Acute colonic pseudo-obstruction post-cesarean section is not a benign entity: A case series and review of the literature

Acute colonic pseudo-obstruction (ACPO) is an infrequent occurrence after cesarean section. Anecdotal evidence suggests that the clinical course of ACPO in the obstetric setting is different to that seen in non-pregnant adult patients with ACPO secondary to alternative causes, such as systemic illnesses, the use of certain medications, and after non-abdominal surgery. The risk of progression to ischemia and perforation, as well as the need for emergency surgery, appears to be higher after cesarean section. Here we describe the clinical course of ACPO in four patients after cesarean section from our institution, followed by a review of the literature and a discussion of the important issues surrounding this condition in the postpartum time period. The findings from our cohort of patients and the reports from the medical literature support a hands-on combined approach from a group of specialists including obstetricians, surgeons, radiologists, and enterostomal therapists. Immediate imaging followed by regular observation is mandatory for any patient being managed conservatively. Early use of endoscopic decompression should be considered for patients who are not resolving with a conservative approach. Clinical signs of peritonism or radiological signs of ischemia or perforation in patients with ACPO mandate immediate surgical intervention. Appropriate postoperative care is necessary to deal with the complex physiological and psychological consequences of emergency surgery and potential stoma formation so soon after cesarean section.

Spatial transcriptomic analysis reveals local effects of intratumoral fusobacterial infection on DNA damage and immune signaling in rectal cancer

Mucinous colorectal cancer (CRC) is a common histological subtype of colorectal adenocarcinoma, associated with a poor response to chemoradiotherapy. The commensal facultative anaerobes fusobacteria, have been associated with poor prognosis specifically in mesenchymal CRC. Interestingly, fusobacterial infection is especially prevalent in mucinous CRC. The objective of this study was therefore to increase our understanding of beneficial and detrimental effects of fusobacterial infection, by contrasting host cell signaling and immune responses in areas of high vs. low infection, using mucinous rectal cancer as a clinically relevant example. We employed spatial transcriptomic profiling of 106 regions of interest from 8 mucinous rectal cancer samples to study gene expression in the epithelial and immune segments across regions of high versus low fusobacterial infection. Fusobacteria high regions were associated with increased oxidative stress, DNA damage, and P53 signaling. Meanwhile regions of low fusobacterial prevalence were characterized by elevated JAK-STAT, Il-17, Il-1, chemokine and TNF signaling. Immune masks within fusobacterial high regions were characterized by elevated proportions of cytotoxic (CD8+) T cells (p = 0.037), natural killer (NK) cells (p < 0.001), B-cells (p < 0.001), and gamma delta T cells (p = 0.003). Meanwhile, fusobacteria low regions were associated with significantly greater M2 macrophage (p < 0.001), fibroblast (p < 0.001), pericyte (p = 0.002), and endothelial (p < 0.001) counts.

Comparing neoadjuvant therapy followed by local excision to total mesorectal excision in the treatment of early stage rectal cancer: a systematic review and meta-analysis of randomised clinical trials

INTRODUCTION

Total mesorectal excision (TME) is the standard-of-care in early, clinical stage (cT2-3 N0 M0) rectal cancer. Local excision (LE) may be an alternative after adequate response to neoadjuvant therapy (NAT), with either long-course chemoradiotherapy (nCRT) or short-course radiotherapy (SCRT), as a means of preserving the rectum and potentially obviating the morbidity of TME.

METHODS

A systematic review was performed according to PRISMA guidelines for studies that randomly assigned patients with cT2-3 N0 M0 rectal cancer to either NAT + LE or TME that reported radiologic, oncologic, surgical, and morbidity outcomes.

RESULTS

A total of 4 RCTs comprise 462 patients (232 patients receiving NAT + LE; nCRT n = 205; SCRT n = 27) and 230 undergoing TME, respectively. NAT compliance was 98.86%. The rate of early completion TME in the NAT + LE group was 22.3%, while the proportion of patients achieving durable organ preservation was 75.4% at mean follow-up of 5.6 years. There was no difference in disease-free survival (DFS) (HR [hazard ratio] 1.19; 95% CI 0.95, 1.49; p = 0.13) or overall survival (OS) (HR 0.94; 95% CI 0.72, 1.23; p = 0.63]) according to the assigned treatment arm. The local recurrence rate (LRR) (HR 1.22; 95% CI 0.5-3.02; p = 0.66) and distant metastases (HR 0.92; 95% CI 0.45, 1.90; p = 0.82) were also comparable between the groups. There was a significant reduction in major (OR 0.45; 95% CI 0.21, 0.95; p = 0.04) and minor morbidity (OR 0.45; 95% CI 0.24, 0.85; p = 0.01) for patients undergoing NAT + LE. Overall stoma formation was decreased in the NAT + LE group (OR 0.03; 95% CI 0.0, 0.23; p ≤ 0.00001).

CONCLUSION

NAT + LE reduces adverse effects of TME, without any compromise in oncological outcomes, and the potential for an organ preserving strategy should be discussed with patients with T2-3N0 rectal cancers prior to treatment.

Is Delaying a Coloanal Anastomosis the Ideal Solution for Rectal Surgery?: Analysis of a Multicentric Cohort of 564 Patients From the GRECCAR

OBJECTIVES

To assess the specific results of delayed coloanal anastomosis (DCAA) in light of its 2 main indications.

BACKGROUND

DCAA can be proposed either immediately after a low anterior resection (primary DCAA) or after the failure of a primary pelvic surgery as a salvage procedure (salvage DCAA).

METHODS

All patients who underwent DCAA intervention at 30 GRECCAR-affiliated hospitals between 2010 and 2021 were retrospectively included.

RESULTS

Five hundred sixty-four patients (male: 63%; median age: 62 years; interquartile range: 53-69) underwent a DCAA: 66% for primary DCAA and 34% for salvage DCAA. Overall morbidity, major morbidity, and mortality were 57%, 30%, and 1.1%, respectively, without any significant differences between primary DCAA and salvage DCAA ( P = 0.933; P = 0.238, and P = 0.410, respectively). Anastomotic leakage was more frequent after salvage DCAA (23%) than after primary DCAA (15%), ( P = 0.016).Fifty-five patients (10%) developed necrosis of the intra-abdominal colon. In multivariate analysis, intra-abdominal colon necrosis was significantly associated with male sex [odds ratio (OR) = 2.67 95% CI: 1.22-6.49; P = 0.020], body mass index >25 (OR = 2.78 95% CI: 1.37-6.00; P = 0.006), and peripheral artery disease (OR = 4.68 95% CI: 1.12-19.1; P = 0.030). The occurrence of this complication was similar between primary DCAA (11%) and salvage DCAA (8%), ( P = 0.289).Preservation of bowel continuity was reached 3 years after DCAA in 74% of the cohort (primary DCAA: 77% vs salvage DCAA: 68%, P = 0.031). Among patients with a DCAA mannered without diverting stoma, 75% (301/403) have never required a stoma at the last follow-up.

