Meta-analysis on resected pancreatic cancer: a comparison between adjuvant treatments and gemcitabine alone

TRAIL receptors are expressed in both malignant and stromal cells in pancreatic ductal adenocarcinoma

This study assesses the expression of all TNF-related apoptosis-inducing ligand (TRAIL) receptors in pancreatic ductal adenocarcinoma (PDAC) tumor tissue. We aimed to include TRAIL receptor expression as an inclusion parameter in a future clinical study using a TRAIL-based therapy approach for PDAC patients. Considering the emerging influence of PDAC desmoplastic stroma on the efficacy of anti-PDAC therapies, this analysis was extended to tumor stromal cells. Additionally, we performed PDAC stroma characterization. Our retrospective cohort study (N=50) included patients with histologically confirmed PDAC who underwent surgery. The expression of TRAIL receptors (DR4, DR5, DcR1, DcR2, and OPG) in tumor and stromal cells was evaluated by immunohistochemistry (IHC). The amount of tumor stroma was assessed by anti-vimentin IHC and Mallory's trichrome staining. The prognostic impact was determined by the univariate Cox proportional hazards regression model. An extensive expression of functional receptors DR4 and DR5 and a variable expression of decoy receptors were detected in PDAC tumor and stromal cells. Functional receptors were detected also in metastatic tumor and stromal cells. A poor prognosis was associated with low or absent expression of decoy receptors in tumor cells of primary PDAC. After assessing that almost 80% of tumor mass was composed of stroma, we correlated a cellular-dense stroma in primary PDAC with reduced relapse-free survival. We demonstrated that TRAIL functional receptors are widely expressed in PDAC, representing a promising target for TRAIL-based therapies. Further, we demonstrated that a low expression of DcR1 and the absence of OPG in tumor cells, as well as a cellular-dense tumor stroma, could negatively impact the prognosis of PDAC patients.

Development of a novel multi-functional integrated bioconjugate that effectively targets K-Ras mutant pancreatic cancer

Folate receptor (FR) overexpression occurs in a variety of cancers, including pancreatic cancer. In addition, enhanced macropinocytosis exists in K-Ras mutant pancreatic cancer. Furthermore, the occurrence of intensive desmoplasia causes a hypoxic microenvironment in pancreatic cancer. In this study, a novel FR-directed, macropinocytosis-enhanced, and highly cytotoxic bioconjugate folate (F)-human serum albumin (HSA)-apoprotein of lidamycin (LDP)-active enediyne (AE) derived from lidamycin was designed and prepared. F-HSA-LDP-AE consisted of four moieties: F, HSA, LDP, and AE. F-HSA-LDP presented high binding efficiency with the FR and pancreatic cancer cells. Its uptake in wild-type cells was more extensive than in K-Ras mutant-type cells. By in vivo optical imaging, F-HSA-LDP displayed prominent tumor-specific biodistribution in pancreatic cancer xenograft-bearing mice, showing clear and lasting tumor localization for 360 h. In the MTT assay, F-HSA-LDP-AE demonstrated potent cytotoxicity in three types of pancreatic cancer cell lines. It also induced apoptosis and caused G2/M cell cycle arrest. F-HSA-LDP-AE markedly suppressed the tumor growth of AsPc-1 pancreatic cancer xenografts in athymic mice. At well-tolerated doses of 0.5 and 1 mg/kg, (i.v., twice), the inhibition rates were 91.2% and 94.8%, respectively (P<0.01). The results of this study indicate that the F-HSA-LDP multi-functional bioconjugate might be effective for treating K-Ras mutant pancreatic cancer.

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We designed and generated a folate receptor-targeted and macropinocytosis-enhanced recombinant protein conjugate.

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F-HSA-LDP displayed highly specific biodistribution and long-lasting tumor accumulation in pancreatic cancer cells.

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F-HSA-LDP-AE induced apoptosis and G2/M cell cycle arrest and markedly suppressed the growth of pancreatic cancer cells.

