Targeting the Ras-ERK pathway in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PAC) stands as the poorest prognostic tumor of the digestive tract with limited therapeutic options. PAC carcinogenesis is associated with the loss of function of tumor suppressor genes such as INK4A, TP53, BRCA2, and DPC4, and only a few activated oncogenes among which K-RAS mutations are the most prevalent. The K-RAS mutation occurs early in PAC carcinogenesis, driving downstream activation of MEK and ERK1/2 which promote survival, invasion, and migration of cancer cells. In PAC models, inhibition of members of the Ras-ERK pathway blocks cellular proliferation and metastasis development. As oncogenic Ras does not appear to be a suitable drug target, inhibitors targeting downstream kinases including Raf and MEK have been developed and are currently under evaluation in clinical trials. In this review, we describe the role of the Ras-ERK pathway in pancreatic carcinogenesis and as a new therapeutic target for the treatment of PAC.

Stromal expression of SPARC in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) stands as the poorest prognostic tumor of the digestive tract, with a 5-year survival rate of less than 5%. Therapeutic options for unresectable PDAC are extremely limited and there is a pressing need for expanded therapeutic approaches to improve current options available with gemcitabine-based regimens. With PDAC displaying one of the most prominent desmoplastic stromal reactions of all carcinomas, recent research has focused on the microenvironment surrounding PDAC cells. Secreted protein acid and rich in cysteine (SPARC), which is overexpressed in PDAC, may display tumor suppressor functions in several cancers (e.g., in colorectal, ovarian, prostate cancers, and acute myelogenous leukemia) but also appears to be overexpressed in other tumor types (e.g., breast cancer, melanoma, and glioblastoma). The apparent contradictory functions of SPARC may yield inhibition of angiogenesis via inhibition of vascular endothelial growth factor, while promoting epithelial-to-mesenchymal transition and invasion through matrix metalloprotease expression. This feature is of particular interest in PDAC where SPARC overexpression in the stroma stands along with inhibition of angiogenesis and promotion of cancer cell invasion and metastasis. Several therapeutic strategies to deplete stromal tissue have been developed. In this review, we focused on key preclinical and clinical data describing the role of SPARC in PDAC biology, the properties, and mechanisms of delivery of drugs that interact with SPARC and discuss the proof-of-concept clinical trials using nab-paclitaxel.

Abstract A238: c-MET as a target for MET inhibitors in patients with poor prognostic pancreatic adenocarcinoma following completed surgical resection

Context: Pancreatic adenocarcinoma (PAC) displays a prominent desmoplastic stromal reaction, leading to tumor hypoxia and driving a selective pressure that selects cells exhibiting aggressive phenotypes. Activation of the HGF/c-MET pathway is involved in tumor-stroma interactions and promotes PAC cells proliferation, invasion, EMT, and stem cellness. As a background for identifying tumors that could benefit from MET inhibitors, we set a study looking at c-MET expression and hypoxia in PAC.

Patients and Methods: Patients who underwent curative surgical resection for PAC and received no adjuvant chemotherapy (“pure” prognostic value) were selected for this study. c-MET expression was assessed using immunochemistry and graded on a scale from 0 to 4, along with the microenvironment characteristics as defined by HIF-1α and CA9 immunostaining (hypoxia), CD31 expression (microvascular density [MVD]), and stroma abundance. Clinical, pathological, and molecular biomarkers have been correlated with disease-free (DFS) and overall (OS) survivals.

Results: thirty-seven patients have been analyzed in this study. Twenty-seven percent of tumors (10/37) expressed high c-MET (score ≥ 3). High c-MET expression was associated with moderate/poor differentiation (p = 0.017), presence of isolated tumor cells in the stroma (p = 0.023), and low stroma abundance (r = -0.445, p = 0.0074), but not with hypoxia-related markers (HIF-1α, CA9, or MVD). High c-MET expression was associated with shorter DFS (median: 7.7 vs 33.0 months, HR: 2,207, p=0.025) and OS (median: 12.1 vs 38.9 months, HR: 2,207, p=0.0099) than low c-MET expression in PAC. High c-MET expression combined with tumor size and lymph node ratio (defined as the ratio of lymph nodes with tumor metastasis to the total lymph nodes dissected) predicted risk of early local or distant recurrence (RFS < 12 months) with an AUC = 0.836.

Conclusion: c-MET appears to be a strong prognostic marker in completely resected PAC that may help to identify patients at high risk of early recurrence. Although the number of patients entered in this study was limited, this study suggests to explore the anti-metastatic potential of MET inhibitors in high c-MET expressing PAC following complete resection.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A238.

