Postresection surveillance for pancreatic cancer performance status, imaging, and serum markers

Suppression of rhomboid domain-containing 1 produces anticancer effects in pancreatic adenocarcinoma through affection of the AKT/GSK-3β/β-catenin pathway

The protumor role of rhomboid domain-containing 1 (RHBDD1) has been observed in multiple cancers. However, the relationship between RHBDD1 and pancreatic adenocarcinoma has not been addressed. This project focused on the potential relevance of RHBDD1 in pancreatic adenocarcinoma. Bioinformatic analysis by publicly available data revealed that RHBDD1 was abundantly expressed in pancreatic adenocarcinoma. We further verified that RHBDD1 was expressed highly in clinical specimens of pancreatic adenocarcinoma. The Kaplan-Meier curve demonstrated that high-RHBDD1 expression was associated with poor prognosis in pancreatic adenocarcinoma patients. The functional studies revealed that depletion of RHBDD1 produced in vitro anticancer effects in pancreatic adenocarcinoma cells, including retardation of proliferation, reduction of metastatic potential, and induction of cell-cycle arrest at the G0/G1 phase and apoptosis. Mechanistic studies indicated that loss of RHBDD1 affected the activation of β-catenin via regulation of AKT. Forced expression of β-catenin reversed the RHBDD1-loss-induced anticancer effects in pancreatic adenocarcinoma cells. Crucially, depletion of RHBDD1 retarded the growth of pancreatic adenocarcinoma xenografts in vivo, a phenomenon associated with the AKT/β-catenin pathway. Collectively, these findings delineated that restraint of RHBDD1 displayed remarkable anticancer effects in pancreatic adenocarcinoma by affecting the AKT/β-catenin pathway. Our work unveils a pivotal role of RHBDD1 in pancreatic adenocarcinoma and proposes it as a novel candidate target for anticancer therapy of pancreatic adenocarcinoma.

Impact of surveillance among patients with resected pancreatic cancer following adjuvant chemotherapy

Background

Pancreatic adenocarcinoma carries a high risk of recurrence even after surgery and adjuvant chemotherapy. Current guidelines do not endorse routine surveillance imaging due to lack of evidence supporting a survival benefit. With current first-line palliative chemotherapy options, it is unclear whether surveillance allows for early detection of asymptomatic disease and therefore an improved opportunity to offer chemotherapy to fit patients. We sought to describe patterns of surveillance of resected pancreatic cancer at British Columbia (BC) Cancer and determine whether utilization of computerized tomography (CT) scans affected likelihood of receiving palliative chemotherapy at the time of recurrence.

Methods

A retrospective review was completed to identify patients treated at BC Cancer centres between 2010-2016 who had undergone curative intent resection and received at least one cycle of adjuvant chemotherapy. Information was collected on baseline characteristics, imaging scans done between adjuvant chemotherapy and recurrence, and receipt of palliative chemotherapy. Two cohorts were defined based on number of scans done between completion of adjuvant chemotherapy and recurrence: those with only 1 scan were defined as "symptomatic" recurrences and patients who had undergone more than 1 scan were considered "surveillance" recurrences.

Results

In total, 142 patients were included of which 115 (81%) patients developed recurrence. There were 22 patients (19%) in the "symptomatic" cohort and 93 patients (81%) in the "surveillance" cohort. Median time to recurrence 274 days (9.1 months) in the symptomatic cohort compared to 471 days (15.7 months) in the surveillance group. Patients who underwent surveillance scans were more likely to receive palliative chemotherapy at the time of recurrence, though statistical significance was not reached: 51% in surveillance group versus 27% in symptomatic group [odds ratio (OR) 2.11, 95% confidence interval (CI): 0.75-6.58, P=0.17].

Conclusions

Despite the absence of surveillance recommendations, the majority of patients underwent surveillance imaging. We demonstrated a non-significant increase in the likelihood of receiving palliative chemotherapy among patients who underwent surveillance scans. With more efficacious palliative chemotherapy options available, studies to determine whether receipt of chemotherapy in asymptomatic recurrences translates into improved survival and/or quality of life are warranted.

Detection of recurrent pancreatic cancer: value of second-opinion interpretations of cross-sectional images by subspecialized radiologists

PURPOSE

To investigate the value of second-opinion interpretation of cross-sectional images by subspecialized radiologists to diagnose recurrent pancreatic cancer after surgery.

