Search PubMed⌕ Search

Biomedical subjects

P W Pisters

Publications and source records attributed to P W Pisters.

At least 19 recordsLinked to original sources
PubMed2001

Up-regulation of vascular endothelial growth factor in breast cancer cells by the heregulin-beta1-activated p38 signaling pathway enhances endothelial cell migration.

Heregulin (HRG) belongs to a family of polypeptide growth factors that bind to receptor tyrosine kinases ErbB3 and ErbB4. HRG binding induces ErbB3 and ErbB4 heterodimerization with ErbB2, activating downstream signal transduction. Vascular endothelial growth factor (VEGF) is a primary regulator of physiological angiogenesis and is a major mediator of pathological angiogenesis, such as tumor-associated neovascularization. In this study, we demonstrate that HRG-beta1 increased secretion of VEGF from breast cancer cells in a time- and dosage-dependent manner and that this increase resulted from up-regulation of VEGF mRNA expression via transcriptional activation of the VEGF promoter. Deletion and mutational analysis revealed that a CA-rich upstream HRG response element located between nucleotide-2249 and -2242 in the VEGF promoter mediated HRG-induced transcriptional up-regulation of VEGF. While investigating the downstream signaling pathways involved in HRG-mediated up-regulation of VEGF, we found that HRG activated extracellular signal-regulated protein kinases, Akt kinase, and p38 mitogen-activated protein kinase (MAPK). However, only the specific inhibitor of p38 MAPK (SB203580), not extracellular signal-regulated kinase inhibitor PD98059 nor the inhibitor of phosphatidylinositol 3-kinase-Akt pathway (Wortmannin), blocked the up-regulation of VEGF by HRG. The HRG-stimulated secretion of VEGF from breast cancer cells resulted in increased migration of murine lung endothelial cells, an activity that was inhibited by either VEGF-neutralizing antibody or SB203580. These results show that HRG can activate p38 MAPK to enhance VEGF transcription via an upstream HRG response element, leading to increased VEGF secretion and angiogenic response in breast cancer cells.

Breast Neoplasms↗
PubMed2001

Alveolar soft part sarcoma: clinical course and patterns of metastasis in 70 patients treated at a single institution.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a rare form of soft tissue sarcoma. Brain metastases have been reported to be a common feature of Stage IV ASPS, and recent practice guidelines recommend routine intracranial imaging as part of the staging evaluation in all patients who present with ASPS. METHODS: The authors performed a comprehensive retrospective review of the clinical presentation, treatment, outcome, and patterns of failure in a consecutive series of patients with localized (American Joint Committee on Cancer [AJCC] Stages II/III) or metastatic (AJCC Stage IV) ASPS who presented to a tertiary care cancer center between 1959 and 1998. RESULTS: Seventy-four patients were identified from the database searches. The anatomic distribution of their primary tumors included: extremities, 44 patients (60%); trunk, 15 patients (20%); head and neck, 9 patients (12%); and retroperitoneum, 6 patients (8%). The median tumor size was 6.5 cm (range, 1.2-24 cm). The AJCC stage at presentation was Stage II or III in 35% of the patients and Stage IV in 65% of the patients. The 5-year actuarial local recurrence free, distant recurrence free, disease free, and overall survival rates among the 22 patients with localized ASPS were 88%, 84%, 71%%, and 87%, respectively. At a median follow-up of 9 years, 2 of 22 patients with localized disease had developed local recurrences and 3 had developed metastatic disease (all to the lung only). Brain metastases were noted in 9 of 48 patients who presented with Stage IV (M1) disease (19%) and always were noted in association with metastasis to other sites. The median survival of patients with M1 disease was 40 months, with a 5-year survival rate of 20%. CONCLUSIONS: Long term follow-up of patients with localized ASPS reveals a relatively indolent clinical course with relatively low rates of local and distant recurrence. In patients with Stage IV ASPS, brain metastases were observed only as part of more disseminated disease. The observations of the current study do not support current practice guidelines for the staging of patients with ASPS and suggest that selective rather than routine intracranial imaging should be used in patients presenting with ASPS.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2001

Neoadjuvant chemoradiotherapy for adenocarcinoma of the pancreas: treatment variables and survival duration.