Citation Format: Cindy Neuzillet, Jérôme Cros, Annemilaï Tijeras-Raballand, Julien Moroch, Louis de Mestier, Maryse Baia, Pierre Bedossa, Valérie Paradis, Alain Sauvanet, Jean-Baptiste Bachet, Eric Raymond, Pascal Hammel, Anne Couvelard. c-MET as a target for MET inhibitors in patients with poor prognostic pancreatic adenocarcinoma following completed surgical resection. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A238.

Tumoral epithelial and stromal expression of SMAD proteins in pancreatic ductal adenocarcinomas

BACKGROUND

SMAD proteins, intracellular mediators of the transforming growth factor (TGF)-beta pathway, function within two axes, the SMAD1/5/8 and SMAD2/3, connected to TGF-beta and bone morphogenetic protein (BMP) ligands. The SMAD proteins of these two axes dimerize with SMAD4 and translocate to the nucleus. SMAD signaling is characterized by a dichotomic functioning, with tumor-suppressive functions and with loss of normal growth inhibitory responses, depending on the carcinogenesis stage. SMAD proteins also have pro-tumor effects including abnormal extracellular matrix production. Among tumors, pancreatic cancers harbor SMAD4 inactivation the most frequently and the SMAD proteins are considered to be key factors in pancreatic carcinogenesis.

METHODS

Our aims were to study the expression patterns of the different types of SMAD proteins in pancreatic ductal adenocarcinomas treated by surgical resection (without neoadjuvant treatment) and their correlations with morphological and clinical characteristics. We examined the immunohistochemical expression of SMAD4, SMAD1/5/8, and SMAD2/3 in 99 pancreatic ductal adenocarcinomas. Antibodies directed against the activated, phosphorylated forms of proteins were used when appropriate (SMAD1/5/8, SMAD2/3). Protein expression in the epithelial tumor cells and in stromal fibroblasts was analyzed with regard to morphological and clinical data.

RESULTS

Epithelial tumor cells showed SMAD1/5/8, SMAD2/3, and, SMAD4 expression in 13, 93, and 45 tumors, respectively, and stromal fibroblast expression in 5, 11, and 22 tumors, respectively. Epithelial SMAD4 was associated with a low, T1 or T2, TNM stage, and with the presence of an abundant stroma (p = 0.05 and <0.01, respectively). Activated stromal fibroblast SMAD2/3 expression was correlated with the presence of a fibrotic focus (p = 0.01), whereas fibroblast SMAD4 was related to a tendency for shorter postsurgical overall survival (p = 0.07). The relationship of stromal, fibroblast SMAD4 to a worse outcome attained statistical significance in the group of patients with T1 and with N1 stage tumors (p < 0.01 and p = 0.04, respectively).

CONCLUSION

In pancreatic ductal adenocarcinomas, SMAD protein expression in epithelial tumor cells or in stromal fibroblasts was related to stromal features and to a shorter postsurgical overall survival. Our results point out that the SMAD proteins play a role in the microenvironment of this highly fibrotic tumor type.

Characterization of two deletions of the CTRC locus

Novel variants associated with chronic pancreatitis are being increasingly reported. However, most studies have so far only analyzed point mutations and small insertions or deletions. Here we report the characterization of two distinct deletions of the CTRC locus. Variants in four chronic pancreatitis genes, PRSS1, SPINK1, CTRC and CFTR, were systematically analyzed in the studied cases. Copy number change of the CTRC gene was analyzed by quantitative fluorescent multiplex PCR (QFM-PCR). Walking QFM-PCR followed by long-range PCR and direct sequencing were employed to identify the deletion breakpoints at the nucleotide level. A heterozygous CTRC-deleting complex rearrangement, which was co-inherited with different trans variants in SPINK1, CFTR or PRSS1, is associated with variable phenotypes (chronic pancreatitis; pancreatic cancer and chronic pancreatitis; and type 1 diabetes). Moreover, a different homozygous deletion of the CTRC locus was found in an unrelated patient with asymptomatic chronic pancreatitis. Our findings revealed a hitherto unrecognized level of complexity of genotype-phenotype correlation in chronic pancreatitis. The CTRC-deleting complex rearrangement probably resulted from LINE-1-mediated Alu insertion, which represents a novel mutational mechanism causing chronic pancreatitis.