METHODS

The IRB approved and issued a waiver of informed consent for this retrospective study. Initial and second-opinion interpretations of 69 consecutive submitted MRI or CT follow-up after pancreatic cancer resection between January 1, 2009 and December 31, 2013 were evaluated by one oncologic imaging radiologist, who was blinded to patient's clinical details and histopathologic data. The reviewer was asked to classify each interpretation in reference of the diagnosis of PDAC recurrence. It was also recorded if the radiologic interpretation recommended additional imaging studies to confirm recurrence. The diagnosis of recurrence was determined by pathology when available, otherwise by imaging follow-up, clinical, or laboratory assessments. Cohen's kappa statistic was used to assess agreement between initial and second-opinion interpretations. The differences between the initial and second-opinion interpretations were examined using McNemar test or Bowker's test of symmetry.

RESULTS

Disagreement on recurrence between the initial report and the second-opinion interpretation was observed in 32% of cases (22/69; k = 0.44). Second-opinion interpretations had a higher sensitivity and a higher specificity on recurrence compared to the initial interpretations (0.93 vs. 0.75 and 0.90 vs. 0.68, respectively), and the difference in specificity was significant (p = 0.016). Additional imaging studies were recommended more frequently in the initial interpretation (22% vs. 6%, p = 0.006).

CONCLUSIONS

Our study shows the second-opinion interpretation by subspecialized radiologists improves the detection of pancreatic cancer recurrence after surgical resection.

Imaging findings of recurrent pancreatic cancer following resection

Pancreatic cancer is a challenging malignancy to treat, largely due to aggressive regional involvement, early systemic dissemination, high recurrence rate, and subsequent low patient survival. Generally, 15-20% of newly diagnosed pancreatic cancers are candidates for possible curative resection. Eighty percent of these patients, however, will experience locoregional or distant recurrence in first 2 years. Although there is no strong evidence-based guideline for optimal surveillance after pancreatic cancer resection, careful comparison of surveillance follow-up multi-detector CT (MDCT) studies with a postoperative baseline MDCT examination aids detection of early recurrent pancreatic cancer. In this review article, we describe imaging findings suggestive of recurrent pancreatic cancer and review routine and alternative imaging options.

Ex Vivo PD-L1/PD-1 Pathway Blockade Reverses Dysfunction of Circulating CEA-Specific T Cells in Pancreatic Cancer Patients

Purpose: Carcinoembryonic antigen (CEA) is a candidate target for cellular immunotherapy of pancreatic cancer. In this study, we have characterized the antigen-specific function of autologous cytotoxic T lymphocytes (CTL) specific for the HLA-A2-restricted peptide, pCEA691-699, isolated from the peripheral T-cell repertoire of pancreatic cancer patients and sought to determine if ex vivo PD-L1 and TIM-3 blockade could enhance CTL function.Experimental Design: CD8⁺ T-cell lines were generated from peripheral blood mononuclear cells of 18 HLA-A2⁺ patients with pancreatic cancer and from 15 healthy controls. In vitro peptide-specific responses were evaluated by flow cytometry after staining for intracellular cytokine production and carboxy fluorescein succinimydyl ester cytotoxicity assays using pancreatic cancer cell lines as targets.Results: Cytokine-secreting functional CEA691-specific CTL lines were successfully generated from 10 of 18 pancreatic cancer patients, with two CTL lines able to recognize and kill both CEA691 peptide-loaded T2 cells and CEA⁺ HLA-A2⁺ pancreatic cancer cell lines. In the presence of ex vivo PD-L1 blockade, functional CEA691-specific CD8⁺ T-cell responses, including IFNγ secretion and proliferation, were enhanced, and this effect was more pronounced on Ag-specific T cells isolated from tumor draining lymph nodes.Conclusions: These data demonstrate that CEA691-specific CTL can be readily expanded from the self-restricted T-cell repertoire of pancreatic cancer patients and that their function can be enhanced by PD-L1 blockade. Clin Cancer Res; 23(20); 6178-89. ©2017 AACR.

Clinical Impact of Structured Follow-up After Pancreatic Surgery

OBJECTIVES

Structured follow-up after surgery for pancreatic ductal adenocarcinoma (PDAC) remains controversial and is currently not recommended due to a supposed lack of therapeutic consequences. Furthermore, it is not clear whether noncancer patients after pancreas resection need to be seen in the clinic on a regular basis. The present study analyzed how follow-up after pancreatic surgery affected postoperative treatment and long-term outcomes.

METHODS

Data of all postoperative visits in a specialized outpatient clinic for pancreatic diseases were analyzed for a 1-year period with regard to symptoms, diagnostic procedures, and therapeutic consequences.

