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1.
J Gastrointest Surg ; 21(7): 1153-1158, 2017 07.
Article in English | MEDLINE | ID: mdl-28386670

ABSTRACT

Small cohort studies demonstrated better oncologic outcomes for patients with pathologic complete response (PathCR) after neoadjuvant treatment for locally advanced rectal cancer. This study reviews long-term outcomes of a large cohort of clinically stage II/III rectal cancer patients who received neoadjuvant chemoradiation and surgery. This is a retrospective analysis of a single-center cohort, including all clinical stage II/III rectal cancer patients who received neoadjuvant chemoradiation and surgery between 2004 and 2014 (n = 271). Cox regressions were done to assess the influence of PathCR on recurrence-free survival (RFS) and overall survival (OS), adjusting for postoperative chemotherapy, clinical AJCC staging, comorbidity, and age where appropriate. PathCR patients had significantly lower distant recurrence rates (4 vs. 15.8%; P = 0.028) and lower disease-specific mortality rates (0 vs. 8.1%; P = 0.052), compared to patients with residual disease. PathCR was associated with longer RFS (HR, 5.6 [95% CI 1.3-23.1] P = 0.018) and longer OS (HR, 3.4 [1.31-10.0] P = 0.014) compared to having pathological residual disease. This large single-center study shows that patients with PathCR have significant longer RFS and OS than patients with residual disease on pathology after neoadjuvant chemoradiation.


Subject(s)
Chemoradiotherapy , Neoadjuvant Therapy , Neoplasm, Residual/therapy , Rectal Neoplasms/therapy , Aged , Female , Humans , Male , Middle Aged , Neoplasm Staging , Neoplasm, Residual/mortality , Neoplasm, Residual/pathology , Rectal Neoplasms/mortality , Rectal Neoplasms/pathology , Retrospective Studies , Survival Rate
2.
Br J Cancer ; 111(3): 430-6, 2014 Jul 29.
Article in English | MEDLINE | ID: mdl-24960403

ABSTRACT

BACKGROUND: Current data suggest that platinum-based combination therapy is the standard first-line treatment for biliary tract cancer. EGFR inhibition has proven beneficial across a number of gastrointestinal malignancies; and has shown specific advantages among KRAS wild-type genetic subtypes of colon cancer. We report the combination of panitumumab with gemcitabine (GEM) and oxaliplatin (OX) as first-line therapy for KRAS wild-type biliary tract cancer. METHODS: Patients with histologically confirmed, previously untreated, unresectable or metastatic KRAS wild-type biliary tract or gallbladder adenocarcinoma with ECOG performance status 0-2 were treated with panitumumab 6 mg kg(-1), GEM 1000 mg m(-2) (10 mg m(-2) min(-1)) and OX 85 mg m(-2) on days 1 and 15 of each 28-day cycle. The primary objective was to determine the objective response rate by RECIST criteria v.1.1. Secondary objectives were to evaluate toxicity, progression-free survival (PFS), and overall survival. RESULTS: Thirty-one patients received at least one cycle of treatment across three institutions, 28 had measurable disease. Response rate was 45% and disease control rate was 90%. Median PFS was 10.6 months (95% CI 5-24 months) and median overall survival 20.3 months (95% CI 9-25 months). The most common grade 3/4 adverse events were anaemia 26%, leukopenia 23%, fatigue 23%, neuropathy 16% and rash 10%. CONCLUSIONS: The combination of gemcitabine, oxaliplatin and panitumumab in KRAS wild type metastatic biliary tract cancer showed encouraging efficacy, additional efforts of genetic stratification and targeted therapy is warranted in biliary tract cancer.


Subject(s)
Adenocarcinoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biliary Tract Neoplasms/drug therapy , Gallbladder Neoplasms/drug therapy , Adenocarcinoma/mortality , Adenocarcinoma/secondary , Adult , Aged , Antibodies, Monoclonal/administration & dosage , Biliary Tract Neoplasms/mortality , Biliary Tract Neoplasms/pathology , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Disease-Free Survival , Female , Gallbladder Neoplasms/mortality , Gallbladder Neoplasms/pathology , Humans , Kaplan-Meier Estimate , Lymphatic Metastasis , Male , Middle Aged , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Panitumumab , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins p21(ras) , Treatment Outcome , ras Proteins/genetics , Gemcitabine
3.
Ann Oncol ; 25(1): 121-6, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24356623

