Parallel evolution of two distinct lymphoid proliferations in clonal haematopoiesis.

AIMS: Angioimmunoblastic T-cell lymphoma (AITL) is genetically characterized by TET2 and DNMT3A mutations occurring in haematopoietic progenitor cells, and late events (e.g. the RHOA-G17V mutation) associated with malignant transformation. As TET2/DNMT3A-mutated progenitor cells can differentiate into multilineage progenies and give rise to both AITL and myeloid neoplasms, they may also have the potential to lead to other metachronous/synchronous neoplasms. We report two cases showing parallel evolution of two distinct potentially neoplastic lymphoid proliferations from a common mutated haematopoietic progenitor cell population. METHODS AND RESULTS: Both cases presented with generalized lymphadenopathy. In case 1 (a 67-year-old female), an initial lymph node (LN) biopsy was dismissed as reactive, but a repeat biopsy showed a nodal marginal zone lymphoma (NMZL)-like proliferation with an increase in the number of T-follicular helper (TFH) cells. Immunohistochemistry, and clonality and mutational analyses by targeted sequencing of both whole tissue sections and microdissected NMZL-like lesions, demonstrated a clonal B-cell proliferation that harboured the BRAF-G469R mutation and shared TET2 and DNMT3A mutations with an underlying RHOA-G17V-mutant TFH proliferation. Review of the original LN biopsy showed histological and immunophenotypic features of AITL. In case 2 (a 66-year-old male), cytotoxic T-cell lymphoma with an increase in the number of Epstein-Barr virus-positive large B cells was diagnosed on initial biopsy. On review together with the relapsed biopsy, we identified an additional occult neoplastic TFH proliferation/smouldering AITL. Both T-cell proliferations shared TET2 and DNMT3A mutations while RHOA-G17V was confined to the smouldering AITL. CONCLUSIONS: In addition to demonstrating diagnostic challenges, these cases expand the potential of clonal haematopoiesis in the development of different lineage neoplastic proliferations.

Integrated molecular analysis to investigate the role of microRNAs in pancreatic tumour growth and progression.

BACKGROUND: MicroRNAs (miRNAs) are small non-coding RNAs involved in the post-transcriptional regulation of mRNAs and are aberrantly expressed in cancer with important roles in tumorigenesis. A broad analysis of the combined effects of altered activities of miRNAs in pancreatic ductal adenocarcinoma (PDAC) has not been done, and how miRNAs might affect tumour progression or patient outcomes is unclear. METHODS: We combined data from miRNA and mRNA expression profiles from PDAC and normal pancreas samples (each n=9) and used bioinformatic analyses to identify a miRNA-mRNA regulatory network in PDAC. We validated our findings in PDAC cell-lines (PANC-1, MIA PaCa-2, LPc006, and LPc167), subcutaneous PDAC xenografts in mice, and laser capture microdissected PDACs from patients (n=91). We used this information to identify miRNAs that contributed most to tumorigenesis. FINDINGS: We identified three miRNAs (miR-21, miR-23a, and miR-27a) that acted as cooperative repressors of a network of tumour suppressor genes that included PDCD4, BTG2, and NEDD4L. Inhibition of miR-21, miR-23a, and miR-27a had synergistic effects in reducing proliferation of PDAC cells in culture and the growth of xenograft tumours. The level of inhibition was greater than that of silencing oncomiR-21 alone. In PDACs from patients, high levels of the combination of miR-21, miR-23a, and miR-27a was a strong independent predictor of short overall survival after surgical resection (hazard ratio 3·21, 95% CI 1·78-5·78). High expression of this combination was also associated with a more aggressive tumour phenotype: more microscopic tumour infiltration at resection margin and increased perineural invasion. INTERPRETATION: In an integrated data analysis, we identified functional miRNA-mRNA interactions that contribute to PDAC growth. These findings indicate that miRNAs act together to promote tumour progression and that future therapeutic strategies might require inhibition of several miRNAs. Furthermore, high tumour expression of the miR-21, miR-23a, and miR-27a combination could have potential use in the future as a prognostic signature for patients with PDAC. FUNDING: Peel Medical Research Trust, Alliance Family Foundation, Action Against Cancer, National Institute for Health Research, Association for International Cancer Research, Jason Boas Fellowship, Imperial Biomedical Research Centre, Rosetrees Trust, Joseph Ettedgui Charitable Foundation.

