The role of multidisciplinary team meeting histopathology review and its impact on revised reports: Analysis of a national quality improvement program

OBJECTIVES

We conducted the first Irish national study assessing the value of multidisciplinary team meeting review in pathology practice and its impact on error detection before treatment.

METHODS

Public and private pathology laboratories across Ireland capture their quality activities using standardized codes and submit their data to a centralized database (National Quality Assurance Intelligence System) overseen by the National Histopathology Quality Improvement (NHQI) program. A total of 1,437,746 histopathology and cytopathology cases submitted to the NHQI program over a 60-month period (January 2017 to December 2021) were included in this study. Cases were analyzed with respect to multidisciplinary team meeting peer review and the presence of a revised report (amended or corrected report), a surrogate marker for error detection before treatment.

RESULTS

Across all cases assessed, 13.74% (197,587) underwent multidisciplinary team meeting discussion. Cases discussed at review had a statistically significantly higher rate of revised reports (1.25% [2470]) than cases not discussed at review (0.16% [1959]) (Pearson χ2, 6619.26; P < .0001; odds ratio, 8.00 [95% CI, 7.54-8.49]). Overall, multidisciplinary team meeting review made it 8 times more likely to detect an error before treatment. Cancer resections had the highest rate of review at 55.29% (46,806), reflecting the prioritization of oncology case discussion at review meetings.

CONCLUSIONS

The multidisciplinary team meeting review process plays a valuable role in pathology error detection. A pathologist's participation in the review process comes with a clinically significant workload that needs to be recognized for future workforce planning. This study highlighted the positive role pathologists play in enhancing patient safety.

Clinical features and outcomes of appendiceal neuroendocrine tumours: 10 year audit from the Irish NET Centre of Excellence

Appendiceal neuroendocrine tumours (aNETs) are rare neoplasms of the gastrointestinal tract often diagnosed incidentally at the time of appendicectomy. Appendicectomy is considered curative in the majority of cases but guidelines recommend right-sided hemicolectomy (RHC) for those with specific high-risk features despite no data supporting a survival benefit. We performed a retrospective search of multi-disciplinary tumour board and pathology databases from 2012 to 2022 to identify cases of aNET treated at our centre. Follow-up data were obtained from the electronic healthcare records. A total of 142 cases of aNET were included for analysis. Mean age at presentation was 34, of which 76% were female and 92% of aNETs were located in the tip/middle of the appendix; 90% were grade 1, and 93% had R0 resection. Tumour size was <1 cm in 54%, 1-2 cm in 36%, >2 cm in 9%. A total of 43 patients (30%) underwent RHC with lymph node metastases identified in 16 (37%). Lymph node metastases were associated with tumour size >2 cm (p = .008) and higher tumour grade (p = .041) on multivariate analysis. For aNET 1-2 cm, lymph node metastases were identified in 7/22 who had RHC (32%) with tumour grade the only significant risk factor (p = .046). Distant metastases were identified in 2 cases (1%), diagnosed synchronously and associated with grade 2 tumours. Overall survival for those with lymph node metastases was 100% after a median 4 years. Progression-free survival was 93%, with a single case of disease progression associated with synchronous distant metastases at initial diagnosis. Lymph node metastases in aNET are associated with higher tumour grade and tumour size >2 cm. Disease progression in the setting of lymph node metastases is rare. The significance of lymph node metastases and need for completion RHC remains uncertain.

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.

Pancreatic medullary carcinoma developed on a pancreatic intraductal papillary mucinous neoplasm with loss of MSH2 and MSH6 expression: a case report

BACKGROUND

Pancreatic medullary carcinoma (PMC) is a rare pancreatic tumor, usually showing the presence of microsatellite instability, mostly MLH1 silencing, and a wild-type KRAS mutation status. We report here a PMC arising from a Pancreatic Intraductal Papillary Mucinous Neoplasm (IPMN), both having KRAS and TP53 mutations.

CASE PRESENTATION

We report the case of a 73-year-old woman presenting with right iliac fossa pain. MRI revealed a 16 mm diameter mass in the pancreas, leading to a pancreatic duct stricture and upstream a dilatation of the distal pancreatic duct of Wirsung. A fine needle aspiration was performed, and pathology analysis revealed malignant glandular cells. The patient underwent distal pancreatectomy. Gross examination revealed an12 mm indurated white lesion, adjacent to a cystic lesion extending into the rest of the pancreatic body. Microscopically, the cystic area represented a mixed (gastric-type and pancreatobiliary-type) IPMN, involving the main and secondary pancreatic ducts with low-grade and high-grade dysplasia. In the periphery of this IPMN, a 14mm associated invasive carcinoma was observed, characterized by focal gland formation and by poorly differentiated cells with a syncytial appearance, associated with a dense lymphoplasmocytic and neutrophilic infiltrate. Immunohistochemical analyses showed loss of MSH2 and MSH6 expression. Microsatellite instability was confirmed by molecular test. Molecular analysis was performed both on the invasive carcinoma and on the high-grade dysplasia IPMN, revealing the same mutation profile with KRAS and TP53 mutations. The proposed diagnosis was mixed IPMN with associated invasive medullary carcinoma that presented loss of MSH2 and MSH6 expression.

CONCLUSIONS

The present case reports for the first time, at the best of our knowledge, the coexistence of IPMN lesions and PMC, both having the same molecular alterations. It also describes the second case of PMC with microsatellite instability, MSH2 and MSH6 silenced.

Robotic-assisted radical prostatectomy-impact of a mentorship program on oncological outcomes during the learning curve

BACKGROUND AND AIMS

The learning curve for robotic-assisted radical prostatectomy (RARP) is estimated to be about 50-200 cases. This study will evaluate the benefit of a mentorship programme after completing a mini-fellowship in RARP by an experienced surgeon who previously trained in open and laparoscopic surgery.

METHODS

Our study was a retrospective comparative analysis of RARP performed by a single consultant urologist. A retrospective chart review of the first 120 cases was performed. The 120 patients were divided into three groups of 40 cases. For the first 40 cases, an appropriately qualified mentor was present. The peri-operative and oncological outcomes were compared between the three groups.