CONCLUSIONS

DCAA makes it possible to definitively avoid a stoma in 75% of patients when mannered initially without a stoma and to save bowel continuity in 68% of the patients in the setting of failure of primary pelvic surgery.

The Impact of Bariatric Surgery on the Incidence of Colorectal Cancer in Patients with Obesity-a Systematic Review and Meta-analysis of Registry Data

PURPOSE

Cancer and obesity represent two of the most significant global health concerns. The risk of malignancy, including colorectal cancer (CRC), increases with obesity. The aim of this study was to perform a systematic review and meta-analysis to determine the value of bariatric surgery in reducing CRC risk in patients with obesity using registry data.

MATERIALS AND METHODS

A systematic review and meta-analysis were performed as per PRISMA guidelines. The risk of CRC was expressed as a dichotomous variable and reported as odds ratios (OR) with 95% confidence intervals (CIs) using the Mantel-Haenszel method. A multi-treatment comparison was performed, examining the risk reduction associated with existing bariatric surgery techniques. Analysis was performed using RevMan, R packages, and Shiny.

RESULTS

Data from 11 registries including 6,214,682 patients with obesity were analyzed. Of these, 14.0% underwent bariatric surgery (872,499/6,214,682), and 86.0% did not undergo surgery (5,432,183/6,214,682). The mean age was 49.8 years, and mean follow-up was 5.1 years. In total, 0.6% of patients who underwent bariatric surgery developed CRC (4,843/872,499), as did 1.0% of unoperated patients with obesity (54,721/5,432,183). Patients with obesity who underwent bariatric surgery were less likely to develop CRC (OR: 0.53, 95% CI: 0.36-0.77, P < 0.001, I2 = 99%). Patients with obesity undergoing gastric bypass surgery (GB) (OR: 0.513, 95% CI: 0.336-0.818) and sleeve gastrectomy (SG) (OR: 0.484, 95% CI: 0.307-0.763) were less likely to develop CRC than unoperated patients.

CONCLUSION

At a population level, bariatric surgery is associated with reduced CRC risk in patients with obesity. GB and SG are associated with the most significant reduction in CRC risk.

PROSPERO REGISTRATION

CRD42022313280.

Comparing minimally invasive surgical and open approaches to pelvic exenteration for locally advanced or recurrent pelvic malignancies - Systematic review and meta-analysis

INTRODUCTION

Pelvic exenteration (PE) is a complex multivisceral surgical procedure indicated for locally advanced or recurrent pelvic malignancies. It poses significant technical challenges which account for the high risk of morbidity and mortality associated with the procedure. Developments in minimally invasive surgical (MIS) approaches and enhanced peri-operative care have facilitated improved long term outcomes. However, the optimum approach to PE remains controversial.

METHODS

A systematic literature search was conducted in accordance with PRISMA guidelines to identify studies comparing MIS (robotic or laparoscopic) approaches for PE versus the open approach for patients with locally advanced or recurrent pelvic malignancies. The methodological quality of the included studies was assessed systematically and a meta-analysis was conducted.

RESULTS

11 studies were identified, including 2009 patients, of whom 264 (13.1%) underwent MIS PE approaches. The MIS group displayed comparable R0 resections (Risk Ratio [RR] 1.02, 95% Confidence Interval [95% CI] 0.98, 1.07, p = 0.35)) and Lymph node yield (Weighted Mean Difference [WMD] 1.42, 95% CI -0.58, 3.43, p = 0.16), and although MIS had a trend towards improved towards improved survival and recurrence outcomes, this did not reach statistical significance. MIS was associated with prolonged operating times (WMD 67.93, 95% CI 4.43, 131.42, p < 0.00001) however, this correlated with less intra-operative blood loss, and a shorter length of post-operative stay (WMD -3.89, 955 CI -6.53, -1.25, p < 0.00001). Readmission rates were higher with MIS (RR 2.11, 95% CI 1.11, 4.02, p = 0.02), however, rates of pelvic abscess/sepsis were decreased (RR 0.45, 95% CI 0.21, 0.95, p = 0.04), and there was no difference in overall, major, or specific morbidity and mortality.

CONCLUSION

MIS approaches are a safe and feasible option for PE, with no differences in survival or recurrence outcomes compared to the open approach. MIS also reduced the length of post-operative stay and decreased blood loss, offset by increased operating time.

Increased Fusobacterium tumoural abundance affects immunogenicity in mucinous colorectal cancer and may be associated with improved clinical outcome

There is currently an urgent need to identify factors predictive of immunogenicity in colorectal cancer (CRC). Mucinous CRC is a distinct histological subtype of CRC, associated with a poor response to chemotherapy. Recent evidence suggests the commensal facultative anaerobe Fusobacterium may be especially prevalent in mucinous CRC. The objectives of this study were to assess the association of Fusobacterium abundance with immune cell composition and prognosis in mucinous CRC. Our study included two independent colorectal cancer patient cohorts, The Cancer Genome Atlas (TCGA) cohort, and a cohort of rectal cancers from the Beaumont RCSI Cancer Centre (BRCC). Multiplexed immunofluorescence staining of a tumour microarray (TMA) from the BRCC cohort was undertaken using Cell DIVE technology. Our cohorts included 87 cases (13.3%) of mucinous and 565 cases (86.7%) of non-mucinous CRC. Mucinous CRC in the TCGA dataset was associated with an increased proportion of CD8 + lymphocytes (p = 0.018), regulatory T-cells (p = 0.001) and M2 macrophages (p = 0.001). In the BRCC cohort, mucinous RC was associated with enhanced CD8 + lymphocyte (p = 0.022), regulatory T-cell (p = 0.047), and B-cell (p = 0.025) counts. High Fusobacterium abundance was associated with an increased proportion of CD4 + lymphocytes (p = 0.031) and M1 macrophages (p = 0.006), whilst M2 macrophages (p = 0.043) were under-represented in this cohort. Patients with increased Fusobacterium relative abundance in our mucinous CRC TCGA cohort tended to have better clinical outcomes (DSS: likelihood ratio p = 0.04, logrank p = 0.052). Fusobacterium abundance may be associated with improved outcomes in mucinous CRC, possibly due to a modulatory effect on the host immune response. KEY MESSAGES: • Increased Fusobacterium relative abundance was not found to be associated with microsatellite instability in mucinous CRC. • Increased Fusobacterium relative abundance was associated with an M2/M1 macrophage switch, which is especially significant in mucinous CRC, where M2 macrophages are overexpressed. • Increased Fusobacterium relative abundance was associated with a significant improvement in disease specific survival in mucinous CRC. • Our findings were validated at a protein level within our own in house mucinous and non-mucinous rectal cancer cohorts.