MicroRNAs cooperatively inhibit a network of tumor suppressor genes to promote pancreatic tumor growth and progression.

BACKGROUND & AIMS: There has not been a broad analysis of the combined effects of altered activities of microRNAs (miRNAs) in pancreatic ductal adenocarcinoma (PDAC) cells, and it is unclear how these might affect tumor progression or patient outcomes. METHODS: We combined data from miRNA and messenger RNA (mRNA) expression profiles and bioinformatic analyses to identify an miRNA-mRNA regulatory network in PDAC cell lines (PANC-1 and MIA PaCa-2) and in PDAC samples from patients. We used this information to identify miRNAs that contribute most to tumorigenesis. RESULTS: We identified 3 miRNAs (MIR21, MIR23A, and MIR27A) that acted as cooperative repressors of a network of tumor suppressor genes that included PDCD4, BTG2, and NEDD4L. Inhibition of MIR21, MIR23A, and MIR27A had synergistic effects in reducing proliferation of PDAC cells in culture and growth of xenograft tumors in mice. The level of inhibition was greater than that of inhibition of MIR21 alone. In 91 PDAC samples from patients, high levels of a combination of MIR21, MIR23A, and MIR27A were associated with shorter survival times after surgical resection. CONCLUSIONS: In an integrated data analysis, we identified functional miRNA-mRNA interactions that contribute to growth of PDACs. These findings indicate that miRNAs act together to promote tumor progression; therapeutic strategies might require inhibition of several miRNAs.

Single stage management of suspected gallbladder cancer guided by intraoperative frozen section analysis: A retrospective cohort study.

BACKGROUND: The management of radiologically suspected gallbladder cancers (GBC) that lack definitive radiological features usually involves performing a first-stage routine laparoscopic cholecystectomy, followed by an open second-stage liver resection (segments IVB and V) and hilar lymphadenectomy (extended cholecystectomy) if subsequent formal histology confirms a malignancy. Performing a cholecystectomy with an intraoperative frozen section to guide the need for conversion to an extended cholecystectomy as a single-stage procedure has multiple benefits compared to a two-stage approach. However, the safety and efficacy of this approach have not yet been evaluated in a tertiary setting. METHODS: A retrospective cohort study was performed using a database of all consecutive patients with suspected GBC who had been referred to our tertiary unit. Following routine cholecystectomy, depending on the operative findings, the gallbladder specimen was removed and sent for frozen-section analysis. If malignancy was confirmed, the depth of tumour invasion was evaluated, followed by simultaneous extended cholecystectomy, when appropriate. The sensitivity and specificity of frozen section analysis for the diagnosis of GBC were measured using formal histopathology as a reference standard. RESULTS: A total of 37 consecutive cholecystectomies were performed. In nine cases, GBC was confirmed by intraoperative frozen section analysis, three of which had standard cholecystectomy only as their frozen section showed adenocarcinoma to be T1a or below (n=2) or were undetermined (n=1). In the remaining six cases, malignant invasion beyond the muscularis propria (T1b or above) was confirmed; thus, a synchronous extended cholecystectomy was performed. The sensitivity (95% CI 66.4%-100%) and specificity (95% CI 87.7%-100%) for identifying GBC using frozen section analysis were both 100%. The net cost of the single-stage pathway in comparison to the two-stage pathway resulted in overall savings of £3894. CONCLUSION: Intraoperative frozen section analysis is a reliable tool for guiding the use of a safe, single-stage approach for the management of GBC in radiologically equivocal cases. In addition to its lower costs compared to a conventional two-stage procedure, intraoperative analysis also affords the benefit of a single hospital admission and single administration of general anaesthesia, thus greatly enhancing the patient's experience and relieving the burden on waiting lists.

Is there a 'margin' for error in pancreatic cancer surgery?

