Tamoxifen enhances therapeutic effects of gemcitabine on cholangiocarcinoma tumorigenesis.

Cholangiocarcinoma is a highly malignant tumor with limited therapeutic options. We have previously reported that tamoxifen (TMX) induces apoptosis of cholangiocarcinoma cells and reduces cholangiocarcinoma tumorigenesis in mice. In the present studies, we determined the effect of combination therapy of TMX and gemcitabine (GMT), another chemotherapeutical reagent for many cancers, on cholangiocarcinoma tumorigenesis and investigated the responsible mechanisms. GMT inhibited cell growth and induced apoptosis of cholangiocarcinoma cells in a concentration-dependent manner. TMX enhanced GMT-induced apoptosis of cholangiocarcinoma cells. Consistently, GMT (15 mg/kg) inhibited cholangiocarcinoma tumorigenesis in nude mice by 50%. TMX (15 mg/kg) enhanced the inhibitory effect of GMT on tumorigenesis by 33%. The inhibition of tumor growth correlated with enhanced apoptosis in tumor tissues. To elucidate the mechanisms underlying the additive effects of TMX on GMT-induced apoptosis, we determined the activation of caspases in cholangiocarcinoma cells exposed to GMT, TMX, or both. Activation of caspases 9 and 3, as well as cytochrome c release to the cytosol, was demonstrated in cells exposed to both reagents. In contrast, TMX activated caspase 2, whereas GMT had no effect. Inhibition of caspase 2 activation decreased TMX-, but not GMT-, induced activation of caspase 3 and apoptosis of cholangiocarcinoma cells. Similarly, activation of caspase 2 was found in tumors from TMX-treated mice, but not GMT-treated mice. Therefore, the enhanced effect of TMX on GMT-induced cholangiocarcinoma cell death is partially mediated by activation of caspase 2. TMX and GMT both induce apoptosis and inhibit cholangiocarcinoma tumorigenesis, which may be attributed to the activation of distinct apoptosis signals by TMX and GMT. Our studies provide in vivo evidence and molecular insight to support the use of TMX and GMT in combination as an effective therapy for cholangiocarcinoma.

Molecular mechanisms of tamoxifen therapy for cholangiocarcinoma: role of calmodulin.

PURPOSE: Cholangiocarcinoma is a fatal tumor with limited therapeutic options. We have reported that calmodulin antagonists tamoxifen and trifluoperazine induced apoptosis in cholangiocarcinoma cells. Here, we determined the effects of tamoxifen on tumorigenesis and the molecular mechanisms of tamoxifen-induced apoptosis. EXPERIMENTAL DESIGN: Nude mice xenograft model of cholangiocarcinoma was used and tamoxifen was given i.p. and intratumorally. Cholangiocarcinoma cells were used to characterize molecular mechanisms of tamoxifen-induced apoptosis in vitro. RESULTS: I.p. or intratumoral injection of tamoxifen decreased cholangiocarcinoma tumorigenesis by 40% to 80% in nude mice. In cells isolated from tumor xenografts, tamoxifen inhibited phosphorylation of AKT (pAKT) and cellular FLICE like inhibitory protein (c-FLIP). Immunohistochemical analysis further showed that pAKT was identified in all nontreated tumors but was absent in tamoxifen-treated tumors. In vitro, tamoxifen activated caspase-8 and caspase-10, and their respective inhibitors partially blocked tamoxifen-induced apoptosis. Overexpression of c-FLIP inhibited tamoxifen-induced apoptosis and enhanced tumorigenesis of cholangiocarcinoma cells in nude mice, whereas deletion of the calmodulin-binding domain on c-FLIP restored the sensitivity to tamoxifen and inhibited tumorigenesis. With two additional cholangiocarcinoma cell lines, we confirmed that the expression of FLIP is an important factor in mediating spontaneous and tamoxifen-induced apoptosis. CONCLUSIONS: Thus, tamoxifen inhibits cholangiocarcinoma tumorigenesis in nude mice. Tamoxifen-induced apoptosis is partially dependent on caspases, inhibition of pAKT, and FLIP expression. Further, calmodulin-FLIP binding seems to be important in FLIP-mediated resistance to tamoxifen. Therefore, the present studies support the concept that tamoxifen may be used as a therapy for cholangiocarcinoma and possibly other malignancies in which the calmodulin targets AKT and c-FLIP play important roles in the tumor pathogenesis.

A prospective evaluation of an algorithm incorporating routine preoperative endoscopic ultrasound-guided fine needle aspiration in suspected pancreatic cancer.