Corrigendum: Mucinous adenocarcinoma of the rectum: a whole genome sequencing study

[This corrects the article DOI: 10.3389/fonc.2020.01682.].

Obesity and outcomes in trauma - a systematic review and meta-analysis

BACKGROUND

The physiological abnormalities relating to obesity and metabolic syndrome can contribute to worse outcomes following trauma especially in class 2 and 3 obesity. The aim of this systematic review was to determine whether patients with a higher class of obesity who suffer traumatic injury have a higher risk of worse outcomes including in-hospital mortality than normal-weight patients.

METHODS

A systematic search of MEDLINE, EMBASE, CENTRAL, Web of Science and CINAHL was performed for studies that reported a comparison of in-hospital obesity-related outcomes against normal-weight individuals aged 15 years and older following trauma. Single or multiple injuries from either blunt and/or penetrating trauma were included. Burn-related injuries, isolated head injury and studies focusing on orthopaedic related perioperative complications were excluded.

RESULTS

The search yielded 7405 articles; 26 were included in this systematic review. 945,511 patients had a BMI>30. A random-effects meta-analysis was performed for analysis of all four outcomes. Patients with class 3 obesity (BMI>40) have significantly higher odds of in-hospital mortality than normal-BMI individuals following blunt and penetrating trauma (OR, 1.75; 95% CI, 1.39-2.19, p=<0.00001), significantly longer hospital LOS (SMD, 0.23; 95% CI, 0.21-0.25; p<0.00001) and significantly longer ICU LOS (SMD, 0.19; 95% CI, 0.12-0.26; p<0.0001). In contrast, studies that examined blunt and penetrating trauma and classified obesity with a threshold of BMI>30 found no significant difference in the odds of in-hospital mortality (OR, 0.94; 95% CI, 0.86-1.02, p=0.13).

CONCLUSIONS

There is a higher risk of in-hospital mortality in patients living with class 3 obesity following trauma when compared with individuals with normal BMI. The management of patients with obesity is complex and trauma systems should develop specific weight related pathways to manage and anticipate the complications that arise in these patients. Systematic review registration number PROSPERO registration: CRD42021234482 Level of Evidence: Level 3.

Management of Cylindrical Battery Ingestion

Presentation A female presented to the Emergency Department following ingestion of an unknown number of cylindrical batteries. Diagnosis Abdominal X-ray confirmed the presence of multiple batteries located throughout the abdomen. Treatment A trial of conservative management was pursued, and five AA batteries were successfully passed per rectum. Serial X-rays over three weeks revealed that the majority of batteries failed to pass. A decision was made to perform a laparotomy, and 46 cylindrical batteries were removed from the stomach through a small gastrotomy. Four batteries located in the colon were milked into the rectum and removed via the transanal route. Discussion Using daily clinical exams and weekly plain films of the abdomen, conservative management is possible if a small number of batteries are ingested and make it to the stomach. However, the potential of cylindrical batteries to result in acute surgical emergencies should not be underestimated.

Short notice cancellations - an insight into Irish surgical waiting lists

Background

The reasons underlying prolonged waiting lists for surgery in Ireland are multifactorial. Patient-related factors including non-attendances contribute in part to the current waiting times.

Aims

To determine the rate of short notice cancellation for day case surgery in a model 2 HSE hospital over a 1-month period and to implement an intervention to try and reduce the rate of cancellation.

Methods

The cancellation rate was documented over a 1-month period in the hospital. An intervention was then implemented, involving a phone call to the patient from a member of the surgical team to attempt to reduce the cancellation rate. Cancellations were re-audited after the implementation of the phone intervention.

Results

The initial audit revealed a cancellation rate of 39.7% during the first month prior to implementation of the phone intervention. A phone call intervention from a member of the surgical team was associated with a decrease in cancellations from 39.7 to 14.6% (p < 0.01).

Conclusions

While cancellations remained high even after our intervention, a simple phone call was effective and more than halved our cancellation rate. Future efforts need to focus on increasing awareness of patient responsibility for attending scheduled appointments and procedures.

An Analysis of Clinicopathological Outcomes and the Utility of Preoperative MRI for Patients Undergoing Resection of Mucinous and Non-Mucinous Colorectal Cancer Liver Metastases

Background and Aims

Mucinous colorectal cancer has traditionally been associated with high rates of recurrence and poor long-term survival. There is limited published data on outcomes for patients undergoing liver resection for metastatic mucinous colorectal cancer. The aim of this study was to compare the clinicopathological outcomes for patients with mucinous colorectal cancer liver metastases (CRCLM) undergoing liver resection to a matched group of patients with adenocarcinoma not otherwise specified (NOS) and to evaluate the accurary of preoperative magnetic resonance imaging (MRI) at detecting the presence of mucin in liver metastases.

Materials and Methods

Patients with mucinous CRCLM undergoing liver resection were matched 1:3 to patients with adenocarcinoma NOS CRCLM. Clinicopathological data from the primary tumour and metastatic lesion were collected and compared between the groups. Hepatic recurrence-free, disease-free and overall survival were compared between the groups. The ability of preoperative MRI to detect mucin in CRCLM was also evaluated.

Results

A total of 25 patients with mucinous CRCLM underwent surgery over the 12-year period and were matched to 75 patients with adenocarcinoma NOS. Clinicopathological findings were similar between the groups. Resection of mucinous CRCLM was feasible and safe with similar levels of morbidity to adenocarcinoma NOS. There were no differences identified in hepatic recurrence-free (p=0.85), disease-free (p=0.25) and overall survival (p=0.98) between the groups. MRI had a sensitivity of 31.3% in detecting the presence of mucin in CRCLM.

Conclusion

Patients with mucinous CRCLM in this study had similar outcomes to patients with adenocarcinoma NOS. Based on our findings, histological subtype should not be taken into account when deciding on resectability of CRCLM.

Hepatic resection for breast cancer related liver metastases: A single institution experience

BACKGROUND & OBJECTIVE

Liver resection for breast cancer liver metastases is becoming a more widely accepted therapeutic option for selected groups of patients. The aim of this study was to describe the outcomes of patients undergoing liver resection for breast cancer-related liver metastases and identify any variables associated with recurrence or survival.