RESULTS

Operative times significantly decreased with experience (250 min vs 234 min vs 225 min, p < 0.05). Complication rates, estimated blood loss, and length of stay were similar between all groups. There was a higher rate of positive margins in the final group (20% vs 17.5% vs 32.5%, p < 0.5). There was a greater number of pT3 tumours in group 3 (42%, n = 17) compared to groups 1 and 2 (20%, n = 8, and 22.5%, n = 9) which may account for the higher rate of positive margins in this group.

CONCLUSION

In the transition of an experienced laparoscopic surgeon to robotic surgery, we showed that there is a benefit of a mentorship programme after a mini-fellowship in reducing the impact of the learning curve on patient outcomes. Ongoing mentorship may be of benefit in cases where a high volume of tumour is suspected and should be avoided in the early part of the learning curve to maximise oncological outcomes.

Prostate cancer detection with magnetic resonance imaging (MRI)/cognitive fusion biopsy: Comparing standard and targeted prostate biopsy with final prostatectomy histology

INTRODUCTION

The use of multiparametric magnetic resonance imaging (MRI) with targeted biopsies of the prostate improves the diagnosis of clinically significant prostate cancer. Recent studies have shown that targeted prostate biopsies also more accurately predict final histopathology after radical prostatectomy (RP). There are three broad techniques for performing MRI-targeted prostate biopsy: cognitive MRI/ultrasound (US) fusion, software MRI/US fusion, and in-bore MRI-guided. Current practices recommend that a standard systematic 12-core prostate biopsy be performed, as well as targeted biopsies in patients with positive MRI findings. This study aimed to evaluate the accuracy of histological grading of cognitive MRI/US fusion prostate biopsy by comparing the histology from the targeted biopsy specimens (TB), standard systematic specimens (SB), and the combination of both (CB) specimens with the final histological grade from subsequent prostatectomy.

METHODS

A retrospective, single-center review of 115 patients who underwent standard systematic and cognitive MRI/US-targeted biopsy of the prostate before undergoing a RP between 2016 and 2019 was performed. MRI findings, biopsy, final histology International Society of Urological Pathology (ISUP) grades, and patient demographics were collected. Cochran's Q test and McNemar test were used to compare the differences in upgrading, downgrading, and concordance between each biopsy group.

RESULTS

The concordance between SB, TB, and CB biopsy were 28.7%, 49.6%, and 50.4%, respectively. There was no significant difference in concordance between TB and CB. Patients were more likely to be downgraded on the final histology when comparing CB with TB alone (26.1% vs. 16.5%, p<0.05). In cases where an ISUP grade 1 cancer was diagnosed on TB (n=24), there was a 62.5% chance that the final histology would be upgraded. In the same sample, when combined with a SB, the risk of upgrading on final histology reduced to 37.5%.

CONCLUSIONS

Although grading concordance between TB and CB were similar, the concomitant use of a SB significantly reduced the rate of upgrading in the final RP histopathology. CB may result in better decision-making regarding treatment options and also have implications for intraoperative planning.

Genomic Profiling and Functional Analysis of let-7c miRNA-mRNA Interactions Identify SOX13 to Be Involved in Invasion and Progression of Pancreatic Cancer

BACKGROUND

Pancreatic cancer is a devastating disease; its lethality is related to rapid growth and tendency to invade adjacent organs and metastasize at an early stage.

OBJECTIVE

The aim of this study was to identify miRNAs and their gene targets involved in the invasive phenotype in pancreatic cancer to better understand the biological behaviour and the rapid progression of this disease.

METHODS

miRNA profiling was performed in isogenic matched high invasive and low-invasive subclones derived from the MiaPaCa-2 cell line and validated in a panel of pancreatic cancer cell lines, tumour, and normal pancreas. Online miRNA target prediction algorithms and gene expression arrays were used to predict the target genes of the differentially expressed miRNAs. miRNAs and potential target genes were subjected to overexpression and knockdown approaches and downstream functional assays to determine their pathological role in pancreatic cancer.

RESULTS

Differential expression analysis revealed 10 significantly dysregulated miRNAs associated with invasive capacity (Student's t-tests; P value <0.05; fold change = ±2). The expression of top upregulated miR-135b and downregulated let-7c miRNAs correlated with the invasive abilities of eight pancreatic cancer cell lines and displayed differential expression in pancreatic cancer and adjacent normal tissue specimens. Ectopic overexpression of let-7c decreased proliferation, invasion, and colony formation. Integrated analysis of miRNA-mRNA using in silico algorithms and experimental validation databases identified four putative gene targets of let-7c. One of these targets, SOX13, was found to be upregulated in PDAC tumour compared with normal tissue in TCGA and an independent data set by qPCR and immunohistochemistry. RNAi knockdown of SOX13 reduced the invasion and colony formation ability of pancreatic cancer cells.

CONCLUSION

The identification of key miRNA-mRNA gene interactions and networks provide potential diagnostic and therapeutic strategies for better treatment options for pancreatic cancer patients.

Selective Resection of Type 1 Gastric Neuroendocrine Neoplasms and the Risk of Progression in an Endoscopic Surveillance Programme

BACKGROUND

Current guidance for type 1 gastric neuroendocrine neoplasms (gNENs) recommends either resection of all visible lesions or selective resection of gNENs >10 mm. We adopt a selective strategy targeting lesions approaching 10 mm for endoscopic mucosal resection (EMR) and provide surveillance for smaller lesions.

OBJECTIVES

This study aimed to describe the incidence of type 1 gNENs requiring endoscopic/surgical resection and the risk of disease progression (both considered significant disease) on endoscopic surveillance. The secondary objective was to assess the risk factors for disease progression during surveillance and the incidence of gastric dysplasia/adenoma/adenocarcinoma.

METHODS

We collected consecutive patients with type 1 gNENs and obtained demographic and clinical data through the electronic patient record.

