Expression of cartilage oligomeric matrix protein in periampullary adenocarcinoma is associated with pancreatobiliary-type morphology, higher levels of fibrosis and immune cell exclusion

Cartilage oligomeric matrix protein (COMP) is an emerging regulator of tumor progression. The aim of this study was to evaluate the expression of COMP in periampullary adenocarcinoma with respect to prognostic value for survival and relapse, levels of fibrosis and infiltrating immune cells. COMP expression was evaluated using immunohistochemistry in primary tumors and subsets of paired lymph node metastases in tissue microarrays including 175 patients with periampullary adenocarcinoma. Collagen content was assessed with Sirius Red-Fast Green staining. High COMP levels were detected in cancer cells and in stroma, in 46% and 57% of the patients, respectively. High COMP expression was strongly associated with more aggressive pancreatobiliary-type (PB-type) compared to intestinal-type tumors (p < .0001). Importantly, high expression of COMP correlated with the exclusion of cytotoxic T-cells from the cancer cell compartment of the tumors, particularly in PB-type tumors. Higher levels of fibrosis measured by the density of collagen fibers correlated with high COMP levels in both cancer cells and stroma. This in turn could lead to exclusion of cytotoxic T-cells from accessing the cancer cells, a recognized immunotherapy resistance mechanism. Targeting COMP could therefore be considered as a novel therapeutic strategy in PB-type periampullary adenocarcinoma.

Branching Copy-Number Evolution and Parallel Immune Profiles across the Regional Tumor Space of Resected Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal disease. The only option for curative treatment is resection of the tumor followed by standard adjuvant chemotherapy. Yet, early relapse due to chemoresistance is almost inevitable. Herein, we delineated the genetic intratumor heterogeneity in resected PDAC, with the aim to identify evolutionary patterns that may be associated with overall survival (OS) following treatment with curative intent. Potential relationships with the adjacent immune microenvironment were also examined. The genetic and immune landscapes of the regional tumor space were analyzed in nine patients with resected PDAC. Targeted deep sequencing and genome wide SNP array were followed by clonal deconvolution and phylogenetic analysis. A mathematical complexity score was developed to calculate the network extent of each phylogeny. Spatial variation in abundancy and tumor nest infiltration of immune cells was analyzed by double IHC staining. Copy-number heterogeneity was denoted as the major contributing factor to the branching architectures of the produced phylogenetic trees. Increased tree complexity was significantly inversely associated with OS, and larger regional maximum aberrations (higher treetops) were associated with increased PD-L1 expression on tumor cells. Contrastingly, an FREM1 gene amplification, found in one patient, coincided with a particularly vigorous immune response. Findings from this limited case series suggest that complex evolutionary patterns may be associated with a shorter survival in surgically treated patients with PDAC. Some hypothesis-generating associations with the surrounding immune microenvironment were also detected.

IMPLICATIONS

Evolutionary copy-number patterns may be associated with survival in patients with resected PDAC.

PRR11 unveiled as a top candidate biomarker within the RBM3-regulated transcriptome in pancreatic cancer

The outlook for patients with pancreatic cancer remains dismal. Treatment options are limited and chemotherapy remains standard of care, leading to only modest survival benefits. Hence, there is a great need to further explore the mechanistic basis for the intrinsic therapeutic resistance of this disease, and to identify novel predictive biomarkers. RNA‐binding motif protein 3 (RBM3) has emerged as a promising biomarker of disease severity and chemotherapy response in several types of cancer, including pancreatic cancer. The aim of this study was to unearth RBM3‐regulated genes and proteins in pancreatic cancer cells in vitro, and to examine their expression and prognostic significance in human tumours. Next‐generation RNA sequencing was applied to compare transcriptomes of MIAPaCa‐2 cells with and without RBM3 knockdown. The prognostic value of differentially expressed genes (DEGs) was examined in The Cancer Genome Atlas (TCGA). Top deregulated genes were selected for further studies in vitro and for immunohistochemical analysis of corresponding protein expression in tumours from a clinically well‐annotated consecutive cohort of 46 patients with resected pancreatic cancer. In total, 19 DEGs (p < 0.01) were revealed, among which some with functions in cell cycle and cell division stood out; PDS5A (PDS cohesin associated factor A) as the top downregulated gene, CCND3 (cyclin D3) as the top upregulated gene, and PRR11 (proline rich 11) as being highly prognostic in TCGA. Silencing of RBM3 in MiaPaCa‐2 cells led to congruent alterations of PDS5A, cyclin D3, and PRR11 levels. High protein expression of PRR11 was associated with adverse clinicopathological features and shorter overall survival. Neither PDS5A nor cyclin D3 protein expression was prognostic. This study unveils several RBM3‐regulated genes with potential clinical relevance in pancreatic cancer, among which PRR11 shows the most consistent association with disease severity, at both transcriptome and protein levels.

Topographical Distribution and Spatial Interactions of Innate and Semi-Innate Immune Cells in Pancreatic and Other Periampullary Adenocarcinoma

Background

The clinical management of pancreatic and other periampullary neoplasms remains challenging. In contrast to other cancer types, immunotherapies are largely ineffective, and the reason for the deprived immune response and the immune inhibiting cellular composition is only fragmentarily understood. The aim of this study was to comprehensively map the abundance, topographic distribution and spatial interaction of innate and innate-like immune cells in the tumor microenvironment of periampullary adenocarcinoma.

Methods

Multiplexed immunofluorescent imaging was performed on tissue microarrays with tumors from a consecutive cohort of 175 patients with resected periampullary adenocarcinoma. To obtain a detailed spatial analysis of immune cell infiltration, two multiplex immune panels including antibodies against CD3, NKp46, CD56, CD68, CD163 and CD1a, CD208, CD123, CD15, CD68 and pan-cytokeratin were applied.

Results

The infiltration of natural killer (NK) and NK-like T (NKT) cells was lower in malignant compared to benign tissue. NKT cells were more abundant in intestinal type compared to pancreatobiliary type tumors, and were associated with more favorable clinicopathological features and a prolonged survival. The interaction of NKp46⁺ NKT cells with macrophages was also associated with a prolonged survival.

Conclusions

This study provides a comprehensive map of the innate immune landscape in periampullary adenocarcinoma. NK cells, and even more so NKT cells, are revealed to be central players in the local immune response in a clinically relevant context.

Additive clinical impact of epidermal growth factor receptor and podocalyxin-like protein expression in pancreatic and periampullary adenocarcinomas

The outcome of periampullary adenocarcinomas remains poor with few treatment options. Podocalyxin-like protein (PODXL) is an anti-adhesive protein, the high expression of which has been shown to confer a poor prognosis in numerous malignancies. A correlation and adverse prognostic synergy between PODXL and the epidermal growth factor receptor (EGFR) has been observed in colorectal cancer. Here, we investigated whether this also applies to periampullary adenocarcinomas. We analyzed the immunohistochemical expression of PODXL and EGFR in tissue microarrays with tumors from two patient cohorts; (Cohort 1, n = 175) and (Cohort 2, n = 189). The effect of TGF-β-induced expression and siRNA-mediated knockdown of PODXL and EGFR, were investigated in pancreatic cancer cells (PANC-1) in vitro. We found a correlation between PODXL and EGFR in these cancers, and a synergistic adverse effect on survival. Furthermore, silencing PODXL in pancreatic cancer cells resulted in the down-regulation of EGFR, but not vice versa. Consequently, these findings suggest a functional link between PODXL and EGFR, and the potential combined utility as biomarkers possibly improving patient stratification. Further studies examining the mechanistic basis underlying these observations may open new avenues of targeted treatment options for subsets of patients affected by these particularly aggressive cancers.

