Local failure continues to be a major problem in the management of pancreatic cancer. Delivery of adequate radiation doses to the pancreas is limited by radiation-sensitive normal structures in the ...upper abdomen. To overcome some of these restrictions, we have developed a regimen of intensity-modulated radiotherapy (IMRT) with concurrent capecitabine.
This is a retrospective analysis of the first 15 patients with adenocarcinoma of the pancreas treated on this regimen (7 as adjuvant therapy after curative resection and 8 patients for unresectable disease). Intensity-modulated radiotherapy was planned using the CORVUS system and delivered with a segmented multileaf collimator, using a 6-MV photon beam and 10 intensity steps. Two target volumes were entered: target 1 consisted of the gross tumor volume (in unresectable cases) or the tumor bed (in postsurgical cases); and target 2 consisted of the draining lymph nodes. Both targets were treated simultaneously in 25 daily fractions, 5 days a week. In the postoperative setting, the total dose to target 1 was 45–54 Gy (median, 54 Gy). For unresectable disease the dose was 54–55 Gy (median, 54 Gy). The total dose to target 2 was 45 Gy in all patients. Patients were treated with one of two six-field beam arrangements found to produce superior dose distributions. Capecitabine was given at 1,600 mg/m
2/day in two divided doses, 5 days per week, concurrently with radiotherapy. In addition, most patients (73%) received gemcitabine-based chemotherapy. Systemic chemotherapy was given before, after, or both before and after chemoradiotherapy in 47%, 7%, and 20% of patients, respectively. Patients were evaluated on a weekly basis.
Treatment was tolerated well. Grade 1/2 nausea/vomiting developed in 8 patients (53%) and Grade 1/2 hematologic toxicity developed in 9 patients (60%). Only 1 patient (7%) had Grade 3 toxicity, a gastric ulceration that responded to medical management. Nine patients (60%) had weight loss (median, 7 lbs; range, 3–12 lbs). The median follow-up time is 8.5 months (10.1 months in patients who are alive). In the resectable group there have been no deaths, and there has been 1 local relapse (14%). In the unresectable group there have been 2 deaths, and the 1-year actuarial survival rate is 69%. Two patients converted to resectability, 5 patients (62.5%) have persistent locoregional disease after chemoradiotherapy, and 1 patient (12%) is locally controlled without surgery.
This regimen of IMRT with tumor-selective radiosensitization is well tolerated. The low toxicity profile compares favorably with that of protocols based on continuous-infusion 5-fluorouracil or gemcitabine, and the preliminary indications of efficacy are encouraging.
Cyclooxygenase-2 (COX-2) is involved in inhibition of apoptosis, potentiation of cell growth, and angiogenesis and as such is a target for drug development. The COX-2 enzyme is frequently ...overexpressed in pancreatic cancer. The aim of this study was to determine the effects of celecoxib on the growth inhibition and induction of apoptosis by gemcitabine in pancreatic cancer cell lines. Baseline expression of COX-2 enzyme was determined by Western blot analysis in five human pancreatic cancer cell lines. Cells were treated with gemcitabine (100 nmol/L), celecoxib (1, 10, and 50 micromol/L), and the combination. No potentiation in growth inhibition was observed in MIAPaCa cells (low COX-2 expression). However, growth inhibition and apoptosis were significantly increased with celecoxib in the BxPC-3 cells that have a high COX-2 expression. Significant down-regulation of nuclear factor-kappaB activation was observed in BxPC-3 cells treated with celecoxib and gemcitabine. Moreover, down-regulation of COX-2 mRNA and protein expression was also observed in the BxPC-3 cells treated with the combination as compared with the untreated and the celecoxib-treated and gemcitabine-treated cell lines. We conclude that celecoxib potentiates gemcitabine-induced growth inhibition and apoptosis in pancreatic cell lines. In addition to inhibition of the COX-2 enzyme, the celecoxib and gemcitabine combination down-regulated nuclear factor-kappaB activation, which in turn may have contributed to the induction of apoptosis and the down-regulation of transcription of the COX-2 enzyme.
