Influence of obesity on the risk of recurrent acute diverticulitis

BACKGROUND

Acute diverticulitis (AD) is a common surgical problem with increasing incidence. Obesity has become epidemic in western countries. Obesity has been shown to increase the risk of developing AD; however, little is known about its influence on the risk of recurrence. The decision to perform elective surgical resection to reduce the risk of recurrent AD is made on an individual basis considering perceived risk of recurrence weighed against patient comorbidity. The aim of this study is to assess whether obesity affects the likelihood of developing recurrent AD.

METHODS

A retrospective audit was conducted of all admissions with AD to a tertiary centre between 1998 and 2010. Medical records were reviewed and patients with an index presentation with AD included in the analysis. Imaging was used to calculate body mass index (BMI) for assessment of obesity. Follow-up was for a minimum of 3 years from admission.

RESULTS

A total of 1299 patients were admitted with an index presentation of AD in the study period. 18.3% overall had recurrent AD, all of whom had confirmation on imaging. Computed tomography was used to calculate BMI in 849 patients, of whom 470 (55.4%) were considered obese (BMI >30). The likelihood of recurrent AD was not significantly different in obese patients compared to their non-obese counterparts (P = 0.2473).

CONCLUSION

While obesity increases the risk of developing AD overall, it does not appear to increase the likelihood of developing recurrent AD. This has implications for risk stratification when considering surgical resection to prevent recurrent AD.

CDH1 gene mutation in early-onset, colorectal signet-ring cell carcinoma

AIM

Colorectal signet-ring cell carcinomas (SRCC) are highly malignant tumours with poor prognosis that disproportionately affect younger patients. There is growing evidence of a unique set of molecular features that separate SRCC from conventional colorectal adenocarcinoma. Identification of these distinct features may have diagnostic and prognostic significance for patients and families. CDH1, which encodes E-cadherin, a cell adhesion protein, is commonly mutated in gastric SRCC and our study aimed to identify whether CDH1 mutation was also a common phenomenon in colorectal SRCC.

METHODS

DNA was extracted from formalin-fixed paraffin embedded tumour tissue, the CDH1 gene was analysed by next generation sequencing and the pathogenicity of mutations assessed in silico. Sections cut from the same blocks were immunostained to identify the presence of the E-cadherin protein.

RESULTS

We found 8 CDH1 mutations that meet our inclusion criteria in seven of 11 samples. Of these, five (from four patients), were likely to be germline mutations. E-cadherin staining was absent or markedly reduced in all of the seven samples with CDH1 mutation.

CONCLUSION

Our finding of CDH1 mutations in a proportion of signet-ring cell carcinomas and associated reduction in E-cadherin in these tumours supports previous findings of a role for mutation of this gene in the development of this disease. In addition, the finding of likely germline mutations suggests that a subset of these tumours may be familial. Loss of E-cadherin staining in the absence of CDH1 mutations however also suggests a role for environmental factors in a subset of these tumours.

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SPAR - a randomised, placebo-controlled phase II trial of simvastatin in addition to standard chemotherapy and radiation in preoperative treatment for rectal cancer: an AGITG clinical trial

BACKGROUND

Retrospective studies show improved outcomes in colorectal cancer patients if taking statins, including overall survival, pathological response of rectal cancer to preoperative chemoradiotherapy (pCRT), and reduced acute and late toxicities of pelvic radiation. Major tumour regression following pCRT has strong prognostic significance and can be assessed in vivo using MRI-based tumour regression grading (mrTRG) or after surgery using pathological TRG (pathTRG).

METHODS

A double-blind phase 2 trial will randomise 222 patients planned to receive long-course fluoropyrimidine-based pCRT for rectal adenocarcinoma at 18+ sites in New Zealand and Australia. Patients will receive simvastatin 40 mg or placebo daily for 90 days starting 1 week prior to standard pCRT. Pelvic MRI 6 weeks after pCRT will assess mrTRG grading prior to surgery. The primary objective is rates of favourable (grades 1-2) mrTRG following pCRT with simvastatin compared to placebo, considering mrTRG in 4 ordered categories (1, 2, 3, 4-5). Secondary objectives include comparison of: rates of favourable pathTRG in resected tumours; incidence of toxicity; compliance with intended pCRT and trial medication; proportion of patients undergoing surgical resection; cancer outcomes and pathological scores for radiation colitis. Tertiary objectives include: association between mrTRG and pathTRG grouping; inter-observer agreement on mrTRG scoring and pathTRG scoring; studies of T-cell infiltrates in diagnostic biopsies and irradiated resected normal and malignant tissue; and the effect of simvastatin on markers of systemic inflammation (modified Glasgow prognostic score and the neutrophil-lymphocyte ratio). Trial recruitment commenced April 2018.

