Fredrik T. Bosman

Distal and proximal colon cancers differ in terms of molecular, pathological and clinical features

BACKGROUND Differences exist between the proximal and distal colon in terms of developmental origin, exposure to patterning genes, environmental mutagens, and gut flora. Little is known on how these differences may affect mechanisms of tumorigenesis, side-specific therapy response or prognosis. We explored systematic differences in pathway activation and their clinical implications. MATERIALS AND METHODS Detailed clinicopathological data for 3045 colon carcinoma patients enrolled in the PETACC3 adjuvant chemotherapy trial were available for analysis. A subset of 1404 samples had molecular data, including gene expression and DNA copy number profiles for 589 and 199 samples, respectively. In addition, 413 colon adenocarcinoma from TCGA collection were also analyzed. Tumor side-effect on anti-epidermal growth factor receptor (EGFR) therapy was assessed in a cohort of 325 metastatic patients. Outcome variables considered were relapse-free survival and survival after relapse (SAR). RESULTS Proximal carcinomas were more often mucinous, microsatellite instable (MSI)-high, mutated in key tumorigenic pathways, expressed a B-Raf proto-oncogene, serine/threonine kinase (BRAF)-like and a serrated pathway signature, regardless of histological type. Distal carcinomas were more often chromosome instable and EGFR or human epidermal growth factor receptor 2 (HER2) amplified, and more frequently overexpressed epiregulin. While risk of relapse was not different per side, SAR was much poorer for proximal than for distal stage III carcinomas in a multivariable model including BRAF mutation status [N = 285; HR 1.95, 95% CI (1.6-2.4), P < 0.001]. Only patients with metastases from a distal carcinoma responded to anti-EGFR therapy, in line with the predictions of our pathway enrichment analysis. CONCLUSIONS Colorectal carcinoma side is associated with differences in key molecular features, some immediately druggable, with important prognostic effects which are maintained in metastatic lesions. Although within side significant molecular heterogeneity remains, our findings justify stratification of patients by side for retrospective and prospective analyses of drug efficacy and prognosis.

Prognosis of stage II and III colon cancer treated with adjuvant 5-fluorouracil or FOLFIRI in relation to microsatellite status: results of the PETACC-3 trial

BACKGROUND Although colon cancer (CC) with microsatellite instability (MSI) has a more favorable prognosis than microsatellite stable (MSS) CC, the impact varies according to clinicopathological parameters. We studied how MSI status affects prognosis in a trial-based cohort of stage II and III CC patients treated with 5-fluorouracil (5-FU)/leucovorin or FOLFIRI. MATERIALS AND METHODS Tissue specimens of 1254 patients were tested for 10 different loci and were classified as MSI-high (MSI-H) when three or more loci were unstable and MSS otherwise. Study end points were overall survival (OS) and relapse-free survival (RFS). RESULTS In stage II, RFS and OS were better for patients with MSI-H than with MSS CC [hazard ratio (HR) 0.26, 95% CI 0.10-0.65, P = 0.004 and 0.16, 95% CI 0.04-0.64, P = 0.01). In stage III, RFS was slightly better for patients with MSI-H CC (HR 0.67, 95% CI 0.46-0.99, P = 0.04), but the difference was not statistically significant for OS (HR 0.70, 95% CI 0.44-1.09, P = 0.11). Outcomes for patients with MSI-H CC were not different between the two treatment arms. RFS was better for patients with MSI-H than with MSS CC in the right and left colon, whereas for OS this was significant only in the right colon. For patients with KRAS- and BRAF-mutated CC, but not for double wild-type patients, RFS and OS were significantly better when the tumors were also MSI-H. An interaction test was statistically significant for KRAS and MSI status (P = 0.005), but not for BRAF status (P = 0.14). CONCLUSIONS Our results confirm that for patients with stage II CC but less so for those with stage III MSI-H is strongly prognostic for RFS and OS. In the presence of 5-FU treatment, stage II patients with MSI-H tumors maintain their survival advantage in comparison with MSS patients and adding irinotecan has no added benefit. CLINICALTRIALS.GOV IDENTIFIER: NCT00026273.BACKGROUND Although colon cancer (CC) with microsatellite instability (MSI) has a more favorable prognosis than microsatellite stable (MSS) CC, the impact varies according to clinicopathological parameters. We studied how MSI status affects prognosis in a trial-based cohort of stage II and III CC patients treated with 5-fluorouracil (5-FU)/leucovorin or FOLFIRI. MATERIALS AND METHODS Tissue specimens of 1254 patients were tested for 10 different loci and were classified as MSI-high (MSI-H) when three or more loci were unstable and MSS otherwise. Study end points were overall survival (OS) and relapse-free survival (RFS). RESULTS In stage II, RFS and OS were better for patients with MSI-H than with MSS CC [hazard ratio (HR) 0.26, 95% CI 0.10-0.65, P = 0.004 and 0.16, 95% CI 0.04-0.64, P = 0.01). In stage III, RFS was slightly better for patients with MSI-H CC (HR 0.67, 95% CI 0.46-0.99, P = 0.04), but the difference was not statistically significant for OS (HR 0.70, 95% CI 0.44-1.09, P = 0.11). Outcomes for patients with MSI-H CC were not different between the two treatment arms. RFS was better for patients with MSI-H than with MSS CC in the right and left colon, whereas for OS this was significant only in the right colon. For patients with KRAS- and BRAF-mutated CC, but not for double wild-type patients, RFS and OS were significantly better when the tumors were also MSI-H. An interaction test was statistically significant for KRAS and MSI status (P = 0.005), but not for BRAF status (P = 0.14). CONCLUSIONS Our results confirm that for patients with stage II CC but less so for those with stage III MSI-H is strongly prognostic for RFS and OS. In the presence of 5-FU treatment, stage II patients with MSI-H tumors maintain their survival advantage in comparison with MSS patients and adding irinotecan has no added benefit. CLINICALTRIALS. GOV IDENTIFIER NCT00026273.