Evaluation of: Gnerlich JL, Luka SR, Deshpande AD et al. Microscopic margins and patterns of treatment failure in resected pancreatic adenocarcinoma. Arch. Surg. 147(8), 753-760 (2012). Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with one of the worst 5-year survival rates of any malignancy. Even after potentially curative surgical resection, disease may progress rapidly. It is therefore important to identify clinicopathologic factors that influence survival and may be modified to improve outcomes. The evaluated article presents data from a retrospective review of patients who underwent surgical resection for PDAC. Local recurrence (LR), distant recurrence and survival were compared between patients with a negative resection margin (R0) and those with a positive resection margin (R1). Patients with R1 posterior margins, in particular, were more likely to have LR and worse LR-free survival. In addition, this was more pronounced if patients had lymph-node involvement. Similar results have been reported in other studies and this study illustrates that standardized pathological reporting of PDAC specimens may allow further investigation of factors affecting R1 patients.

Poorly-differentiated signet-ring cell carcinoma of the ampulla of Vater: report of a rare malignancy.

CONTEXT: Signet-ring cell carcinoma (SRCC) of the ampulla of Vater is a very rare clinical entity, which is infrequently reported in medical literature. CASE REPORT: A 78-year-old woman was admitted with jaundice, pruritus and postprandial vomiting. Abdominal ultrasound and computed tomography scanning demonstrated gross dilatation of the common bile and pancreatic ducts with gallbladder calculi. Endoscopic retrograde cholangiopancreatography suggested a duodenal tumour at the ampulla. The patient underwent Whipple's procedure with cholecystectomy. Immunohistopathological examination confirmed poorly-differentiated SRCC of the ampulla of Vater. The tumour had infiltrated the duodenal muscularis propria and pancreatic parenchyma, but local lymph nodes were clear (T3N0M0). The patient was disease-free at 6-month follow-up. CONCLUSIONS: We here report a case of poorly-differentiated SRCC of the Ampulla of Vater. The majority of patients with such tumours undergo pancreaticoduodenectomy, which affords good outcomes in early disease. However, owing to the rarity of cases, the exact prognosis of ampullary SRCC remains as yet undetermined.

Can we predict long-term survival in resectable pancreatic ductal adenocarcinoma?

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive tumour associated with poor 5-year survival. We aimed to determine factors which differentiate short and long-term survivors and identify a prognostic biomarker. METHODS: Over a ten-year period, patients with resected PDAC who developed disease recurrence within 12 months (Group I) and those who had no disease recurrence for 24 months (Group II) were identified. Clinicopathological data was analysed. Ion Torrent high-throughput sequencing on DNA extracted from FFPE tumour samples was used to identify mutations. Additionally, peripheral blood samples were analysed for variants in cell-free DNA, circulating tumour cells (CTCs), and microRNAs. RESULTS: Multivariable analysis of clinicopathological factors showed that a positive medial resection margin was significantly associated with short disease-free survival (p = 0.007). Group I patients (n = 21) had a higher frequency of the KRAS mutant mean variant allele (16.93% ± 11.04) compared to those in Group II (n = 13; 7.55% ± 5.76, p = 0.0078). Group I patients also trended towards having a KRAS c.35G>A p.Gly12Asp mutation in addition to variants in other genes, such as TP53, CDKN2A, and SMAD4. Mutational status of cell-free DNA, and number of CTCs, was not found to be useful in this study. A circulating miRNA (hsa-miR-548ah-5p) was found to be significantly differentially expressed. CONCLUSIONS: Medial resection margin status and the frequency of KRAS mutation in the tumour tissue are independent prognostic indicators for resectable PDAC. Circulating miRNA hsa-miR-548ah-5p has the potential to be used as a prognostic biomarker.

Diagnostic Utility of Lymphoid Enhancer Binding Factor 1 Immunohistochemistry in Small B-Cell Lymphomas.