BACKGROUND: For patients with potentially resectable pancreatic cancer, the poor outcome associated with resection alone and the survival advantage demonstrated for combined-modality therapy have stimulated interest in preoperative chemoradiotherapy. The goal of this study was to analyze the effects of different preoperative chemoradiotherapy schedules, intraoperative radiation therapy, patient factors. and histopathologic variables on survival duration and patterns of treatment failure in patients who underwent pancreaticoduodenectomy for adenocarcinoma of the pancreatic head. METHODS: Data on 132 consecutive patients who received preoperative chemoradiation followed by pancreaticoduodenectomy for adenocarcinoma of the pancreatic head between June 1990 and June 1999 were retrieved from a prospective pancreatic tumor database. Patients received either 45.0 or 50.4 Gy radiation at 1.8 Gy per fraction in 28 fractions or 30.0 Gy at 3.0 Gy per fraction in 10 fractions with concomitant infusional chemotherapy (5-fluorouracil, paclitaxel, or gemcitabine). If restaging studies demonstrated no evidence of disease progression, patients underwent pancreaticoduodenectomy. All patients were evaluated with serial postoperative computed tomography scans to document first sites of tumor recurrence. RESULTS: The overall median survival from the time of tissue diagnosis was 21 months (range 19-26, 95%CI). At last follow-up, 41 patients (31%) were alive with no clinical or radiographic evidence of disease. The survival duration was superior for women (P = .04) and for patients with no evidence of lymph node metastasis (P = .03). There was no difference in survival duration associated with patient age, dose of preoperative radiation therapy, the delivery of intraoperative radiotherapy, tumor grade, tumor size, retroperitoneal margin status, or the histologic grade of chemoradiation treatment effect. CONCLUSION: This analysis supports prior studies which suggest that the survival duration of patients with potentially resectable pancreatic cancer is maximized by the combination of chemoradiation and pancreaticoduodenectomy. Furthermore, there was no difference in survival duration between patients who received the less toxic rapid-fractionation chemoradiotherapy schedule (30 Gy, 2 weeks) and those who received standard-fractionation chemoradiotherapy (50.4 Gy, 5.5 weeks). Short-course rapid-fractionation preoperative chemoradiotherapy combined with pancreaticoduodenectomy, when performed on accurately staged patients, maximizes survival duration and is associated with a low incidence of local tumor recurrence.

Adenocarcinoma↗
PubMed2001

Laparoscopy in the staging of pancreatic cancer.

BACKGROUND: Over the past decade, laparoscopy has emerged as a popular method of detecting extrapancreatic metastatic disease in patients presumed to have localized pancreatic cancer. METHODS AND RESULTS: The English language literature on laparoscopic staging of pancreatic cancer was reviewed. Interpretation of this literature on staging laparoscopy is difficult because (1) there has been inconsistent use of high-quality computed tomography (CT) in prospective studies, (2) many studies have included patients with locally advanced disease, and (3) the R0/R1/R2 resection rates among patients staged by laparoscopy have not been reported, making it impossible to correlate laparoscopic findings with the R0 resection rate. Laparoscopy may prevent unnecessary laparotomy in a proportion of CT-staged patients presumed to have resectable pancreatic cancer. However, routine laparoscopy is performed on patients judged to have resectable disease by high-quality CT, this fraction of patients is between 4 and 13 per cent. CONCLUSION: When state-of-the-art CT is available, the routine use of staging laparoscopy may not be easily justified from the data in the recent literature. Selective use of laparoscopy may be more appropriate and will probably be a more cost-effective staging approach. Criteria are presented for the selective use of laparoscopy in the staging of patients with localized pancreatic cancer.

Cost-Benefit Analysis↗
PubMed2001

Pilot study of concurrent 5-fluorouracil/paclitaxel plus radiotherapy in patients with carcinoma of the esophagus and gastroesophageal junction.

Preoperative concurrent chemotherapy and radiotherapy can be highly effective but are often associated with significant rates of morbidity and even mortality. We studied the toxicity of continuous infusion of 5-fluorouracil (5-FU) and weekly paclitaxel combined with radiotherapy. Patients had histologic proof of local-regional carcinoma of the esophagus or gastroesophageal (GE) junction, a Karnofsky performance status of 70 or greater, and normal liver, renal, and bone marrow functions. Chemotherapy consisted of continuous infusion of 5-FU (300 mg/m2/d) for 5 days a week for 5 weeks, plus paclitaxel (45 mg/m2) given during 3 hours every week for 5 weeks. Based on the tumor location and its resectability, the total dose of concurrent radiation varied between 45 Gy and 50.4 Gy. Nine men and one woman, with a median age of 61 years, were evaluated. One had GE junction cancer, six had distal esophageal cancer, and three had midesophageal cancer. Weight loss, nausea, vomiting, and dysphagia of grades I and II were noted. The hematologic toxicity was mild. No patients required transfusion. There was no leukopenia or thrombocytopenia. None of the patients was hospitalized during chemoradiation; all patients completed treatment as outpatients. Five patients had subsequent surgical resections: one had a pathologically complete response, and two had a partial response (>90% necrosis). Continuous infusion of 5-FU plus paclitaxel given concurrently with radiotherapy was well tolerated. We plan to study this regimen further in upper gastrointestinal cancers.

Adenocarcinoma↗
PubMed2001

Irinotecan plus cisplatin in advanced gastric or gastroesophageal junction carcinoma.