RESULTS

In our cohort of 57 patients, 12 patients had EMR at index gastroscopy; 7 patients had surgery (4: large/multiple gNENs and 3: nodal metastases) (5.2% [3/57] risk of nodal metastases); and a patient with nodal and liver metastases (1.8% [1/57] risk of distant metastases). The prevalence of gastric adenocarcinoma in our study was 3.5% with an incidence rate of 9.59 per 1,000 persons per year. For patients undergoing surveillance, 29.5% (13/44) of patients progressed requiring resection. Serum gastrin was significantly higher in patients who progressed to resection (p value = 0.023).

CONCLUSION

We concluded that up to a third of patients with type 1 gNENs have significant disease requiring resection. Hence, endoscopic surveillance and resect strategy would benefit patients.

Abstract 1678: Establishment and characterization by expression microarrays of a patient-derived xenograft biobank for human pancreatic adenocarcinoma

Pancreatic cancer survival rate is poor, with a 5-year survival rate of 7% in the Republic of Ireland. Over the last 40 years, pancreatic cancer is one of the only solid tumor types to have minimal improvement in patient outcome. In Ireland, pancreatic cancer surgical resection is limited to two hospitals: Cork University Hospital and St Vincent's University Hospital (SVUH) in Dublin. In collaboration with SVUH, we have established Ireland's only pancreatic cancer patient-derived xenograft (PDX) biobank program. Tumor material from candidate patients following surgical resection was cold transferred and implanted subcutaneously into CB17/Icr-Prkdcscid mice. At time of implant and continuation of generations, snap frozen material was collected. Using miRNA and mRNA microarray technology, matched adjacent normal tissue, original tumor material and first generation (F1) PDX tumor material was interrogated. Differential expression analysis was carried out on all samples with comparisons of normal, tumor and F1 generation. Across all comparisons there were approximately 4000 genes and miRNAs found to be differential expressed. In focusing on genes that were upregulated in tumor samples compared to normal and further upregulated in the PDX F1 samples compared to the tumor samples, we identified 88 genes of interest. Biological processes such as cell division, mitotic cell cycle processes and cell cycle processes characterized a significant number of these genes. Two of the key genes of interest in this analysis were TSPAN1 and TPX2. TSPAN1 was upregulated 9.5-fold in tumor-normal comparison and upregulated a further 2.3-fold in the PDX F1 compared to the patient tumor. TPX2 was upregulated 4.4-fold in the tumor-normal comparison and a further 3.9-fold increase in the PDX tumor compared to patient tumor. TSPAN1 has previously been shown to increase the metastatic and invasive potential of pancreatic ductal adenocarcinoma cell lines. TPX2, a microtubule-associated protein, has been shown to reduce tumor growth in vivo when silenced. The pancreatic PDX biobank represents a versatile, expandable patient cohort for preclinical investigation. Analysis of gene expression profiles of normal vs tumor and tumor Vs PDX showed genes with associated tumor proliferation and aggressiveness.

Citation Format: Sandra Roche, Fiona O'Neill, Niall Swan, Ninfa L. Straubinger, Neil T. Conlon, Jean Murphy, Kevin Conlon, Ray McDermott, Justine Meiller, Justin Geoghegan, Michael Moriarty, Robert M. Straubinger, Martin Clynes. Establishment and characterization by expression microarrays of a patient-derived xenograft biobank for human pancreatic adenocarcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1678.

A multimodality test to guide the management of patients with a pancreatic cyst

Pancreatic cysts are common and often pose a management dilemma, because some cysts are precancerous, whereas others have little risk of developing into invasive cancers. We used supervised machine learning techniques to develop a comprehensive test, CompCyst, to guide the management of patients with pancreatic cysts. The test is based on selected clinical features, imaging characteristics, and cyst fluid genetic and biochemical markers. Using data from 436 patients with pancreatic cysts, we trained CompCyst to classify patients as those who required surgery, those who should be routinely monitored, and those who did not require further surveillance. We then tested CompCyst in an independent cohort of 426 patients, with histopathology used as the gold standard. We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.

Modelling of pancreatic cancer biology: transcriptomic signature for 3D PDX-derived organoids and primary cell line organoid development

With a five-year survival rate of 9%, pancreatic ductal adenocarcinoma (PDAC) is the deadliest of all cancers. The rapid mortality makes PDAC difficult to research, and inspires a resolve to create reliable, tractable cellular models for preclinical cancer research. Organoids are increasingly used to model PDAC as they maintain the differentiation status, molecular and genomic signatures of the original tumour. In this paper, we present novel methodologies and experimental approaches to develop PDAC organoids from PDX tumours, and the simultaneous development of matched primary cell lines. Moreover, we also present a method of recapitulating primary cell line cultures to organoids (CLOs). We highlight the usefulness of CLOs as PDAC organoid models, as they maintain similar transcriptomic signatures as their matched patient-derived organoids and patient derived xenografts (PDX)s. These models provide a manageable, expandable in vitro resource for downstream applications such as high throughput screening, functional genomics, and tumour microenvironment studies.

Establishment and Characterisation by Expression Microarray of Patient-Derived Xenograft Panel of Human Pancreatic Adenocarcinoma Patients

Pancreatic cancer remains among the most lethal cancers worldwide, with poor early detection rates and poor survival rates. Patient-derived xenograft (PDX) models have increasingly been used in preclinical and clinical research of solid cancers to fulfil unmet need. Fresh tumour samples from human pancreatic adenocarcinoma patients were implanted in severe combined immunodeficiency (SCID) mice. Samples from 78% of treatment-naïve pancreatic ductal adenocarcinoma patients grew as PDX tumours and were confirmed by histopathology. Frozen samples from F1 PDX tumours could be later successfully passaged in SCID mice to F2 PDX tumours. The human origin of the PDX was confirmed using human-specific antibodies; however, the stromal component was replaced by murine cells. Cell lines were successfully developed from three PDX tumours. RNA was extracted from eight PDX tumours and where possible, corresponding primary tumour (T) and adjacent normal tissues (N). mRNA profiles of tumour vs. F1 PDX and normal vs. tumour were compared by Affymetrix microarray analysis. Differential gene expression showed over 5000 genes changed across the N vs. T and T vs. PDX samples. Gene ontology analysis of a subset of genes demonstrated genes upregulated in normal vs. tumour vs. PDX were linked with cell cycle, cycles cell process and mitotic cell cycle. Amongst the mRNA candidates elevated in the PDX and tumour vs. normal were SERPINB5, FERMT1, AGR2, SLC6A14 and TOP2A. These genes have been associated with growth, proliferation, invasion and metastasis in pancreatic cancer previously. Cumulatively, this demonstrates the applicability of PDX models and transcriptomic array to identify genes associated with growth and proliferation of pancreatic cancer.