OBJECTIVES: Recent studies have shown that lymphoid enhancer binding factor 1 (LEF1) is a useful marker for chronic lymphocytic B-cell leukemia (CLL)/small lymphocytic lymphoma. Yet, it is not still being widely used in a diagnostic setting. In this study, we document the experience with LEF1 immunohistochemistry during routine diagnostics. METHODS: In total, 191 B-cell lymphoma cases from Hammersmith Hospital, Imperial College NHS Healthcare Trust (London, UK) were investigated by immunohistochemistry for LEF1 during routine diagnostic workup. These cases included both bone marrow trephines and lymph node biopsy specimens. The monoclonal antibody clone EPR2029Y was used. RESULTS: LEF1 expression was strong and diffuse (>70% of cells) in most cases. Few CLL cases showed a staining in proliferation centers only. Seventy-seven of 80 CLL cases expressed LEF1. Other entities expressing LEF1 included one of 38 follicular lymphomas, two of 33 marginal zone lymphomas, and one diffuse large B-cell lymphoma with a background of follicular lymphoma grade 3B. Sensitivity for LEF1 for the diagnosis of CLL was 0.96, and specificity was 0.93. CONCLUSIONS: In this study, we could demonstrate the diagnostic utility of LEF1. LEF1 is a sensitive and specific marker for CLL and is helpful in the diagnosis of diagnostically challenging small B-cell lymphomas.

Epithelial inclusion cyst arising within an intra-pancreatic splenunculus.

INTRODUCTION: An accessory spleen (splenunculus) may occur in up to 10% of the general population. However, an epithelial inclusion cyst originating within an intra-pancreatic splenunculus is an extremely rare finding, with only twenty-two previous cases described in medical literature. PRESENTATION OF CASE: A 51-year-old male presented to our institution for investigation of altered bowel habit. Endoscopic ultrasound examination and CT scanning demonstrated an 18 mm cystic, well-demarcated lesion in the tail of the pancreas, resembling malignancy. Following laparoscopic spleen-preserving distal pancreatectomy, histological analysis confirmed epithelial inclusion cyst arising within an intra-pancreatic splenunculus. DISCUSSION: The pre-operative radiological identification of such cystic pancreatic lesions is challenging. Surgical resection is usually performed for clinical suspicion of pancreatic malignancy. CONCLUSION: Epithelial inclusion cyst originating within an intra-pancreatic accessory spleen is an extremely rare finding, which can mimic malignancy. Nevertheless, it should be carefully considered in the differential diagnosis of cystic lesions of the tail of the pancreas.

Loco-recurrence after resection for ductal adenocarcinoma of the pancreas: predictors and implications for adjuvant chemoradiotherapy.

PURPOSE: Loco (regional)-recurrence rate after pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC) remains high, and the efficiency of adjuvant chemoradiotherapy is still debated. We aimed to assess predictors of loco-recurrence in order to tailor the indications for adjuvant chemoradiotherapy. METHODS: Patients who underwent PD for PDAC between January 2001 and December 2010 were retrieved from a prospective database. Tumor recurrence was categorized as either loco-recurrence or distant recurrence. Clinicopathological characteristics and survivals were compared between patients with different recurrence patterns. The predictors for loco-recurrence were assessed. RESULTS: Seventy-nine patients were included. Loco-recurrence alone was identified in 22 patients (27.8%), distant recurrence alone in 33 (41.8%), both loco- and distant recurrences in 17 (21.5%) and no recurrence in 7 (8.9%). Median survival after recurrence (SAR) was significantly better in patients with loco-recurrence alone than in those with distant recurrence alone (10.4 vs. 5.0 months, P = 0.002) or in those with both loco- and distant recurrences (10.4 vs. 5.8 months, P = 0.044); the survival for patients with distant recurrence alone and those with both patterns was identical. Patients with early recurrence had a significantly poorer SAR than those with late recurrence (median, 5.5 vs. 9.0 months, P = 0.001). Logistic regression analysis revealed that positive resection margin (P = 0.001, HR = 14.532; 95% CI 7.399-38.466), early T stage (P = 0.018, HR = 0.014; 95% CI 0.000-0.475) and large tumor size (P = 0.030, HR = 4.345; 95% CI 1.152-16.391) were the determinant factors directly related to loco-recurrence alone. CONCLUSIONS: Patients with PDAC loco-recurrence alone had a significantly better SAR than those with distant recurrence. Adjuvant chemoradiotherapy should be considered to reduce loco-recurrence further and improve long-term survival.

Tumor infiltration in the medial resection margin predicts survival after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma.

