Irshad Soomro

Barrett's dysplasia and the Vienna classification: reproducibility, prediction of progression and impact of consensus reporting and p53 immunohistochemistry.

Aims:  The Vienna classification is used to classify dysplasia in Barrett’s oesophagus (BO), but reproducibility and value of diagnosis of lower grades in particular are often questioned. The aim was to test the diagnostic variability and correlation with patient outcome and to attempt to define histological features causing discrepant diagnoses, as well as to test the impact of adding p53 immunohistochemistry on reproducibility and prediction of outcome.

Prognostic significance of circumferential resection margin involvement following oesophagectomy for cancer.

The factors affecting long-term survival following oesophagectomy for oesophageal cancer are poorly understood. We examined the significance of microscopic tumour involvement at the circumferential resection margin (CRM) on postoperative survival following oesophagectomy. The case notes of 329 patients who underwent a potentially curative oesophagectomy for squamous or adenocarcinoma were reviewed retrospectively. As part of the procedure, all patients underwent an en-bloc resection of their perioesophageal tissue. The presence of tumour either at, or within, 1 mm of the CRM was recorded and correlated with their TNM and survival data. A total of 67 patients (20%) were noted to have a positive CRM, of which 40 cases (12%) had tumour at the resection margin and the remainder had tumour within 1 mm of the margin. Univariate analysis showed no statistically significant association between survival and either category of CRM involvement. Multivariate analysis showed that only T-stage, nodal status and tumour grade were prognostic markers. In conclusion, the presence of microscopic tumour at the CRM following an en-bloc oesophagectomy is not a significant prognostic marker.

Biomarkers of response to therapy in oesophago-gastric cancer

Cancer of the oesophagus, gastro-oesophageal junction (GOJ) and stomach remains a major health problem worldwide. The evidence base for the optimal management of patients with operable oesophago-gastric cancer is evolving. Accepted approaches include preoperative chemotherapy followed by surgery (oesophageal cancer), chemo-radiotherapy alone (oesophageal cancer) and perioperative chemotherapy (gastric and gastro-oesophageal adenocarcinomas). The underlying principles behind neoadjuvant therapy are to improve resectability of the tumour by tumour shrinkage/downstaging and to treat occult metastatic disease as early as possible. The response rate to cytotoxic therapy is about 40% in oesophago-gastric cancer. Available evidence suggests that a favourable histopathological response to cytotoxic therapy may be a useful positive predictive marker in oesophago-gastric cancer. However, the ability to predict tumour response in routine clinical practice is difficult and is an area of intense investigation. There is evolving evidence for the role of predictive biomarkers in cancer in general and oesophago-gastric cancer in particular. We provide an overview on the current status of radiological and biological predictive biomarkers. We have focussed on clinical translational investigations and, where appropriate, provided pre-clinical insights. Whether predictive markers will be routinely incorporated in clinical practice remains to be seen as biomarker research is expensive and the data generated from these investigations are complex. It is clear that a concerted international effort between academia and industry is critical if personalised medicine as a practical reality for our cancer patients is to be realised.

Human apurinic/apyrimidinic endonuclease (APE1) is a prognostic factor in ovarian, gastro-oesophageal and pancreatico-biliary cancers

Background:Altered DNA repair may be associated with aggressive tumour biology and impact upon response to chemotherapy and radiotherapy. We investigated whether expression of human AP endonuclease (APE1), a key multifunctional protein involved in DNA BER, would impact on clinicopathological outcomes in ovarian, gastro-oesophageal, and pancreatico-biliary cancer.Methods:Formalin-fixed human ovarian, gastro-oesophageal, and pancreatico-biliary cancers were constructed into TMAs. Expression of APE1 was analysed by IHC and correlated to clinicopathological variables.Results:In ovarian cancer, nuclear APE1 expression was seen in 71.9% (97 out of 135) of tumours and correlated with tumour type (P=0.006), optimal debulking (P=0.009), and overall survival (P=0.05). In gastro-oesophageal cancers previously exposed to neoadjuvant chemotherapy, 34.8% (16 out of 46) of tumours were positive in the nucleus and this correlated with shorter overall survival (P=0.005), whereas cytoplasmic localisation correlated with tumour dedifferentiation (P=0.034). In pancreatico-biliary cancer, nuclear staining was seen in 44% (32 out of 72) of tumours. Absence of cytoplasmic staining was associated with perineural invasion (P=0.007), vascular invasion (P=0.05), and poorly differentiated tumours (P=0.068). A trend was noticed with advanced stage (P=0.077).Conclusions:Positive clinicopathological correlations of APE1 expression suggest that APE1 is a potential drug target in ovarian, gastro-oesophageal, and pancreatico-biliary cancers.