Expression of Selenoprotein Genes and Association with Selenium Status in Colorectal Adenoma and Colorectal Cancer

Dietary selenium (Se) intake is essential for synthesizing selenoproteins that are important in countering oxidative and inflammatory processes linked to colorectal carcinogenesis. However, there is limited knowledge on the selenoprotein expression in colorectal adenoma (CRA) and colorectal cancer (CRC) patients, or the interaction with Se status levels. We studied the expression of seventeen Se pathway genes (including fifteen of the twenty-five human selenoproteins) in RNA extracted from disease-normal colorectal tissue pairs, in the discovery phase of sixty-two CRA/CRC patients from Ireland and a validation cohort of a hundred and five CRC patients from the Czech Republic. Differences in transcript levels between the disease and paired control mucosa were assessed by the Mann-Whitney U-test. GPX2 and TXNRD3 showed a higher expression and GPX3, SELENOP, SELENOS, and SEPHS2 exhibited a lower expression in the disease tissue from adenomas and both cancer groups (p-values from 0.023 to <0.001). In the Czech cohort, up-regulation of GPX1, SELENOH, and SOD2 and down-regulation of SELENBP1, SELENON, and SELENOK (p-values 0.036 to <0.001) was also observed. We further examined the correlation of gene expression with serum Se status (assessed by Se and selenoprotein P, SELENOP) in the Irish patients. While there were no significant correlations with both Se status markers, SELENOF, SELENOK, and TXNRD1 tumor tissue expression positively correlated with Se, while TXNRD2 and TXNRD3 negatively correlated with SELENOP. In an analysis restricted to the larger Czech CRC patient cohort, Cox regression showed no major association of transcript levels with patient survival, except for an association of higher SELENOF gene expression with both a lower disease-free and overall survival. Several selenoproteins were differentially expressed in the disease tissue compared to the normal tissue of both CRA and CRC patients. Altered selenoprotein expression may serve as a marker of functional Se status and colorectal adenoma to cancer progression.

A Comparative Quantitative LC-MS/MS Profiling Analysis of Human Pancreatic Adenocarcinoma, Adjacent-Normal Tissue, and Patient-Derived Tumour Xenografts

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers worldwide; it develops in a relatively symptom-free manner, leading to rapid disease progression and metastasis, leading to a 5-year survival rate of less than 5%. A lack of dependable diagnostic markers and rapid development of resistance to conventional therapies are among the problems associated with management of the disease. A better understanding of pancreatic tumour biology and discovery of new potential therapeutic targets are important goals in pancreatic cancer research. This study describes the comparative quantitative LC-MS/MS proteomic analysis of the membrane-enriched proteome of 10 human pancreatic ductal adenocarcinomas, 9 matched adjacent-normal pancreas and patient-derived xenografts (PDXs) in mice (10 at F1 generation and 10 F2). Quantitative label-free LC-MS/MS data analysis identified 129 proteins upregulated, and 109 downregulated, in PDAC, compared to adjacent-normal tissue. In this study, analysing peptide MS/MS data from the xenografts, great care was taken to distinguish species-specific peptides definitively derived from human sequences, or from mice, which could not be distinguished. The human-only peptides from the PDXs are of particular value, since only human tumour cells survive, and stromal cells are replaced during engraftment in the mouse; this list is, therefore, enriched in tumour-associated proteins, some of which might be potential therapeutic or diagnostic targets. Using human-specific sequences, 32 proteins were found to be upregulated, and 113 downregulated in PDX F1 tumours, compared to primary PDAC. Differential expression of CD55 between PDAC and normal pancreas, and expression across PDX generations, was confirmed by Western blotting. These data indicate the value of using PDX models in PDAC research. This study is the first comparative proteomic analysis of PDAC which employs PDX models to identify patient tumour cell-associated proteins, in an effort to find robust targets for therapeutic treatment of PDAC.

Follicular dendritic cell sarcoma of the duodenum: an extremely rare entity

Extranodal follicular dendritic cell sarcoma (FDCS) is a very rare tumour, only reported in case reports and case series. It poses diagnostic and management challenge both to the clinician and pathologist. We present such a rare case of duodenal FDCS in a 56-year-old woman who was recently managed in our institution. Repeated pre surgical biopsies were non-diagnostic and the final diagnosis was made only after surgical excision of the tumour and with the help of histopathological and immunohistochemical studies. The patient had a complete en block resection of the tumour and was discharged home well 5 days postsurgery. To the best of our knowledge, this is the first case of FDCS reported arising from the duodenum.

A novel inhibitory anti-invasive MAb isolated using phenotypic screening highlights AnxA6 as a functionally relevant target protein in pancreatic cancer

Background:

Discovery and validation of new antibody tractable targets is critical for the development of new antibody therapeutics to address unmet needs in oncology.

Methods:

A highly invasive clonal variant of the MDA-MB-435S cell line was used to generate monoclonal antibodies (MAbs), which were screened for anti-invasive activity against aggressive cancer cells in vitro. The molecular target of selected inhibitory MAb 9E1 was identified using immunoprecipitation/liquid chromatography-tandem mass spectrometry. The potential anti-tumour effects of MAb 9E1 were investigated in vitro together with immunohistochemical analysis of the 9E1 target antigen in normal and cancer tissues.