METHODS

A retrospective review of a prospectively maintained database was undertaken for the 12 year period between 2009 and 2021. Clinicopathological, treatment, intraoperative, recurrence, survival and follow-up data were collected on all patients. Kaplan-Meier methods, the log-rank test and Cox proportional hazards regression analysis were used to identify variables that were associated with recurrence and survival.

RESULTS

A total of 20 patients underwent 21 liver resections over the 12-year period. There were no deaths within 30 days of surgery and an operative morbidity occurred in 23.8% of cases. The median local recurrence free survival and disease free survival times were both 50 months, while the 5 year overall survival rate was 65%. The presence of extrahepatic metastases were associated with a decreased time to local recurrence (p < 0.01) and worse overall survival (p = 0.02).

CONCLUSIONS

This study has demonstrated that liver resection for breast cancer-related liver metastases is feasible, safe and associated with prolonged disease free and overall survival in selected patients. It is likely that this option will be offered to more patients going forward, however, the difficulty lies in selecting out those who will benefit from liver resection particularly given the increasing number of systemic treatments and local ablative methods available that offer good long-term results.

Apoptotic and Necroptotic Mediators are Differentially Expressed in Mucinous and Non-Mucinous Colorectal Cancer

Background

Mucinous colorectal cancer (CRC) represents 10% of all CRC and is associated with chemotherapy resistance. This study aimed to determine expression of apoptosis and necroptosis mediators in mucinous CRC.

Methods

RNA gene expression data were extracted from TCGA. Protein levels in 14 mucinous and 39 non-mucinous tumors were measured by multiplexed immunofluorescence. Levels of apoptosis and necroptosis signalling proteins were analysed in SW1463 (mucinous rectal), SW837 (non-mucinous rectal), LS174T (mucinous colon) and HCT116 (non-mucinous colon) cell lines by western blot. Cell death was investigated by flow cytometry measurement of propidium iodide stained cells.

Results

High cleaved-Caspase 3 expression was noted in resected mucinous tumors. Western blot identified alterations in apoptosis proteins in mucinous CRC, most prominently downregulation of Bcl-xL protein levels (p=0.029) which was also observed at the mRNA level in patients by analysis of TCGA gene expression data (p<0.001). Treatment with 5-FU did not significantly elevate cell death in mucinous cells, while non-mucinous cells showed robust cell death responses. However, 5-FU-induced phosphorylation of MLKL in mucinous cancer cells, suggestive of a switch to necroptotic cell death signaling.

Conclusion

Apoptotic and necroptotic mediators are differentially expressed in mucinous and non-mucinous colorectal cancers and represent targets for investigation of cell death mechanisms in the mucinous subtype.

Surgical Strategies to Reduce Postoperative Recurrence of Crohn's Disease After Ileocolic Resection

Postoperative recurrence after ileocaecal resection for fibrostenotic terminal ileal Crohn's disease is a significant issue for patients as it can result in symptom recurrence and requirement for further surgery. There are very few modifiable factors, aside from smoking cessation, that can reduce the risk of postoperative recurrence. Until relatively recently, the surgical technique used for resection and anastomosis had little or no impact on postoperative recurrence rates. Novel surgical techniques such as the Kono-S anastomosis and extended mesenteric excision have shown promise as ways to reduce postoperative recurrence rates. This manuscript will review and discuss the evidence regarding a range of surgical techniques and their potential role in reducing disease recurrence. Some of the techniques have been shown to be associated with significant benefits for patients and have already been integrated into the routine clinical practice of some surgeons, while other techniques remain under investigation. Current techniques such as resection of the mesentery close to the intestine and stapled side to side anastomosis are being challenged. It is looking more likely that surgeons will have a major role to play when it comes to reducing recurrence rates for patients undergoing ileocaecal resection for Crohn's disease.

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.

An Insight Into the Driver Mutations and Molecular Mechanisms Underlying Mucinous Adenocarcinoma of the Rectum

BACKGROUND

Mucinous adenocarcinoma of the rectum accounts for 10% of all rectal cancers and has an impaired response to neoadjuvant chemoradiotherapy and worse overall survival. To date, insufficient genomic research has been performed on this histological subtype.

OBJECTIVE

This study aims to define the mismatch repair deficiency rate and the driver mutations underpinning mucinous adenocarcinoma of the rectum and to compare it with rectal adenocarcinoma not otherwise specified.

DESIGN

Immunohistochemistry and sequencing were performed on tumor samples from our tumor biobank.

SETTINGS

This study was conducted across 2 tertiary referral centers.

PATIENTS

Patients with mucinous adenocarcinoma and rectal adenocarcinoma not otherwise specified who underwent rectal resection between 2008 and 2018 were included.

MAIN OUTCOME MEASURES

Mismatch repair status was performed by immunohistochemical staining. Mutations in the panel of oncogenes and tumor suppressor genes were determined by sequencing on the MiSeq V3 platform.

RESULTS

The study included 33 patients with mucinous adenocarcinoma of the rectum and 100 patients with rectal adenocarcinoma not otherwise specified. Those with mucinous adenocarcinoma had a mismatch repair deficiency rate of 12.1% compared to 2.0% in the adenocarcinoma not otherwise specified cohort (p = 0.04). Mucinous adenocarcinoma and adenocarcinoma not otherwise specified rectal tumors had similar mutation frequencies in most oncogenes and tumor suppressor genes. No difference was found in the KRAS mutation rate (50.0% vs 37.1%, p = 0.29) or BRAF mutation rate (6.7% vs 3.1%, p = 0.34) between the cohorts. No difference was found between the cohorts regarding recurrence-free (p = 0.29) or overall survival (p = 0.14).

LIMITATIONS

The major limitations of this study were the use of formalin-fixed, paraffin-embedded tissue over fresh-frozen tissue and the small number of patients included, in particular, in the mucinous rectal cohort.

CONCLUSIONS

Most mucinous rectal tumors develop and progress along the chromosomal instability pathway. Further research in the form of transcriptomics, proteomics, and analysis of the effects of the mucin barrier may yield valuable insights into the mechanisms of resistance to chemoradiotherapy in this cohort. See Video Abstract at http://links.lww.com/DCR/B464.

