Publications

BACKGROUND:

Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is a minimally invasive alternative technique for mediastinal staging of non-small cell lung cancer. A metaanalysis was performed to estimate the diagnostic accuracy of EUS-FNA for staging mediastinal lymph nodes (N2/N3 disease) in patients with lung cancer.

METHODS:

Relevant studies were identified using Medline (1966 to November 2005), CINAHL, and citation indexing. Included studies used histology or adequate clinical follow-up (> 6 months) as the “gold standard,” and provided sufficient data for calculating sensitivity and specificity. Summary receiver operating characteristic curves metaanalysis was performed to estimate the pooled sensitivity and specificity.

RESULTS:

In 18 eligible studies, EUS-FNA identified 83% of patients (95% confidence interval [CI], 78 to 87%) with positive mediastinal lymph nodes (pooled sensitivity) and 97% of patients (95% CI, 96 to 98%) with negative mediastinal lymph nodes (pooled specificity). In eight studies that were limited to patients who had abnormal mediastinal lymph nodes seen on CT scans, the sensitivity was 90% (95% CI, 84 to 94%) and the specificity was 97% (95% CI, 95 to 98%). In patients without abnormal mediastinal lymph nodes seen on CT scans (four studies), the pooled sensitivity was 58% (95% CI, 39 to 75%). Minor complications were reported in 10 cases (0.8%). There were no major complications.

CONCLUSIONS:

EUS-FNA is a safe modality for the invasive staging of lung cancer that is highly sensitive when used to confirm metastasis to mediastinal lymph nodes seen on CT scans. In addition, among lung cancer patients with normal mediastinal adenopathy seen on CT scans, despite lower sensitivity, it has the potential to prevent unnecessary surgery in a large proportion of cases missed by CT scanning.

Authors:

Micames CG, McCrory DC, Pavey DA, Jowell PS, Gress FG.

PMID: 17296659 [PubMed – indexed for MEDLINE]

Pancreatic ductal adenocarcinoma is a lethal cancer with fewer than 7% of patients surviving past 5 years. T-cell immunity has been linked to the exceptional outcome of the few long-term survivors, yet the relevant antigens remain unknown. Here we use genetic, immunohistochemical and transcriptional immunoprofiling, computational biophysics, and functional assays to identify T-cell antigens in long-term survivors of pancreatic cancer. Using whole-exome sequencing and in silico neoantigen prediction, we found that tumours with both the highest neoantigen number and the most abundant CD8⁺ T-cell infiltrates, but neither alone, stratified patients with the longest survival. Investigating the specific neoantigen qualities promoting T-cell activation in long-term survivors, we discovered that these individuals were enriched in neoantigen qualities defined by a fitness model, and neoantigens in the tumour antigen MUC16 (also known as CA125). A neoantigen quality fitness model conferring greater immunogenicity to neoantigens with differential presentation and homology to infectious disease-derived peptides identified long-term survivors in two independent datasets, whereas a neoantigen quantity model ascribing greater immunogenicity to increasing neoantigen number alone did not. We detected intratumoural and lasting circulating T-cell reactivity to both high-quality and MUC16 neoantigens in long-term survivors of pancreatic cancer, including clones with specificity to both high-quality neoantigens and predicted cross-reactive microbial epitopes, consistent with neoantigen molecular mimicry. Notably, we observed selective loss of high-quality and MUC16 neoantigenic clones on metastatic progression, suggesting neoantigen immunoediting. Our results identify neoantigens with unique qualities as T-cell targets in pancreatic ductal adenocarcinoma. More broadly, we identify neoantigen quality as a biomarker for immunogenic tumours that may guide the application of immunotherapies.