DISCUSSION

When completed this study will be able to observe meaningful differences in measurable tumour outcome parameters and/or toxicity from simvastatin. A positive result will require a larger RCT to confirm and validate the merit of statins in the preoperative management of rectal cancer. Such a finding could also lead to studies of statins in conjunction with chemoradiation in a range of other malignancies, as well as further exploration of possible mechanisms of action and interaction of statins with both radiation and chemotherapy. The translational substudies undertaken with this trial will provisionally explore some of these possible mechanisms, and the tissue and data can be made available for further investigations.

TRIAL REGISTRATION

ANZ Clinical Trials Register ACTRN12617001087347. (www.anzctr.org.au, registered 26/7/2017) Protocol Version: 1.1 (June 2017).

Complications After Extended Radical Resections for Locally Advanced and Recurrent Pelvic Malignancies: A 25-Year Experience

BACKGROUND

The oncological role of pelvic exenteration for locally advanced and recurrent pelvic malignancies arising from the anorectum, gynaecological, or urological systems is now well-established. Despite this, the surgical community has been slow to accept pelvic exenteration, undoubtedly due to concerns about high morbidity and mortality rates. This study assessed the general major complications and predictors of morbidity following extended radical resections for locally advanced and recurrent pelvic malignancies.

METHODS

Data were collected from prospective databases at two high-volume institutions specialising in beyond TME surgery for locally advanced and recurrent pelvic malignancies between 1990 and 2015. The primary outcome measures were major complications (Clavien-Dindo 3 or above) and predictors for morbidity.

RESULTS

A total of 646 consecutive patients required extended surgery for local advanced pelvic malignancies. The median age was 63 (range 19-89) years, and the majority were female (371; 57.4%). One or more major complications were observed in 106 patients (16.4%). The most common major complications were intra-abdominal collection (43.7%; n = 59/135) and wound infection (14.1%; n = 19/135). The overall inpatient mortality rate was 0.46% (n = 3/646). Independent predictors for major morbidity following surgery for locally advanced or recurrent pelvic malignancies were squamous cell carcinoma of anus, sacrectomy, and blood transfusion requirement.

CONCLUSIONS

This series adds increasing evidence that good outcomes can be achieved for extended radical resections in locally advanced and recurrent pelvic malignancies. A coordinated approach in specialist centres for beyond TME surgery demonstrates that this is a safe and feasible procedure, offering low major complication rates.

Detection of the Bacteroides fragilis toxin gene in sheep with and without small intestinal adenocarcinoma

Aims: To determine if presence of the Bacteroides fragilis toxin (bft) gene, a molecular marker of colonic carriage of entertoxigenic Bacteroides fragilis (ETBF) in humans, was associated with a finding of small intestinal adenocarcinomas (SIA) in sheep in New Zealand. Methods: Samples of jejunal tissue were collected from the site of tumours and from grossly normal adjacent tissue in 20 sheep, in different consignments, diagnosed with SIA based on gross examination of viscera following slaughter. Two jejunal samples were also collected from a control sheep in the same consignment that had no gross evidence of SIA. A PCR assay was used to detect the presence of the bft gene in the samples. Results: Of the sheep with SIA, the bft gene was amplified from one or both samples from 7/20 (35%) sheep, and in sheep that had no gross evidence of SIA the bft gene was amplified from at least one sample in 11/20 (55%) sheep (RR 0.61; 95% CI = 0.30-1.25; p = 0.34). Of 11 positive samples analysed, ETBF subtype bft-1 was detected in one, bft-2 was detected in 10, and none were bft-3. Conclusions and Clinical Relevance: There was a high prevalence of detection of the bft gene in both SIA-affected and non-affected sheep, but there was no apparent association between carriage of ETBF, evidenced by detection of the bft gene, and the presence of SIA. ETBF are increasingly implicated in the aetiology of human colorectal cancer, raising the possibility that sheep may provide a zoonotic reservoir of this potentially carcinogenic bacterium. Abbreviation: Bft: Bacteroides fragilis toxin; ETBF: Enterotoxigenic Bacteroides fragilis; SIA: Small intestinal adenocarcinoma.

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.

Prevalence of frailty in a tertiary hospital: A point prevalence observational study

INTRODUCTION

Frailty is an important concept in modern healthcare due to its association with adverse outcomes. Its prevalence varies in the literature and there is a paucity of literature looking at the prevalence of frailty in an inpatient setting. Its significance lies on its impact on resource utilisation and costs.

AIM

To determine the prevalence of frailty in the adult population in a tertiary New Zealand hospital.

METHODS

Eligible patients aged 18 years and over were invited to participate, and frailty assessment was performed using the Reported Edmonton Frail Scale. A score of 8 or more was considered frail. Factors associated with frailty were assessed.