UNA PERCEPCIN SOBRE MUTACIONES IMPULSORAS Y MECANISMOS MOLECULARES SUBYACENTES AL ADENOCARCINOMA MUCINOSO DEL RECTO

ANTECEDENTES:El adenocarcinoma mucinoso del recto, representa el 10% de todos los cánceres rectales y tiene una respuesta deficiente a la quimioradioterapia neoadyuvante y una peor supervivencia en general. A la fecha, se han realizado muy pocas investigaciones genómicas sobre este subtipo histológico.OBJETIVO:Definir la tasa de deficiencia en la reparación de desajustes y mutaciones impulsoras, que sustentan el adenocarcinoma mucinoso del recto y compararlo con el adenocarcinoma rectal no especificado de otra manera.DISEÑO:Se realizaron inmunohistoquímica y secuenciación en muestras tumorales de nuestro biobanco de tumores.AJUSTE:El estudio se realizó en dos centros de referencia terciarios.PACIENTES:Se incluyeron pacientes con adenocarcinoma mucinoso y adenocarcinoma no especificado de otra manera, sometidos a resección rectal entre 2008 y 2018.PRINCIPALES MEDIDAS DE RESULTADO:El estado de reparación de desajustes se realizó mediante tinción inmunohistoquímica. Las mutaciones en el panel de oncogenes y genes supresores de tumores, se determinaron mediante secuenciación en la plataforma MiSeq V3.RESULTADOS:El estudio incluyó a 33 pacientes con adenocarcinoma mucinoso del recto y 100 pacientes con adenocarcinoma del recto no especificado de otra manera. Aquellos con adenocarcinoma mucinoso, tenían una tasa de deficiencia de reparación de desajustes del 12,1% en comparación con el 2,0% en la cohorte de adenocarcinoma no especificado de otra manera (p = 0,04). El adenocarcinoma mucinoso y el adenocarcinoma no especificado de otra manera, tuvieron frecuencias de mutación similares en la mayoría de los oncogenes y genes supresores de tumores. No se encontraron diferencias en la tasa de mutación de KRAS (50,0% frente a 37,1%, p = 0,29) o la tasa de mutación de BRAF (6,7% frente a 3,1%, p = 0,34) entre las cohortes. No se encontraron diferencias entre las cohortes con respecto a la supervivencia libre de recurrencia (p = 0,29) o la supervivencia global (p = 0,14).LIMITACIONES:Las mayores limitaciones de este estudio, fueron el uso de tejido embebido en parafina y fijado con formalina, sobre el tejido fresco congelado y el pequeño número de pacientes incluidos, particularmente en la cohorte mucinoso rectal.CONCLUSIONES:La mayoría de los tumores rectales mucinosos se desarrollan y progresan a lo largo de la vía de inestabilidad cromosómica. La investigación adicional en forma transcriptómica, proteómica y análisis de los efectos de la barrera de la mucina, puede proporcionar información valiosa sobre los mecanismos de resistencia a la quimioradioterapia, en esta cohorte. Consulte Video Resumen en http://links.lww.com/DCR/B464.

Association between availability of medications for opioid use disorder in specialty treatment and use of medications among patients: A state-level trends analysis

INTRODUCTION

Access to medication for opioid use disorder (MOUD) is a recognized public health challenge to improving the health of people with opioid use disorder (OUD) in many communities. Prior studies have shown that although MOUD availability has increased over time, particularly in some states, many substance use treatment facilities still do not offer medications. The relationship between greater availability of MOUD and use of MOUD among patients in treatment programs is not well understood.

METHODS

We used the National Survey of Substance Abuse Treatment Services to calculate the percent of specialty facilities per state providing MOUD from 2007 to 2018 and the Treatment Episode Data Set-Admissions (TEDS-A) to estimate the likelihood that a patient would have MOUD as part of their treatment plan during the same time period. We estimated models with patient-level TEDS-A data as the outcome and state-aggregated one-year lagged availability of MOUD in facilities as the main predictor, stratifying by treatment facility type (intensive outpatient, non-intensive outpatient, and residential).

RESULTS

We found that increasing MOUD availability at the facility level was associated with increased MOUD use in non-intensive and residential facilities at the patient level. Specifically, a 10 percentage point increase in MOUD availability was associated with a 4.5 percentage point increase in MOUD use among patients of non-intensive outpatient facilities (p-value = 0.03), and a 2.5 percentage points increase in residential facilities (p-value = 0.02). Non-Whites and patients in the Northeast had greater likelihoods of increased MOUD use in response to increased availability by facilities.

CONCLUSION

Increasing MOUD availability among specialty treatment facilities is likely to promote better access to MOUD for patients seeking treatment for OUD.

Mucinous Colorectal Cancer is Associated With Expression of the TIM-3 Immune Checkpoint Independently of Microsatellite Instability (MSI) Status

BACKGROUND

Immune checkpoint inhibition has demonstrated success in overcoming tumor-mediated immune suppression in several types of cancer. However, its clinical use is limited to a small subset of colorectal cancer (CRC) patients, and response is highly variable between CRC subtypes. This study aimed to determine the profile of immune checkpoints and factors associated with immune checkpoint inhibitor response in mucinous CRC.

METHODS

Gene expression data from CRC was extracted from the TCGA PanCanAtlas data-freeze release. Gene expression data were reported as batch-corrected and normalized RNA expression derived from RNA-Seq quantification. Clinical, pathologic, and transcriptomic data were compared between mucinous and non-mucinous CRC cohorts.

RESULTS

The 557 cases of CRC eligible for inclusion in this study comprised 486 cases of non-mucinous CRC (87.3 %) and 71 cases of mucinous CRC (12.7 %). High correlation was observed in the expression of the included immune checkpoints. Significantly higher expression of programmed cell death protein 1 ligand (PD-L1) and T cell immunoglobulin and mucin domain 3 (TIM-3) was observed in mucinous CRC than in non-mucinous CRC. In a multiple regression model, significant contributors to the prediction of TIM-3 gene expression were microsatellite instability (MSI) (unstandardized regression coefficient [B] = 1.223; p < 0.001), stage (American Joint Committee on Cancer [AJCC] 2; B = 0.423; p < 0.05), and mucinous status (B = 0.591; p < 0.01).

CONCLUSION

Expression of TIM-3, an emerging immune checkpoint inhibition target, was significantly higher in mucinous CRC, and expression was predicted by mucinous status independently of MSI. These findings should prompt investigation of immune checkpoint signaling in the mucinous tumor microenvironment to clarify the potential for immune checkpoint inhibition in mucinous CRC.