We have previously demonstrated that transcriptionally active high-risk HPV (hr-HPV) is strongly incriminated in Barrett’s dysplasia (BD) and oesophageal adenocarcinoma (OAC) using mainly fresh frozen tissue. This study aimed to identify biomarkers of active HPV infection in Barrett’s metaplasia, (BM)/BD/OAC by immunohistochemical staining (IHC) of formalin-fixed paraffin embedded (FFPE) tissue for aberrations of p53 and the retinoblastoma (pRb) pathway, which are targets for the viral oncoproteins, E6/E7, respectively. Prospectively, BM (n = 81)/BD (n = 72)/OAC (n = 65) FFPE specimens were subjected to IHC staining for pRb, p16^INK4A , cyclin D₁ , p53 and RNA in-situ hybridization for E6/E7 transcripts. HPV DNA was determined via PCR in fresh frozen specimens. Viral load measurement (real-time PCR) and Next Generation Sequencing of TP53 was performed. Of 218 patients, 56 were HPV DNA positive [HPV16 (n = 42), 18 (n = 13), 6 (n = 1)]. Viral load was low. Transcriptionally active HPV (DNA⁺ /RNA⁺ ) was only found in the dysplastic and adenocarcinoma group (n = 21). The majority of HPV DNA⁺ /RNA⁺ BD/OAC were characterized by p 16highINK4A (14/21, 66.7%), pRb_low (15/21, 71.4%) and p53_low (20/21, 95%) and was significantly different to controls [combination of HPV DNA^– /RNA^– (n = 94) and HPV DNA⁺ /RNA^– cohorts (n = 22)]. p53_low had the strongest association with DNA⁺ /RNA⁺ oesophageal lesions (OR = 23.5, 95% CI = 2.94-187.8, p = 0.0029). Seventeen HPV DNA⁺ /RNA⁺ BD/OAC identified as p53_low, were sequenced and all but one exhibited wild-type status. pRb_low /p53_low provided the best balance of strength of association (OR = 8.0, 95% CI = 2.6-25.0, p = 0.0003) and sensitivity (71.4%)/specificity (71.6%) for DNA⁺ /RNA⁺ BD/OAC. Active HPV involvement in BD/OAC is characterized by wild-type p53 and aberrations of the retinoblastoma protein pathway.

CONTEXT:

The role of EUS to evaluate subtle radiographic abnormalities of the pancreas is not well defined.

OBJECTIVE:

To assess the yield of EUS+/-FNA for focal or diffuse pancreatic enlargement/fullness seen on abdominal CT scan in the absence of discrete mass lesions.

DESIGN:

Retrospective database review.

SETTING:

Tertiary referral center.

PATIENTS AND INTERVENTIONS:

Six hundred and 91 pancreatic EUS exams were reviewed. Sixty-nine met inclusion criteria of having been performed for focal enlargement or fullness of the pancreas. Known chronic pancreatitis, pancreatic calcifications, acute pancreatitis, discrete mass on imaging, pancreatic duct dilation (greater than 4 mm) and obstructive jaundice were excluded.

MAIN OUTCOME MEASUREMENT:

Rate of malignancy found by EUS+/-FNA.

RESULTS:

FNA was performed in 19/69 (27.5%) with 4 new diagnoses of pancreatic adenocarcinoma, one metastatic renal cell carcinoma, one metastatic colon cancer, one chronic pancreatitis and 12 benign results. Eight patients had discrete mass lesions on EUS; two were cystic. All malignant diagnoses had a discrete solid mass on EUS.

CONCLUSIONS:

Pancreatic enlargement/fullness is often a benign finding related to anatomic variation, but was related to malignancy in 8.7% of our patients (6/69). EUS should be strongly considered as the next step in the evaluation of patients with focal enlargement of the pancreas when clinical suspicion of malignancy exists.

BACKGROUND:

The receptor tyrosine kinase RON exhibits increased expression during pancreatic cancer progression and promotes migration, invasion and gemcitabine resistance of pancreatic cancer cells in experimental models. However, the prognostic significance of RON expression in pancreatic cancer is unknown.

METHODS:

RON expression was characterized in several large cohorts, including a prospective study, totaling 492 pancreatic cancer patients and relationships with patient outcome and clinico-pathologic variables were assessed.

RESULTS:

RON expression was associated with outcome in a training set, but this was not recapitulated in the validation set, nor was there any association with therapeutic responsiveness in the validation set or the prospective study.

CONCLUSIONS:

Although RON is implicated in pancreatic cancer progression in experimental models, and may constitute a therapeutic target, RON expression is not associated with prognosis or therapeutic responsiveness in resected pancreatic cancer.