Results:

MAb 9E1 significantly decreases invasion in pancreatic, lung squamous and breast cancer cells and silencing of its target antigen, which was revealed as AnxA6, leads to markedly reduced invasive capacity of pancreatic and lung squamous cancer in vitro. IHC using MAb 9E1 revealed that AnxA6 exhibits a high prevalence of membrane immunoreactivity across aggressive tumour types with restricted expression observed in the majority of normal tissues. In pancreatic ductal adenocarcinoma, high AnxA6 IHC score correlated with the presence of tumour budding at the invasive front of tumours (P=0.082), the presence of perineural invasion (P= <0.0001) and showed a weak correlation with reduced survival (P=0.2242).

Conclusions:

This study highlights the use of phenotypic hybridoma screening as an effective strategy to select a novel function-blocking MAb, 9E1 with anti-cancer activity in vitro. Moreover, through characterisation of the 9E1 target antigen, AnxA6, our findings support further investigation of AnxA6 as a potential candidate target for antibody-mediated inhibition of pancreatic cancer.

A Case of Autoimmune Pancreatitis Presenting as a Deterioration in Glycaemic Control in a Patient with Pre-Existing Type 2 Diabetes

We report a case of Type 1 autoimmune pancreatitis presenting as a rare cause of worsening hyperglycaemia in a patient with Type 2 diabetes and discuss the difficulties in differentiating this disease from pancreatic cancer.

Pulmonary metastasis from renal epithelioid angiomyolipoma in the setting of breast cancer

A 68-year-old woman presented with visible haematuria. Ultrasonography and triphasic CT revealed a 2.6 cm mass in the lower pole of the left kidney. A biopsy suggested low-grade renal cell carcinoma. Radical nephrectomy was performed and revealed an epithelioid angiomyolipoma. At year 3, the patient developed ductal carcinoma of the right breast and underwent a wide local excision and sentinel lymph node biopsy followed by chemotherapy and radiotherapy. 4 months later, she was noted to have a 1.6 cm nodule in the middle lobe of her right lung. The primary differential diagnosis was a breast cancer metastasis. Biopsy revealed a metastatic renal epithelioid angiomyolipoma. The patient elected to have stereotactic radiotherapy over surgical excision. Renal angiomyolipomata are generally regarded as benign tumours. In the present report, we describe the first case of pulmonary metastasis from renal epithelioid angiomyolipoma in the setting of breast cancer.

Osteoclastic-Type Giant Cell Tumours of the Pancreas: A Homogenous Series of Rare Tumours Diagnosed by Endoscopic Ultrasound

BACKGROUND

Giant cell tumors (GCT) of the pancreas are a rare form of pancreatic cancer. Although data are limited, clinical outcomes appear to depend largely on histological subtype with osteoclastic tumors carrying a better prognosis. We report on a homogenous series of patients with osteoclastic-type GCTs of the pancreas presenting to a national pancreatico-biliary gastrointestinal oncology center.

METHODS

Patients underwent endoscopic, radiological and histopathological assessments. Data were collected in relation to consecutive patients presenting with osteoclastic-type tumors of the pancreas and analyzed with survival as a primary end point.

RESULTS

Four patients were treated over a 4-year period. Median age was 77 years with equal gender distribution. Median tumor size was 42 mm. Histology was osteoclast-type giant cells in all 4 patients. Two patients underwent surgery with curative intent. Median overall survival was 13.1 months.

CONCLUSION

This is the largest reported series of osteoclast-type histology in GCTs of the pancreas.

A combination of molecular markers and clinical features improve the classification of pancreatic cysts

BACKGROUND & AIMS

The management of pancreatic cysts poses challenges to both patients and their physicians. We investigated whether a combination of molecular markers and clinical information could improve the classification of pancreatic cysts and management of patients.

METHODS

We performed a multi-center, retrospective study of 130 patients with resected pancreatic cystic neoplasms (12 serous cystadenomas, 10 solid pseudopapillary neoplasms, 12 mucinous cystic neoplasms, and 96 intraductal papillary mucinous neoplasms). Cyst fluid was analyzed to identify subtle mutations in genes known to be mutated in pancreatic cysts (BRAF, CDKN2A, CTNNB1, GNAS, KRAS, NRAS, PIK3CA, RNF43, SMAD4, TP53, and VHL); to identify loss of heterozygozity at CDKN2A, RNF43, SMAD4, TP53, and VHL tumor suppressor loci; and to identify aneuploidy. The analyses were performed using specialized technologies for implementing and interpreting massively parallel sequencing data acquisition. An algorithm was used to select markers that could classify cyst type and grade. The accuracy of the molecular markers was compared with that of clinical markers and a combination of molecular and clinical markers.

RESULTS

We identified molecular markers and clinical features that classified cyst type with 90%-100% sensitivity and 92%-98% specificity. The molecular marker panel correctly identified 67 of the 74 patients who did not require surgery and could, therefore, reduce the number of unnecessary operations by 91%.

CONCLUSIONS

We identified a panel of molecular markers and clinical features that show promise for the accurate classification of cystic neoplasms of the pancreas and identification of cysts that require surgery.

A Rare Case of BRCA2-Associated Breast Cancer in Pregnancy

A 30-year old woman was referred to our department with symptomatic breast cancer at 35 weeks gestation. Genetic testing revealed a pathogenic BRCA2 mutation. Labour was induced at 38 weeks. Mastectomy and axillary clearance were performed with a view to adjuvant chemotherapy, radiation and hormonal therapy. Multidisciplinary involvement is crucial for management of BRCA-associated breast cancer, especially in the context of pregnancy. Bilateral mastectomy may be indicated given the increased risk of ipsilateral and contralateral breast cancers. Tamoxifen may lower contralateral breast cancer risk in those in whom risk-reducing surgery is not performed.

Pancreatic metastasectomy: experience of the Irish National Surgical Centre for Pancreatic Cancer

BACKGROUND

Metastatic tumours of the pancreas are rare and the optimal management of these tumours remains unclear, given the paucity of data existing in the literature. We report our experience of pancreatic metastasectomy.

METHODS

Data were reviewed on all patients who underwent pancreatic resection for pathologically confirmed metastatic lesions over a consecutive 7-year period.