Resistance to Cell Death in Mucinous Colorectal Cancer-A Review

Mucinous colorectal cancer (CRC) is estimated to occur in approximately 10-15% of CRC cases and is characterized by abundant extracellular mucin. Mucinous CRC is frequently associated with resistance to apoptosis. Inferior prognosis is observed in mucinous CRC, particularly in rectal cancer and metastatic cases. Mucins are heavily glycosylated secretory or transmembrane proteins that participate in protection of the colonic epithelium. MUC2 overexpression is a hallmark of mucinous CRCs. Mucinous CRC is associated with KRAS and BRAF mutation, microsatellite instability and the CpG island methylator phenotype. Mutations of the APC gene and p53 mutations which are characteristic non-mucinous colorectal adenocarcinoma are less common in mucinous CRC. Both physical and anti-apoptotic properties of mucin provide mechanisms for resistance to cell death. Mucin glycoproteins are associated with decreased expression of pro-apoptotic proteins, increased expression of anti-apoptotic proteins and increased cell survival signaling. The role for BCL-2 proteins, including BCL-X_L, in preventing apoptosis in mucinous CRC has been explored to a limited extent. Additional mechanisms opposing cell death include altered death receptor expression and altered mutation rates in genes responsible for chemotherapy resistance. The roles of alternate cell death programs including necroptosis and pyroptosis are not well understood in mucinous CRC. While the presence of MUC2 is associated with an immunosuppressive environment, the tumor immune environment of mucinous CRC and the role of immune-mediated tumor cell death likewise require further investigation. Improved understanding of cell death mechanisms in mucinous CRC may allow modification of currently used regimens and facilitate targeted treatment.

Clinicopathological characteristics and survival outcomes for patients with mucinous colorectal cancer liver metastases undergoing hepatic resection: A systematic review and meta-analysis

BACKGROUND

Mucinous adenocarcinoma represents a distinct histological subtype of colorectal cancer. To date there has been limited data available for patients with colorectal cancer liver metastases (CRCLM) derived from mucinous adenocarcinoma. This systematic review and meta-analysis aims to provide data on the clinicopathological and survival outcomes of this cohort.

METHODS

Databases were searched for studies comparing clinicopathological and survival outcomes between patients with mucinous CRCLM and CRCLM from adenocarcinoma not otherwise specified who underwent liver resection. A random-effects model was used for analysis.

RESULTS

Eight studies describing 9157 patients were included. Mucinous CRCLM were positively associated with colon tumors (OR 1⋅64, P = 0⋅01), T3/T4 tumors (OR 1⋅58, P = 0⋅02), node positive tumors (OR 1⋅55, P = 0⋅005). The review also identified a trend towards worse overall survival in patients with mucinous CRCLM.

CONCLUSIONS

Despite the distinct clinicopathological characteristics and impaired long term outcomes of mucinous CRCLM, resection should remain the gold standard where possible.

A comparison of oncological outcomes after abdominoperineal excision before and after the implementation of a selective perineal flap closure program

BACKGROUND AND OBJECTIVES

Abdominoperineal excision (APE) is the operation chosen when a patient has low rectal cancer unamenable to sphincter preserving surgery. Perineal flap reconstruction is associated with less wound morbidity but little is known about oncological outcomes. The objective was to compare outcomes in patients undergoing APE before and after the introduction of a program that utilized flap reconstruction of the perineum.

METHODS

A retrospective review of a prospectively maintained database was performed. Patients who underwent APE followed by primary closure or flap reconstruction between 1998 and 2018 were selected. The cohorts were divided according to the implementation of the flap reconstruction program in July 2009. Clinicopathological data, recurrence and survival were compared between the cohorts.

RESULTS

One hundred and forty nine patients underwent APE for rectal adenocarcinoma between 1998 and 2018. There were 57 patients in the pre-flap era and 92 in the post-flap era. Forty-six patients underwent flap reconstruction in the latter cohort (50%). More patients in the post-flap era underwent neoadjuvant chemoradiotherapy (85.9% vs. 63.2%; p < .01). Margin positivity rates decreased from 21.1% in the pre-flap era to 10.9% in the post-flap era (p = .10) and there was an associated improvement in incidence and time to local recurrence (p = .03).

CONCLUSION

The use of perineal flap reconstruction is associated with a longer median time to local recurrence. Perineal flap reconstruction may contribute to reduced margin positivity.

Mucinous Adenocarcinoma of the Rectum: A Whole Genome Sequencing Study

Introduction

Mucinous adenocarcinoma of the rectum is an infrequently encountered histological subtype that is associated with an impaired response to chemoradiotherapy and a worse overall prognosis. A genomic profile analysis of mucinous rectal tumors has not yet been performed. The aim of this study was to comprehensively describe the burden of somatic mutations and copy number variation as well as perform mutational signature and microbial analysis of an in-house collected cohort of mucinous adenocarcinoma of the rectum.

Methods

Genomic DNA was extracted from 10 cases of mucinous rectal cancer and matched normal tissue. Whole genome sequencing (WGS) was carried out on these 10 cases and a comprehensive bioinformatic analysis was undertaken.

Results

The average number of SNVs, InDels and SVs in the cohort was 16,600, 1,855, and 120, respectively. A single case was MSI-H. KRAS mutations were found in 70% of cases while TP53 was mutated in only 40% of cases. CNA gain was identified on chromosomes 7, 8, 12, 13, and 20 while CNA loss was found on chromosomes 4, 8, 17, and 18 corresponding to oncogenes and tumor suppressor genes, respectively. Overall mucinous rectal cancers are more likely to be MSI-H and to have KRAS, BRAF, and PIK3CA mutations when compared to rectal adenocarcinoma NOS. Microbial analysis demonstrated an abundance of Fusobacterium nucleatum in tumor samples compared to normal tissue.

Conclusion

This study provides a detailed WGS analysis of 10 cases of mucinous rectal cancer. It demonstrates an important lesson in tumor biology in that histologically similar tumors can have extensive differences at the genomic level. This study is relevant as it raises important questions about the relationship between bacteria and malignancy.

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.

Mucin glycoproteins block apoptosis; promote invasion, proliferation, and migration; and cause chemoresistance through diverse pathways in epithelial cancers

Overexpression of mucin glycoproteins has been demonstrated in many epithelial-derived cancers. The significance of this overexpression remains uncertain. The aim of this paper was to define the association of mucin glycoproteins with apoptosis, cell growth, invasion, migration, adhesion, and clonogenicity in vitro as well as tumor growth, tumorigenicity, and metastasis in vivo in epithelial-derived cancers by performing a systematic review of all published data. A systematic review of PubMed, Embase, and the Cochrane Central Register of Controlled Trials was performed to identify all papers that evaluated the association between mucin glycoproteins with apoptosis, cell growth, invasion, migration, adhesion, and clonogenicity in vitro as well as tumor growth, tumorigenicity, and metastasis in vivo in epithelial-derived cancers. PRISMA guidelines were adhered to. Results of individual studies were extracted and pooled together based on the organ in which the cancer was derived from. The initial search revealed 2031 papers, of which 90 were deemed eligible for inclusion in the study. The studies included details on MUC1, MUC2, MUC4, MUC5AC, MUC5B, MUC13, and MUC16. The majority of studies evaluated MUC1. MUC1 overexpression was consistently associated with resistance to apoptosis and resistance to chemotherapy. There was also evidence that overexpression of MUC2, MUC4, MUC5AC, MUC5B, MUC13, and MUC16 conferred resistance to apoptosis in epithelial-derived cancers. The overexpression of mucin glycoproteins is associated with resistance to apoptosis in numerous epithelial cancers. They cause resistance through diverse signaling pathways. Targeting the expression of mucin glycoproteins represents a potential therapeutic target in the treatment of epithelial-derived cancers.