Comparison of chemoradiotherapy (CRT) and chemotherapy (CT) in patients with a locally advanced pancreatic cancer (LAPC) controlled after 4 months of gemcitabine with or without erlotinib: Final results of the international phase III LAP 07 study

LBA4003

Background: CRT in patients with LAPC controlled after induction CT could be superior to continuing CT (Huguet, JCO 2007). The role of erlotinib is unknown. We aimed to define the role of 1) CRT after disease control with gemcitabine, 2) erlotinib in LAPC. Methods: LAPC PS 0-2 patients were first randomized to gemcitabine alone or plus erlotinib 100 mg/d for 4 months (R1, stratification: center, PS). Patients with controlled disease were then randomized to 2 additional months of CT (Arm 1) or CRT (Arm 2) 54 Gy and capecitabine 1600 mg/m2/d (R2, stratification: center, initial arm). Patients receiving erlotinib at R1 had maintenance with this drug after protocol completion. Quality control for radiotherapy included dummy runs and assessment of treated patients. Primary objective: overall survival (OS) in R2 patients. Secondary objectives: role of erlotinib on OS (R1), tolerance, predictive markers, and circulating tumor cells. Taking into account a 30% progression rate between R1 and R2, and 5% lost to follow-up, 722 patients were required to observe 392 deaths to show a median OS increase from 9 to 12 m (HR=0.75) in the CRT arm (2 sided α=5% and β=20%) with planned interim analyses using alpha spending function and O’Brien Fleming boundaries (to reject H0 or H1). Kaplan-Meier, log rank and univariate Cox tests were used. Results: From 442 pts included for R1, 269 pts reached R2 (arm1:136; arm 2:133). Main baseline characteristics in arms 1/2: female 44%/56%, mean age 63/62, head tumor 65%/62%, PS 0 56%/48%. After a median follow-up of 36 m, 221 deaths had occurred allowing the planned interim analysis (information fraction 56.4%). OS in R2 pts was 16.5 m [15.5-18.5] and 15.3 m [13.9–17.3] in arms 1 and 2, respectively (HR=1.03 [0.79-1.34], p=0.83). IDMC has confirmed that the futility boundary for the hypothesis of CRT superiority was crossed and considered this as the final analysis of the study. Conclusions: Administering CRT is not superior to continuing CT in patients with controlled LAPC after 4 months of CT. Clinical trial information: NCT00634725.

S100A2 is a predictive biomarker of adjuvant therapy benefit in pancreatic adenocarcinoma

BACKGROUND

Prognosis of patients with pancreatic adenocarcinoma (PAC) remains poor. S100A2 has been recently suggested as a negative prognostic biomarker in PAC. We aimed to investigate its prognostic and/or predictive value in a large independent multicentric cohort of patients with resected PAC.

METHODS

Sequential samples of 471 patients were retrospectively collected; 142 patients did not receive adjuvant treatment (30%) and 329 (70%) received an adjuvant treatment. We measured protein levels of S100A2 by semiquantitative immunohistochemistry with tissue microarrays and correlated with patients' overall survival (OS) and disease-free survival (DFS).

RESULTS

S100A2 protein status was obtained in 462 (98%) patients. Its expression was low, moderate or high in 59%, 12% and 2% of cases, respectively. It was not correlated with DFS or OS in the whole population, neither in the subgroup of patients who did not receive adjuvant treatment. However among patients who received an adjuvant therapy, moderate/high levels of S100A2 were significantly associated with longer OS and DFS in multivariate analysis (hazard ratios of 0.63, p=0.022 and 0.67, p=0.017, respectively), whereas low S100A2 was not. Interaction tests for adjuvant therapy were statistically significant both for the OS and the DFS (p=0.001 and p=0.023, respectively). On multivariate analysis, S100A2 retained independent predictive values (OS: p<0.001, DFS: p=0.003) with a significant benefit of adjuvant therapy for those patients with moderate/high S100A2.

CONCLUSIONS

S100A2 expression predicts longer DFS and OS in patients treated with adjuvant therapy and should be evaluated as a predictive biomarker.

Comparison of chemoradiotherapy (CRT) and chemotherapy (CT) in patients with a locally advanced pancreatic cancer (LAPC) controlled after 4 months of gemcitabine with or without erlotinib: Final results of the international phase III LAP 07 study

LBA4003

The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Monday, June, 3, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Monday edition of ASCO Daily News.