Therapeutic targeting of pancreatic cancer stem cells by dexamethasone modulation of the MKP-1-JNK axis

Postoperative recurrence from microscopic residual disease must be prevented to cure intractable cancers, including pancreatic cancer. Key to this goal is the elimination of cancer stem cells (CSCs) endowed with tumor-initiating capacity and drug resistance. However, current therapeutic strategies capable of accomplishing this are insufficient. Using in vitro models of CSCs and in vivo models of tumor initiation in which CSCs give rise to xenograft tumors, we show that dexamethasone induces expression of MKP-1, a MAPK phosphatase, via glucocorticoid receptor activation, thereby inactivating JNK, which is required for self-renewal and tumor initiation by pancreatic CSCs as well as for their expression of survivin, an anti-apoptotic protein implicated in multidrug resistance. We also demonstrate that systemic administration of clinically relevant doses of dexamethasone together with gemcitabine prevents tumor formation by CSCs in a pancreatic cancer xenograft model. Our study thus provides preclinical evidence for the efficacy of dexamethasone as an adjuvant therapy to prevent postoperative recurrence in patients with pancreatic cancer.

A systematic review and network meta-analysis of phase III randomised controlled trials for adjuvant therapy following resection of pancreatic ductal adenocarcinoma (PDAC)

BACKGROUND

Several randomised controlled trials (RCTs) have reported various systemic adjuvant therapy regimens following resection of pancreatic ductal adenocarcinoma (PDAC). The most commonly applied include modified FOLFRINOX (mFFX), Gemcitabine/Capecitabine (GemCap) and S1, usually compared to gemcitabine (Gem) alone. However, many of these regimens have not been directly compared in RCTs. This network meta-analysis aims to characterise the impact of adjuvant therapies on overall and disease-free survival in patients having resection of PDAC.

METHODS

A systematic review was conducted using MEDLINE, EMBASE, Cochrane Central and American Society of Clinical Oncology (ASCO) abstracts to identify published phase III RCTs articles up to 9th May 2019 that examined adjuvant systemic therapy in resected pancreatic cancer. Data including study characteristics and outcomes including overall survival (OS) and disease-free survival (DFS) were extracted. Indirect comparisons of all regimens were simultaneously compared using random-effects network meta-analyses (NMA) which maintains randomisation within trials.

RESULTS

Twelve phase III RCTs involving 4947 patients and nine different regimens (5-Flourouracil/Folinic acid (5-FU/FA), Gemcitabine, Gemcitabine/Erlotinib (GemErl), GemCap), mFFX, S1, chemoradiotherapy (CRT), CRT with either 5-FU or Gemcitabine) were identified. S1 was ranked best for overall and disease-free survival followed by mFFX. Whilst there were no significant difference between S1 and mFFX for overall survival (mean difference: 1.6 months, p = 0.8), S1 had significantly longer disease-free survival than mFFX (mean difference: 2.8 months, p < 0.001). Furthermore, S1 was ranked best for lowest overall and haematological grade 3/4 toxicities.

CONCLUSION

This network meta-analysis demonstrates that chemotherapy with S1 or mFFX is superior to GemCap for adjuvant treatment for PDAC, improves survival after surgical resection and should be considered as reasonable standard treatment options in the adjuvant setting and as control arm for future adjuvant clinical trials.

Adjuvant treatment for resected pancreatic adenocarcinoma: A systematic review and network meta-analysis

Adjuvant chemotherapy has significantly improved outcomes following surgical resection for pancreatic adenocarcinoma; however, the optimal adjuvant strategy remains unclear. This systematic review and network meta-analysis was conducted to provide indirect comparative evidence across adjuvant chemotherapies. Electronic searches of EMBASE, MEDLINE, Cochrane and ASCO databases were conducted to identify eligible randomized controlled trials (RCT). Direct pairwise meta-analysis was conducted for disease-free survival (DFS), overall-survival (OS) and adverse events (AE). Network meta-analysis of DFS and OS was conducted to evaluate indirect comparisons. Ten publications of eleven RCT met eligibility criteria. Indirect DFS comparison demonstrated superiority of mFOLFIRINOX versus gemcitabine-capecitabine, gemcitabine-erlotinib and gemcitabine-nab-paclitaxel. S-1 demonstrated a DFS benefit versus gemcitabine-capecitabine, gemcitabine-erlotinib, gemcitabine-nab-paclitaxel. OS benefits were demonstrated for mFOLFIRINOX verus gemcitabine-erlotinib and for S-1 versus gemcitabine-based combination with erlotinib, capecitabine and nab-paclitaxel. In conclusion, mFOLFIRINOX is the preferred approach for adjuvant therapy. For mFOLFIRINOX-ineligible patients no additional benefit is seen with gemcitabine-nab-paclitaxel.