Quantitative, qualitative and spatial analysis of lymphocyte infiltration in periampullary and pancreatic adenocarcinoma

Immunotherapeutic modalities are currently revolutionizing cancer treatment. In pancreatic cancer, however, early clinical trials have been disappointing. The optimization of immunotherapeutic strategies requires better understanding of the inflammatory tumor microenvironment. Therefore, the aim of our study was to perform a detailed in situ description of lymphocyte infiltration patterns in resected pancreatic and other periampullary cancers. Multiplexed immunofluorescence imaging was applied to tissue microarrays with tumors from a cohort of 175 patients with resected periampullary adenocarcinoma. A panel of immune cell markers including CD4, CD8α, FoxP3, CD20, CD45RO and pan-cytokeratin was applied to allow for simultaneous spatial analysis of multiple lymphocyte populations. The majority of lymphocyte populations were significantly more abundant in intestinal (I-type) compared to pancreatobiliary (PB-type) tumors. Hierarchical cluster analysis revealed several immune cell signatures of potential clinical relevance. Notably, in the stromal compartment of PB-type tumors, high infiltration of B cells, CD8α⁺ CD45RO⁺ and single-positive CD4⁺ T cells, but low levels of FoxP3⁺ CD45RO^high and single-positive CD8α⁺ T cells were associated with improved overall survival (OS). The study also defined prognostic relevant topographical patterns of lymphocytic infiltration, in particular proximity of CD8α⁺ cells to cancer cells. Moreover, the presence of lymphocytes with potential T-helper capacities (CD4⁺ ) in the nearest vicinity to CD8α⁺ cells was associated with a prolonged OS. Our data demonstrate that the composition and clinical impact of immune infiltrates in periampullary adenocarcinoma differ by morphological type as well as localization. Furthermore, spatial in situ analysis identified potential immunological mechanisms of prognostic significance.

Clinical significance of stromal ER and PR expression in periampullary adenocarcinoma

BACKGROUND

Tamoxifen treatment has previously been reported to confer life-prolonging effects in patients with advanced pancreatic cancer, and most evidently so in women. None of these trials did however include biomarkers, and the relevance of female hormone signaling in pancreatic or other periampullary adenocarcinoma remains largely unexplored. The aim of this study was to examine the extent and potential clinical significance of estrogen receptor-α (ER) and progesterone receptor (PR) expression in pancreatic and other periampullary cancers.

METHODS

ER and PR expression was examined using immunohistochemistry on tissue microarrays with primary tumors from a retrospective consecutive cohort of 175 patients with resected periampullary adenocarcinoma, with long-term clinical follow-up. Non-parametric and Chi square tests were applied to examine the associations of stromal ER and PR expression with patient and tumor characteristics. Kaplan-Meier analysis and log rank test were applied to illustrate survival differences in relation to ER and PR expression. Cox regression proportional hazards models were applied to examine the associations between investigative factors and risk of death and recurrence, and to test for interactions between KRAS mutation status and hormone receptor expression in relation to survival.

RESULTS

Expression of both ER and PR was more frequent in the tumor-associated stroma than in the epithelium. A significant prognostic interaction, independent of tumor morphology, was found between stromal PR expression and KRAS mutation status in relation to both overall and recurrence-free survival (pinteraction = 0.026 and pinteraction = 0.005), in particular in women (pinteraction = 0.002 and pinteraction = 0.005). Specifically, stromal PR expression was associated with a prolonged survival in patients with KRAS-mutated tumors, whereas the opposite was seen for KRAS wild-type tumors. The prognostic value of ER positivity was limited to the subgroup of women with tumors of pancreatic origin.

CONCLUSIONS

These results demonstrate that stromal PR rather than ER expression, together with KRAS mutation status, provides long-term prognostic information in patients with periampullary adenocarcinoma. Further study into the mechanistic basis for these observations may unveil important clues to the pathogenesis of these cancers and open up for the discovery of novel treatment options.

Mutational Landscape in Resected Periampullary Adenocarcinoma: Relationship With Morphology and Clinical Outcome

PURPOSE

Periampullary adenocarcinomas encompass a heterogeneous group of tumors with dismal prognosis and limited treatment options. Emerging evidence shows that tumor morphology (ie, intestinal type [I-type] or pancreatobiliary type [PB-type]) is a more relevant prognostic factor than tumor origin. Knowledge is sparse, however, on whether key mutations differ according to morphology.

MATERIALS AND METHODS

Next-generation sequencing was applied to assess the mutational status of 70 genes in 102 tumors from a retrospective cohort of 175 patients with resected periampullary adenocarcinoma. Brahma-related gene 1 protein expression was examined by immunohistochemistry on tissue microarrays with primary tumors from the original cohort.

RESULTS

APC mutations were significantly more common in I-type than in PB-type tumors (27.5% v 0%; P < .001), as were ERBB3 mutations (20.8% v 4.8%; P = .016), whereas CDKN2A mutations were more common in PB-type than in I-type tumors (19.4% v 2.5%; P = .013). KRAS mutation was an independent factor of poor prognosis in I-type tumors (hazard ratio, 3.73; 95% CI, 1.10 to 12.67). In PB-type tumors, SMARCA4 mutation was an adverse prognostic factor in patients not receiving adjuvant chemotherapy, and there was a significant treatment interaction between expression of Brahma-related gene 1 protein, the protein encoded by SMARCA4, and adjuvant chemotherapy (P_interaction = .007).

CONCLUSION

To our knowledge, this is the first description of the mutational landscape in the full spectrum of periampullary adenocarcinoma that demonstrates that the distribution and prognostic and predictive significance of commonly mutated genes differ by morphology. The results emphasize that morphology is an important factor to consider in the search for novel biomarkers and targeted personalized treatment of these patients. In addition, the findings support the concept that molecular profiling of these tumors could be of clinical benefit.

Endoscopic submucosal dissection of malignant non-pedunculated colorectal lesions

BACKGROUND AND STUDY AIMS

 Endoscopic submucosal dissection (ESD) is an established method for en bloc resection of large non-pedunculated colorectal lesions in Asia but dissemination of ESD in Western countries is limited. The aim of this study was to evaluate the role of ESD in the management of malignant non-pedunculated colorectal lesions in a European center.

PATIENTS AND METHODS

Among 255 patients undergoing colorectal ESD between 2014 and 2016, 29 cases were identified as submucosal invasive cancers and included in this study. The main outcomes were en bloc, R0 and curative resection as well as procedural time, complications and recurrence.

RESULTS

Median tumor size was 40 mm (range 20 - 70 mm). Thirteen cancers were located in the colon and 16 were located in the rectum. Procedural time was 89 minutes (range 18 - 594 minutes). Complete resection was achieved in 28 cases, en bloc and R0 resection rates were 83 % and 69 %, respectively. Curative resection rate was 38 %. One case had a perforation in the sigmoid colon requiring emergency surgery. No significant bleeding occurred. Six patients underwent additional surgery after ESD, one of whom had residual tumor. One recurrence was detected in 20 patients that were followed-up endoscopically, median follow-up time was 13 months (range 2 - 30 months).

CONCLUSION

ESD seems to be a safe and effective method for treating non-pedunculated malignant colorectal lesions after careful patient selection and proper endoscopic training.

Relationship between mismatch repair immunophenotype and long-term survival in patients with resected periampullary adenocarcinoma

Background

Periampullary adenocarcinomas, including pancreatic cancer, are a heterogeneous group of tumors with poor prognosis, where classification into intestinal type (I-type) or pancreatobiliary type (PB-type) is a relevant prognostic factor. The clinical significance of deficient mismatch repair (dMMR) in periampullary adenocarcinoma is comparatively unexplored. Herein, we examined the associations of MMR immunophenotype with long-term survival in patients with resected periampullary adenocarcinoma, with particular reference to morphology and adjuvant treatment response.