RESULTS

Seven patients (two men and five women) underwent a pancreatectomy for a metastatic pancreatic tumour. The primary tumours were renal cell carcinoma (n = 3), colorectal carcinoma (n = 2) and leiomyosarcoma (n = 2). There was no operative mortality. Postoperative morbidities occurred in two patients. The median follow-up was 49 months (range 17-76). Overall 1- and 2-year survivals were 100 and 86 %, respectively, with a 2-year disease-free survival of 72 %.

CONCLUSIONS

Our series further supports that pancreatic metastasectomy can be performed safely and achieves acceptable survival outcomes.

Pancreatectomy for metastatic disease: a systematic review

AIM

Tumours rarely metastasise to the pancreas. While surgical resection of such metastases is believed to confer a survival benefit, there is limited data to support such management. We present a systematic review of case series of pancreatic metastasectomy and analysis of survival outcomes.

METHODS

A literature search was performed using the PubMed and Cochrane databases and the reference lists of relevant articles, searching for sizeable case series of pancreatic metastasectomy with curative intent. Data extracted included basic demographics, histological primary tumour, presentation, operative management, complications and survival, while the MINORS index was used to assess study quality.

RESULTS

18 studies were found which met our inclusion criteria, involving 399 patients. Renal cell carcinoma (RCC) was the commonest malignancy metastasising to the pancreas, responsible for 62.6% of cases, followed by sarcoma (7.2%) and colorectal carcinoma (6.2%). While survival data was not uniformly reported, the median survival post-metastasectomy was 50.2 months, with a one-year survival of 86.81% and five-year survival of 50.02%. Median survival for RCC was 71.7 months with 70.4% five-year survival. Median survival was similar in patients with synchronous and metachronous pancreatic metastases, but patients with additional extrapancreatic metastases had a significantly shorter survival than patients with isolated pancreatic metastases (26 versus 45 months). Study quality was poor, with a median MINORS score of 10/16.

CONCLUSIONS

Within the limitations of a review of non-randomised case series, it would appear that pancreatic metastasectomy confers a survival benefit in selected patients. Better evidence is required, but may prove difficult to acquire.

Initial impact of a systematic multidisciplinary approach on the management of patients with gastroenteropancreatic neuroendocrine tumor

According to the international guidelines, a multidisciplinary approach is currently advised for the optimal care of patients with a gastroenteropancreatic neuroendocrine tumor (GEP NET). In our institution (tertiary care center), a systematic multidisciplinary approach was established in May 2007. In this study, we have aimed to assess the initial impact of establishing a systematic multidisciplinary approach to the management of GEP NET patients. We have collected and compared the biochemical, imaging, and pathological data and the therapeutic strategies in GEP NET patients diagnosed, treated, or followed-up from January 1993 to April 2007 versus GEP NET patients attending our institution after the multidisciplinary approach starting, from May 2007 to October 2008. Data of 91 patients before and 42 patients after the establishment of the multidisciplinary approach (total: 133 consecutive GEP NET patients) have been finally collected and analyzed. Before the establishment of the multidisciplinary approach, a lack of consistency in the biochemical, imaging, and pathological findings before treatment initiation as well as during follow-up of GEP NET patients was identified. These inconsistencies have been reduced by the systematic multidisciplinary approach. In addition, the therapeutic management of GEP NET patients has been altered by the multidisciplinary approach and became more consistent with recommended guidelines. We think that a systematic multidisciplinary approach significantly impacts on GEP NET patient care and should be established in all centers dealing with these tumors.

An analysis of the duplicate testing strategy of an Irish immunochemical faecal occult blood test colorectal cancer screening programme

AIM

This study examined the relevance of using a two-sample quantitative immunochemical faecal occult blood test (FIT) at a high cut-off stringency by the first population-based colorectal cancer (CRC) pilot screening programme in Ireland.

METHOD

Approximately 10,000 individuals between the ages of 50 and 74 years were invited to perform two consecutive FITs. These were analysed in tandem using the OC Sensor and participants with at least one positive result with a haemoglobin cut-off for positivity at 100 ng/ml were offered colonoscopy.

RESULTS

A total of 5023 (52%) [2177 (43%) male, 2846 (57%) female] individuals with a median age of 64 years participated. At least one positive FIT was detected from 514 (10%) individuals. From the 419 (82%) patients who proceeded to colonoscopy 17 (4%) had CRC and 132 (33%) had an advanced adenoma. The detection rate for these screen-relevant lesions was 3% (95% CI 2.5-3.5) and the FIT-positive colonoscopy detection rate was 36% (95% CI 31-40). The number needed to undergo colonoscopy to find an advanced lesion was 2.8. The two-test system detected four (23.5%) additional patients with CRC and 37 (28%) with an advanced adenoma compared with a single test.

CONCLUSION

The CRC miss rate estimated for a single test (23.5%) was unacceptably high when the goal was to maximize the discovery of advanced lesions in the initial screening round. We conclude that the two-test protocol at a high cut-off threshold is suitable for optimizing FIT screening in Ireland.

Metastatic chordoma detected by endobronchial ultrasound-guided transbronchial needle aspiration

Chordomas are rare, slow-growing malignant bone tumours arising from cellular remnants of the notochord. These tumours are locally invasive but have also a metastastic potential.Chordomas are characterized by the presence of physaliferous cells in a myxofibrillary stromal background. In cytological aspirates, these characteristic cells are usually absent, revealing only clusters of cells with varying degrees of vacuolation. This makes definitive diagnosis of chordoma difficult as the tumor can mimic other myxoid neoplasms including renal cell carcinomas and well-differentiated chondrosarcomas. In such situations, a confident diagnosis of chordoma requires comparison with histology of the primary tumor.We describe the first case of metastatic chordoma diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA).