Pimasertib plus gemcitabine in metastatic pancreatic adenocarcinoma: Results of a safety run-in part of a phase II trial

4041

Background: Activating MAPK pathway mutations (predominantly RAS) occur with a high incidence in metastatic pancreatic adenocarcinoma (mPaCa). Pimasertib is a MEK1/2 inhibitor with potent activity in cell lines and xenografts with an activated MAPK pathway. This two-part trial in patients (pts) with mPaCa comprises a dose-escalation safety run-in and a randomized phase II part (EudraCT 2009-011992-61). We defined the maximum tolerated dose (MTD), safety, pharmacokinetics (PK) and antitumor activity of two pimasertib dosing schedules (S), and the recommended phase II dose (RP2D). Methods: Dose-escalation (3+3 design) in two dosing S of oral pimasertib: once-daily (qd) - 5 days on, 2 days off (S1); and twice-daily (bid) - continuous (S2) combined with the standard dose of gemcitabine (gem). Results: 53 pts (median age 61 years and ECOG performance status 0-1) have been treated at six dose levels in S1 (15 to 120 mg qd) and at 60 and 75 mg bid in S2. MTDs were defined as 120 mg qd and 75 mg bid. Two pts had a dose-limiting toxicity (DLT) in the DLT observation period: a grade (G) 3 confusion with ataxia and disorientation at 60 mg bid and a G4 suicidal ideation at 75 mg bid. G3-4 adverse events (AEs) in >5% of pts were: neutropenia (32%), thrombocytopenia (25%), asthenia (19%), dyspnea (9%), transaminitis (9%), anemia (8%), and diarrhea, pulmonary embolism, pulmonary sepsis (6% each). Most common AEs were asthenia (70%), ocular AEs (68%), skin rash (62%), nausea (58%), diarrhea (58%), peripheral edema (51%), thrombocytopenia (49%), vomiting (45%), mucositis (43%), neutropenia (38%), decreased appetite (36%) and anemia (34%). The main ocular AE was serous retinal detachment (58%); manageable retinal vein occlusion occurred in five pts. PK data were comparable to pimasertib monotherapy and published gem data. Partial responses were noted in 10 pts and stabilisation ≥3 months in 13 pts. Hot spot mutations in genes activating the MAPK and PI3K/AKT pathway and correlation with clinical outcome are being investigated. Conclusions: Pimasertib MTDs were reached. The RP2D was defined as 60 mg bid. PK was dose proportional and associated with target inhibition. Sustained responses were seen in both dosing schedules. Clinical trial information: 2009-011992-61.

Circulating tumor cells in locally advanced pancreatic adenocarcinoma: The ancillary study Circe 07 of the LAP 07 trial

4046

Background: Pancreatic carcinoma is one of the leading causes of cancer-related mortality. At time of diagnosis, 30% of patients present with a locally advanced unresectable but non metastatic carcinoma (LAPC). Theoretically, patients with micrometastatic dissemination at diagnosis should benefit from systemic treatments, whereas radiation therapy should be favored in the others. Based on the hypothesis that circulating tumor cells (CTC) count is a surrogate of the cancer metastatic abilities, CTC detection rates and prognostic value were studied in a prospective cohort of LAPC patients. Methods: LAP07 international multicenter randomized study assesses in patients whose LAPC is controlled after 4 months of gemcitabine-based chemotherapy whether to administrate a chemoradiotherapy could increase overall survival versus continuation of chemotherapy alone. A subgroup of patients included in LAP 07 trial were prospectively screened for CTC before the start of the chemotherapy and after two months of treatment, using the CellSearch technique. Clinico-pathological characteristics and survival of patients were obtained prospectively and were correlated with CTC detection. Results: Seventy-nine patients were included in this ancillary study. One or more CTC/7.5ml were detected in 5% of patients before treatment and in 9% of patients after two months of chemotherapy (overall detection rate: 11% of patients). CTC positivity was associated with poor tumor differentiation (p=0.04), and with shorter overall survival in multivariable analysis (RR=2.5, p=0.01), together with anemia (p=0.005). Conclusions: The evaluation of micrometastatic disease using CTC detection appears as a promising tool which could help to personalize treatment modalities in LAPC patients. Clinical trial information: NCT00634725.

Circulating tumor cells in locally advanced pancreatic adenocarcinoma: the ancillary CirCe 07 study to the LAP 07 trial

BACKGROUND

Pancreatic carcinoma is one of the leading causes of cancer-related mortality. At the time of diagnosis, 30% of patients present with a locally advanced pancreatic carcinoma (LAPC). As circulating tumor cells (CTCs) count may be a surrogate of the cancer metastatic abilities, CTC detection rates and prognostic value were studied in a prospective cohort of LAPC patients.

PATIENTS AND METHODS

An LAP07 international multicenter randomized study assesses in patients whose LAPC is controlled after 4 months of chemotherapy whether chemoradiotherapy could increase survival versus continuation of chemotherapy. A subgroup of patients included in the LAP07 trial was screened for CTCs (CellSearch®) before the start of the chemotherapy and after 2 months of treatment. Patient characteristics and survival were obtained prospectively and were correlated with CTC detection.