ABSTRACT

BACKGROUND: To determine the maximal tolerated dose of erlotinib when added to 5-fluorouracil (5-FU) chemoradiation and bevacizumab and safety and efficacy of this combination in patients with locally advanced rectal cancer. PATIENTS AND METHODS: Patients with Magnetic resonance imaging (MRI) or ultrasound defined T3 or T4 adenocarcinoma of the rectum and without evidence of metastatic disease were enrolled. Patients received infusional 5-FU 225 mg/M2/day continuously, along with bevacizumab 5 mg/kg days 14, 1, 15 and 29. Standard radiotherapy was administered to 50.4 Gy in 28 fractions. Erlotinib started at a dose of 50 mg orally daily and advanced by 50 mg increments in the subsequent cohort. Open total mesorectal excision was carried out 6-9 weeks following the completion of chemoradiation. RESULTS: Thirty-two patients received one of three dose levels of erlotinib. Erlotinib dose level of 100 mg was determined to be the maximally tolerated dose. Thirty-one patients underwent resection of the primary tumor, one refused resection. Twenty-seven patients completed study therapy, all of whom underwent resection. At least one grade 3-4 toxicity occurred in 46.9% of patients. Grade 3-4 diarrhea occurred in 18.8%. The pathologic complete response (pCR) for all patients completing study therapy was 33%. With a median follow-up of 2.9 years, there are no documented local recurrences. Disease-free survival at 3 years is 75.5% (confidence interval: 55.1-87.6%). CONCLUSIONS: Erlotinib added to infusional 5-FU, bevacizumab and radiation in patients with locally advanced rectal cancer is relatively well tolerated and associated with an encouraging pCR.


Subject(s)
Adenocarcinoma/therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Rectal Neoplasms/therapy , Antibodies, Monoclonal, Humanized/administration & dosage , Bevacizumab , Chemoradiotherapy , Chemotherapy, Adjuvant , Disease-Free Survival , Erlotinib Hydrochloride , Female , Fluorouracil/administration & dosage , Humans , Male , Neoadjuvant Therapy , Quinazolines/administration & dosage , Treatment Outcome
4.
Ann Oncol ; 24(7): 1792-1801, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23448807

ABSTRACT

BACKGROUND: We evaluated AGS-1C4D4, a fully human monoclonal antibody to prostate stem cell antigen (PSCA), with gemcitabine in a randomized, phase II study of metastatic pancreatic cancer. PATIENTS AND METHODS: Patients with Eastern Cooperative Oncology Group (ECOG) performance status 0/1 and previously untreated, metastatic pancreatic adenocarcinoma were randomly assigned 1:2 to gemcitabine (1000 mg/m(2) weekly seven times, 1 week rest, weekly three times q4weeks) or gemcitabine plus AGS-1C4D4 (48 mg/kg loading dose, then 24 mg/kg q3weeks IV). The primary end point was 6-month survival rate (SR). Archived tumor samples were collected for pre-planned analyses by PSCA expression. RESULTS: Between April 2009 and May 2010, 196 patients were randomly assigned to gemcitabine (n = 63) or gemcitabine plus AGS-1C4D4 (n = 133). The 6-month SR was 44.4% (95% CI, 31.9-57.5) in the gemcitabine arm and 60.9% (95% CI, 52.1-69.2) in the gemcitabine plus AGS-1C4D4 arm (P = 0.03), while the median survival was 5.5 versus 7.6 months and the response rate was 13.1% versus 21.6% in the two arms, respectively. The 6-month SR was 57.1% in the gemcitabine arm versus 79.5% in the gemcitabine plus AGS-1C4D4 arm among the PSCA-positive subgroup and 31.6% versus 46.2% among the PSCA-negative subgroup. CONCLUSIONS: This randomized, phase II study achieved its primary end point, demonstrating an improved 6-month SR with addition of AGS-1C4D4 to gemcitabine among patients with previously untreated, metastatic pancreatic adenocarcinoma. ClinicalTrials.gov identifier: NCT00902291.


