Neoadjuvant/preoperative gemcitabine for patients with localized pancreatic cancer: a meta-analysis of prospective studies.

BACKGROUND: Long-term prognosis for localized pancreatic cancer remains poor. We sought to assess the benefit of neoadjuvant/preoperative chemotherapy with or without radiotherapy. METHODS: Prospective studies where gemcitabine with or without radiotherapy was provided before surgery in patients with initially resectable or unresectable disease were reviewed by meta-analysis. Primary outcome was survival, and secondary outcomes were tumor response after therapy, toxicity, surgical exploration, and resection rates. RESULTS: Twenty independent studies with 707 participants were included, 366 with resectable lesions and 341 with unresectable lesions. Seven studies were phase I/II trials, 10 phase II, and 3 prospective cohort studies. Estimated 1- and 2-year survival probabilities after resection were 91.7% (95% confidence interval [CI] 75-100) and 67.2% (95% CI 38-87) for initially resectable patients, and 86.3% (95% CI 78-100) and 54.2% (95% CI 25-100) for initially unresectable patients. The complete/partial response rate was 12% (95% CI 4-23) and 27% (95% CI 18-38) in resectable and unresectable lesions, respectively. The rate of treatment-related grade 3-4 toxicity was 31% (95% CI 21-42). Of resectable patients evaluable after restaging, 91% (95% CI 83-97) underwent surgery, and 82% (95% CI 65-95) of explored patients underwent resection. R0 resections amounted to 89% (95% CI 83-94). Of unresectable patients evaluable after restaging, 39% (95% CI 28-50) underwent surgery, and 68% (95% CI 53-82) of explored patients were resected, with 60% (95% CI 50-71) R0 resections. CONCLUSIONS: Current analysis provides marginal support to the assumed benefits of neoadjuvant therapies for patients with resectable cancer, and indicates a potential advantage only for a minority of those with unresectable lesions.

Altered anti-inflammatory response of mononuclear cells to neuropeptide PACAP is associated with deregulation of NF-{kappa}B in chronic pancreatitis.

Although it is recognized that neurogenic influences contribute to progression of chronic inflammatory diseases, the molecular basis of neuroimmune interactions in the pathogenesis of chronic pancreatitis (CP) is not well defined. Here we report that responsiveness of peripheral blood mononuclear cells (PBMC) to the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is altered in CP. Expression of PACAP and its receptors in human CP was analyzed with quantitative RT-PCR, laser-capture microdissection, and immunohistochemistry. Regulation of PACAP expression was studied in coculture systems using macrophages and acinar cells. Responsiveness of donor and CP PBMC to PACAP was determined based on cytokine profiles and NF-kappaB activation of LPS- or LPS+PACAP-exposed cells. Although donor and CP PBMC responded equally to LPS, PACAP-mediated counteraction of LPS-induced cytokine response was switched from inhibiting TNF-alpha to decreasing IL-1beta and increasing IL-10 secretion. The change of PACAP-mediated anti-inflammatory pattern was associated with altered activation of NF-kappaB: compared with LPS alone, a combination of LPS and PACAP had no effect on NF-kappaB p65 nuclear translocation in CP PBMC, whereas NF-kappaB was significantly decreased in donor PBMC. According to laser-capture microdissection and coculture experiments, PBMC also contributed to generation of a PACAP-rich intrapancreatic environment by upregulating PACAP expression in macrophages encountering apoptotic pancreatic acini. The nociceptive status of CP patients correlated with pancreatic PACAP levels and with IL-10 bias of PACAP-exposed CP PBMC. Thus the ability of PBMC to produce and to respond to PACAP might influence neuroimmune interactions that regulate pain and inflammation in CP.