RESULTS

Seventy-nine patients were included. One or more CTCs/7.5 ml were detected in 5% of patients before treatment and in 9% of patients after 2 months of treatment (overall detection rate: 11% of patients). CTC positivity was associated with poor tumor differentiation (P = 0.04), and with shorter overall survival (OS) in multivariable analysis (RR = 2.5, P = 0.01), together with anemia.

CONCLUSIONS

The evaluation of micrometastatic disease using CTC detection appears as a promising prognostic tool in LAPC patients.

Abstract 3261: Cellular effects of MEK inhibition in pancreatic cancer cell lines are not correlated with « classical » predictive markers of response to MEK inhibitors

Background: Deregulations of the Ras-Raf-MEK-ERK pathway, driven by K-RAS mutations (&gt;70%), are frequent in pancreatic adenocarcinoma (PAC). MEK inhibitors (MEKi) are currently under clinical evaluation in PAC. K-RAS and B-RAF mutations, epithelial-to-mesenchymal transition (EMT), PI3K-Akt-mTOR pathway activation, and pERK inhibition under treatment have been suggested as predictive markers for response to MEKi in various cancers, but remain unvalidated in PAC. This study aimed to compare the cellular effects of MEKi in a panel of PAC cell lines, according to their status for these “classical” predictive markers.

Materials and Methods: UO126, AZD6244, AS703026 and GSK1120212 are allosteric non-ATP competitive MEKi. Antiproliferative effects were evaluated by MTT assay. Cell cycle modifications were analyzed by flow cytometry. Protein expression was assessed by Western blot. Combinations were analyzed using the Chou-Talalay method.

Results: MIAPaCa-2, PANC-1 and Capan-1 were K-RAS mutated while BxPC-3 was wild-type. No activating mutations were found for B-RAF. MIAPaCa-2 and PANC-1 were mesenchymal (low E-cadherin/high vimentin) while Capan-1 and BxPC-3 were epithelial. PANC-1 exhibited high basal level of Akt, associated with high level of pAkt and downstream pP70S6K and pS6, suggesting basal activation of the pathway. MEKi exerted antiproliferative effects on PAC cell lines. UO126 and AZD6244 had low cytotoxic activity (72h-IC50=5.0-26.0μM) as compared to AS703026 and GSK1120212 (72h-IC50=0.009-0.65μM). Although both K-RAS mutated and mesenchymal, MIAPaCa-2 and PANC-1 exhibited very different response profile to MEKi: MIAPaCa-2 was the most sensitive (72h-IC50=0.009-13.7μM) and PANC-1 the most resistant (72h-IC50=33-61.3μM). These two cell lines were selected to compare the effects of UO126 (lowest activity) and GSK1120212 (highest activity). 24h-exposure to UO126 and GSK1120212 (30%) was observed after 48h of GSK1120212 in MIAPaCa-2, but not in PANC-1. Apoptosis induction was confirmed by PARP cleavage after 48h of GSK1120212 in MIAPaCa-2. The same pERK inhibition profile was observed in both cell lines with UO126 (partial&lt;5h) and GSK1120212 (complete, 72h). Moreover, MEKi induced an increase in pAkt in both cell lines. Co-treatment with MEKi and low-dose everolimus (mTOR inhibitor) for 72h was synergistic (CI&lt;1) in MIAPaCa-2 but not in PANC-1.

Conclusion: MEKi exerted their antiproliferative effects in PAC cells regardless of their K-RAS mutation and EMT status. There was no correlation between cellular effects and pERK inhibition. MEKi induced an activation of the Akt pathway. Dual MEK and mTOR inhibition had a synergistic effect in MIAPaCa-2 sensitive cells but not in PANC-1, suggesting that basal Akt pathway activation may be a factor of resistance to combined MEK/Akt pathway inhibition.