Subject(s)
Adenocarcinoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Liver Neoplasms/drug therapy , Pancreatic Neoplasms/drug therapy , Adenocarcinoma/metabolism , Adenocarcinoma/mortality , Adenocarcinoma/secondary , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal, Humanized , Antigens, Neoplasm/metabolism , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Disease-Free Survival , Female , GPI-Linked Proteins/metabolism , Humans , Kaplan-Meier Estimate , Liver Neoplasms/metabolism , Liver Neoplasms/mortality , Liver Neoplasms/secondary , Male , Middle Aged , Neoplasm Proteins/metabolism , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/mortality , Pancreatic Neoplasms/pathology , Proportional Hazards Models , Treatment Outcome , Gemcitabine
5.
Ann Oncol ; 22(6): 1367-1373, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21217058

ABSTRACT

BACKGROUND: Epidermal growth factor receptor (EGFR) is overexpressed in a significant proportion of esophageal and gastric carcinomas. Although previous studies have examined tyrosine kinase inhibitors of EGFR, there remains limited data regarding the role of EGFR-directed monoclonal antibody therapy in these malignancies. We carried out a multi-institutional phase II study of cetuximab, a monoclonal antibody against EGFR, in patients with unresectable or metastatic esophageal or gastric adenocarcinoma. PATIENTS AND METHODS: Thirty-five patients with previously treated metastatic esophageal or gastric adenocarcinoma were treated with weekly cetuximab, at an initial dose of 400 mg/m(2) followed by weekly infusions at 250 mg/m(2). Patients were followed for toxicity, treatment response, and survival. RESULTS: Treatment with cetuximab was well tolerated; no patients were taken off study due to drug-related adverse events. One (3%) partial treatment response was noted. Two (6%) patients had stable disease after 2 months of treatment. Median progression-free survival and overall survival were 1.6 and 3.1 months, respectively. CONCLUSION: Although well tolerated, cetuximab administered as a single agent had minimal clinical activity in patients with metastatic esophageal and gastric adenocarcinoma. Ongoing studies of EGFR inhibitors in combination with other agents may define a role for these agents in the treatment of esophageal and gastric cancer.


Subject(s)
Adenocarcinoma/drug therapy , Antibodies, Monoclonal/therapeutic use , Antineoplastic Agents/therapeutic use , Esophageal Neoplasms/drug therapy , Stomach Neoplasms/drug therapy , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized , Antineoplastic Agents/adverse effects , Cetuximab , Female , Humans , Male , Middle Aged , Treatment Outcome
6.
Dis Esophagus ; 23(4): 316-23, 2010 May.
Article in English | MEDLINE | ID: mdl-19788436

ABSTRACT

Randomized trials of chemoradiation for esophageal cancer have included very few patients age > or = 75. In this retrospective study, we describe the outcomes and toxicity of full-dose chemoradiation in elderly patients with esophageal cancer. Patients, age > or = 75, treated with full-dose chemoradiation for esophageal carcinoma from 2002 to 2008 were retrospectively reviewed. Thirty-four patients were identified with a median age of 79.5 (range 75-89). The median Eastern Cooperative Oncology Group performance status was 1 (range 0-3) and the median Adult Comorbidity Evaluation-27 score was 1 (range 0-3). Twenty-eight patients received definitive and six received neoadjuvant chemoradiation. The median radiation dose delivered was 50.4 Gray (range 3.6-68.4 Gray). Platinum-based chemotherapy was used in 79.4% of patients. Fifty percent of the patients completed all planned radiation therapy (RT) and chemotherapy; 85.3% completed RT. Acute toxicity > or = grade 4 occurred in 38.2% of patients, and 70.6% of the patients required hospitalization, emergency department visit, and/or RT break. Median follow-up was 14.5 months among 7 survivors, and median survival was 12.0 months (95% confidence interval [CI]: 9.7 to 24.1 months). The actuarial overall survival at 2 years was 29.7% (95% CI: 16.6 to 52.6%). There were four treatment-related deaths. The median time to any recurrence was 10.4 months. Nineteen patients had a local and/or distant recurrence. In conclusion, elderly patients experienced substantial morbidity from chemoradiation, and long-term survival was low. Future efforts to improve treatment tolerability in the elderly are needed.