Report of an Amsterdam working group on Barrett esophagus.

More than 50 years have passed since Barrett described a case of peptic ulcer disease of the esophagus and the condition that would carry his name [1]. It is now generally accepted that Barrett esophagus is the result of long-standing gastroesophageal reflux disease leading to replacement of the normal stratified squamous epithelial lining of the esophagus by glandular epithelium of various types [24, 32]. The importance of a diagnosis of Barrett esophagus is its association with the development of an esophageal adenocarcinoma. In contrast to what Norman Barrett originally thought, Barrett esophagus is a premalignant condition, and the incidence of Barrett carcinoma has increased dramatically since his publication in 1950 [12]. Barrett adenocarcinoma is preceded by a well-defined premalignant lesion, i.e., dysplasia (intraepithelial neoG. J. A. Offerhaus · S. van Eeden · F. J. W. ten Kate · A. Bosma Department of Pathology, Academic Medical Center Amsterdam, The Netherlands

Altered expression of CD44 and DKK1 in the progression of Barrett's esophagus to esophageal adenocarcinoma

Barrett’s esophagus (BE) is an acquired condition in which the normal lining of the esophagus is replaced by intestinal metaplastic epithelium. BE can evolve to esophageal adenocarcinoma (EAC) through low-grade dysplasia (LGD) and high-grade dysplasia (HGD). The only generally accepted marker for increased risk of EAC is the presence of HGD, diagnosed on endoscopic biopsies. More specific markers for the prediction of EAC risk are needed. A tissue microarray was constructed comprising tissue samples from BE, LGD, HGD, and EAC. Marker expression was studied by immunohistochemistry using antibodies against CD44, DKK1, CDX2, COX2, SOX9, OCT1, E-cadherin, and β-catenin. Immunostaining was evaluated semi-quantitatively. CD44 expression decreased in HGD and EAC relative to BE and LGD. DKK1 expression increased in HGD and EAC relative to BE and LDG. CDX2 expression increased in HGD but decreased in EAC. COX2 expression decreased in EAC, and SOX9 expression increased only in the upper crypt epithelial cells in HGD. E-cadherin expression decreased in EAC. Nuclear β-catenin was not significantly different between BE, LGD, and HGD. Loss of CD44 and gain of DKK1 expression characterizes progression from BE and LGD to HGD and EAC, and their altered expression might indicate an increased risk for developing an EAC. This observation warrants inclusion of these immunohistochemically detectable markers in a study with a long patient follow-up.

microRNAs in colon cancer: A roadmap for discovery

Here we review the main research findings on miRNA of the first 10 years in colon cancer research with an emphasis on possible uses in clinical practice. This review intends to provide a road map in the jungle of publications of miRNA in colorectal cancer, focusing on data availability and new ways to generate biologically relevant information out of these huge amounts of data.