Citation Format: Cindy Neuzillet, Maria Serova, Annemilai Tijeras-Raballand, Lucile Astorgues-Xerri, Maria E. Riveiro, Armand de Gramont, Philippe Ruszniewski, Pascal Hammel, Sandrine Faivre, Eric Raymond. Cellular effects of MEK inhibition in pancreatic cancer cell lines are not correlated with « classical » predictive markers of response to MEK inhibitors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3261. doi:10.1158/1538-7445.AM2013-3261

Masitinib in nonresectable pancreatic cancer: Results of a phase III randomized placebo-controlled trial

158

Background: Masitinib is a selective c-Kit inhibitor that efficiently inhibits mast cell function. Increased mast cell activity in the tumor microenvironment has been linked to poor prognosis in pancreatic cancer (PC) patients. Methods: In a randomized (1:1 ratio), double-blind, international phase III trial, chemo-naïve PC patients (n=348) received either masitinib (9 mg/kg/day) in combination with gemcitabine (1000 mg/m2/wk) (M+G) or placebo plus gemcitabine (P+G). Primary endpoint was overall survival (OS). An ancillary pharmacogenomic study, based on RNA extracted from whole blood prior to treatment, was conducted in a subset of patients. Results: In the overall population median OS was not significantly improved in the M+G arm as compared with the P+G arm (median OS: 7.7 vs. 7.0 months, respectively; p=0.74, HR=0.90 [0.71; 1.14]). However, M+G treatment led to a significant survival advantage in two subpopulations. First, in patients with ‘pain’ at baseline (defined as a VAS score >20 mm on a 100 mm scale) (44% of patients with pain intensity data available) median OS was significantly increased from 5.4 months in the P+G arm to 8.1 months in the M+G arm (p=0.010; HR:0.61 [0.42; 0.88]); OS rates at 12 and 18 months were respectively, 32.2% and 18.2% in the M+G arm vs. 17.8% and 7.8% in the P+G arm. Second, in patients with a specific deleterious genomic biomarker (GBM) consisting of a limited number of genes (66% of patients with genetic data available), median OS was significantly increased in the M+G arm as compared with the P+G arm (11.0 vs. 5.0 months, respectively) (p=0.000038; HR=0.29 [0.17; 0.51]); OS rates at 12 and 18 months were respectively, 41.4% and 18.5% in the M+G arm vs. 11.1% and 4.2% in the P+G arm. In patients without pain (defined as VAS <5 mm and no need for opioid analgesics), median OS was 15.4 months in the P+G arm. In patients without the deleterious GBM, median OS in the P+G arm was 14.3 months. In these two patient populations M+G treatment was contraindicated. The general safety profile of the M+G combination regimen was acceptable. Conclusions: Masitinib in combination with gemcitabine provides a significant survival advantage over gemcitabine monotherapy in PC patients with ‘pain’ and patients with a specific GBM. Clinical trial information: NCT00789633.

Circulating tumor cells in locally advanced pancreatic adenocarcinoma: The ancillary study Circe 07 of the LAP 07 trial

188

Background: Pancreatic carcinoma is one of the leading causes of cancer-related mortality. At time of diagnosis, 30% of patients present with a locally advanced unresectable but non metastatic carcinoma (LAPC). Theoretically, patients with micrometastatic dissemination at diagnosis should benefit from systemic treatments, whereas radiation therapy should be favored in the others. Based on the hypothesis that circulating tumor cells (CTC) count is a surrogate of the cancer metastatic abilities, CTC detection rates and prognostic value were studied in a prospective cohort of LAPC patients. Methods: LAP07 international multicenter randomized study assesses in patients whose LAPC is controlled after 4 months of gemcitabine-based chemotherapy whether to administrate a chemoradiotherapy could increase overall survival versus continuation of chemotherapy alone. A subgroup of patients included in LAP 07 trial were prospectively screened for CTC before the start of the chemotherapy and after two months of treatment, using the CellSearch technique. Clinico-pathological characteristics and survival of patients were obtained prospectively and were correlated with CTC detection. Results: Seventy-nine patients were included in this ancillary study. One or more CTC/7.5ml were detected in 5% of patients before treatment and in 9% of patients after two months of chemotherapy (overall detection rate: 11% of patients). CTC positivity was associated with poor tumor differentiation (p=0.04), and with shorter overall survival in multivariable analysis (RR=2.5, p=0.01), together with anemia (p=0.005). Conclusions: The evaluation of micrometastatic disease using CTC detection appears as a promising tool which could help to personalize treatment modalities in LAPC patients. Clinical trial information: CDR0000589283.