Subject(s)
Esophageal Neoplasms/drug therapy , Esophageal Neoplasms/radiotherapy , Aged , Aged, 80 and over , Combined Modality Therapy , Female , Humans , Male , Radiation Dosage , Radiotherapy/adverse effects , Retrospective Studies
7.
Ann Oncol ; 20(3): 475-80, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19139178

ABSTRACT

BACKGROUND: Recent studies have examined the addition of docetaxel to fluorouracil and cisplatin in advanced esophagogastric cancer. PATIENTS AND METHODS: We carried out a phase I dose-escalation study of weekly docetaxel, cisplatin, and irinotecan (TPC), given on days 1 and 8 every 3 weeks, in patients with chemonaive solid tumors. Subsequently, we completed a multiinstitutional phase II study of TPC in patients with previously untreated, metastatic esophagogastric cancer. RESULTS: Thirty-nine patients were enrolled in the phase I trial; a weekly schedule of TPC was well tolerated. On that basis, docetaxel 30 mg/m(2), cisplatin 25 mg/m(2), and irinotecan 65 mg/m(2) were selected for the phase II trial, where in the first 18 patients irinotecan 65 mg/m(2) caused too much diarrhea and was reduced to 50 mg/m(2). Among 56 eligible patients with previously untreated, metastatic esophagogastric cancer enrolled in the phase II trial, three complete and 27 partial responses were observed (overall response rate=54%), and 15 patients (30%) had stable disease. Median progression-free survival was 7.1 months, and median survival was 11.9 months. At the final irinotecan dose of 50 mg/m(2), grade 3 or higher toxicity included diarrhea (26%), neutropenia (21%), nausea (18%), fatigue (16%), anorexia (13%), and thrombosis/embolism (13%). CONCLUSIONS: Weekly TPC is an active and well-tolerated regimen for patients with esophagogastric cancer.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Esophageal Neoplasms/drug therapy , Stomach Neoplasms/drug therapy , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Camptothecin/administration & dosage , Camptothecin/analogs & derivatives , Cisplatin/administration & dosage , Docetaxel , Esophageal Neoplasms/pathology , Female , Humans , Irinotecan , Male , Middle Aged , Neoplasm Metastasis , Stomach Neoplasms/pathology , Taxoids/administration & dosage
8.
Ann Oncol ; 18(7): 1185-9, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17483115

ABSTRACT

BACKGROUND: Targeting the epidermal growth factor receptor and angiogenesis have proven useful strategies against metastatic colorectal cancer. The benefit of combining inhibitors of both pathways is unknown. PATIENTS AND METHODS: Patients with previously untreated metastatic colorectal cancer were enrolled in a phase II trial of infusional 5-fluorouracil, leucovorin, oxaliplatin (FOLFOX), bevacizumab and erlotinib. The primary end point was progression-free survival. RESULTS: Thirty-five patients were enrolled and all came off trial for reasons other than progression; 18 (51%) had protocol-defined adverse events requiring removal, nine (26%) withdrew consent due to toxicity, six pursued surgery or localized therapies and two requested a treatment holiday. Principal toxic effects included rash, neuropathy and diarrhea. Seven patients came off trial before first restaging. By intention-to-treat analysis, one patient had a confirmed complete response, 10 had confirmed partial responses and one had an unconfirmed partial response (response rate = 34%). One patient had progressive disease at time of withdrawal from the trial, thus progression-free survival could not be calculated. CONCLUSION: The combination of FOLFOX, bevacizumab and erlotinib led to higher than expected early withdrawal due to toxicity, limiting conclusions regarding efficacy. These findings raise concern regarding the tolerability of adding more agents to already complex combination regimens for metastatic colorectal cancer.


Subject(s)
Adenocarcinoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Colorectal Neoplasms/drug therapy , Adenocarcinoma/mortality , Adenocarcinoma/secondary , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Bevacizumab , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , Erlotinib Hydrochloride , Female , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Humans , Kaplan-Meier Estimate , Leucovorin/administration & dosage , Leucovorin/adverse effects , Male , Middle Aged , Organoplatinum Compounds/administration & dosage , Organoplatinum Compounds/adverse effects , Quinazolines/administration & dosage , Quinazolines/adverse effects
9.
Australas Radiol ; 50(5): 507-9, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16981954

ABSTRACT

Positron emission tomography/CT is an established imaging method in the diagnosis and staging of cancers. (18)F-fluoro-2-deoxy-d-glucose (FDG) is the most commonly used radiotracer in positron emission tomography/CT. It is a tumour viability agent and usually its uptake within a lesion reflects the presence of a viable tumour tissue. However, false-positive FDG uptake is known to occur in benign processes of either inflammatory or infectious aetiology. We describe FDG uptake at the site of laparoscopic scar that mimicked Sister Mary Joseph's nodule in a patient with gastric adenocarcinoma. Here, the knowledge of the patient's history and subtle imaging findings helped in accurate staging of the patient. In this case report, we emphasize the value of the knowledge of the patient history and awareness of different pitfalls of FDG to achieve a correct diagnosis on positron emission tomography/CT.


