The role of the systemic inflammatory response, the JAK STAT pathway and the MAPK pathway in the prognosis of resectable pancreatic cancer

Pancreatic cancer is a devastating disease with a five year survival of only 2-3%. Only 10-15% of patients have resectable disease at presentation and the only potential cure is major surgery with adjuvant chemotherapy. The outcomes of surgery are disappointing with a median survival of only15-17 months and operative mortality and morbidity figures of 5-10% and 40% respectively. This abysmal prognosis is likely due to the highly aggressive nature of the tumour, its resistance to adjuvant therapy, its late presentation and the likely presence of micro-metastases not detectable at staging or surgery. A pre-operative systemic inflammatory response (as measured by CRP) is known to be associated with a poor prognosis in a number of cancers including pancreatic cancer. The reasons behind this poor prognosis are not yet known. The main driver of plasma CRP levels is the cytokine IL-6, known to be elevated in the plasma of patients with pancreatic cancer. This thesis hypothesises that upregulation of two IL-6-dependent pathways, the JAK STAT and MAPK pathways is responsible for the poor prognosis associated with an inflammatory response in pancreatic cancer. Both of these pathways are known to be involved in cellular growth, differentiation and apoptosis and when activated they may confer a growth or survival advantage to tumour cells. The aims of this thesis were to establish the prognostic role of a systemic inflammatory response in resectable pancreatic cancer in both a retrospective and prospective cohort and establish whether increased protein expression in either the JAK STAT or MAPK pathways is associated with a poor prognosis in the same retrospective cohort. A retrospective database of 148 patients who had undergone Whipple resection for either pancreatic cancer (PC) or non-pancreatic peri-ampullary cancer (NPPC) was created with pre-operative CRP values and survival data. The author then created tissue micro-arrays (TMA’s) with both tumour and normal pancreatic duct tissue from each of the 148 patients in the retrospective cohort and carried out immunohistochemistry on 12 antibodies known to be crucial in IL-6 signalling (6 in the JAK STAT and 6 in the MAPK pathways). Following staining the author scored each of the antibodies using the weighted histoscore to allow analysis of antigen expression. During the period of research the author also created a prospective database of 36 patients who underwent surgery for either PC or NPPC. Plasma was stored pre-operatively from each of the patients and this was later thawed and using an ELISA kit another research fellow (JL) was able to establish plasma levels of IL-6 in the prospective cohort. On univariate analysis a raised pre-operative CRP was associated with poorer survival, 374 days versus 618 days (p=0.0001) in the retrospective PC group only. On multivariate analysis, only pre-operative CRP retained statistical significance amongst those factors shown to be significant on univariate analysis (P=0.009). In the prospective group, patients with low levels of IL-6 had a median survival of 799 days, against a median survival of 537 days in those with high plasma IL-6 levels (P=0.002) when all 36 patients were analysed together. On analysis of protein expression, no significant relationship between increased expression and poor survival was seen for any of the 12 proteins analysed. The results from this thesis confirm that a pre-operative inflammatory response is associated with poor survival in patients with resectable pancreatic cancer. Raised plasma levels of IL-6 are also associated with poorer survival in similar patients. However, the poor prognosis appears to be via a JAK STAT/ MAPK independent mechanism. Other possible explanations for this poor prognosis including the connection between inflammation and cachexia and other important inflammatory proteins such as NF-κB and SOCS are explored in the discussion of this thesis

Expression of KOC, S100P, mesothelin and MUC1 in pancreatico-biliary adenocarcinomas: development and utility of a potential diagnostic immunohistochemistry panel