FOLFIRI regimen: an effective second-line chemotherapy after failure of etoposide-platinum combination in patients with neuroendocrine carcinomas grade 3

Patients with neuroendocrine carcinomas (NECs) grade 3 have a poor prognosis. Etoposide-platinum combination is the standard chemotherapy but the role of a second-line therapy remains unknown. Irinotecan alone or in combination has shown some efficacy in patients treated for small cell lung cancer which had pathological similarities with neuroendocine tumors. The aim of this study is to determine safety and efficacy of the FOLFIRI regimen in patients with NECs grade 3 after failure of etoposide-platinum combination. This study was retrospective, including patients with NECs grade 3 and treated with the FOLFIRI regimen after progression or toxicity of etoposide-platinum combination in first-line. Patients with Eastern Cooperative Oncology Group (ECOG) performance status ≥3 and/or serum alkaline phosphatase ≥5×upper limit of normal value (ULN) and/or bilirubin ≥1.5×ULN were excluded. Among 39 patients who failed etoposide-platinum combination, 19 (49%; 12 women, median age 53 (29-78) years) received the FOLFIRI regimen with a median number of 6 (1-16) courses. Six patients (31%) had at least one episode of grades 3-4 toxicity (neutropenia, n=3; diarrhea, n=3) without toxic death. Six patients (31%) had objective response, 6 (31%) stable disease, and 7 (38%) tumor progression. Median progression-free survival under FOLFIRI was 4 months. Overall survival was 18 vs 6.8 months in noneligible patients. FOLFIRI regimen is a safe and potentially efficient chemotherapy given as second-line in patients with NECs grade 3 who remain in good condition and with correct liver tests after failure of etoposide-platinum combination. These results should be confirmed in a future prospective study.

FOLFIRI regimen in metastatic pancreatic adenocarcinoma resistant to gemcitabine and platinum-salts

AIM: To evaluate the efficacy and safety of the FOLFIRI regimen in patients with metastatic pancreatic adenocarcinoma (PAC) after the failure of gemcitabine and platinum salts.

METHODS: All consecutive patients with histologically confirmed, metastatic PAC and World Health Organization performance status (PS) ≤ 2 received FOLFIRI-1 [irinotecan 180 mg/m² on day 1 and leucovorin 400 mg/m² followed by 5-fluorouracil (5-FU) 400 mg/m² bolus, then 5-FU 2400 mg/m² as a 46-h infusion, biweekly] or FOLFIRI-3 (irinotecan 100 mg/m² on day 1 and leucovorin 400 mg/m², then 5-FU 2400 mg/m² as a 46-h infusion and irinotecan 100 mg/m² repeated on day 3, biweekly) after failure of gemcitabine and platinum-based chemotherapies as a systematic policy in two institutions between January 2005 and May 2010. Tumor response, time to progression (TTP), overall survival rate (OS) and grade 3-4 toxicities were retrospectively studied. Subgroup analyses were performed to search for prognostic factors.

RESULTS: Sixty-three patients (52.4% male, median age 59 years) were analyzed. Among them, 42.9% were PS 0, 38.1% were PS 1 and 19.0% were PS 2. Fifty one patients (81.0%) had liver metastases. Before the FOLFIRI regimen, patients had received 1 line (n = 19), 2 lines (n = 39) or 3 lines (n = 5) of chemotherapy. Median TTP obtained with the line before FOLFIRI was 3.9 mo (95% CI: 3.4-5.3 mo). A total of 480 cycles was completed (median: 6 cycles, range: 1-51 cycles). The main reason for discontinuing FOLFIRI was tumor progression (90.3%). Tumor control was achieved in 25 patients (39.7%) (partial response: n = 5, stable disease: n = 20) with FOLFIRI. Median TTP was 3.0 mo (95% CI: 2.1-3.9 mo) and median OS was 6.6 mo (95% CI: 5.3-8.1 mo). Dose adaptation was required in 36 patients (57.1%). Fifteen patients (23.8%) had grade 3-4 toxicities, mainly hematological (n = 11) or digestive (n = 4). Febrile neutropenia occurred in 3 patients. There was no toxic death. PS 2 was significantly associated with poor TTP [hazard ratio (HR): 16.036, P < 0.0001] and OS (HR: 4.003, P = 0.004).

CONCLUSION: The FOLFIRI regimen had an acceptable toxicity and an interesting efficacy in our study, limited to patients in good condition (PS 0-1).

Contribution of CXCR4 and SMAD4 in predicting disease progression pattern and benefit from adjuvant chemotherapy in resected pancreatic adenocarcinoma

BACKGROUND

Prognosis of patients with pancreatic adenocarcinoma is poor. Many prognostic biomarkers have been tested, but most studies included heterogeneous patients. We aimed to investigate the prognostic and/or predictive values of four relevant biomarkers in a multicentric cohort of patients.

PATIENTS AND METHODS

A total of 471 patients who had resected pancreatic adenocarcinoma were included. Using tissue microarray, we assessed the relationship of biomarker expressions with the overall survival: Smad4, type II TGF-β receptor, CXCR4, and LKB1.