The use of computerised tomography guided percutaneous fine needle aspiration in the evaluation of solitary pulmonary nodules

The evaluation of a solitary pulmonary nodule (SPN) has changed over the years with increased access to percutaneous computerised tomography (CT) guided fine needle aspiration (FNA), where bronchoscopy is unhelpful. The aim of our study was to evaluate the sample adequacy, diagnostic and complication rate of CT-FNA of a SPN at our academic teaching hospital over an 18 month period. CT-FNA was performed by a radiologist, with a cytopathologist in attendance to confirm the adequacy of the sample obtained. The size of the nodule, sample material and adequacy, diagnosis and complications were recorded. A total of 101 patients were included, 54 male and the mean age was 68 +/- 11 years. The mean size of the SPN was 2.3 cm (range 1-11 cm). 56 (56%) patients had a right SPN, 45 (45%) had a left SPN. CT-FNA was diagnostic in 80 (80%) patients and non-diagnostic in 21 (20%) patients. The sample was insufficient for immunocytochemistry, although the morphological appearance was diagnostic in 20 (25%) of the 80 patients. Pneumothorax occurred in 26/101 (26%) patients post CT-FNA, of these 7 (27%) required chest drain insertion, while 19 (73%) were managed conservatively. CT FNA is a useful tool for the diagnosis of a SPN, with our diagnostic accuracy comparable to that reported in the literature. However, CT-FNA may not provide adequate sample volume to perform ancillary testing and has a moderate complication rate.

Invasive markers identified by gene expression profiling in pancreatic cancer

BACKGROUND

Molecular profiling has proven utility as a diagnostic and predictive tool in clinical oncology. However, a clinically relevant gene expression profile in pancreatic cancer remains elusive.

METHODS

Primary and metastatic pancreatic cancer cell lines (BxPC-3 and AsPC-1), were stimulated with phorbol-12-myristate 13-acetate (PMA), a known inducer of cell invasion. Affymetrix gene expression microarray analysis was performed, comparing gene expression to unstimulated controls. Differential expression was identified using ArrayAssist, and confirmed using quantitative real-time PCR. Bioinformatic analysis was performed using Pathway Studio and GOstat. The derived gene expression was further validated in fresh frozen pancreatic tumour samples. The ability of the derived 3 gene expression markersto differentiate between pancreatic adenocarcinoma (PDAC) and other neoplasms, and its association with clinicopathological variables was examined.

RESULTS

PMA-induced significant changes in cell line gene expression, from which distinctive 3 potential invasive markers were derived. Expression of these genes, uPA, MMP-1 and IL1-R1 was confirmed in human pancreatic tumours, and was found to differentiate PDAC from other pancreatic neoplasms. The expression of IL1-R1 in PDAC is a novel finding. We found that the expression of MMP-1 was associated with high-grade PDAC (p = 0.035, Wilcoxon rank sum).

CONCLUSION

We have identified three potential invasive markers, uPA, MMP-1 and IL1-R1, whose gene expression may differentiate PDAC from other pancreatic neoplasms, and potentially reflect a more invasive phenotype.

Complex rectal polyps: other treatment modalities required when offering a transanal endoscopic microsurgery service

PURPOSE

Complex rectal polyps may present a clinical challenge. The study aim was to assess different treatment modalities required in the management of patients referred for transanal endoscopic microsurgery.

METHODS

Patients referred with complex rectal polyps from 1998 to 2008 were entered prospectively to a colorectal database. These data was analyzed for referral pattern, histology, surgical procedures performed, and subsequent outcome.

RESULTS

Of the 209 patients referred (101 female, 108 male, median age of 65 years, range of 24-89), 132 (63%) were deemed suitable for transanal endoscopic microsurgery. Seventeen patients required a second staged procedure; three patients required an anterior resection at time of index surgery. Seventeen patients referred for transanal endoscopic microsurgery went direct to anterior resection, 37 underwent snare polypectomy (SP), and 17 patients underwent transanal excision. Six patients had no surgery (three unfit for anesthesia and three had no residual lesions). Thus, 37% of the patients referred for transanal endoscopic microsurgery required a different treatment modality.

CONCLUSIONS

Majority of patients referred to our unit with complex rectal polyps were suitable for transanal endoscopic microsurgery. However, this study highlights that in offering a transanal microsurgery service, one should be prepared for a diversity of pathology necessitating a range of management options.

Laparoscopic resection for low rectal cancer: evaluation of oncological efficacy

INTRODUCTION

Laparoscopic resection of low rectal cancer poses significant technical difficulties for the surgeon. There is a lack of published follow-up data in relation to the surgical, oncological and survival outcomes in these patients.

AIM

The aim of this study is to evaluate the surgical, oncological and survival outcomes in all patients undergoing laparoscopic resection for low rectal cancer.

METHODS

Consecutive patients undergoing laparoscopic resection for low rectal cancers were included in the study. Clinical, pathological and follow-up data were recorded over a 4-year period. The mean follow-up was 25 months

RESULTS

A total of 53 patients were included in the study, 30 of whom were males. The mean age was 64.14 years (range, 34-86 years). The mean hospital stay was 8.2 days (range, 4-42 days). Fifty were completed laparoscopically and three were converted to an open procedure. Thirty-eight were anterior resections and 15 were abdominoperineal resections. Twenty-four patients received neoadjuvant chemoradiotherapy. The total mesorectal excision was optimal in 51 (98%) cases. There were no anastomotic sequelae and no surgical mortality. There was no local recurrence detected. The overall survival (mean follow-up, 25 months) was 93.5%.

CONCLUSION

Laparoscopic resection for low rectal cancers permits optimum oncological control. In our series, this technical approach is associated with excellent 4-year survival and clinical outcomes.

Genetic Mechanisms and Aberrant Gene Expression during the Development of Gastric Intestinal Metaplasia and Adenocarcinoma

Gastric adenocarcinoma occurs via a sequence of molecular events known as the Correa’s Cascade which often progresses over many years. Gastritis, typically caused by infection with the bacterium H. pylori, is the first step of the cascade that results in gastric cancer; however, not all cases of gastritis progress along this carcinogenic route. Despite recent antibiotic intervention of H. pylori infections, gastric adenocarcinoma remains the second most common cause of cancer deaths worldwide. Intestinal metaplasia is the next step along the carcinogenic sequence after gastritis and is considered to be a precursor lesion for gastric cancer; however, not all patients with intestinal metaplasia develop adenocarcinoma and little is known about the molecular and genetic events that trigger the progression of intestinal metaplasia into adenocarcinoma. This review aims to highlight the progress to date in the genetic events involved in intestinal-type gastric adenocarcinoma and its precursor lesion, intestinal metaplasia. The use of technologies such as whole genome microarray analysis, immunohistochemical analysis and DNA methylation analysis has allowed an insight into some of the events which occur in intestinal metaplasia and may be involved in carcinogenesis. There is still much that is yet to be discovered surrounding the development of this lesion and how, in many cases, it develops into a state of malignancy.