<b>Background</b> Pancreatico-biliary adenocarcinomas (PBA) have a poor prognosis. Diagnosis is usually achieved by imaging and/or endoscopy with confirmatory cytology. Cytological interpretation can be difficult especially in the setting of chronic pancreatitis/cholangitis. Immunohistochemistry (IHC) biomarkers could act as an adjunct to cytology to improve the diagnosis. Thus, we performed a meta-analysis and selected KOC, S100P, mesothelin and MUC1 for further validation in PBA resection specimens.<p></p> <b>Methods</b> Tissue microarrays containing tumour and normal cores in a ratio of 3:2, from 99 surgically resected PBA patients, were used for IHC. IHC was performed on an automated platform using antibodies against KOC, S100P, mesothelin and MUC1. Tissue cores were scored for staining intensity and proportion of tissue stained using a Histoscore method (range, 0–300). Sensitivity and specificity for individual biomarkers, as well as biomarker panels, were determined with different cut-offs for positivity and compared by summary receiver operating characteristic (ROC) curve.<p></p> <b>Results</b> The expression of all four biomarkers was high in PBA versus normal ducts, with a mean Histoscore of 150 vs. 0.4 for KOC, 165 vs. 0.3 for S100P, 115 vs. 0.5 for mesothelin and 200 vs. 14 for MUC1 (p < .0001 for all comparisons). Five cut-offs were carefully chosen for sensitivity/specificity analysis. Four of these cut-offs, namely 5%, 10% or 20% positive cells and Histoscore 20 were identified using ROC curve analysis and the fifth cut-off was moderate-strong staining intensity. Using 20% positive cells as a cut-off achieved higher sensitivity/specificity values: KOC 84%/100%; S100P 83%/100%; mesothelin 88%/92%; and MUC1 89%/63%. Analysis of a panel of KOC, S100P and mesothelin achieved 100% sensitivity and 99% specificity if at least 2 biomarkers were positive for 10% cut-off; and 100% sensitivity and specificity for 20% cut-off.<p></p> <b>Conclusion</b> A biomarker panel of KOC, S100P and mesothelin with at least 2 biomarkers positive was found to be an optimum panel with both 10% and 20% cut-offs in resection specimens from patients with PBA.<p></p&gt

Two week rule compliance: assessing general practice use of the 'Two Week Rule' referral pathway for the suspicion of colorectal cancer

Background: The 'Two-Week-Rule' (TWR) for referring patients with a suspicion of colorectal cancer (CRC) was implemented in 2000 to improve CRC survival rates. Guidelines exist to assist general practitioners (GPs) identify patients based on high-risk symptomology. Our aim was to evaluate the effectiveness of these guidelines, to determine whether a correlation exists between individual criteria within the guidelines and CRC, and to assess GP compliance of guidelines in referring symptomatic patients. Methods: 485 consecutive 'TWR' referrals to colorectal unit in a district general hospital and all patients diagnosed with CRC or high grade dysplasia (HGD) regardless of referral route, were prospectively collected between July and December 2015. Both lists were independently maintained and retrospectively analysed. Results were cross-examined for accuracy and main measures include: reason(s) for referral, secondary-care investigation(s) and diagnoses. Results: GPs referred 333 patients based on symptomology suggestive of CRC; while referring an additional 152 patients (31.3%) that failed to meet NICE guidelines for TWR referral. CRC or HGD was diagnosed in 28 patients; 27 of whom (96.4%, p = 0.0005) were identified through a guideline compliant referral. During the study period 79 cases of CRC or HGD were diagnosed from all referral routes; 36.7% through the 'TWR' referral pathway. Conclusion: Updated NICE referral guidelines for suspected CRC appear to be effective in identifying patients with CRC based on high-risk symptomology. Guideline compliance from GPs remains a barrier in the 'TWR' referral system. GPs paradoxically over-refer guideline non-complaint patients, while under-referring guideline complaint patients; reducing the effectiveness of the 'TWR' referral system

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

A prospective comparison of the prognostic value of tumor- and patient-related factors in patients undergoing potentially curative surgery for pancreatic ductal adenocarcinoma

Outcome prediction after resection with curative intent for pancreatic ductal adenocarcinoma remains a challenge. There is increasing evidence that the presence of an ongoing systemic inflammatory response is associated with poor outcome in patients undergoing resection for a variety of common solid tumors. Our aim was to prospectively evaluate the prognostic value of tumor- and patient-related factors including the systemic inflammatory response in patients undergoing potentially curative surgery for pancreatic ductal adenocarcinoma of the head of pancreas. The prognostic impact of tumor factors such as stage and host factors, including the systemic inflammatory response (modified Glasgow Prognostic Score [mGPS]), were evaluated in a prospective study of 135 patients who underwent elective pancreaticoduodenectomy for pancreatic ductal adenocarcinoma from January 2002 to April 2009. In addition to the established tumor-related pathological factors (in particular margin involvement; hazard ratio [HR] 2.82, 95% confidence interval [CI] 1.65-4.84, P &lt; 0.001), an elevated mGPS (HR 2.26, 95% CI 1.43-3.57, P &lt; 0.001) was independently associated with lower overall survival after pancreaticoduodenectomy. Additionally, in an adjuvant therapy subgroup of 74 patients, both margin involvement and an elevated mGPS remained independently associated with reduced overall survival. We have prospectively validated the influence of tumor-related and patient-related factors. Margin involvement and the preoperative mGPS were the most important determinants of overall survival in patients undergoing potentially curative pancreaticoduodenectomy. Furthermore, both had independent prognostic value in those patients receiving adjuvant chemotherapy. In the future, this may be considered a stratification factor for entry onto therapeutic trials