Methods

MMR protein expression was assessed by immunohistochemistry on tissue microarrays with primary tumors from a retrospective cohort of 175 patients with periampullary adenocarcinoma treated with pancreaticoduodenectomy during 2001–2011 in Malmö and Lund University Hospitals, Sweden. Cox proportional hazards models were applied to calculate hazard ratios (HR) and 95% confidence intervals (CI).

Results

After a mean follow-up of 46.5 (1.9–185.1) months, 35 patients (20.3%) were alive, 24 with I-type and 11 with PB-type tumors. MMR protein expression could be evaluated in 172 cases, in which dMMR was denoted in 20 (11.6%) cases, 13/63 (20.6%) in I-type and 7/109 (6.4%) in PB-type tumors. dMMR was associated with a significantly prolonged overall survival in the entire cohort (HR = 0.28, 95% CI 0.13–0.57), and in I-type tumors (HR = 0.20, 95% CI 0.06–0.68), however not independent of conventional prognostic factors. In PB-type tumors, dMMR was not prognostic, but there was a significant negative interaction between dMMR and adjuvant treatment (p_interaction = 0.015).

Conclusions

dMMR is more frequent in I-type compared to PB-type periampullary adenocarcinoma, and is a prognostic factor for long-term survival only in the former. The finding of the small number of PB-type tumors with dMMR potentially lacking benefit from adjuvant chemotherapy is however noteworthy and merits further validation.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1444-4) contains supplementary material, which is available to authorized users.

Expression of PD-L1 in periampullary adenocarcinoma: Relationship with morphological type, the immune microenvironment and prognosis

268

Background: Overall survival for patients with periampullary adenocarcinoma, including pancreatic cancer, continues to be poor. Pancreatic cancer is characterized by a largely immunosuppressive microenvironment, but blockade of the programmed death ligand 1 (PD-L1) pathway has still not been effective. Reports on the prognostic value of PD-L1 expression in pancreatic and in particular periampullary cancer are sparse. The aim of this study was therefore to analyze PD-L1 expression in periampullary adenocarcinoma, with specific reference to morphological type, tumor-infiltrating immune cells, and survival. Methods: PD-L1 expression in tumor cells (TC) and immune cells (IC) was assessed by immunohistochemistry on tissue microarrays with primary tumors from a retrospective consecutive cohort of 175 patients with resected periampullary adenocarcinoma, 65 of intestinal(I)-type and 110 of pancreatobiliary(PB)-type. Correlations with various immune cells were calculated with non-parametric tests. Cox proportional hazards models were applied to calculate hazard ratios (HR) and 95% confidence intervals (CI) for death. Results: TC PD-L1 expression was not associated with any clinicopathological factors nor with survival. IC PD-L1 ( > 10%) expression was higher in I-type than in PB-type tumors (p < 0.001), and correlated with defect mismatch repair (p = 0.012) and lymph node negativity (p = 0.016). IC PD-L1 was not prognostic in PB-type tumors. High IC PD-L1 was associated with a prolonged survival in the entire cohort (HR = 0.59, CI 0.40-0.88), and in I-type tumors (HR = 0.38, CI 0.18-0.81), but not after adjustment for other prognostic factors. In I-type tumors, high IC PD-L1 correlated with high density of T cells (CD3+, CD8+, FoxP3+), but not with B cell or macrophage density. There were no significant associations between IC PD-L1 expression and any other immune cells in PB-type tumors. Conclusions: High PD-L1 expression in IC is associated with a T cell dense tumor microenvironment and a prolonged survival in I-type, but not in PB-type, periampullary adenocarcinoma, thus indicating that the effect of immune-modulating therapies may differ by morphological type.

A translational effort to identify prognostic and predictive biomarkers in pancreatic cancer among RBM3-regulated genes

305

Background: Pancreatic cancer has a dismal prognosis and clinical protocols are still lacking predictive biomarkers. RNA-binding motif protein 3 (RBM3) has emerged as a promising biomarker in several solid cancers, including pancreatic cancer. High RBM3 expression in human tumors has been associated with good response to chemotherapy, as well as to confer increased chemosensitivity in vitro. The aim of this study was to identify RBM3-regulated genes in pancreatic cells in vitro, and further interrogate their potential utility as prognostic and predictive biomarkers in a translational setting. Methods: Next generation RNA-sequencing was applied to compare gene expression between MIAPaCa-2 cells with siRNA-downregulated RBM3 and control cells. Single genes with the strongest association to RBM3 were further selected by gene set enrichment analysis, and their prognostic value in pancreatic cancer was examined in The Cancer Genome Atlas (TCGA). The most promising biomarker candidates with well-validated antibodies were then analyzed by immunohistochemistry in tissue microarrays with tumors from a consecutive, retrospective cohort of 175 patients with periampullary and pancreatic adenocarcinoma. Results: MIAPaCa-2 cells with downregulated RBM3 displayed 21 differentially expressed genes (p < 0.01). One of the top downregulated genes was PDS cohesion associated factor A (PDS5A) encoding a protein involved in sister chromatid cohesion. PDS5A protein expression was reduced in siRBM3-treated MIAPaCa-2 cells compared to control cells. High PDS5A mRNA expression was significantly associated with a reduced survival in pancreatic cancer in the TCGA (n = 176, p = 0.026). High PDS5A protein expression in the separate cohort was significantly associated with a poor prognosis but predictive of improved response to adjuvant chemotherapy in KRAS-mutated, but not wild-type, pancreatobiliary-type tumors (p for interaction = 0.043). Conclusions: Here, we provide the first report of the expression of PDS5A in pancreatic and periampullary cancer, suggesting its potential utility as a prognostic and predictive biomarker. Further studies to unravel the underlying mechanisms are encouraged.

Clinical impact of tumour-infiltrating B-cells in periampullary adenocarcinoma in relation to adjuvant chemotherapy

330

Background: The prognostic significance of tumour-infiltrating lymphocytes of the B lineage in solid cancers has only recently begun to receive attention. Herein, we explored the relationship between B cell and plasma cell density and survival in patients with periampullary adenocarcinoma, including pancreatic cancer, with particular reference to morphological type. Methods: Immunohistochemistry was applied to quantify the abundance of B cells (CD20+), and plasma cells (CD138+) in tissue microarrays with tumours from a retrospective consecutive cohort of 175 patients who had undergone pancreaticoduodenectomy for periampullary adenocarcinoma. Cox regression was applied to calculate univariable and multivariable hazard ratios (HR) for recurrence and death within five years up until March 2017. Multivariable HRs were adjusted for established clinical parameters. Results: High CD20+ cell density was an independent prognostic factor for a prolonged overall survival in both intestinal-type (HR 0.32; 95% CI 0.12-0.86) and pancreatobiliary-type (HR 0.38; 95% CI 0.23-0.66) tumours. CD138+ was an independent prognostic factor in pancreatobiliary-type tumours (HR 0.51; 95% CI 0.32-0.82) only. A significant positive interaction was seen between adjuvant chemotherapy and CD20+ cells in relation to OS for PB-type tumours (pinteraction= 0.027). Conclusions: These results demonstrate that dense infiltration into the tumour by cells of the B lymphocyte lineage confers an improved prognosis in periampullary adenocarcinoma including pancreatic cancer. The impact of B cells in the local anti-tumour response is gradually being unravelled, and their potential influence on adjuvant chemotherapy response in the more aggressive pancreatobiliary-type tumours may be clinically relevant and merits further study.