Mucinous adenocarcinoma of the colon and rectum: A genomic analysis

BACKGROUND AND OBJECTIVES

Mucinous adenocarcinoma is a distinct subtype of colorectal cancer (CRC) with a worse prognosis when compared with non-mucinous adenocarcinoma. The aim of this study was to compare somatic mutations and copy number alteration (CNA) between mucinous and non-mucinous CRC.

METHODS

Data from The Cancer Genome Atlas-colon adenocarcinoma and rectum adenocarcinoma projects were utilized. Mucinous and non-mucinous CRC were compared with regard to microsatellite status, overall mutation rate, the most frequently mutated genes, mutations in genes coding for mismatch repair (MMR) proteins and genes coding for mucin glycoproteins. CNA analysis and pathway analysis was undertaken.

RESULTS

Mucinous CRC was more likely to be microsatellite instability-high (MSI-H) and hypermutated. When corrected for microsatellite status the single-nucleotide variation and insertion-deletion rate was similar between the two cohorts. Mucinous adenocarcinoma was more likely to have mutations in genes coding for MMR proteins and mucin glycoproteins. Pathway analysis revealed further differences between the two histological subtypes in the cell cycle, RTK-RAS, transforming growth factor-β, and TP53 pathways.

CONCLUSIONS

Mucinous CRC has some distinct genomic aberrations when compared with non-mucinous adenocarcinoma, many of which are driven by the increased frequency of MSI-H tumors. These genomic aberrations may play an important part in the difference seen in response to treatment and prognosis in mucinous adenocarcinoma.

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.

The significance of mucin pools following neoadjuvant chemoradiotherapy for locally advanced rectal cancer

BACKGROUND

Neoadjuvant chemo-radiotherapy is utilized for locally advanced rectal cancer to optimize local control. A subset of patients form mucin pools following radiotherapy but the association between mucin pools and pathological and oncological outcomes following curative proctectomy for rectal cancer remains unknown.

OBJECTIVE

The aim of this study was to determine the significance of mucin pool formation after neoadjuvant chemoradiotherapy for rectal cancer.

METHODS

This is a retrospective analysis of a prospectively maintained rectal cancer database. Patients who underwent curative proctectomy for rectal cancer following long course chemoradiotherapy between January 2007 and December 2016 were eligible for inclusion.

RESULTS

A total of 297 patients were eligible for inclusion; of these 36 (12.1%) had mucin pools on final histopathology. Tumors with mucin pools were less likely to be ypT3/T4 (25.0 vs 51.0%, P = 0.003), were more likely to have a good response (83.3 vs 53.6%, P < 0.001) and more likely to have a pathologic complete response (41.7 vs 19.2%, P = 0.006) to radiotherapy. The presence of mucin pools was associated with less distant recurrence ( P < 0.05) and improved overall survival ( P = 0.02).

CONCLUSIONS

The presence of mucin pools following neoadjuvant chemoradiotherapy for rectal cancer represents a surrogate marker of response to treatment and downstaging and is associated with improved survival.

Thirty-seven-year Population-based Study of Colorectal Cancer Rates in Renal Transplant Recipients in Ireland

BACKGROUND

Renal transplantation is associated with an increased risk of neoplasia, including colorectal cancer (CRC). Advances in surgical techniques and immunosuppressive medications have resulted in increased survival rates of both patients and grafts, but the incidence of CRC in the Irish renal transplant population is currently unknown. The aim of this study is to review the incidence of CRC in the Irish renal transplant population and compare it to the general population.

METHODS

A retrospective review of a prospectively maintained database of all renal transplant recipients in Ireland between January 1980 and July 2017 was performed.

RESULTS

Thirty-three out of 4230 transplant recipients (men = 20, women = 13) developed CRC subsequent to transplantation and were eligible for inclusion in the series. The mean age at transplantation was 51.5 years, with patients developing CRC on average 10.9 years post-transplantation; 6.1% (n = 2/33) had stage IV disease at diagnosis. The majority of patients (87.8%) had a pathologic T stage of T3/T4 and 45.5% had involvement of locoregional lymph nodes (N1/N2); 42.4% also had a mucinous component at histopathologic assessment. The incidence of CRC was higher in the transplant population compared to the general population.

CONCLUSION

This is the first population-based assessment of CRC development in the Irish renal transplant population. Our data suggest that Irish transplant recipients have an increased risk of being diagnosed with a more advanced tumor than the general population, with most being diagnosed almost a decade after transplantation. This highlights the need for increased awareness among patients and clinicians and the potential need for coordinated lifelong surveillance of this patient population to ensure early detection and treatment.

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.

A meta-analysis of the clinicopathological characteristics and survival outcomes of inflammatory bowel disease associated colorectal cancer

PURPOSE

The current study aims to use meta-analytical techniques to compare the clinicopathological characteristics and survival outcomes of inflammatory bowel disease (IBD) associated and sporadic colorectal carcinoma (CRC). Patients with IBD have an established increased risk of developing CRC. There is no consensus, however, on the clinicopathological characteristics and survival outcomes of IBD associated CRC when compared to sporadic CRC.

METHODS

A comprehensive search for published studies comparing IBD associated and sporadic CRC was performed. Random effect methods were used to combine data. This study adhered to the recommendations of the MOOSE guidelines.

RESULTS

Data were retrieved from 20 studies describing 571,278 patients. IBD associated CRC had an increased rate of synchronous tumors (OR 4.403, 95% CI 2.320-8.359; p < 0.001), poor differentiation (OR 1.875, 95% CI 1.425-2.466; p < 0.001), and a reduced rate of rectal cancer (OR 0.827, 95% CI 0.735-0.930; p = 0.002). IBD associated CRC however did not affect the frequency of T3/T4 tumors (OR 0.931, 95% CI 0.782-1.108; p = 0.421), lymph node positivity (OR 1.061, 95% CI 0.929-1.213; p = 0.381), metastasis at presentation (OR 0.970, 95% CI 0.776-1.211; p = 0.786), sex distribution (OR 0.978, 95% CI 0.890-1.074; p = 0.640), or 5-year overall survival (OR 1.105, 95% CI 0.414-2.949; p = 0.842).