BACKGROUND: Microscopic tumor involvement (R1) in different surgical resection margins after pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC) has been debated. METHODS: Clinico-pathological data for 258 patients who underwent PD between 2001 and 2010 were retrieved from a prospective database. The rates of R1 resection in the circumferential resection margin (pancreatic transection, medial, posterior, and anterior surfaces) and their prognostic influence on survival were assessed. RESULTS: For PDAC, the R1 rate was 57.1% (48/84) for any margin, 31.0% (26/84) for anterior surface, 42.9% (36/84) for posterior surface, 29.8% (25/84) for medial margin, and 7.1% (3/84) for pancreatic transection margin. Overall and disease-free survival for R1 resections were significantly worse than those for R0 resection (17.2 vs. 28.7 months, P = 0.007 and 12.3 vs. 21.0 months, P = 0.019, respectively). For individual margins, only medial positivity had a significant impact on survival (13.8 vs. 28.0 months, P < 0.001), as opposed to involvement in the anterior (19.7 vs. 23.3 months, P = 0.187) or posterior margin (17.5 vs. 24.2 months, P = 0.104). Multivariate analysis demonstrated R0 medial margin was an independent prognostic factor (P = 0.002, HR = 0.381; 95% CI 0.207-0.701). CONCLUSION: The medial surgical resection margin is the most important after PD for PDAC, and an R1 resection here predicts poor survival.

MicroRNAs targeting oncogenes are down-regulated in pancreatic malignant transformation from benign tumors.

BACKGROUND: MicroRNA (miRNA) expression profiles have been described in pancreatic ductal adenocarcinoma (PDAC), but these have not been compared with pre-malignant pancreatic tumors. We wished to compare the miRNA expression signatures in pancreatic benign cystic tumors (BCT) of low and high malignant potential with PDAC, in order to identify miRNAs deregulated during PDAC development. The mechanistic consequences of miRNA dysregulation were further evaluated. METHODS: Tissue samples were obtained at a tertiary pancreatic unit from individuals with BCT and PDAC. MiRNA profiling was performed using a custom microarray and results were validated using RT-qPCR prior to evaluation of miRNA targets. RESULTS: Widespread miRNA down-regulation was observed in PDAC compared to low malignant potential BCT. We show that amongst those miRNAs down-regulated, miR-16, miR-126 and let-7d regulate known PDAC oncogenes (targeting BCL2, CRK and KRAS respectively). Notably, miR-126 also directly targets the KRAS transcript at a "seedless" binding site within its 3'UTR. In clinical specimens, miR-126 was strongly down-regulated in PDAC tissues, with an associated elevation in KRAS and CRK proteins. Furthermore, miR-21, a known oncogenic miRNA in pancreatic and other cancers, was not elevated in PDAC compared to serous microcystic adenoma (SMCA), but in both groups it was up-regulated compared to normal pancreas, implicating early up-regulation during malignant change. CONCLUSIONS: Expression profiling revealed 21 miRNAs down-regulated in PDAC compared to SMCA, the most benign lesion that rarely progresses to invasive carcinoma. It appears that miR-21 up-regulation is an early event in the transformation from normal pancreatic tissue. MiRNA expression has the potential to distinguish PDAC from normal pancreas and BCT. Mechanistically the down-regulation of miR-16, miR-126 and let-7d promotes PDAC transformation by post-transcriptional up-regulation of crucial PDAC oncogenes. We show that miR-126 is able to directly target KRAS; re-expression has the potential as a therapeutic strategy against PDAC and other KRAS-driven cancers.

Wide-field fluorescence lifetime imaging of cancer.

Optical imaging of tissue autofluorescence has the potential to provide rapid label-free screening and detection of surface tumors for clinical applications, including when combined with endoscopy. Quantitative imaging of intensity-based contrast is notoriously difficult and spectrally resolved imaging does not always provide sufficient contrast. We demonstrate that fluorescence lifetime imaging (FLIM) applied to intrinsic tissue autofluorescence can directly contrast a range of surface tissue tumors, including in gastrointestinal tissues, using compact, clinically deployable instrumentation achieving wide-field fluorescence lifetime images of unprecedented clarity. Statistically significant contrast is observed between cancerous and healthy colon tissue for FLIM with excitation at 355 nm. To illustrate the clinical potential, wide-field fluorescence lifetime images of unstained ex vivo tissue have been acquired at near video rate, which is an important step towards real-time FLIM for diagnostic and interoperative imaging, including for screening and image-guided biopsy applications.