Relationship between mismatch repair status and long-term survival in patients with resected periampullary adenocarcinoma

289

Background: Periampullary adenocarcinomas, including pancreatic cancer, are a heterogenous group of tumors with poor prognosis. Emerging evidence indicates that tumor morphology, i.e. intestinal type (I-type) or pancreatobiliary type (PB-type), is a more relevant prognostic factor than anatomical tumor origin. The extent and clinical significance of deficient mismatch repair (dMMR) in periampullary adenocarcinoma is relatively unexplored. In this study, we examined the associations of MMR status with survival in patients with resected periampullary adenocarcinoma, with particular reference to tumor morphology and adjuvant treatment response. Methods: MMR status was assessed by immunohistochemistry on tissue microarrays with primary tumors from a retrospective consecutive cohort of 172 patients with periampullary adenocarcinoma treated with pancreaticoduodenectomy during 2001-2011 in Malmö and Lund University Hospitals, Sweden. Cox proportional hazards models were applied to calculate hazard ratios (HR) and 95% confidence intervals (CI) for death. Results: After a mean follow-up of 46.5 months (range 1.9-185.1), 35 patients (20.3%) were alive, 24 with I-type and 11 with PB-type tumors. Adjuvant chemotherapy was given in 77 (44.8%) cases, 18/63 (28.6%) I-type tumors and 59/109 (54.1%) PB-type tumors. MMR status could be evaluated in 170 cases, in which dMMR was denoted in 22 (12.9%) cases, 13/61(21.3%) in I-type and 9/109 (8.3%) in PB-type tumors. dMMR was associated with a significantly prolonged overall survival in the entire cohort (HR = 0.32, 95% CI 0.17-0.61), and in I-type tumors (HR = 0.27, 95% CI 0.09-0.79), however not independent of conventional prognostic factors. In PB-type tumors, dMMR was only prognostic in non-adjuvant treated cases (HR = 0.26, 95% CI 0.08-0.85), and there was a significant negative interaction between dMMR and adjuvant treatment (pinteraction= 0.008). Conclusions: dMMR signifies a prolonged survival in patients with periampullary adenocarcinoma, but may be a negative predictor of response to adjuvant chemotherapy in PB-type tumors. This finding may be highly relevant for clinical decision making and warrants further study.

Translational study reveals a two-faced role of RBM3 in pancreatic cancer and suggests its potential value as a biomarker for improved patient stratification

Periampullary adenocarcinoma, including pancreatic cancer, is a heterogeneous group of tumors with dismal prognosis, partially due to lack of reliable targetable and predictive biomarkers. RNA-binding motif protein 3 (RBM3) has previously been shown to be an independent prognostic and predictive biomarker in several types of cancer. Herein, we examined the prognostic value of RBM3 in periampullary adenocarcinoma, as well as the effects following RBM3 suppression in pancreatic cancer cells in vitro. RBM3 mRNA levels were examined in 176 pancreatic cancer patients from The Cancer Genome Atlas. Immunohistochemical expression of RBM3 was analyzed in tissue microarrays with primary tumors and paired lymph node metastases from 175 consecutive patients with resected periampullary adenocarcinoma. Pancreatic cancer cells were transfected with anti-RBM3 siRNA in vitro and the influence on cell viability following chemotherapy, transwell migration and invasion was assessed. The results demonstrated that high mRNA-levels of RBM3 were significantly associated with a reduced overall survival (p = 0.026). RBM3 protein expression was significantly higher in lymph node metastases than in primary tumors (p = 0.005). High RBM3 protein expression was an independent predictive factor for the effect of adjuvant chemotherapy and an independent negative prognostic factor in untreated patients (p for interaction = 0.003). After siRNA suppression of RBM3 in vitro, pancreatic cancer cells displayed reduced migration and invasion compared to control, as well as a significantly increased resistance to chemotherapy. In conclusion, the strong indication of a positive response predictive effect of RBM3 expression in pancreatic cancer may be highly relevant in the clinical setting and merits further validation.

The clinical importance of tumour-infiltrating macrophages and dendritic cells in periampullary adenocarcinoma differs by morphological subtype

Background

Dendritic cells (DC) and tumour-associated macrophages (TAM) are essential in linking the innate and adaptive immune response against tumour cells and tumour progression. These cells are also potential target for immunotherapy as well as providing a handle to investigate immune status in the tumour microenvironment. The aim of the present study was to examine their impact on prognosis and chemotherapy response in periampullary adenocarcinoma, including pancreatic cancer, with particular reference to morphological subtype.

Methods

The density of tolerogenic immature CD1a⁺ dendritic cells (DC), and MARCO⁺, CD68⁺ and CD163⁺ tissue-associated macrophages (TAM) was analysed by immunohistochemistry in tissue micro arrays with tumours from 175 consecutive cases of periampullary adenocarcinoma who had undergone pancreaticoduodenectomy, 110 with pancreatobiliary type (PB-type) and 65 with intestinal type (I-type) morphology. Kaplan–Meier and Cox regression analyses were applied to determine the impact of immune cell infiltration on 5-year overall survival (OS).

Results

High density of CD1a⁺ DCs was an independent prognostic factor for a reduced OS in PB-type but not in I-type tumours (adjusted HR = 2.35; 95% CI 1.13–4.87). High density of CD68⁺ and CD163⁺ TAM was significantly associated with poor OS in the whole cohort, however only in unadjusted analysis (HR = 1.67; 95% CI 1.06–2.63, and HR = 1.84; 95% CI 1.09–3.09, respectively) and not in strata according to morphological subtype. High density of MARCO⁺ macrophages was significantly associated with poor prognosis in I-type but not in PB-type tumours (HR = 2.14 95% CI 1.03–4.44), and this association was only evident in patients treated with adjuvant chemotherapy. The prognostic value of the other investigated immune cells did not differ significantly in strata according to adjuvant chemotherapy.

Conclusions

The results from this study demonstrate that high infiltration of tolerogenic immature DCs independently predicts a shorter survival in patients with PB-type periampullary adenocarcinoma, and that high density of the MARCO⁺ subtype of TAMs predicts a shorter survival in patients with I-type tumours. These results emphasise the importance of taking morphological subtype into account in biomarker studies related to periampullary cancer, and indicate that therapies targeting dendritic cells may be of value in the treatment of PB-type tumours, which are associated with the worst prognosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1256-y) contains supplementary material, which is available to authorized users.

The prognostic impact of CD3, CD8, FoxP3, and IL17 tumor-infiltrating immune cells in periampullary cancer differs by morphological type and adjuvant chemotherapy

53

Background: The prognostic impact of tumor-infiltrating T lymphocytes has been evaluated in periampullary carcinoma, but previous studies have not taken into consideration the different morphological subtypes of cancers derived from the periampullary region. Herein, we investigated the prognostic impact and distribution of tumor-infiltrating CD3+, CD8+, FoxP3+ T lymphocytes as well as IL-17+cells in periampullary adenocarcinoma, with particular reference to morpohological subtyoe. Methods: Counts of CD3+, CD8+, FoxP3+ T lymphocytes, and IL-17+cells were assessed using immunohistochemistry on tissue microarrays with tumors from a consecutive retrospective cohort of 175 patients with resected periampullary adenocarcinoma; 110 of pancreatobiliary type (PB-type) and 65 of I intestinal type (I-type). Results: Distribution of all evaluated immune cells differed significantly between PB- and I-type tumors. In I-type tumors, the ratios of IL-17+/FoxP3+ and IL-17+/CD3+ were independent factors of poor prognosis. Notably, the unfavorable prognostic impact of IL-17+ was only evident in cases that had not received adjuvant chemotherapy. In PB-type tumors, CD3+was an independent marker of good prognosis. Conclusions: The results from this study highlight that the composition and prognostic importance of various subsets of infiltrating immune cells in periampullary adenocarcinoma differ by morphological subtype, and potentially by adjuvant chemotherapy.