RESULTS

High CXCR4 expression was found to be the only independent negative prognostic biomarker [hazard ratio (HR) = 1.74; P < 0.0001]. In addition, it was significantly associated with a distant relapse pattern (HR = 2.19; P < 0.0001) and was the strongest prognostic factor compared with clinicopathological factors. In patients who did not received adjuvant treatment, there was a trend toward decrease in the overall survival for negative Smad4 expression. Loss of Smad4 expression was not correlated with recurrence pattern but was shown to be predictive for adjuvant chemotherapy (CT) benefit (HR = 0.59; P = 0.002).

CONCLUSIONS

CXCR4 is a strong independent prognostic biomarker associated with distant metastatic recurrence and appears as an attractive target to be evaluated in pancreatic adenocarcinoma. Negative SMAD4 expression should be considered as a potential predictor of adjuvant CT benefit.

Levels of gemcitabine transport and metabolism proteins predict survival times of patients treated with gemcitabine for pancreatic adenocarcinoma

BACKGROUND & AIMS

Patients who undergo surgery for pancreatic ductal adenocarcinoma (PDAC) frequently receive adjuvant gemcitabine chemotherapy. Key determinants of gemcitabine cytotoxicity include the activities of the human equilibrative nucleoside transporter 1 (hENT1), deoxycytidine kinase (dCK), and ribonucleotide reductase subunit 1 (RRM1). We investigated whether tumor levels of these proteins were associated with efficacy of gemcitabine therapy following surgery.

METHODS

Sequential samples of resected PDACs were retrospectively collected from 434 patients at 5 centers; 142 patients did not receive adjuvant treatment (33%), 243 received adjuvant gemcitabine-based regimens (56%), and 49 received nongemcitabine regimens (11%). We measured protein levels of hENT1, dCK, and RRM1 by semiquantitative immunohistochemistry with tissue microarrays and investigated their relationship with patients' overall survival time.

RESULTS

The median overall survival time of patients was 32.0 months. Among patients who did not receive adjuvant treatment, levels of hENT1, RRM1, and dCK were not associated with survival time. Among patients who received gemcitabine, high levels of hENT1 and dCK were significantly associated with longer survival time (hazard ratios of 0.34 [P < .0001] and 0.57 [P = .012], respectively). Interaction tests for gemcitabine administration and hENT1 and dCK status were statistically significant (P = .0007 and P = .016, respectively). On multivariate analysis of this population, hENT1 and dCK retained independent predictive values, and those patients with high levels of each protein had the longest survival times following adjuvant therapy with gemcitabine.

CONCLUSIONS

High levels of hENT1 and dCK in PDAC predict longer survival times in patients treated with adjuvant gemcitabine.

Gemcitabine and oxaliplatin (GEMOX) alone or in combination with cetuximab as first-line treatment for advanced biliary cancer: Final analysis of a randomized phase II trial (BINGO)

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Background: Gemcitabine-platinum chemotherapy (CTx) regimens are widely accepted as first-line standard of care for patients (pts) with advanced biliary cancers (ABC). EGFR overexpression has been observed in ABC, suggesting that the combination with anti-EGFR monoclonal antibodies may be appropriate. Methods: Patients with ABC, WHO performance status (PS) 0-1, and without prior palliative CTx were eligible for this international, open-label, two-stage, non-comparative, randomized phase II trial. Patients received GEMOX (gemcitabine, 1 g/m² [10 mg/m²/min] at day [D]1 + oxaliplatin, 100 mg/m² at D2, arm A) or GEMOX + cetuximab (500 mg/m² at D1 or 2, arm B), every 2 weeks. The primary endpoint was crude 4-month progression-free survival (PFS) rate (H0, <40%; H1, ≥60%; planned sample size, 100 pts, increased to 150 pts by amendment to allow subgroup analyses). Secondary endpoints were objective response rate (ORR), disease control rate (DCR), PFS, overall survival (OS), and toxicity (NCI-CTC v3.0). Exploratory endpoints included early metabolic response as assessed by PET at 1 month, and tumor KRAS mutational analysis. Results: From Oct. 2007 to Dec. 2009, we enrolled 150 pts (median age, 62 years; male, 57%; metastatic, 79%; cholangiocarcinoma, 84%; median follow-up, 30 months) (Table). Conclusions: GEMOX-cetuximab regimen was well tolerated and met its primary endpoint (4-month PFS ≥60%). However, median PFS and OS were similar in both arms. Exploratory analyses (e.g., KRAS tumor status) are underway to identify pt subgroups deriving benefit from the addition of cetuximab to CTx. [Table: see text]