Subject(s)
Adenocarcinoma/pathology , Cicatrix/diagnosis , Laparoscopy/adverse effects , Positron-Emission Tomography/methods , Stomach Neoplasms/pathology , Tomography, X-Ray Computed/methods , Adenocarcinoma/diagnosis , Adenocarcinoma/surgery , Aged , Cicatrix/etiology , Contrast Media/administration & dosage , Diagnosis, Differential , Fluorodeoxyglucose F18 , Humans , Male , Neoplasm Staging/methods , Radiographic Image Enhancement/methods , Stomach Neoplasms/diagnosis , Stomach Neoplasms/surgery
10.
Cancer ; 89(9): 1946-52, 2000 Nov 01.
Article in English | MEDLINE | ID: mdl-11064351

ABSTRACT

BACKGROUND: The current study was conducted to review the authors' experience in treating consecutive patients with American Joint Committee on Cancer (1997 revision) Stage III nonsmall cell lung carcinoma with aggressive preoperative chemoradiation followed by surgical resection. METHODS: The records of all patients who received preoperative chemoradiation were evaluated. Patients received 2 cycles of concurrent cisplatin and etoposide with 5940 centigrays of radiation therapy. They then were reevaluated to determine whether they were surgical candidates. If so, resection of the primary tumor with mediastinal lymph node dissection was performed 4-6 weeks after the completion of preoperative treatment. After adequate healing, an additional four cycles of cisplatin/etoposide or carboplatin/paclitaxel was given. RESULTS: Forty-two patients received preoperative chemoradiation, 33 of whom underwent surgical resection (79%), including 9 patients who underwent pneumonectomies. Complete pathologic responses were observed in 27% of these patients. Postoperative complications were noted in 21% of the patients and included persistent air leak, supraventricular arrhythmia, and empyema. There were no reported treatment-related deaths. The median follow-up was 26 months. The overall 5-year survival rate for all patients was 36.5% and was 45. 3% for patients who underwent resection. A trend toward increased 5-year survival was observed in patients who had a complete pathologic response (57.1%). Univariate analysis revealed the N stage classification to be significant for predicting a complete response. Patterns of failure revealed the brain to be the most common site of first recurrence (50%) and the only site of recurrence in 36% of patients. There was only one case of local failure. CONCLUSIONS: Preoperative chemoradiation using high radiation doses is feasible with acceptable toxicity. The results of the current study suggest an increased complete pathologic response rate and increased overall survival rate compared with reports in the published literature.


Subject(s)
Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/radiotherapy , Lung Neoplasms/drug therapy , Lung Neoplasms/radiotherapy , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/surgery , Combined Modality Therapy , Female , Humans , Lung Neoplasms/pathology , Lung Neoplasms/surgery , Male , Middle Aged , Multivariate Analysis , Neoplasm Staging , Pneumonectomy , Radiotherapy Dosage , Radiotherapy, High-Energy , Survival Analysis , Treatment Failure
11.
Oncology ; 58(3): 215-8, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10765123

ABSTRACT

Gemcitabine has recently been compared favorably to 5-fluorouracil (5-FU) as the standard chemotherapy for advanced pancreas cancer. Based on phase I data that combining gemcitabine with 5-FU is safe and has evidence for clinical activity, a phase II trial was conducted by the Eastern Cooperative Oncology Group (ECOG). Patients with metastatic disease, good performance status and organ function were eligible and enrolled after providing informed consent. Patients were given gemcitabine (1,000 mg/m(2)) followed by 5-FU (600 mg/m(2)) weekly for 3 weeks of every 4. Of 37 patients enrolled over a 3-month period, 36 were eligible. Partial responses were seen in 5 patients (14%). Median survival was 4.4 months with a 1-year survival rate of 8.6%. A randomized trial of the combination of 5-FU and gemcitabine versus gemcitabine alone is currently accruing patients in ECOG.