Tumour regression and ERCC1 nuclear protein expression predict clinical outcome in patients with gastro-oesophageal cancer treated with neoadjuvant chemotherapy

Aims:Neoadjuvant chemotherapy followed by surgery is the standard of care for patients with gastro-oesophageal adenocarcinoma. Previously, we validated the utility of the tumour regression grade (TRG) as a histopathological marker of tumour downstaging in patients receiving platinum-based neoadjuvant chemotherapy. In this study we profiled key DNA repair and damage signalling factors and correlated them with clinicopathological outcomes, including TRG response.Methods and results:Formalin-fixed human gastro-oesophageal cancers were constructed into tissue microarrays (TMAs). The first set consisted of 142 gastric/gastro-oesophageal cancer cases not exposed to neoadjuvant chemotherapy and the second set consisted of 103 gastric/gastro-oesophageal cancer cases exposed to preoperative platinum-based chemotherapy. Expressions of ERCC1, XPF, FANCD2, APE1 and p53 were investigated using immunohistochemistry.In patients who received neoadjuvant chemotherapy, favourable TRG response (TRG 1, 2 or 3) was associated with improvement in disease-specific survival (P=0.038). ERCC1 nuclear expression correlated with lack of histopathological response (TRG 4 or 5) to neoadjuvant chemotherapy (P=0.006) and was associated with poor disease-specific (P=0.020) and overall survival (P=0.040).Conclusions:We provide evidence that tumour regression and ERCC1 nuclear protein expression evaluated by immunohistochemistry are promising predictive markers in gastro-oesophageal cancer patients receiving neoadjuvant platinum-based chemotherapy.

The sensitivity of cytologic evaluation of pleural fluid in the diagnosis of malignant mesothelioma

Pleural malignant mesothelioma (MM), which is an aggressive neoplasm with a high mortality, frequently manifests initially as pleural effusions. The sensitivity of cytologic examination for its diagnosis varies widely in literature and most of the figures are from earlier studies with conventional cytologic preparations. The objective of this study was to provide the current evidence on the role and sensitivity of cytologic examination of pleural fluid in the diagnosis of MM. We reviewed the cytologic findings in pleural effusions of a large series of histologically proven MM (234 cases) diagnosed in our institution between 2001 and 2008. Of all cases, 154 (66%) had cytologic material examined. A specific diagnosis of MM was rendered or suspected in 53% (79 patients). The lowest sensitivity (20%) was noticed in sarcomatoid MM cases. MM was favored over adenocarcinoma in 97% of patients with positive cytologic findings that have been confirmed with immunohistochemistry. In this series, five cases were inadequate and five cases were initially reported as atypical, whereas 65 cases (44%) were reported as negative for malignancy. On review of the cytology slides, only four cases were upgraded from benign to suspicious compared to four cases downgraded from suspicious to atypical but no significant improvement to the diagnosis could be made on revision. These data suggested that a cytologic diagnosis contributed useful information in patients with epithelioid and biphasic pleural MM. Limitations of the cytologic examination of MM should also be acknowledged. Diagn. Cytopathol. 2010;38:874–879.

Pathological determinants of survival in node-negative oesophageal cancer.

Many studies have analysed prognostic factors following oesophagectomy, but few have examined survival determinants in node‐negative (N0) oesophageal cancer. The prognostic significance of a number of histological variables following surgical resection of N0 oesophageal cancer was studied.