RESULTS

Of 640 occupied inpatient beds, 420 patients were assessed. 220 patients were excluded, of which 89 were absent from their bed-space, 73 declined and 41 were critically unwell. The overall prevalence of frailty across assessed patients was 48.8%. The prevalence of frailty increased significantly with age; patients aged 85 and over were significantly more likely to be frail compared to those aged under 65 (OR 6.25, 95% CI 3.17-12.7). Maori patients were significantly more likely to be frail (OR 4.0, 95% CI 1.45-11.9). When compared to those patients admitted to a medical specialty, patients admitted to surgical specialty were less likely to be frail (OR 0.52 95% CI 0.31-0.86) and those admitted for rehabilitation were more likely to be frail (OR 1.86 95% CI 1.03-3.41). Frail patients were more likely to come from a rest home (OR 2.81, 95% CI 1.38-6.14) or hospital level care (OR 9.62, 95% CI 2.68-61.6).

CONCLUSION

Frailty is highly prevalent in the hospital setting with 48.8% of all inpatients classified as frail. This high number of frail patients has significant resource implications and an increased understanding of the burden of frailty in this population may aid targeting of interventions towards this vulnerable population.

Clinical implications of the genetics of sporadic colorectal cancer

Colorectal cancer (CRC) is common and at least 80% of cases are sporadic, without any significant family history. Prognostication and treatment have been relatively empirical for what has become increasingly identified as a genetically heterogeneous disease. There are three main genetic pathways in sporadic CRC: the chromosomal instability pathway, the microsatellite instability pathway and the CpG island methylator phenotype pathway. There is significant overlap between these complex molecular pathways and this limits the clinical application of CRC genetics. Recent Australian and New Zealand guidelines recommend routine testing of mismatch repair (MMR) status for new cases of CRC and selective KRAS and BRAF testing on the basis of diagnostic, prognostic and therapeutic implications. It is important that all clinicians treating CRC have an understanding of the importance of and basis for identifying key genetic features of CRC. It is likely that in the future better molecular characterization such as that allowed by the consensus molecular subtype classification will allow improved prognostication and targeted therapy in order to deliver more personalized treatment for CRC.

Influence of the level of sacrectomy on survival in patients with locally advanced and recurrent rectal cancer

BACKGROUND

Exenterative surgery for locally advanced rectal cancer may involve partial sacrectomy to achieve complete resection. High sacrectomy is technically challenging, and can be associated with high morbidity and mortality rates. The aim of this study was to determine the influence of the level of sacrectomy on the survival of patients with locally advanced rectal cancer.

METHODS

This was an international multicentre retrospective analysis of patients undergoing exenterative abdominosacrectomy between July 2006 and June 2016. High sacrectomy was defined as resection at or above the junction of S2-S3; low sacrectomy was below the S2-S3 junction. Kaplan-Meier survival analysis was used to assess overall survival and cancer-specific survival. Predictive factors were determined using Cox regression analysis.

RESULTS

A total of 345 patients were identified, of whom 91 underwent high sacrectomy and 254 low sacrectomy. There was no difference in 5-year overall survival (53 versus 44·1 per cent; P = 0·216) or cancer-specific survival (60 versus 56·1 per cent; P = 0·526) between high and low sacrectomy. Negative margin rates were similar for primary and recurrent disease: 65 of 90 (72 per cent) versus 97 of 153 (63·4 per cent) (P = 0·143). Level of sacrectomy was not a significant predictor of mortality (P = 0·053). Positive resection margin and advancing age were the only significant predictors for death, with hazard ratios of 2·78 (P < 0·001) and 1·02 (P = 0·020) respectively.

CONCLUSION

There was no survival difference between patients who underwent high or low sacrectomy. In appropriately selected patients, high sacrectomy is feasible and safe.

Frailty in surgical patients

OBJECTIVE

To describe the current definitions, aetiology, assessment tools and clinical implications of frailty in modern surgical practice.

BACKGROUND

Frailty is a critical issue in modern surgical practice due to its association with adverse health events and poor post-operative outcomes. The global population is rapidly ageing resulting in more older patients presenting for surgery. With this, the number of frail patients presenting for surgery is also increasing. Despite the identification of frailty as a significant predictor of poor health outcomes, there is currently no consensus on how to define, measure and diagnose this important syndrome.

METHODS

Relevant references were identified through keyword searches of the Cochran, MEDLINE and EMbase databases.

RESULTS

Despite the lack of a gold standard operational definition, frailty can be conceptualised as a state of increased vulnerability resulting from a decline in physiological reserve and function across multiple organ systems, such that the ability to withstand stressors is impaired. Multiple studies have shown a strong association between frailty and adverse peri-operative outcomes. Frailty may be assessed using multiple tools; however, the ideal tool for use in a clinical setting has yet to be identified. Despite the association between frailty and adverse outcomes, few interventions have been shown to improve outcomes in these patients.