Prognostic significance of professional antigen presenting cells according to morphological subtype of periampullary adenocarcinoma

121

Background: Dendritic cells (DCs) and macrophages play vital roles in tumorigenesis and may, depending on the context, promote or inhibit tumor progression. In this study, we examined the prognostic significance of DCs and macrophages in periampullary adenocarcinoma, with particular reference to morphological type. Methods: Immune cell-specific expression of CD68, CD163 and CD1a was analysed by immunohistochemistry on tissue microarrays with tumours from 175 consecutive cases of periampullary adenocarcinoma, 110 of pancreatobiliary type (PB-type) and 65 of intestinal type (I-type) morphology. Kaplan-Meier and Cox regression analysis were applied to determine the impact of the investigated cells on 5-year overall survival (OS). Results: Low density of CD68+ cells or CD163 + cells was significantly associated with an improved 5-year OS in unadjusted Cox regression analysis in the entire cohort (HR = 1.66; 95% CI 1.05-2.63 and HR = 1.84; 95 % CI 1.09-3.09, respectively), but not in adjusted analysis or in strata according to subtype. CD1a+ cell density was not prognostic in entire cohort or in I-type tumours. However, in PB-type tumors, high CD1a+ cell density was significantly associated with a reduced OS in unadjusted as well as in adjusted analysis (HR = 2.09; 95% CI 1.07-4.09 and HR = 2.35; 95% CI 1.13-4.87). The prognostic value of the investigated markers did not differ in strata according to adjuvant chemotherapy, neither in the entire cohort nor according to morphological type. Conclusions: The results from study demonstrate that the prognostic significance of dendritic cells, but not macrophages, differs by morphological subtype in periampullary adenocarcinoma. Hence, morphological subtype is an important factor to consider in studies on the prognostic and predictive role of the immune microenvironment in these types of cancer.

Expression and Prognostic Significance of Human Epidermal Growth Factor Receptors 1, 2 and 3 in Periampullary Adenocarcinoma

Periampullary adenocarcinoma, including pancreatic cancer, is a heterogeneous group of tumours with dismal prognosis, for which there is an urgent need to identify novel treatment strategies. The human epithelial growth factor receptors EGFR, HER2 and HER3 have been studied in several tumour types, and HER-targeting drugs have a beneficial effect on survival in selected types of cancer. However, these effects have not been evident in pancreatic cancer, and remain unexplored in other types of periampullary cancer. The prognostic impact of HER-expression in these cancers also remains unclear. The aim of this study was therefore to examine the expression and prognostic value of EGFR, HER2 and HER3 in periampullary cancer, with particular reference to histological subtype. To this end, protein expression of EGFR, HER2 and HER3, and HER2 gene amplification was assessed by immunohistochemistry and silver in situ hybridization, respectively, on tissue microarrays with tumours from 175 periampullary adenocarcinomas, with follow-up data on recurrence-free survival (RFS) and overall survival (OS) for up to 5 years. EGFR expression was similar in pancreatobiliary (PB) and intestinal (I) type tumours, but high HER2 and HER3 expression was significantly more common in I-type tumours. In PB-type cases receiving adjuvant gemcitabine, but not in untreated cases, high EGFR expression was significantly associated with a shorter OS and RFS, with a significant treatment interaction in relation to OS (p_{interaction =} 0.042). In I-type cases, high EGFR expression was associated with a shorter OS and RFS in univariable, but not in multivariable, analysis. High HER3 expression was associated with a prolonged RFS in univariable, but not in multivariable, analysis. Neither HER2 protein expression nor gene amplification was prognostic. The finding of a potential interaction between the expression of EGFR and response to adjuvant chemotherapy in PB-type tumours needs validation, and merits further study.

Expression and prognostic significance of human epidermal growth factor receptors 1, 2, and 3 by histological type in periampullary adenocarcinoma

258

Background: Periampullary adenocarcinoma, including pancreatic cancer, is a heterogeneous group of tumors with dismal prognosis. The human epithelial growth factor receptor family consists of four closely related members EGFR (HER1) - HER4. HER-targeting drugs have a beneficial effect on survival in several types of cancer, but the benefits have been modest in pancreatic cancer and the prognostic value of HER-expression remains unclear. The aim of this study was therefore to examine the expression and prognostic value of EGFR, HER2 and HER3 in periampullary cancer, with particular reference to histological subtype. Methods: Immunohistochemical expression of EGFR, HER2 and HER3 was analyzed in tissue microarrays with 175 periampullary adenocarcinomas consecutively operated at the University hospitals of Lund and Malmö, Sweden, 2001 – 2011, with follow up data on RFS and OS for up to 5 years. Results: The expression of EGFR and HER2 was similar in pancreatobiliary (PB) and intestinal (I) type tumors but HER3 was more often highly expressed in I-type tumors (52% vs 21%, p < 0.001). In PB-type tumors there were no associations between expression of HERs and clinicopathological parameters or survival. In I-type tumors, high EGFR expression was associated with larger tumors and high expression of HER3 was inversely associated with growth in peripancreatic fat (p = 0.003) and T-stage (p = 0.006). HER2 expression was not associated with any clinicopathological parameter. In I-type tumors, high expression of EGFR was associated with shorter OS and RFS in univariable Cox regression analysis (HR = 2.74, CI 1.32-5.69 for OS and HR = 2.58, CI 1.23-5.38 for RFS) but not in multivariable analysis. HER2 expression was not prognostic. High HER3 expression was associated with a prolonged RFS in univariable (HR = 0.45, CI 0.21-0.95) but not in multivariable analysis. Conclusions: High EGFR expression is an unfavorable prognostic factor and high HER3 expression a favorable prognostic factor in I-type periampullary cancer. Expression of HERs in PB-type tumors had no evident prognostic value. The prognostic value of HERs in periampullary cancer thus differ by histological subtype.

Prognostic significance of tumor infiltrating natural killer cells in periampullary adenocarcinoma

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Background: Adenocarcinomas in in the pancreas and the periampullary region are heterogenous with the shared trait of having dismal prognosis. Despite recent progress in cancer therapy this has not been reflected in better prognosis for this patient group. Research has thus begun to explore the role of the immune system in pancreatic cancer. The aim of this study was to analyze the prognostic value of CD56+ natural killer (NK) cells in periampullary cancer, with particular reference to morphological type. Methods: Immunohistochemical expression of CD56 in lymphocytes and tumor cells was analyzed in tissue microarrays with tumors from 175 consecutive cases of operated periampullary adenocarcinoma, 110 of pancreatobiliary-type (PB type) and 65 of intestinal-type (I type) morphology. Kaplan-Meier and Cox regression analysis, unadjusted and adjusted for sex, age, stage, grade, size, growth in peripancreatic fat, perineural tissue and blood vessels, adjuvant chemotherapy and resection margins, were applied to determine the impact of CD56 expression on 5-year overall survival (OS). Results: A high density of CD56+ NK cells correlated significantly with low T- and N-stage (p = 0.003; p = 0.009), absent lymphatic, vascular and perineural infiltration (p = 0.007; p = 0.006; p = 0.023) and growth in peripancreatic fat (p = 0.016). High density of CD56+ NK cells was associated with a prolonged OS in univariable, but not multivariable, analysis in PB type, but not in I type, tumors (HR = 0.60; 95% CI 0.37-0.98). Interestingly, high density of CD56+ NK cells was a negative predictor of response to adjuvant chemotherapy in patients with PB-type tumors (p for interaction = 0.020). Tumor specific CD56 expression was significantly associated with reduced OS in univariable, but not in multivariable analysis, in patients with PB type but not in I type tumors (HR = 1.65; 95% CI 1.09-2.49). Conclusions: These results demonstrate that stromal CD56+ NK cell infiltration has a significant favorable impact on prognosis in PB type, but not in I type, periampullary cancer. Of note, this beneficial effect was only seen in patients not receiving chemotherapy, indicating that chemotherapy may modulate the beneficial prognostic effect of NK cells.