Novel staining pattern of p53 in Barrett’s dysplasia – the absent pattern

Sir: Barrett’s oesophagus (BO) is conversion of oesophageal squamous mucosa to a glandular phenotype, and is a consequence of gastro-oesophageal reflux. This is a precursor to oesophageal adenocarcinoma (OA), which is rising rapidly in western countries and carries a poor prognosis. This pathway is characterized by intestinal metaplasia and increasing grades of dysplasia before cancer supervenes. Recognizing dysplasia early allows close monitoring as well as treatment preventing OA or cure at an early stage. The recog‘nition of dysplasia by pathologists is critical, and while pathologists can recognize dysplasia reproducibly this may sometimes be difficult. Therefore additional prognostic markers would be helpful. Several studies have shown that p53 overexpression is associated closely with dysplasia and predicts progression in its own right. Overexpression is a consequence of mutations which stabilize the inactivated protein. However, a subset of unequivocal Barrett’s dysplasia cases are negative for p53. In some cases p53 may not be involved in the dysplastic progression, but in other cases truncating TP53 mutations or epigenetic silencing may cause protein inactivation. In these cases it is lack of expression rather than overexpression which would be expected. With this in mind, we re-analysed the dysplastic and indefinite p53negative cases from our previously published study to see if this pattern might have accounted for some p53negative dysplasias and to assess its significance prognostically. As described in detail previously, cases of oesophageal glandular dysplasia were identified from pathology databases at Queens Medical Centre and City Hospital, Nottingham between 1987 and 2004. Thirtytwo random cases of BO without dysplasia were also included. Five pathologists blinded to the original diagnosis classified each case independently using the revised Vienna classification. One pathologist scored each p53-stained section (D07 antibody with microwave antigen retrieval; Dako, Ely, UK) as positive, negative or not representative. A consensus Vienna score for each case was determined. Cases negative for p53 but with a study diagnosis of dysplasia or indefinite for dysplasia were reviewed again by two pathologists (PVK and MI). Two distinct patterns were identified: (i) wild-type (p53-wt) with weak immunoreactivity in dysplastic ⁄ atypical epithelium similar to the background non-dysplastic epithelium and (ii) absent staining (p53-abs) with complete lack of staining in dysplastic ⁄ atypical epithelium relative to weak positivity in surrounding non-dysplastic epithelium (Figure 1). This contrasted with positive staining described above, where the dysplastic epithelium showed much stronger staining than the surrounding non-dysplastic epithelium (p53-pos). Patient records were examined to determine length of followup and progression. A total of 175 cases were identified. In 33 cases p53 staining could not be assessed due to lack of representative tissue, 43 cases were p53-positive (42 dysplasia, one indefinite) and 99 p53-negative (11 dysplasia, 10 indefinite). Re-analysis of categories 2–4 p53-negatives are shown in Table 1. The 10 indefinite for dysplasia cases all had staining in equivocal areas indistinguishable from background non-dysplastic Barrett’s epithelium (p53-wt). Of the 11 cases with dysplasia, five showed the absent pattern of staining in dysplastic areas (p53-abs), while six showed weak staining indistinguishable from background Barrett’s epithelium (p53-wt) (Table 1). Of the 40 patients with positive p53 with follow-up data available, 28 progressed within 10 years. Of the 10 patients with indefinite for dysplasia and p53-wt, two progressed within 10 years. Of the 11 dysplastic cases, all five with p53-abs progressed clinically or histologically but only two of six with p53-wt progressed; four remained alive with regression without intervention. We and others have shown that in addition to dysplasia, immunohistochemical analysis of p53 overexpression is a powerful predictor of progression in BO. Herein we have identified a novel pattern of complete absence of staining (p53-abs) which has a similar predictive value to the classical pattern of overexpression (p53-pos). This should add power to the technique of p53 immunohistochemistry by including cases with abnormal expression of the protein which was formally regarded as negative. p53-abs may correlate with truncating mutations in TP53 which cannot be recognized by the commonly used D07 antibody. Alternatively, a variety of other non-mutational mechanisms for TP53 inactivation have been described. The proportion of oesophageal cancers harbouring mutant p53 ranges up to 80%. Of our assessable definite dysplasia cases, 47 of 53 (89%) showed an abnormal p53 immunophenotype.

Tumour regression grade (TRG) analyses in patients with resectable gastro-oesophageal adenocarcinomas treated with platinum-based neoadjuvant chemotherapy.

Aims:  Neoadjuvant chemotherapy followed by surgery is the standard of care for patients with gastro‐oesophageal adenocarcinoma. The aims were to validate the utility of the tumour regression grade (TRG) in patients who have received chemotherapy and to investigate if (i) TRG correlates with tumour downstaging and (ii) TRG could provide a comparative platform for future predictive biomarker investigations.

BAI3, CDX2 and VIL1: a panel of three antibodies to distinguish small cell from large cell neuroendocrine lung carcinomas.

Discriminating small‐cell lung carcinoma (SCLC) from large‐cell neuroendocrine carcinoma (LCNEC) rests on morphological criteria, and reproducibility has been shown to be poor. We aimed to identify immunohistochemical markers to assist this diagnosis.