CONCLUSIONS

In this large analysis of available data, IBD associated CRC was characterized by less rectal tumors and more synchronous and poorly differentiated tumors compared with sporadic cancers, but no discernable difference in sex distribution, stage at presentation, or survival could be identified.

The Utility of Neutrophil to Lymphocyte Ratio as a Predictor of Intervention in Acute Diverticulitis

BACKGROUND

Neutrophil to lymphocyte ratio (NLR) is a novel biomarker that has been recently studied in diverticulitis. The primary aim of this study was to assess the accuracy of NLR in predicting which patients had complicated diverticulitis and which patients required a radiological or surgical intervention. The accuracy of NLR was compared to C-reactive protein (CRP), white blood cell (WBC) count, neutrophil count and white cell to lymphocyte ratio (WLR).

METHODS

Details of all patients admitted with acute diverticulitis over an 18-month period were collected prospectively. Median CRP, WBC, neutrophil count, WLR and NLR values at initial presentation were compared using the Mann-Whitney U test. The diagnostic accuracy of each test was assessed using receiver operating characteristic curve analysis. Optimal cut-off points were determined for each biomarker using Youden's Index (J).

RESULTS

CRP, WBC, neutrophil count, WLR and NLR had variable accuracy in predicting complicated diverticulitis. NLR had the greatest accuracy of the 5 biomarkers in predicting the need for intervention with an area under the curve of 0.79 (p < 0.0001). The optimal cut-off point for NLR was 5.34 (J = 0.45).

CONCLUSION

NLR was more accurate than CRP, WBC, neutrophil count and WLR in predicting the need for intervention. This cost-neutral, readily available biomarker can easily be calculated from the complete blood count and is a useful adjunct to CT.

Endoscopic tattooing to aid tumour localisation in colon cancer: the need for standardisation

BACKGROUND/AIMS

An increasing number of colon and rectal tumours are being resected using laparoscopic techniques. Identifying these tumours intraoperatively can be difficult. The use of tattooing can facilitate an easier resection; however, the lack of standardised guidelines can potentially lead to errors intraoperatively and potentially result in worse outcomes for patients. The aim of this study was to identify the most reliable method of preoperative tumour localisation from the available literature to date.

METHODS

A literature review was undertaken to identify any articles related to endoscopic tattooing and tumour localisation during colorectal surgery.

RESULTS

To date there is still mixed evidence regarding tattooing techniques and the choice of ink that should be used. There are numerous studies demonstrating safe tattooing techniques and highlighting the risks and benefits of different types of ink available.

CONCLUSION

Based on the available studies we have recommended a standardised approach to endoscopic tattooing of colorectal tumours prior to laparoscopic resection.

An unusual cause of dyspnea and tachycardia

Diaphragmatic hernias are typically congenital or caused by trauma. Delayed presentation is not uncommon. Repair can be undertaken through an open or minimally invasive abdominal or thoracic approach. Small defects can be repaired with sutures, while larger defects require a mesh repair. This patient's comorbidities precluded him from surgery.

Assessing the safety and effectiveness of devices after US Food and Drug Administration approval: FDA-mandated postapproval studies

IMPORTANCE

Postmarketing surveillance is critical to evaluating the safety and effectiveness of medical devices. The US Food and Drug Administration (FDA) may order the manufacturer of a high-risk device to conduct postmarketing surveillance studies, known as postapproval studies (PASs), at the time of approval.

OBJECTIVES

To understand the characteristics of PASs ordered in recent years and inform discussions about the direction of the PASs program.

DESIGN

Descriptive study of the PASs ordered for medical devices using the FDA's PASs website, the Premarket Approval database, and supplemental information provided by the FDA.

MAIN OUTCOMES AND MEASURES

The proportion of medical devices that received a PAS order and study characteristics.

RESULTS

Between January 1, 2005, and December 31, 2011, the FDA ordered 223 studies of 158 medical devices, including studies for 93 (48%) new high-risk devices approved during this period. The median required sample size for a study was 350 patients (interquartile range, 160-1500). If the protocol of a study was not in place at the time the device was approved, which occurred frequently, a median of 180 days elapsed until the protocol was agreed on. The FDA has never issued a warning letter or penalty owing to study delays, inadequate progress, or any other issue related to a PAS. Of the approved protocols, 41 (19%) were subsequently revised, including 29 (21%) protocols in place by application approval. Some studies generated significant clinical findings. The most common effect of a PAS finding after study completion was that the FDA requested a labeling change for 31 studies (53%).

CONCLUSIONS AND RELEVANCE

Postapproval studies have the potential to provide additional information to better understand medical device performance. However, small sample sizes, delays in reaching protocol agreement, and lack of availability of findings may hinder their ability to be clinically useful. Owing to the lack of information on the effect of studies, it is unclear whether the program achieves its aims. Improved completion and accessibility of PASs could help answer important questions of safety and effectiveness about medical devices. To better understand the real-world performance of these products, they should be better integrated with other sources of information about device performance.

Dislocation following total hip replacement

An analysis of 142 dislocations from a multicentre study of 6774 total hip replacements is reported. The incidence of dislocation was 2.1 per cent. Patients with neuromuscular disorder, those in a confused mental state, and those undergoing revision operations are at special risk. The commonest surgical error, present in nearly half the patients, was placing the acetabular cup too vertically or too anteverted. A less common fault was placing the femoral component too anteverted. Neither the original pathology nor the approach to the hip appeared to affect the likelihood of dislocation. The dislocations were divided into early and late, single and recurrent, and the success rate of treatment is described in these groups. One hundred and eleven patients (78.2 per cent) eventually obtained stability. Of those with a single dislocation, 62 per cent remained stable after a single manipulation. Thirty-four per cent of the patients required an open operation to achieve stability and it is suggested that, in many cases, open reduction alone is not enough; the mechanical fault needs to be corrected.

Dorsal radiocarpal dislocation

Dorsal radiocarpal dislocation is rare. Large forces are necessary to produce such injuries and the majority of these patients have severe associated injuries and are unable to remember exactly how they occurred. A case is reported in which there was an isolated dorsal radiocarpal fracture-dislocation associated with contusion of the median nerve. The manner of injury is well demonstrated.