Pancreatic cancer is a highly lethal malignancy with few effective therapies. We performed exome sequencing and copy number analysis to define genomic aberrations in a prospectively accrued clinical cohort (n = 142) of early (stage I and II) sporadic pancreatic ductal adenocarcinoma. Detailed analysis of 99 informative tumours identified substantial heterogeneity with 2,016 non-silent mutations and 1,628 copy-number variations. We define 16 significantly mutated genes, reaffirming known mutations (KRAS, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1), and uncover novel mutated genes including additional genes involved in chromatin modification (EPC1 and ARID2), DNA damage repair (ATM) and other mechanisms (ZIM2, MAP2K4, NALCN, SLC16A4 and MAGEA6). Integrative analysis with in vitro functional data and animal models provided supportive evidence for potential roles for these genetic aberrations in carcinogenesis. Pathway-based analysis of recurrently mutated genes recapitulated clustering in core signalling pathways in pancreatic ductal adenocarcinoma, and identified new mutated genes in each pathway. We also identified frequent and diverse somatic aberrations in genes described traditionally as embryonic regulators of axon guidance, particularly SLIT/ROBO signalling, which was also evident in murine Sleeping Beauty transposon-mediated somatic mutagenesis models of pancreatic cancer, providing further supportive evidence for the potential involvement of axon guidance genes in pancreatic carcinogenesis.

OBJECTIVES:

The role of human papillomavirus (HPV) in Barrett’s esophagus (BE) remains unclear. The few studies that have previously investigated HPV and esophageal adenocarcinoma (EAC) or BE have produced either negative data or positive results of doubtful clinical/etiological significance or have detected only low-risk HPV types. We therefore prospectively determined the prevalence of biologically active HPV in esophageal epithelium of patients representing the Barrett’s metaplasia-dysplasia-adenocarcinoma sequence.

METHODS:

HPV DNA was estimated by nested PCR and viral transcriptional activity detected by E6/7 oncogene mRNA expression and p16INK4A immunohistochemistry in fresh frozen and paraffin-embedded esophageal biopsies of patients with BE, Barrett’s dysplasia (BD), and EAC, as well as controls. Biopsies were obtained from the transformation zone (squamocolumnar junction (SCJ)) and the lesion, or corresponding site in controls, i.e., 2 cm above the gastroesophageal junction (GEJ).

RESULTS:

Of the 261 patients, 81 were positive for HPV DNA. In controls and BE, the virus was mostly detected at the transformation zone. Compared with controls (18.0%), HPV positivity was significantly more common in BD (68.6%, incidence rate ratio (IRR) 2.94, 95% confidence interval (CI) 1.78-4.85, P<0.001) and EAC (66.7%, IRR 2.87, 95% CI 1.69-4.86, P<0.001), but not in BE (22.1%, IRR 1.06, 95% CI 0.60-1.85, P=0.85). Of the patients, 92.6% were high-risk (HR) HPV, i.e., types 16 and 18. Again, p16INK4A positivity was greatest in BD and EAC and much less in BE patients (44.1%, IRR 17.0 (95% CI 4.86-59.6, P<0.001), 44.4%, 17.0 (95% CI 4.87-59.4, P<0.001), and 10.6%, 3.93 (95% CI 1.01-15.3, P=0.048) respectively). In 66 HPV DNA-positive patients tested for E6/E7 mRNA, none of the control (n=16) or BE (n=13) individuals were positive, whereas 9/22 BD and 9/15 EAC patients demonstrated oncogene expression (P<0.001). When HPV DNA, p16INK4A, and E6/E7 mRNA were all positive, there was a very strong association with disease severity (SCJ: odds ratio (OR) 104, 95% CI 20.3-529, P<0.001; lesion: OR 62.2, 95% CI 12.4-311, P<0.001) than when all were negative.

CONCLUSIONS:

Transcriptionally active HR-HPV was strongly associated with BD and EAC, but was largely biologically irrelevant in BE and controls, suggesting a potential role in esophageal carcinogenesis. These data provide robust justification for further detailed longitudinal, interventional, and molecular studies.