RESULTS

Six hundred eighteen patients underwent 940 postoperative follow-ups. Nearly half of them needed a change of medication due to altered pancreatic function. In 74 (40%) of 184 resected PDAC patients, recurrence (local or systemic) was detected during follow-up, although only 19 of these had shown associated symptoms (26%). In all patients with recurrence, a cancer-directed treatment was induced. Eleven (69%) of 16 patients with isolated local recurrence were referred for reresection.

CONCLUSIONS

Follow-up examinations are a substantial part of the clinical management after pancreas resections. Follow-up is particularly important for PDAC because recurrence is often asymptomatic, but its detection allows for therapeutic interventions and potentially improved prognosis. This should be implemented in future guidelines.

siRNA-mediated knockdown against NUF2 suppresses pancreatic cancer proliferation in vitro and in vivo

NUF2 (NUF2, Ndc80 kinetochore complex component) plays an important role in kinetochore-microtubule attachment. It has been reported that NUF2 is associated with multiple human cancers. However, the functional role of NUF2 in pancreatic cancer remains unclear. In this study, we found that NUF2 expression was stronger in tumour tissues than in normal pancreatic tissues, and its overexpression could be related to poor prognosis. Moreover, NUF2 was highly expressed in several human pancreatic cancer cell lines. We took advantage of lentivirus-mediated siRNA (small interfering RNA) to suppress NUF2 expression in PANC-1 and Sw1990 cell lines aiming to investigate the role of NUF2 in pancreatic cancer. NUF2 silencing by RANi (RNA interference) reduced the proliferation and colony formation ability of pancreatic cancer cells in vitro. Cell cycle analysis showed that NUF2 knockdown induced cell cycle arrest at G0/G1 phase via suppression of Cyclin B1, Cdc2 and Cdc25A. More importantly, NUF2 silencing was able to alleviate in vivo tumourigenesis in pancreatic cancer xenograft nude mice. Collectively, the present study indicates that the siRNA-mediated knockdown against NUF2 may be a promising therapeutic method for the treatment of pancreatic cancer.

NUF2 is overexpressed in pancreatic cancer tissues and cell lines. siRNA-mediated knockdown against NUF2 resulted in a significant reduction in pancreatic cancer cell growth both in vitro and in vivo. NUF2 may be a promising therapeutic target in pancreatic cancer.

Readmission after pancreatic resection: causes and causality pattern

BACKGROUND

Readmission rates have been targeted for cost/reimbursement control. Our goal was to identify causes for readmission and delineate the pattern of early and late readmission.

METHODS

Between 2011 and 2012, a total of 490 patients underwent pancreaticoduodenectomy, distal pancreatectomy or central pancreatectomy. Logistic regression was used to identify predictors of readmission. K-medoids clustering was performed to identify the major readmission subgroups.

RESULTS

Median postoperative length of stay (LOS) was 7 days, and the 30- and 90-day readmission rates were 23 and 29 %, respectively. The most common cause for 30-day readmissions was procedure-related infections (58 %), while the most common cause for 31-90-day readmissions was failure to thrive and chemotherapy-related symptoms (38 %). Independent predictors of 30-day readmissions were central pancreatectomy, discharge with a drain, pancreatic duct <3 mm, previous abdominal surgery, and postoperative LOS. Independent predictors for 31-90-day readmissions were age and preoperative serum carcinoembryonic antigen. Cancer-related covariates were more common in the 31-90-day readmission group. Postoperative carbohydrate antigen 19-9 levels were twofold higher in the 31-90-day readmission group compared with the no readmission group (p = 0.03). K-medoids clustering identified a subgroup where 74 % of readmissions occur at a median of 7 days after discharge.

CONCLUSIONS

Readmissions after pancreatic operations are procedure-related in the first 30 days, but those after this period are influenced by the natural history of the underlying diagnosis. The readmission penalty policy should account for the timing of readmission and the natural history of the underlying disease and procedure. Early follow-up for patients at high risk for readmission may minimize early readmissions.

Postradiotherapy CA19-9 kinetics correlate with outcomes in patients with pancreatic adenocarcinoma

OBJECTIVES

We sought to determine if carbohydrate antigen 19-9 (CA19-9 ) nadir (nCA19-9), time to nadir (TTN), and doubling time (DT) after radiotherapy (RT) correlate with outcomes in pancreatic ductal adenocarcinoma.

METHODS

We examined the records of 102 patients treated with RT for primary, nonmetastatic pancreatic ductal adenocarcinoma between August 1998 and July 2011. Of these, 33 patients were treated with postoperative chemoradiotherapy (PORT) and 69 patients with definitive chemoradiotherapy (CRT).