Correlation of high density of CD8+and FoxP3+ lymphocytes with overall survival in intestinal-type periampullary adenocarcinoma

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Background: Periampullary cancers can be divided into different morphological subtypes where those having an intestinal-type (I-type) morphology have a better prognosis than those with a pancreatobiliary-type (PB-type) morphology. In recent years much focus of antineoplastic research has been directed towards the central role played by various subsets of T-lymphocytes. Yet, very little is known of their role in different subtypes of periampullary cancer. Therefore, the aim of this study was to analyze the density of CD8+ (cytotoxic) and FoxP3+ (regulatory) T-cells in periampullary cancer, with particular reference to their relationship with survival by morphological subtype. Methods: Immunohistochemical expression of CD8 and FoxP3-positive tumor-infiltrating lymphocytes (TILs) was analyzed in tissue microarrays with tumors from 175 consecutive cases of periampullary adenocarcinoma, 110 of PB-type and 65 of I-type morphology, treated with pancreaticoduodenectomy. Kaplan-Meier and univariable and multivariable Cox regression analysis, adjusted for age, T-stage, N-stage, grade, sex, invasion of blood vessels, lymphatic vessels, adjuvant chemotherapy and resection margins were applied to determine the impact of CD8 and FoxP3 expression on 5-year overall survival (OS). Results: In I-type tumors, a high density of CD8+ as well as FoxP3+ TILs was significantly associated with a prolonged overall survival (HR = 0.39, 95% CI 0.19-0.80 and HR = 0.32, 95% CI 0.15 –0.67). The association between high density of FoxP3+ TILs and survival remained significant in multivariable analysis (HR = 0.37, 95% CI 0.17-0.84) while the association between CD8+ TILs and survival did not. The density of CD8+ and FoxP3+ TILs was not prognostic in PB-type tumors. Conclusions: High density of CD8+ and FoxP3+ TILs correlates with a prolonged overall survival in I-type but not in PB-type periampullary adenocarcinomas. Thus, morphological subtype appears to be an important determinant of the prognostic and predictive impact of the inflammatory microenvironment in periampullary carcinoma, and should be considered in future studies.

Prognostic effect of hENT1, dCK and HuR expression by morphological type in periampullary adenocarcinoma, including pancreatic cancer

BACKGROUND

Putative biomarkers of gemcitabine response have been extensively studied in pancreatic cancer, but less so in other types of periampullary adenocarcinoma. The most studied biomarker is human equilibrative nucleoside transporter 1 (hENT1), and the activating enzyme deoxycytidine kinase (dCK) has also been linked to treatment response. The RNA-binding protein human antigen R (HuR) has been demonstrated to confer increased dCK levels in vitro and to predict gemcitabine response in vivo. Here, we investigated the prognostic impact of hENT1, dCK and HuR in pancreatobiliary (PB) and intestinal (I) type periampullary cancers, respectively.

MATERIAL AND METHODS

Immunohistochemical expression of hENT1, dCK and HuR was evaluated in tissue microarrays with all primary tumours and 103 paired lymph node metastases from a consecutive retrospective cohort of 175 patients with resected periampullary adenocarcinomas.

RESULTS

In patients with PB-type tumours, neither hENT1 nor dCK expression was prognostic. A high HuR cytoplasmic/nuclear ratio was associated with a significantly reduced five-year overall survival (OS) in patients receiving adjuvant gemcitabine (HR 2.07, 95% CI 1.03-4.17) but not in untreated patients (pinteraction = 0.028). In patients with I-type tumours receiving adjuvant chemotherapy, high dCK expression was significantly associated with a prolonged recurrence-free survival (RFS) (HR 0.09, 95% CI 0.01-0.73, pinteraction = 0.023). Furthermore, HuR expression was associated with a prolonged OS and RFS in unadjusted but not in adjusted analysis and hENT1 expression was an independent predictor of a prolonged RFS (HR 0.24, 95% CI 0.10-0.59), regardless of adjuvant treatment.

CONCLUSION

hENT1 expression is a favourable prognostic factor in I-type, but not in PB-type tumours. High dCK expression is a favourable prognostic factor in patients with I-type tumours receiving adjuvant treatment and a high cytoplasmic/nuclear HuR ratio is a negative prognostic factor in gemcitabine-treated PB-type tumours. Morphological subtype should always be considered in biomarker studies on periampullary cancer.

Abstract B30: High expression of PIGR is an independent favorable prognostic factor in pancreatic and periampullary adenocarcinoma

Introduction: The polymeric immunoglobulin receptor (PIGR) is a member of the immunoglobulin superfamily and key component of the mucosal immune system that mediates epithelial transcytosis of polymeric immunoglobulins. High PIGR expression has been reported to correlate with a less aggressive tumor phenotype and favorable prognosis in e.g. gastro-esophageal, colon, urinary bladder and ovarian cancer, and with a greater metastatic potential and poor prognosis in hepatitis B-derived hepatocellular carcinoma, PIGR has recently been demonstrated to be up-regulated in pancreatic cancer cells upon exposure to stromal cells in vitro, but its expression and prognostic significance in human pancreatic cancer has not yet been reported. The aim of the present study was therefore to examine the longitudinal expression and prognostic significance of PIGR in a large consecutive series of pancreatic and periampullary adenocarcinoma.

Material and Methods: The study cohort encompasses a consecutive series of 175 patients surgically treated by means of pancreaticoduodenectomy for pancreatic and periampullary adenocarcinomas in the University hospitals of Malmö and Lund, Sweden, from January 1, 2001 to December 31, 2011. Tissue microarrays were constructed from all primary tumors (n =175) and paired lymph node metastases from 105 cases. PIGR was expressed in the cytoplasm and both the staining intensity and fraction of positive cells was denoted. For statistical purposes, a multiplier of the fraction and intensity of staining was applied. Mann Whitney U test was applied for analysis of PIGR expression in relation to clinicopathological characteristics. Classification and regression tree analysis was used for selection of prognostic cut-off. The impact of PIGR expression on 5-year overall survival (OS) and hazard ratios (HR) was calculated by adjusted and unadjusted Cox proportional hazards modeling.

Results: PIGR expression could be evaluated in 172/175 (98.3%) of the primary tumors and in 96/105 (91.4%) lymph node metastases. High PIGR expression was significantly associated with more well differentiated tumors (p=&lt;0.001), and inversely associated with perineural growth (p=0.016), lymphatic invasion (p=0.010), vascular invasion (p=0.027) and infiltration of the peripancreatic fat (p=0.024). PIGR expression was significantly down regulated in lymph node metastases as compared to primary tumors (p=0.018). High PIGR expression was significantly associated with a prolonged 5-year survival (unadjusted HR 0.21, 95% CI 0.09-0.48, p=&lt;0.001) and this association remained significant after adjustment for T-stage, N-stage, tumor size, tumor grade, perineural growth, invasion in lymphatic vessels, invasion in blood vessels, growth in peripancreatic fat, involved margins, age and sex (HR 0.27, 95% CI 0.12-0.63, p=0.002).