Elevated hepatocyte paraffin 1 and neprilysin expression in hepatocellular carcinoma are correlated with longer survival

Hepatocyte paraffin 1 (Hep Par 1) and neprilysin (CD10) are well-known markers of hepatocellular carcinoma (HCC). To assess their potential prognostic role, we conducted a retrospective analysis of 97 formalin-fixed and paraffin-embedded HCC from patients treated by surgery with curative intent, using standard immunohistochemical procedures and semiquantitative analysis. Strong Hep Par 1 expression and canalicular CD10 staining pattern were significantly correlated with smaller tumor size (p=0.007 and 0.04, respectively). On univariate analysis, longer overall survival was observed in patients with strong Hep Par 1 expression (p=0.0005) and in patients with a CD10can staining pattern (p=0.02). On multivariate analysis, the combined immunohistochemical score (CIS) obtained by addition of Hep Par 1 and CD10can scores and subtraction of cytoplasmic CD10 score was retained as the single most important prognostic factor (p=0.001). Patients with a CIS <4 had a 3.5-fold increased risk of death, as compared to those with a CIS ≥4. In conclusion, strong Hep Par 1 expression, presence of CD10can labeling, and absence of CD10cyt staining are favorable prognostic factors in HCC, which can be easily combined into a single immunohistochemical score for routine clinical use.

Reduced Expression of SMAD4 Is Associated with Poor Survival in Colon Cancer.

Purpose: SMAD4 loss is associated with the development of metastases and poor prognosis. We evaluated expression of SMAD4 protein and its association with tumor characteristics, including biomarkers and outcome in terms of relapse-free survival and overall survival. Experimental design: We used 1,564 stage II/III colon cancer samples from PETACC-3 to evaluate SMAD4 expression by immunohistochemistry. SMAD4 protein expression was validated by assessing mRNA expression using available expression array data. SMAD4 expression was also studied on 34 adenomas and 10 colon cancer liver metastases with their primaries. Loss of SMAD4 immunoreactivity was defined as focal or diffuse. Cases without SMAD4 loss were subdivided into those with strong and weak expression. Results: SMAD4 protein expression was informative in 1,381/1,564 cases. SMAD4 loss was found in 293/1,381 (21%) cases. Of 1,088 cases without SMAD4 loss (79%), 530 showed weak and 558 strong expression. SMAD4 loss occurred also in adenomas, but less extensively than in carcinomas. Liver metastases followed mostly the expression pattern of the primary tumor. SMAD4 loss, including weak expression, identified patients with poor survival in stage II as well as III and in both treatment arms. SMAD4 loss was less frequent in tumors with microsatellite instability and more frequent in those with loss of heterozygosity of 18q. Conclusions: We conclude that clonal loss of SMAD4 expression in adenomas, carcinomas, and liver metastases increases with disease progression. SMAD4 loss, and to a lesser extent weak expression, is strongly associated with poor survival regardless of stage. Clin Cancer Res; 22(12); 3037–47. ©2016 AACR.

Abstract 4722: A BRAF-mutated gene expression signature identifies BRAF wild type colon cancer patients with poor prognosis

Background: We previously identified highly conserved gene expression patterns associated with BRAF V600E mutant MSS colon cancer (Tejpar et al, ASCO 2010). Since these tumors have very poor overall survival and are refractory to therapy, a better understanding of their molecular characteristics is relevant. In this study we explored if the observed BRAF-mutated characteristic gene expression patterns are also present in any non BRAF-mutant subgroup of colon cancer and what the prognostic implications might be. Methods: A representative set of 667 stage II and III FFPE colon cancers from the PETACC3 clinical trial with 7 years follow up data were used for this study. Samples were characterized for KRAS (39% of samples) and BRAF (6.5%) mutation status, Microsatellite instability (9.7%) (Roth et al, JCO 2009) and gene expression data was obtained with the ALMAC “Colorectal Cancer DSA(tm)” platform. A BRAF signature was built using top scoring pairs and was validated internally (split-sample and cross-validation) and externally (in two independent data sets). It was then applied to KRAS mutant and KRAS wild type (WT) MSI and MSS colon carcinomas. Prognostic value of the signature for overall survival (OS) and survival after relapse (SAR) was assessed by Cox proportional hazard models and survival distributions were compared using likelihood ratio tests. Results: A novel 78-gene BRAF signature was identified and validated, with independent validation performance measured by area under the ROC curve between 0.83 and 0.95. The BRAF signature had high sensitivity in predicting BRAF mutants (>88% internal and >75% external validation) and, in addition, it identified a subpopulation of ‘BRAF-like’ patients with poor prognosis, consisting of 37% of all KRAS mutants and of 13% of all double WT (WT2 – non BRAF and non KRAS mutants). In the whole population and in the MSS subpopulation the signature was prognostic for OS (whole population: hazard ratio HR=1.63, p=0.001; MSS HR=2.25, p Conclusions: Using a BRAF mutated derived gene expression signature, we identified a new subgroup within the BRAF WT population that bears a similar gene expression pattern and displays a similar bad prognosis. The signature identifies patients for whom additional therapeutic interventions would be important and the genes included might provide new therapeutic targets. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4722. doi:10.1158/1538-7445.AM2011-4722