CONCLUSION

Frailty encompasses a group of individuals at high risk of adverse post-operative outcomes. Further work exploring ways to optimally assess and target interventions towards these patients should be the focus of ongoing research.

Frailty in surgical patients

OBJECTIVE

To describe the current definitions, aetiology, assessment tools and clinical implications of frailty in modern surgical practice.

BACKGROUND

Frailty is a critical issue in modern surgical practice due to its association with adverse health events and poor post-operative outcomes. The global population is rapidly ageing resulting in more older patients presenting for surgery. With this, the number of frail patients presenting for surgery is also increasing. Despite the identification of frailty as a significant predictor of poor health outcomes, there is currently no consensus on how to define, measure and diagnose this important syndrome.

METHODS

Relevant references were identified through keyword searches of the Cochran, MEDLINE and EMbase databases.

RESULTS

Despite the lack of a gold standard operational definition, frailty can be conceptualised as a state of increased vulnerability resulting from a decline in physiological reserve and function across multiple organ systems, such that the ability to withstand stressors is impaired. Multiple studies have shown a strong association between frailty and adverse peri-operative outcomes. Frailty may be assessed using multiple tools; however, the ideal tool for use in a clinical setting has yet to be identified. Despite the association between frailty and adverse outcomes, few interventions have been shown to improve outcomes in these patients.

CONCLUSION

Frailty encompasses a group of individuals at high risk of adverse post-operative outcomes. Further work exploring ways to optimally assess and target interventions towards these patients should be the focus of ongoing research.

Complete resection of colorectal cancer with ovarian metastases combined with chemotherapy is associated with improved survival

BACKGROUND

Ovarian metastases (OM) from colorectal cancer (CRC) are uncommon, and data about optimal management are lacking. The aim of this study was to examine the management and outcomes of patients with OM from CRC.

METHODS

A retrospective review of records of patients with a histopathological diagnosis of OM from CRC who were treated at Christchurch Hospital between 1 January 2000 and 31 December 2016. Data related to presentation, clinicopathological characteristics, treatment and outcomes were recorded. The primary outcomes were overall survival and disease-free survival.

RESULTS

Thirty-one patients were identified (median age 55 years, range 28-77), with a median follow-up of 23 months (range 3-84 months). Abdominal pain was the most common presenting symptom (22 patients). Synchronous OM occurred in 22 patients, 14 patients had bilateral ovarian involvement. Twenty-one patients received adjuvant chemotherapy. R0 resection was achieved in 14 patients. For all patients the 5-year disease-free and overall survival were 11% and 12%, respectively, while 5-year overall survival for R0 resections was 30%. Improved median survival was associated with negative colon resection margins (26.7 months versus 7.8 months, P = 0.03), R0 resection (30.5 months versus 23.5 months, P = 0.04), and use of adjuvant chemotherapy (28.8 months versus 8.2 months, P < 0.0001); however, on multivariate analysis adjuvant chemotherapy was the only independent factor associated with improved prognosis (P = 0.01).

CONCLUSIONS

OM from CRC are uncommon and carry a poor prognosis. Improved survival was associated with complete surgical resection of the primary tumour and metastatic disease in combination with systemic chemotherapy.

Impact of restenting for recurrent colonic obstruction due to tumour ingrowth

Background

Endoscopic stenting is used to palliate malignant large bowel obstruction. A proportion of patients will develop recurrent obstruction due to tumour ingrowth and require reintervention. This study aimed to assess the outcome (clinical success and complication rates) of endoscopic reintervention compared with surgical intervention in patients with stent obstruction due to tumour ingrowth.

Methods

This was an observational study using data from a database of patients who underwent palliative colonic stenting between January 1998 and March 2017 at Christchurch Public Hospital.

Results

A total of 190 patients underwent colonic stent insertion, for palliation in 182 cases. Reintervention was performed in 55 (30·2 per cent). Thirty-one patients (17·0 per cent) developed obstruction within the stent at a median of 4·6 (i.q.r. 2·3-7·7) months after the procedure. Of these, 21 had endoscopic restenting and ten underwent surgery. Restenting had technical and clinical success rates of 100 per cent, and involved a significantly shorter length of stay compared with surgery (median 2 (i.q.r. 1-4) versus 11 (6-19) days respectively; P = 0·006). Seven of the 21 patients in the restented group underwent a third palliative intervention. The overall stoma rate in the restented group was significantly lower than that in the surgical group (4 of 21 versus 10 of 10; P < 0·001). There was no difference in complications or survival between the two groups.

Conclusion

Among palliative patients who develop malignant stent obstruction, endoscopic restenting had a high chance of technical success. It resulted in a shorter hospital stay and lower stoma rate than those seen after surgery.