Conclusion: The results from this study demonstrate, for the first time, that high PIGR expression is associated with a more favorable tumor phenotype and is an independent marker of improved prognosis in pancreatic and periampullary cancer. The observed down regulation of PIGR expression in lymph node metastases as compared with primary tumors further supports a tumor suppressing role for PIGR in these cancers. These findings are of potential clinical relevance and warrant confirmation in additional patient cohorts. In addition, elucidating the mechanistic basis for the role of PIGR in tumor progression, with particular reference to the interplay of tumor cells and stroma, remains an intriguing challenge for future functional work.

Citation Format: Richard Fristedt, Jacob Elebro, Alexander Gaber, Björn Nodin, Mathias Uhlén, Karin Jirström. High expression of PIGR is an independent favorable prognostic factor in pancreatic and periampullary adenocarcinoma. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B30.

Abstract B32: Special AT-rich sequence-binding protein 1 (SATB1) is an independent prognostic marker of poor prognosis in operated pancreatic and pancreatobiliary type adenocarcinomas

Background: Special AT-rich sequence-binding protein 1 (SATB1) is a global gene regulator that has been demonstrated to confer a more aggressive tumor phenotype and a shorter patient survival in several major cancer forms. The expression and prognostic significance of SATB1 in pancreatic, distal bile duct, ampullary or duodenal adenocarcinomas has however not yet been reported.

Material and methods: A consecutive retrospective cohort of 175 patients with pancreatic and periampullary adenocarcinomas, operated with pancreaticoduodenectomy from January 1 2001 – December 31 2011, in the University hospitals of Lund and Malmö, Sweden, were followed up until December 31 2013. Microscopic slides were revised in a blinded manner and histopathological parameters relevant for classification and prognosis were recorded. Tissue microarrays were constructed from all primary tumors and 103 matched lymph node metastases. The expression of SATB1 was assessed by immunohistochemistry, and any intensity in more than 1% of cancer cells was considered a positive staining. Five-year overall survival was calculated and visualized using the Kaplan-Meier method and log rank analysis, stratified for tumor morphology and expression of SATB1. Cox regression models were used to estimate the impact of SATB1-expression on 5-year overall survival in multivariable analysis, adjusted for clinicopathological parameters. The Chi-square test and Fischer’s Exact test were used for calculations of correlations between SATB1-expression and other parameters.

Results: SATB1-expression could be assessed in 107 pancreatobiliary type primary tumors (pancreatic, distal bile duct and ampullary origin) and in 61 intestinal type tumors (ampullary and duodenal origin). Median 5-year overall survival was 26.4 months in pancreatobiliary type adenocarcinomas and 53.3 months in intestinal type adenocarcinomas. There were 15% (16/107) SATB1-positive pancreatobiliary type adenocarcinomas and 25% (15/61) SATB1-positive intestinal type adenocarcinomas. Pancreatobiliary type SATB1-positive cases had a shorter median 5-year overall survival; median 14.6 months (interquartile range 8.9 – 24.7) vs. 27.5 months (interquartile range 15.8 – 46.3) compared to negative cases (p=0.014). The difference in 5-year overall survival remained significant in multivariable analysis (p=0.014) and the hazard ratio was 2.2 (95% CI 1.2 – 4.0) adjusted for T-stage, N-stage, tumor size, tumor grade, perineural growth, invasion in lymphatic vessels, invasion in blood vessels, growth in peripancreatic fat, involved margins, age and sex. Other independent parameters in pancreatobiliary type tumors were tumor grade, tumor size and invasion in blood vessels. SATB1-expression was correlated to invasion in blood vessels (p=0.009), but not to any other clinicopathological parameter.

In intestinal type adenocarcinomas there was no correlation between primary tumor SATB1-positivity and overall survival.

SATB1-expression could be assessed in metastases of 65 pancreatobiliary type adenocarcinomas and 24 intestinal type adenocarcinomas. There was a significant correlation between SATB1-positivity in primary tumors and metastases, but SATB1-expression in metastases was neither associated with clinicopathological parameters nor with survival.

Conclusions: Our results show that SATB1-expression is an independent marker of poor prognosis in primary periampullary cancer of pancreatic and pancreatobiliary type and that SATB1-positivity is correlated to tumor invasion in blood vessels. This is the first report on the expression and prognostic significance of SATB1 in pancreatic cancer, distal bile duct cancer, ampullary cancer and duodenal cancer.

Citation Format: Jacob Elebro, Karin Jirstrom. Special AT-rich sequence-binding protein 1 (SATB1) is an independent prognostic marker of poor prognosis in operated pancreatic and pancreatobiliary type adenocarcinomas. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B32.

Reduced expression of the polymeric immunoglobulin receptor in pancreatic and periampullary adenocarcinoma signifies tumour progression and poor prognosis

The polymeric immunoglobulin receptor (pIgR) is a key component of the mucosal immune system that mediates epithelial transcytosis of immunoglobulins. High pIgR expression has been reported to correlate with a less aggressive tumour phenotype and an improved prognosis in several human cancer types. Here, we examined the expression and prognostic significance of pIgR in pancreatic and periampullary adenocarcinoma. The study cohort encompasses a consecutive series of 175 patients surgically treated with pancreaticoduodenectomy for pancreatic and periampullary adenocarcinoma in Malmö and Lund University Hospitals, Sweden, between 2001–2011. Tissue microarrays were constructed from primary tumours (n = 175) and paired lymph node metastases (n = 105). A multiplied score was calculated from the fraction and intensity of pIgR staining. Classification and regression tree analysis was used to select the prognostic cut-off. Unadjusted and adjusted hazard ratios (HR) for death and recurrence within 5 years were calculated. pIgR expression could be evaluated in 172/175 (98.3%) primary tumours and in 96/105 (91.4%) lymph node metastases. pIgR expression was significantly down-regulated in lymph node metastases as compared with primary tumours (p = 0.018). Low pIgR expression was significantly associated with poor differentiation grade (p<0.001), perineural growth (p = 0.027), lymphatic invasion (p = 0.016), vascular invasion (p = 0.033) and infiltration of the peripancreatic fat (p = 0.039). In the entire cohort, low pIgR expression was significantly associated with an impaired 5-year survival (HR = 2.99, 95% confidence interval (CI) 1.71–5.25) and early recurrence (HR = 2.89, 95% CI 1.67–4.98). This association remained significant for survival after adjustment for conventional clinicopathological factors, tumour origin and adjuvant treatment (HR = 1.98, 95% CI 1.10–3.57). These results demonstrate, for the first time, that high tumour-specific pIgR expression signifies a more favourable tumour phenotype and that low expression independently predicts a shorter survival in patients with pancreatic and periampullary cancer. The mechanistic basis for the putative tumour suppressing properties of pIgR in these cancers merits further study.

Prognostic and treatment predictive significance of SATB1 and SATB2 expression in pancreatic and periampullary adenocarcinoma

BACKGROUND

Pancreatic cancer and other pancreaticobiliary type periampullary adenocarcinomas have a dismal prognosis even after resection and neoadjuvant chemotherapy. Intestinal type periampullary adenocarcinomas generally have a better prognosis, but little is known on optimal neoadjuvant and adjuvant treatment. New prognostic and treatment predictive biomarkers are needed for improved treatment stratification of patients with both types of periampullary adenocarcinoma. Expression of the Special AT-rich sequence-binding protein 1 (SATB1) has been demonstrated to confer a worse prognosis in several tumour types, whereas its close homologue SATB2 is a proposed diagnostic and favourable prognostic marker for colorectal cancer. The prognostic value of SATB1 and SATB2 expression in periampullary adenocarcinoma has not yet been described.

