanced colonic neoplasia, including one (0·5 per cent) with a colorectal cancer. One patient had inflammatory bowel disease (IBD). The patients with colorectal cancer and IBD had clinical indicators that independently warranted colonoscopy. None of the 87 patients who did not undergo colonic evaluation had a diagnosis of colorectal cancer registered with the New Zealand Cancer Registry. CONCLUSION: The yield of advanced colonic neoplasia in this cohort was equivalent to, or less than that detected on screening asymptomatic average-risk individuals. In the absence of other indications, subsequent evaluation of the colon may not be required to confirm the diagnosis of diverticulitis.

Ileal disease is associated with surgery for perianal disease in a population-based Crohn's disease cohort.

BACKGROUND: The aim of this study was describe the frequency and characteristics of perianal surgical intervention (PSI) for Crohn's disease in a population-based cohort of patients with inflammatory bowel disease (IBD). METHODS: A total of 1421 patients with IBD were recruited, representing approximately 91 per cent of people with IBD in Canterbury, New Zealand. The clinical notes were screened to confirm the diagnosis and extract clinical data, including details of PSIs. RESULTS: Some 649 patients with Crohn's disease were included in the analysis, of whom 119 (18.3 per cent) had at least one PSI. Of these, 61 (51.3 per cent) required further procedures. Operations for perianal abscess and fistula accounted for 72.4 per cent of interventions. PSI rates did not differ between the sexes (P = 0.218). Age less than 17 years (adjusted odds ratio (OR) 1.89 (95 per cent confidence interval 1.08 to 3.28)) and ileal disease (OR 1.76 (1.06 to 2.92)) were identified as predictors of PSI. As disease duration increased, so did the proportion of patients with complicated intestinal disease among those who had undergone PSI. The median time to first PSI from diagnosis of Crohn's disease was 28 (interquartile range 7-82) months. Sex, age at diagnosis and disease location did not influence the time to first PSI. CONCLUSION: PSIs are frequent in patients with Crohn's disease, particularly those with ileal disease and those diagnosed at a young age.

Computed tomographic colonography in the diagnosis of colorectal cancer.

BACKGROUND: This study aimed to determine the sensitivity of computed tomographic colonography (CTC) in diagnosing colorectal cancer and to explore the reasons why these cancers are missed on CTC. METHODS: Patients who underwent CTC in the 56-month period from 1 January 2004 to 1 September 2008, and all cases of colorectal cancer recorded in the National Cancer Registry database from 1 January 2004 to 1 December 2008, were identified. Cases from the two data sets were then matched to identify all patients in whom CTC had been performed more than 6 weeks before a histological report was available. CTC reports and patients' records were reviewed to determine the cancer site, and images were reviewed. RESULTS: A total of 3888 patients underwent CTC over a 56-month interval. After matching with the National Cancer Registry database, colorectal cancer was identified in 131 patients, whereas it had been suspected on CTC in 123 patients. One of the patients with missed cancer was excluded, leaving seven (5.3 per cent) missed cancers, four of which were located in the caecum. Five cancers were missed because of technical limitations of CTC and two were due to perceptive errors. Systems errors and severe patient co-morbidity contributed to three of the cases. The sensitivity of CTC for colorectal cancer was 95 (95 per cent confidence interval 89 to 98) per cent. CONCLUSION: The sensitivity of 95 per cent for CTC in the diagnosis of colorectal cancer compares favourably with that of double-contrast barium enema (92 per cent) and colonoscopy (94 per cent).