The aims of this study were to determine the effects of (a) combining the epidermal growth factor receptor (EGFR) blocker (erlotinib) and the cyclooxygenase-2 inhibitor (celecoxib) on cell growth and ...apoptosis in human pancreatic cancer cell lines, (b) baseline EGFR expression on the potentiation of erlotinib-induced apoptosis by celecoxib, and (c) the effects of the combination on the expression of the COX-2, EGFR, HER-2/neu, and nuclear factor-kappaB (NF-kappaB). Baseline expression of EGFR was determined by Western blot analysis in five human pancreatic cancer cell lines. BxPC-3, PANC-1, and HPAC had high EGFR and MIAPaCa had low EGFR. Cells were grown in culture and treated with erlotinib (1 and 10 micromol/L), celecoxib (1 and 10 micromol/L), and the combination. Growth inhibition was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and apoptosis was assayed by ELISA. Reverse transcriptase-PCR was used to evaluate COX-2 and EGFR mRNA. EGFR, COX-2, and HER-2/neu expression was determined by Western immunoblotting. Electrophoretic mobility shift assay was used to evaluate NF-kappaB activation. Growth inhibition and apoptosis were significantly (P < 0.05) higher in BxPC-3, HPAC, and PANC-1 cells treated with celecoxib and erlotinib than cells treated with either celecoxib or erlotinib. However, no potentiation in growth inhibition or apoptosis was observed in the MIAPaCa cell line with low expression of the EGFR. Significant down-regulation of COX-2 and EGFR expression was observed in the BxPC-3 and HPAC cells treated with the combination of erlotinib (1 micromol/L) and celecoxib (10 micromol/L) compared with celecoxib- or erlotinib-treated cells. Celecoxib significantly down-regulated HER-2/neu expression in BxPC-3 and HPAC cell lines. Significant inhibition of NF-kappaB activation was observed in BxPC-3 and HPAC cell lines treated with erlotinib and celecoxib. (a) Celecoxib can potentiate erlotinib-induced growth inhibition and apoptosis in pancreatic cell lines, (b) high baseline EGFR expression is a predictor of this potentiation, and (c) the down-regulation of EGFR, COX-2, and HER-2/neu expression and NF-kappaB inactivation contributes to the potentiation of erlotinib by celecoxib.
The cytochrome P-450 (CYP) and glutathione S-transferase (GST) enzyme systems may influence the biological effects of carcinogens, including estrogens. As such, these enzymes may predict the ...developmental risk of breast cancer, as well as be potential targets for chemoprevention. The purpose of this study was to compare the expression of GST-Pi and CYPs 1A1, 2B6, 2E1, and 3A4 in paired samples of normal and malignant breast tissue from patients with breast cancer and women undergoing reduction mammoplasty.
Expression of CYPs 1A1, 2B6, 2E1, 3A4, and GST-Pi was quantified in breast tissue from 33 patients with breast cancer and in 17 women without history of cancer who underwent reduction mammoplasty. The expression of CYP 1A1, 2B6, 2E1, 3A4, and GST-Pi was quantified by immunoblotting.
CYP 1A1, 2E1, and 3A4 expression was significantly lower (P < 0.05) in malignant tissue as compared with morphologically normal adjacent tissue. Conversely, GST-Pi expression was marginally lower in the normal tissue (P = 0.08). No significant difference in enzyme expression was seen between the tissue from reduction mammoplasty and normal tissue from breast cancer patients. There was a trend for higher expression of CYP 2B6 and GST-Pi in the estrogen receptor expressing tumors than those tumors without expression (P > 0.28).
The expression of these enzymes was similar in morphologically normal breast tissue from patients with or without breast cancer. The expression of CYPs was down-regulated in the tumor tissue. The clinical significance of CYP alterations in breast cancer will need further characterization.
Pancreatic cancer is amongst the most chemoresistant malignancies. Expression of the cyclooxygenase-2 (COX-2) enzyme plays a major role in tumor progression and resistance to therapy. A Phase II ...study was undertaken to determine the effect of gemcitabine by fixed-dose rate infusion (FDR), cisplatin and the COX-2 inhibitor, celecoxib, on the 6-month survival rate in patients with metastatic pancreatic cancer.
The eligibility criteria included a pathologically or cytologically confirmed diagnosis of adenocarcinoma of the pancreas. No prior gemcitabine therapy was allowed. Patients received a combination of gemcitabine 1,000 mg/m(2) over 100 minutes, cisplatin 35 mg/m(2) I.V. on days 1 and 8, and celecoxib continuously at a daily dose of 800 mg. Cycles were repeated every 21 days.
Twenty-two patients with metastatic pancreas cancer were enrolled (median age, 59.5 years; M:F, 13:9). The median number of cycles was 2 per patient. The median survival time was 5.8 months (90% CI, 3.6-7.6 months). The probability of survival at 6 months was 46% (90% CI, 27-62%). The major toxicity was neutropenia with grade 3 or 4 toxicities seen in 65% of patients.
The addition of celecoxib to gemcitabine (by FDR) and cisplatin did not appear to increase activity of the chemotherapy doublet in patients with advanced pancreatic cancer. Celecoxib alone may not be sufficient to sensitize pancreatic cancer to the effects of conventional cytotoxic therapy.
Phase I study of bryostatin 1 and gemcitabine El-Rayes, Basil F; Gadgeel, Shirish; Shields, Anthony F ...