METHODS

Immunohistochemical expression of SATB1 and SATB2 was analysed in tissue microarrays with primary tumours and a subset of paired lymph node metastases from 175 patients operated with pancreaticoduodenectomy for periampullary adenocarcinoma. Kaplan-Meier and Cox regression analysis were applied to explore the impact of SATB1 and SATB2 expression on recurrence free survival (RFS) and overall survival (OS).

RESULTS

Positive expression of SATB1 was denoted in 16/106 primary pancreatobiliary type tumours and 11/65 metastases, and in 15/63 primary intestinal type tumours and 4/26 metastases, respectively. Expression of SATB1 was an independent predictor of a significantly shorter RFS and OS in pancreatobiliary type, but not in intestinal type adenocarcinomas. Moreover, SATB1 expression predicted an improved response to adjuvant chemotherapy in both tumour types. SATB2-expression was seen in 3/107 pancreatobiliary type primary tumours, and in 8/61 intestinal type primary tumours. The small number of cases with positive SATB2 expression did not allow for any firm conclusions on its prognostic value.

CONCLUSIONS

These findings demonstrate the potential utility of SATB1 as a prognostic and predictive biomarker for chemotherapy response in both intestinal type and pancreatobiliary type periampullary adenocarcinomas, including pancreatic cancer.

Use of a standardized diagnostic approach improves the prognostic information of histopathologic factors in pancreatic and periampullary adenocarcinoma

BACKGROUND

Variability in reported histopathology parameters in operated periampullary adenocarcinomas may affect the prognostic weight of the parameters. Standardized axial sectioning produces a higher incidence of involved margins and also seems to produce a lower relative incidence of pancreatic compared with distal bile duct origin and a higher incidence of involved lymph nodes, compared with non-standardized procedure. The aims of this study were to 1) assess how a previously not described standardized pathology procedure, with longitudinal sectioning along the distal bile duct, affects reported tumour origin, margin status and involved lymph nodes, compared with non-standardized procedure, 2) assess if re-evaluation of microscopic slides affects the prognostic value of margin status and 3) compare the results of this standardized procedure with reported results of other standardized and non-standardized procedures.

METHODS

One hundred seventy-five consecutive pancreaticoduodenectomy specimens with primary adenocarcinomas, operated during 2001 - 2011 at the University hospitals of Lund and Malmö, Sweden, were re-evaluated histologically, and parameters relevant for classification and prognosis were assessed, with 1 mm as a threshold for involved or uninvolved margins. Follow-up lasted until 31 December 2013. Five-year overall survival (OS) and hazard ratios (HR) were calculated for the margin status stated in the original reports and margin status after re-evaluation.

RESULTS

Compared with non-standardized cases (n = 129), standardized cases (n = 46) had more involved lymph nodes in the specimens (median 3 vs 1), a higher fraction of distal bile duct origin (39% vs 21%) and a higher fraction of involved margins (74% vs 47%). The prognostic value of uninvolved margins increased by re-evaluation of slides (p < 0.001) and the adjusted HR for involved margins increased from 1.6 (95% CI 1.1 - 2.4) to 3.3 (95% CI 1.5 - 7.0). Uninvolved margins remained a significant predictor of OS in adjusted analysis.

CONCLUSIONS

Both the method of sectioning the specimen and the microscopic assessment affect prognostic pathology parameters significantly. The results of the herein described standardized method are similar to the results of other standardized procedures. The 1-mm threshold for involved margins in pancreaticoduodenectomies is relevant for OS, and margin status is an independent prognostic parameter.

VIRTUAL SLIDES

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1056639379120615.

Single-institution experience with solid pseudopapillary neoplasm of the pancreas

OBJECTIVE

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare clinical entity. The objective of this study was to review a single institution's experience with this uncommon tumor, as well as review the literature.

MATERIAL AND METHODS

Consecutive patients, who underwent surgery for a pathologically confirmed SPN between 1991 and 2010, were retrospectively reviewed. A PubMed search (January 1980-June 2011) was conducted to identify risk factors for death among SPN patients.

RESULTS

The institutional review identified 16 patients with SPN. Thirteen patients were female and three patients were male (median age 34 years). All patients underwent radical resection. Two patients had metastatic disease at the time of operation as evident by the presence of lymph node metastasis and gallbladder metastasis. One developed liver metastasis 4 months postoperatively and subsequently died. The other patient received adjuvant chemotherapy (gemcitabine and capecitabine), and 23 months after the initial operation, no tumor recurrence was detected and the patient is still alive. All other patients remain disease-free. Analysis of 29 fatalities reported in the English literature (including the present case) revealed several atypical features including male gender, old age, tumor size >5 cm, diffuse growth pattern, cellular or nuclear atypia, high mitotic rate, extensive necrosis, extrapancreatic invasion, metastasis and incomplete resection.

CONCLUSIONS

SPN is not always indolent. Male patients and those with old age, atypical histopathology (large tumors, diffuse growth, cellular/nuclear atypia, mitotic activity, necrosis, invasion/metastasis) and incomplete resection may have a higher risk of recurrence and death, deserving particular attention.

Systematic review of immunohistochemical biomarkers to identify prognostic subgroups of patients with pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) carries a dismal prognosis. There is a need to identify prognostic subtypes of PDAC to predict clinical and therapeutic outcomes accurately, and define novel therapeutic targets. The purpose of this review was to provide a systematic summary and review of available data on immunohistochemical (IHC) prognostic and predictive markers in patients with PDAC.

METHODS

Relevant articles in English published between January 1990 and June 2010 were obtained from PubMed searches. Other articles identified from cross-checking references and additional sources were reviewed. The inclusion was limited to studies evaluating IHC markers in a multivariable setting.

RESULTS

Database searches identified 76 independent prognostic and predictive molecular markers implicated in pancreatic tumour growth, apoptosis, angiogenesis, invasion and resistance to chemotherapy. Of these, 11 markers (Ki-67, p27, p53, transforming growth factor β1, Bcl-2, survivin, vascular endothelial growth factor, cyclo-oxygenase 2, CD34, S100A4 and human equilibrative nucleoside transporter 1) provided independent prognostic or predictive information in two or more separate studies.

CONCLUSION

None of the molecular markers described can be recommended for routine clinical use as they were identified in small cohorts and there were inconsistencies between studies. Their prognostic and predictive values need to be validated further in prospective multicentre studies in larger patient populations. A panel of molecular markers may become useful in predicting individual patient outcome and directing novel types of intervention.

Interobserver variability in the evaluation of mismatch repair protein immunostaining

Immunohistochemical staining for mismatch repair proteins has during recent years been established as a routine analysis in many pathology laboratories with the aim to identify tumors linked to the hereditary nonpolyposis colorectal cancer syndrome. Despite widespread application, data on reliability are lacking. We therefore evaluated interobserver variability among 6 pathologists, 3 experienced gastrointestinal pathologists and 3 residents. In total, 225 immunohistochemically stained colorectal cancers were evaluated as having normal, weak, loss of, or nonevaluable mismatch repair protein staining. Full consensus was achieved in 51% of the stainings for MLH1, 61% for PMS2, 83% for MSH2, and 45% for MSH6. Weak stainings were the main cause of reduced consensus, whereas contradictory evaluations with normal as well as loss of staining were reported in 2% to 6% of the tumors. Interobserver variability was considerable, though experienced pathologists and residents reached the same level of consensus. Because results from immunohistochemical mismatch repair protein stainings are used for decisions on mutation analysis and as an aid in the interpretation of gene variants of unknown significance in hereditary nonpolyposis colorectal cancer, the interobserver variability identified highlights the need for quality assessment programs, including guidelines for classification of different expression patterns.