BACKGROUND: Whether tissue diagnosis is required in the preoperative evaluation of patients with suspected pancreatic cancer remains controversial. We prospectively evaluated the accuracy, safety, and potential impact on surgical intervention of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in the preoperative evaluation of suspected pancreatic cancer. METHODS: All patients who underwent EUS-FNA at our institution (n = 547) over a 4.5-year period were enrolled. Patients underwent surgical exploration and resection based on their comorbidity status, evidence of resectability based on spiral computed tomography (CT) and EUS imaging reviewed in a multidisciplinary approach. RESULTS: Of 547 patients enrolled (median age 64 years, 60% male), 49% presented with obstructive jaundice. The operating characteristics of EUS-FNA of solid pancreatic masses were: sensitivity 95% (95% CI: 93.2-95.4), specificity 92% (95% CI: 86.6-95.7), positive predictive value 98% (95% CI: 97-99), negative predictive value 80% (95% CI: 74.9-82.7). The overall accuracy of EUS-FNA was 94.1% (95% CI: 92.0-94). Of the 414 true positive patients by EUS-FNA, 138 (33%) were explored. Of patients deemed operable by combined imaging, 42% had surgical resection. Eighty-two percent of true positive patients were ultimately found inoperable and received palliative therapy or chemotherapy. Of the 94 patients with true negative cytology based on extended follow-up, only 7 (7%) underwent surgical resection. Of those with false negative diagnoses (n = 24), 5 patients underwent exploration/resection based on detection of mass lesions by EUS. The remaining patients had unresectable disease. Mild self-limiting pancreatitis occurred in (0.91%). CONCLUSIONS: EUS-FNA is a safe and highly accurate method for tissue diagnosis in suspected pancreatic cancer. This approach allows for preoperative counseling of patients, minimizing surgeon's operative time in cases of unresectable disease, and avoids surgical biopsies in the majority of patients with inoperable disease. In addition, it allows for conservative management of patients with benign biopsies. We still, however, recommend exploration of patients with clinical scenario suspicious for pancreatic cancer, a mass found on EUS or CT, but inconclusive or negative cytology.

Preoperative chemoradiation in the management of adenocarcinoma of the body of the pancreas.

Adenocarcinoma of the body of the pancreas has been traditionally associated with low resectability and poor prognosis. We reviewed 30 consecutive cases of pancreatic body adenocarcinoma presenting between 1988 and 2001. Twenty-six (87%) patients received preoperative chemotherapy (either 5-fluorouracil with or without mitomycin C or gemcitabine) plus radiation therapy (50.4 Gy), and four patients received chemoradiation postoperatively. During or shortly after chemoradiation 16 (53%) patients developed distant metastasis (n = 12), tumor progression (n = 2), or fatal septic complications (n = 2). Fourteen patients underwent surgical resection with curative intent. Resections performed included distal subtotal pancreatectomies (n = 6), extended pancreaticoduodenectomies (n = 6), and total pancreatectomies (n = 2). Ten patients (71%) required vascular reconstruction as a result of involvement of the portal vein or the superior mesenteric, hepatic arterial, or celiac vessels. Median overall survival was 34 months (range 8-152) for the resected group as compared with 8 months (range 1-14) in the unresected group (P = 0.005). Five-year actuarial overall survival is projected at 45 per cent for the resected group. In this poor-prognostic subset of patients with pancreatic cancer preoperative chemoradiation followed by an aggressive surgical approach was associated with resectability and long-term survival of a significant minority of patients.

Primary pancreatic Ewing's sarcoma with portal vein tumor thrombosis.

BACKGROUND: Extraosseous Ewing's sarcoma (EES) is a mesenchyme-derived small blue cell tumor, which is distinguished by its rarity, aggressiveness, dismal prognosis, and distinct pathogenesis. Occurring almost exclusively among children and young adults, EES can arise from a variety of organs and portends a rapid clinical deterioration and high likelihood of recurrence. DISCUSSION: We present the first reported case of a primary pancreatic Ewing's sarcoma in a patient with concomitant portal vein thrombosis. The atypical presentation of this extraordinarily rare tumor underscores the imperative to maintain EES in the differential diagnosis of suspicious, indistinct pancreatic lesions in young patients. In addition, we review the available literature describing additional cases of primary pancreatic Ewing's sarcoma.

Serum biomarker panels for the detection of pancreatic cancer.

PURPOSE: Serum-biomarker based screening for pancreatic cancer could greatly improve survival in appropriately targeted high-risk populations. EXPERIMENTAL DESIGN: Eighty-three circulating proteins were analyzed in sera of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC, n = 333), benign pancreatic conditions (n = 144), and healthy control individuals (n = 227). Samples from each group were split randomly into training and blinded validation sets prior to analysis. A Metropolis algorithm with Monte Carlo simulation (MMC) was used to identify discriminatory biomarker panels in the training set. Identified panels were evaluated in the validation set and in patients diagnosed with colon (n = 33), lung (n = 62), and breast (n = 108) cancers. RESULTS: Several robust profiles of protein alterations were present in sera of PDAC patients compared to the Healthy and Benign groups. In the training set (n = 160 PDAC, 74 Benign, 107 Healthy), the panel of CA 19-9, ICAM-1, and OPG discriminated PDAC patients from Healthy controls with a sensitivity/specificity (SN/SP) of 88/90%, while the panel of CA 19-9, CEA, and TIMP-1 discriminated PDAC patients from Benign subjects with an SN/SP of 76/90%. In an independent validation set (n = 173 PDAC, 70 Benign, 120 Healthy), the panel of CA 19-9, ICAM-1 and OPG demonstrated an SN/SP of 78/94% while the panel of CA19-9, CEA, and TIMP-1 demonstrated an SN/SP of 71/89%. The CA19-9, ICAM-1, OPG panel is selective for PDAC and does not recognize breast (SP = 100%), lung (SP = 97%), or colon (SP = 97%) cancer. CONCLUSIONS: The PDAC-specific biomarker panels identified in this investigation warrant additional clinical validation to determine their role in screening targeted high-risk populations.