RESULTS

Among the patients treated with PORT, TTN and DT were associated with both overall survival (OS; P = <0.01 for both) and freedom from progression (FFP; P = <0.01 for both). In patients treated with CRT, nCA19-9 and TTN correlated with both OS (P = <0.01 and P = 0.02, respectively) and FFP (P = 0.01 and <0.01, respectively). On multivariable analysis, in patients treated with PORT, TTN remained independently correlated with OS and FFP (P = 0.01; hazard ratios [HR], 6.43 and P = 0.02; HR, 4.00, respectively), whereas DT remained independently correlated to FFP (P = 0.04; HR, 0.27). In patients treated with CRT, controlling for pretreatment CA19-9, nCA19-9 and TTN independently correlated with OS (P = <0.01; HR, 3.0 and P = 0.03; HR, 2.56, respectively) and FFP (P = 0.04; HR, 2.31 and P = <0.01; HR, 4.0, respectively).

CONCLUSIONS

CA19-9 kinetics after RT correlate with disease progression and survival and could serve as a prognostic tool to guide treatment decisions.

A soluble form of the giant cadherin Fat1 is released from pancreatic cancer cells by ADAM10 mediated ectodomain shedding

In pancreatic cancer, there is a clear unmet need to identify new serum markers for either early diagnosis, therapeutic stratification or patient monitoring. Proteomic analysis of tumor cell secretomes is a promising approach to indicate proteins released from tumor cells in vitro. Ectodomain shedding of transmembrane proteins has previously been shown to contribute significant fractions the tumor cell secretomes and to generate valuable serum biomarkers. Here we introduce a soluble form of the giant cadherin Fat1 as a novel biomarker candidate. Fat1 expression and proteolytic processing was analyzed by mass spectrometry and Western blotting using pancreatic cancer cell lines as compared to human pancreatic ductal epithelial cells. RNA expression in cancer tissues was assessed by in silico analysis of publically available microarray data. Involvement of ADAM10 (A Disintegrin and metalloproteinase domain-containing protein 10) in Fat1 ectodomain shedding was analyzed by chemical inhibition and knockdown experiments. A sandwich ELISA was developed to determine levels of soluble Fat1 in serum samples. In the present report we describe the release of high levels of the ectodomain of Fat1 cadherin into the secretomes of human pancreatic cancer cells in vitro, a process that is mediated by ADAM10. We confirm the full-length and processed heterodimeric form of Fat1 expressed on the plasma membrane and also show the p60 C-terminal transmembrane remnant fragment corresponding to the shed ectodomain. Fat1 and its sheddase ADAM10 are overexpressed in pancreatic adenocarcinomas and ectodomain shedding is also recapitulated in vivo leading to increased Fat1 serum levels in some pancreatic cancer patients. We suggest that soluble Fat1 may find an application as a marker for patient monitoring complementing carbohydrate antigen 19-9 (CA19-9). In addition, detailed analysis of the diverse processed protein isoforms of the candidate tumor suppressor Fat1 can also contribute to our understanding of cell biology and tumor behavior.

Expansion of anti-mesothelin specific CD4+ and CD8+ T cell responses in patients with pancreatic carcinoma

We aimed to assess the status of naturally occurring CD4(+) and CD8(+) T cell responses to a tumour associated antigen, Mesothelin, in patients with pancreatic carcinoma and study the effects of elevated IL-10 on Mesothelin-specific T cell responses. For that sake, short term T cell lines were generated from PBMCs of 16 healthy controls, 15 patients with benign pancreatic diseases and 25 patients with pancreatic carcinoma and Mesothelin-specific CD4(+) and CD8(+) T cell responses were analysed using intracellular cytokine assays for IFN-γ. Plasma levels of IL-10 and Mesothelin were measured using cytometric bead array and ELISA assay, respectively. The blocking assays were performed to assess the effects of IL-10 on Mesothelin-specific T cell responses. Here, we demonstrate that the plasma levels of Mesothelin and IL-10 are significantly increased in patients with pancreatic carcinoma. Additionally, we found that (a) Mesothelin-specific T cell responses are significantly expanded in cancer patients (p = 0.0053), (b) the multifunctional CD4(+) T cell response is directed toward a broad repertoire of epitopes within the Mesothelin protein. (c) Mesothelin-specific CD4+ T cell response is directly inhibited by elevated IL-10 in cancer patients. These data provides evidence for the use of Mesothelin as an immunogen for tumour-specific T cell response.