Subject(s)
Antimetabolites, Antineoplastic/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Antimetabolites, Antineoplastic/administration & dosage , Antimetabolites, Antineoplastic/adverse effects , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Drug Administration Schedule , Female , Fluorouracil/administration & dosage , Humans , Male , Middle Aged , New England , Survival Analysis , Treatment Outcome , Gemcitabine
12.
Front Biosci ; 3: E214-25, 1998 Nov 01.
Article in English | MEDLINE | ID: mdl-9792894

ABSTRACT

The majority of adenocarcinoma of the pancreas are non-resectable at diagnosis due to locally advanced or metastatic disease. There will be an estimated 28,900 new cases of pancreatic cancer diagnosed in the United States in 1998. In data collected from 1986-1993, the five year survival of all stages combined was 4%. Realizing that most patients present with advanced disease, and there are no acceptable screening methods to detect early stage disease, efforts to develop active anti-cancer agents with minimal toxicity are essential in order to improve the quality of life and survival. Several 5-fluorouracil based regimens have been tried without a significant impact on palliation or survival. Recently, the anti-metabolite gemcitabine has been approved for use in individuals with locally advanced and metastatic disease, primarily on the basis of improved functional status. Many cytotoxic agents have proven ineffective in the treatment of this disease. There are several ongoing studies investigating the role of new cytotoxic and biologic agents.


Subject(s)
Adenocarcinoma/therapy , Pancreatic Neoplasms/therapy , Adenocarcinoma/pathology , Antimetabolites, Antineoplastic/administration & dosage , Antimetabolites, Antineoplastic/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cisplatin/administration & dosage , Cisplatin/therapeutic use , Clinical Trials as Topic , Cytotoxins/therapeutic use , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Deoxycytidine/therapeutic use , Doxorubicin/therapeutic use , Drug Therapy, Combination , Fluorouracil/administration & dosage , Fluorouracil/therapeutic use , Genetic Therapy , Humans , Immunotherapy , Mitomycin/therapeutic use , Neoplasm Metastasis , Nitrosourea Compounds/administration & dosage , Pancreatic Neoplasms/pathology , Gemcitabine
13.
J Biol Chem ; 272(45): 28258-62, 1997 Nov 07.
Article in English | MEDLINE | ID: mdl-9353278

ABSTRACT

The propeptides of the vitamin K-dependent proteins contain a gamma-carboxylation recognition site that is required for gamma-glutamyl carboxylation. To determine whether the propeptide is sufficient to direct carboxylation, two mutant prothrombin species were expressed and characterized with regard to posttranslational gamma-carboxylation. A double point mutant, in which serine substituted for cysteines 17 and 22 disrupted a conserved loop formed by a disulfide bond, was fully carboxylated when expressed in Chinese hamster ovary cells. A propeptide/thrombin chimeric protein, constructed by deleting the Gla, aromatic amino acid stack, and kringle domains of prothrombin, has the signal peptide and propeptide juxtaposed to a glutamate-rich COOH-terminal region of prothrombin, residues 249-530. Of the 8 glutamic acid residues contained within the first 40 residues of the NH2 terminus adjacent to the propeptide, at least seven were fully carboxylated as demonstrated by direct gamma-carboxyglutamic acid analysis of the alkaline hydrolysate and by NH2-terminal sequence analysis. These results indicate that the gamma-carboxylation recognition site within the prothrombin propeptide in a prothrombin propeptide-thrombin chimeric protein is sufficient to direct gamma-carboxylase-catalyzed carboxylation of adjacent glutamic acid residues in a glutamate-rich region of thrombin that is not normally gamma-carboxylated. Furthermore, the disulfide loop in the Gla domain of prothrombin is not required for complete carboxylation.


Subject(s)
Carbon-Carbon Ligases/metabolism , Glutamic Acid/metabolism , Prothrombin/metabolism , Thrombin/metabolism , Vitamin K/metabolism , Amino Acid Sequence , Animals , CHO Cells , Cricetinae , Disulfides/chemistry , Kringles , Molecular Sequence Data , Mutagenesis, Site-Directed , Peptide Fragments/genetics , Peptide Fragments/metabolism , Protein Precursors/genetics , Protein Precursors/metabolism , Prothrombin/genetics , Recombinant Fusion Proteins/metabolism , Thrombin/genetics
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