RNAi knockdown of Hop (Hsp70/Hsp90 organising protein) decreases invasion via MMP-2 down regulation

We previously identified Hop as over expressed in invasive pancreatic cancer cell lines and malignant tissues of pancreatic cancer patients, suggesting an important role for Hop in the biology of invasive pancreatic cancer. Hop is a co-chaperone protein that binds to both Hsp70/Hsp90. We hypothesised that by targeting Hop, signalling pathways modulating invasion and client protein stabilisation involving Hsp90-dependent complexes may be altered. In this study, we show that Hop knockdown by small interfering (si)RNA reduces the invasion of pancreatic cancer cells, resulting in decreased expression of the downstream target gene, matrix metalloproteinases-2 (MMP-2). Hop in conditioned media co-immunoprecipitates with MMP-2, implicating a possible extracellular function for Hop. Knockdown of Hop expression also reduced expression levels of Hsp90 client proteins, HER2, Bcr-Abl, c-MET and v-Src. Furthermore, Hop is strongly expressed in high grade PanINs compared to lower PanIN grades, displaying differential localisation in invasive ductal pancreatic cancer, indicating that the localisation of Hop is an important factor in pancreatic tumours. Our data suggests that the attenuation of Hop expression inactivates key signal transduction proteins which may decrease the invasiveness of pancreatic cancer cells possibly through the modulation of Hsp90 activity. Therefore, targeting Hop in pancreatic cancer may constitute a viable strategy for targeted cancer therapy.

A rare case of thyroid metastasis from pancreatic adenocarcinoma

CONTEXT

Thyroid metastasis from pancreatic adenocarcinoma is extremely rare, with only two previous cases in the literature. We report a case of pancreatic adenocarcinoma metastasising to the thyroid. We review the incidence, diagnosis, and management of this rare occurrence.

CASE REPORT

A 38-year-old man with a synchronous 6-month history of thyroid swelling, presented with epigastric pain and signs of obstructive jaundice. He was investigated by abdominal computerised tomography and endoscopic retrograde cholangiopancreatography. The diagnosis of pancreatic neoplasm was made. His thyroid neoplasm was investigated at another tertiary centre and thought to be a papillary neoplasm. He underwent a pancreaticoduodenectomy and recovered well post-operatively. Eight weeks later he had a total thyroidectomy. Histology confirmed that the thyroid mass was both morphologically and immunophenotypically similar to the pancreatic neoplasm.

CONCLUSION

This case demonstrates the importance of a full investigation when a patient with suspected neoplastic history presents with a thyroid nodule. We outline the crucial role that immunohistochemistry plays in detecting and classifying primary and secondary thyroid neoplasms. The detection of a solitary thyroid metastasis from pancreatic adenocarcinoma may indicate a poor prognosis, and it is debatable whether resection of the primary should be undertaken when it presents with a solitary metastasis.

A Case of Metastatic Renal Cell Cancer Presenting as Jaundice

Renal cell carcinoma is the second most common urological malignancy and it runs a highly variable clinical course. We describe a case of metastatic renal cell carcinoma in a 50-year-old lady with metastasis to the ampulla of Vater, clinically masquerading as cholelithiasis and biliary colic. The clinical, radiographic and endoscopic findings are presented. Ampullary metastases are rare, and prompt recognition and intervention are necessary before patient's performance status is compromised.

Metastatic phyllodes tumor causing small-bowel obstruction

Cystosarcoma phyllodes is an important but relatively uncommon fibroepithelial breast neoplasm that accounts for 0.5%-1.0% of female breast carcinomas. Malignant forms comprise nearly 25% of cases. These usually metastasize to the lung, pleura, bone, and liver. Metastases to the small intestine are extremely rare, with only 1 case of metastatic spread to the duodenum reported in the literature. No previous reports of metastatic spread to the ileum have been published. This report highlights a unique case of a metastatic phyllodes breast tumor leading to small bowel obstruction. Phyllodes tumors are generally classified into histologic subtypes of benign, intermediate, and malignant, using agreed classification systems. The tumor characteristics that can lead to the dedifferentiation of a relatively benign phenotype to an overt malignant process are discussed. Chemotherapeutic regimens that might be effective treatments are discussed, and the importance of regular clinical and radiologic follow-up in patients with poor prognostic factors is outlined.

Assessment of the clinical significance of intestinal spirochaetosis

Background:

Spirochaetes are well known causative agents of diarrhoea in veterinary medicine. However, there is no agreement as to whether or not they have any clinical significance in humans.

Aims:

To assess the symptoms associated with intestinal spirochaetosis, their response to treatment and the natural history of untreated cases.

Methods:

A retrospective review of all cases of intestinal spirochaetosis identified within an eight year period in a single university teaching hospital was performed. A chart review and follow up telephone interview was performed to assess the indications for colonoscopy that led to the diagnosis, treatment received, and duration and nature of symptoms.

Results:

18 cases were identified. The indications for colonoscopy were diarrhoea in 50% and rectal bleeding in 16.7%; also investigation of constipation, anaemia and abdominal pain, and in two cases reassessment of chronic proctitis. Two subjects were treated with metronidazole and two were treated with aminosalicylates. 69% had complete resolution of symptoms at follow-up, 15% had persistent symptoms and 15% had intermittent symptoms. Of the two patients treated with metronidazole, one had resolution of symptoms and one has persistent abdominal pain.

Conclusion:

Symptoms do not appear to parallel spirochaete persistence or eradication and therefore it seems appropriate to adopt a wait and see approach to treatment of patients in whom spirochaetes are identified, giving a trial of antimicrobial treatment only in those who have severe or persistent symptoms. Careful consideration of both host and pathogen should be undertaken.