Adjuvant treatment of pancreatic cancer in 2009: where are we? Highlights from the 45th ASCO annual meeting. Orlando, FL, USA. May 29-June 2, 2009.

JOP. 2009;10(4):373-7

Authors: Saif MW

Despite attempted curative resection of localized pancreatic adenocarcinoma, most patients succumb a recurrence and die of their disease. The Gastrointestinal Tumor Study Group, European Organization for Research and Treatment of Cancer, and European Study Group for Pancreatic Cancer trials have suggested the benefit of adjuvant therapy. However, the relatively few randomized trials available have not established a definite standard of care due to study limitations. Although these trials, and the recently published Charité Onkologie (CONKO)-001 trial, have shown a definite advantage of adjuvant chemotherapy, the most effective chemotherapy and the role of radiation therapy remain unclear. This review will discuss the data available from reported trials of adjuvant therapy in pancreatic cancer, especially the results of the ESPAC-3 study presented at the annual meeting of ASCO 2009, and consider future directions for clinical trials.

PMID: 19581737 [PubMed - in process]

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Inactivation of TIF1gamma cooperates with Kras to induce cystic tumors of the pancreas.

PLoS Genet. 2009 Jul;5(7):e1000575

Authors: Vincent DF, Yan KP, Treilleux I, Gay F, Arfi V, Kaniewsky B, Marie JC, Lepinasse F, Martel S, Goddard-Leon S, Iovanna JL, Dubus P, Garcia S, Puisieux A, Rimokh R, Bardeesy N, Scoazec JY, Losson R, Bartholin L

Inactivation of the Transforming Growth Factor Beta (TGFbeta) tumor suppressor pathway contributes to the progression of Pancreatic Ductal AdenoCarcinoma (PDAC) since it is inactivated in virtually all cases of this malignancy. Genetic lesions inactivating this pathway contribute to pancreatic tumor progression in mouse models. Transcriptional Intermediary Factor 1 gamma (TIF1gamma) has recently been proposed to be involved in TGFbeta signaling, functioning as either a positive or negative regulator of the pathway. Here, we addressed the role of TIF1gamma in pancreatic carcinogenesis. Using conditional Tif1gamma knockout mice (Tif1gamma(lox/lox)), we selectively abrogated Tif1gamma expression in the pancreas of Pdx1-Cre;Tif1gamma(lox/lox) mice. We also generated Pdx1-Cre;LSL-Kras(G12D);Tif1gamma(lox/lox) mice to address the effect of Tif1gamma loss-of-function in precancerous lesions induced by oncogenic Kras(G12D). Finally, we analyzed TIF1gamma expression in human pancreatic tumors. In our mouse model, we showed that Tif1gamma was dispensable for normal pancreatic development but cooperated with Kras activation to induce pancreatic tumors reminiscent of human Intraductal Papillary Mucinous Neoplasms (IPMNs). Interestingly, these cystic lesions resemble those observed in Pdx1-Cre;LSL-Kras(G12D);Smad4(lox/lox) mice described by others. However, distinctive characteristics, such as the systematic presence of endocrine pseudo-islets within the papillary projections, suggest that SMAD4 and TIF1gamma don't have strictly redundant functions. Finally, we report that TIF1gamma expression is markedly down-regulated in human pancreatic tumors by quantitative RT-PCR and immunohistochemistry supporting the relevance of these findings to human malignancy. This study suggests that TIF1gamma is critical for tumor suppression in the pancreas, brings new insight into the genetics of pancreatic cancer, and constitutes a promising model to decipher the respective roles of SMAD4 and TIF1gamma in the multifaceted functions of TGFbeta in carcinogenesis and development.

PMID: 19629168 [PubMed - in process]

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Interstitial chemotherapy with ricin-loaded thermosensitive hydrogel in pancreatic cancer xenograft.

Hepatobiliary Pancreat Dis Int. 2009 Aug;8(4):418-23

Authors: Chen ZK, Lin LW, Weng XH, Xue ES, Lin YH

BACKGROUND: Pancreatic cancer is one of the most aggressive malignancies, and has a poor prognosis. Despite efforts made in multiple fields, there has been little success in improving the disease-free survival rate of patients. This study was undertaken to investigate the effectiveness and feasibility of using intra-tumoral injection of ricin-loaded thermosensitive hydrogel for treatment of pancreatic cancer xenografts, attempting to develop a new treatment for human pancreatic cancer.

METHODS: BALB/c-(nu/nu) nude mice were inoculated subcutaneously in the right flank with the human pancreatic cancer cells, SW1990. Fourteen days after inoculation, 32 mice, bearing tumors of volume 1.5-2.0 cm3, were randomly assigned to one of four groups, and given an intra-tumoral injection of: (1) saline; (2) 23% w/w thermosensitive hydrogel alone; (3) ricin, 10 microg/kg; or (4) 10 microg/kg ricin loaded in thermosensitive hydrogel. On day 14 after administration, the tumors were excised to calculate the inhibition rate of tumor growth and perform histopathological examination. Tumor cell apoptosis was detected by flow cytometry, and RT-PCR was performed to evaluate the mRNA expression levels of Bcl2 and Bax.

RESULTS: Intra-tumoral injection of ricin-loaded thermosensitive hydrogel resulted in remarkable control of tumor growth. The tumor became necrotic by day 14 after administration. The histological results clearly confirmed that the tumor cells were lysed. The percentage of apoptotic cells detected by flow cytometry was higher in the ricin hydrogel group than in the other groups. Semi-quantitative RT-PCR revealed that the mRNA expression level of Bcl2 was down-regulated whereas Bax was upregulated.

CONCLUSIONS: Intra-tumoral injection of ricin-loaded thermosensitive hydrogel may provide an effective approach for interstitial chemotherapy in pancreatic cancer. Inducing apoptosis by downregulating Bcl2 expression and upregulating Bax expression may be a key molecular mechanism.

PMID: 19666413 [PubMed - in process]

Read Full Article pubmed: pancreatic cancer