Clinical cancer research,
12/2006, Letnik:
12, Številka:
23
Journal Article
Recenzirano
Odprti dostop
Bryostatin 1 is a macrocyclic lactone with protein kinase C inhibitory activity. Gemcitabine is a nucleotide analogue with a broad spectrum of anticancer activity. Bryostatin 1 enhanced the activity ...of antitumor agents including gemcitabine in preclinical models. The primary objective of this phase I study was to determine the recommended doses for phase II trials of bryostatin 1 and gemcitabine.
Eligible patients had histologic or cytologic diagnosis of nonhematologic cancer refractory to conventional treatment; life expectancy of >3 months; normal renal, hepatic, and bone marrow function; and a Southwest Oncology Group performance status of 0 to 2. Gemcitabine was administered i.v. over 30 minutes and was followed by bryostatin 1 by i.v. infusion over 24 hours on days 1, 8, and 15 of a 28-day cycle. Bryostatin 1 (microg/m(2)) and gemcitabine (mg/m(2)) doses were escalated as follows: 25/600, 25/800, 25/1,000, 30/1,000, 35/1,000, and 45/1,000, respectively.
Thirty-six patients (mean age, 57 years; male/female 15:21) were treated. The median number of treatment cycles per patient was 3 (range, 0-24). Four patients developed dose limiting toxicities: myalgia, 2; myelosuppression, 1; and elevation of serum alanine aminotransferase levels, 1. Ten grade 3 toxicities were observed (anemia, 2; neutropenia, 5; thrombocytopenia, 3). No treatment-related death was seen. The recommended doses for phase II trials for bryostatin 1 and gemcitabine were 35 microg/m(2) and 1,000 mg/m(2), respectively. Two heavily pretreated patients with breast and colon cancer experienced partial responses lasting 22 and 8 months, respectively. Eight patients had stable disease.
The combination of bryostatin 1 and gemcitabine seemed to be well tolerated with limited grade 3 toxicity. The recommended dose of bryostatin 1 in combination with full doses of gemcitabine was 35 microg/m(2).
Prostate cancer is the most commonly diagnosed cancer and the second leading cause of cancer related deaths in men in the United States. Ciprofloxacin is a relatively non-toxic antibiotic that can be ...easily administered orally with large volume of distribution and good tissue penetration. Studies from others and our laboratory have recently reported its anti-tumor activity in a variety of human tumor cells. In our current experiment, we studied the effect of ciprofloxacin on a hormone resistant prostate cancer (HRPC) cell line, PC-3. Our study shows significant in vitro cell growth inhibition of PC-3 cell line (p=0.0001) and also shows that there is a synergistic increase in the antiproliferative effect of etoposide when these cells are pretreated with ciprofloxacin for 24 h, prior to etoposide exposure (p=0.0001). Western blot analysis of the protein extracts from these cells showed down-regulation of Bcl-2, altering the ratio of Bax:Bcl-2 favoring apoptosis. In our study no significant effect was seen on p21WAF1 expression by the combination of ciprofloxacin and etoposide but there was down-regulation of p21WAF1 gene by ciprofloxacin alone. Ciprofloxacin also inhibited NF-kappaB binding to DNA. Further studies in this area are warranted as the roles of p21WAF1, Bax/Bcl-2 and NF-kappaB may be important molecular events in mediating the antiproliferative and apoptosis inducing effect of etoposide in combination with ciprofloxacin in HRPC cells.
Flavopiridol is a cyclin dependent kinase inhibitor. Preclinical models suggest a sequence dependent synergy between flavopiridol and taxanes. The primary objective of this study was to determine the ...maximum tolerated dose (MTD) of flavopiridol and docetaxel and the influence of flavopiridol on the pharmacokinetics of docetaxel.
The major eligibility criteria included: a diagnosis of non-hematologic cancer with no conventional effective therapy, normal organ function, and ECOG performance status of 0-2. Patients were treated with docetaxel followed 24 h later by flavopiridol given via continuous intravenous infusion over a 24-h period. The starting doses of docetaxel and flavopiridol were 60 and 60 mg/m2, respectively. Cycles were repeated every 21 days. All patients received diarrhea prophylaxis consisting of bismuth subsalicylate.
Ten patients (M:F 4:6; median age 56 years) were treated. The median number of cycles per patient was 2 (range 1-6). Two of the three patients on dose level 1 developed dose-limiting toxicities consisting of neutropenia and fever. Seven patients were subsequently enrolled on dose level -1 (docetaxel 60 mg/m2, flavopiridol 50 mg/m2). One episode of grade 3 diarrhea was reported at dose level -1.
Neutropenia complicated by infection was the major dose-limiting toxicity. The recommended doses of flavopiridol and docetaxel for phase II trials are 50 and 60 mg/m2 every three weeks, respectively.
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