A phase II study was conducted to assess the response rate and toxicity profile of the combination of irinotecan (CPT-11, Camptosar) and cisplatin (Platinol) administered weekly to patients with untreated advanced adeno-carcinoma of the stomach or gastroesophageal junction. Patients with histologic proof of adenocarcinoma of the stomach or gastroesophageal junction and with adequate liver, kidney, and bone marrow functions were included. Patients were treated with 65 mg/m2 of irinotecan plus 30 mg/m2 of cisplatin, both administered intravenously 1 day per week for 4 consecutive weeks, followed by a 2-week recovery period. Response rate, time to progression, survival, and toxic effects were analyzed. Thirty-six (95%) of 38 registered patients were assessable for toxicity and response. The median number of 6-week cycles per patient was 2.5 (range: 1 to 7 cycles). Four patients (11%) achieved a complete response and 17 (47%) had a partial response for an overall response rate of 58%. Median time to progression of carcinoma was 24 weeks, and median survival was 9 months (range: 1 to 23+ months). There was one treatment-related death. Major toxic effects included diarrhea, neutropenia, and fatigue. The combination of irinotecan and cisplatin is active against gastric or gastroesophageal adenocarcinoma and should undergo further study. The addition of other active drugs or radiation therapy to this regimen would be of interest.

Antineoplastic Agents↗
PubMed2000

Primary treatment of cystosarcoma phyllodes of the breast.

BACKGROUND: Cystosarcoma phyllodes is a rare sarcoma of the breast. Although surgical removal is the mainstay of treatment, the extent of surgery required (excision vs. mastectomy) and the need for additional local therapy, such as radiotherapy, are unclear. The current study evaluated the rate of local and distant failure, as well as potential prognostic factors, to better define appropriate treatment strategies. METHODS: One hundred one patients treated primarily for cystosarcoma phyllodes of the breast were evaluated. These tumors were classified histologically into benign (58%), indeterminate (12%), and malignant (30%) based on well defined criteria. Stromal overgrowth (29%) was considered separately. Surgery was comprised of local excision with breast conservation (47%) or mastectomy (53%). Microscopic surgical margins were negative in 99% of cases. Six patients received adjuvant radiotherapy. RESULTS: Overall survival for the 101 patients was 88%, 79%, and 62% at 5, 10, and 15 years, respectively. For patients with nonmalignant (benign or indeterminate) and malignant cystosarcoma phyllodes, the overall survival was 91% and 82%, respectively, at 5 years, and 79% and 42%, respectively, at 10 years. Similar rates were observed based on the presence or absence of stromal overgrowth. Local recurrence occurred in 4 patients, with an actuarial 10-year rate of 8%. Eight patients developed distant metastases, with an actuarial 10-year rate of 13%. Multivariate analysis using Cox proportional hazards regression revealed stromal overgrowth to be the only independent predictor of distant failure. CONCLUSIONS: Local failure in this group of largely margin negative patients with cystosarcoma phyllodes of the breast was low, showing that breast-conserving surgery with appropriate margins is the preferred primary therapy. The current study data do not support the use of adjuvant radiotherapy for patients with adequately resected disease. Patients with stromal overgrowth, particularly when the tumor size was > 5 cm, were found to have a high rate of distant failure; such patients merit consideration of a trial that examines the efficacy of systemic therapy.

Adult↗
PubMed2000

Impact of neoadjuvant chemotherapy on postoperative morbidity in soft tissue sarcomas.

PURPOSE: The purpose of this study was to test the hypothesis that neoadjuvant chemotherapy (NeoCT) does not increase morbidity in patients undergoing radical surgery for soft tissue sarcomas. PATIENTS AND METHODS: The records of 309 patients who presented to The University of Texas M.D. Anderson Cancer Center for definitive surgical management of primary soft tissue sarcomas were retrospectively reviewed. One hundred five patients who received NeoCT were compared with 204 patients who had surgery first (Surg). Patients had extremity sarcomas (71 NeoCT patients and 130 Surg patients) or retroperitoneal/visceral sarcomas (34 NeoCT and 74 Surg). RESULTS: NeoCT patients had larger tumors (median, 12 v 8 cm), more frequently had high-grade tumors (90% v 64%), and were younger (median age 47 v 55 years). The incidence of surgical complications was not different for NeoCT patients than for Surg patients, both in those with extremity sarcomas (34% v 41%) and in those with retroperitoneal/visceral sarcomas (29% v 34%). The most common complications were wound infections and other wound complications. Preoperative radiation therapy, autologous flap coverage, and extremity tumors were associated with increased wound complications. No significant differences in length of hospital stay, rate of readmission, or rate of reoperation for complications were found between the NeoCT and Surg groups. One of the three postoperative deaths in our series occurred in the NeoCT group. CONCLUSION: In this retrospective review, there was no evidence that NeoCT increased postoperative morbidity in patients with soft tissue sarcomas. Prospective, randomized studies are needed to confirm these results.

Antibiotics, Antineoplastic↗
PubMed2000

Cost and utilization impact of a clinical pathway for patients undergoing pancreaticoduodenectomy.

BACKGROUND: When implemented in several common surgical procedures, clinical pathways have been reported to reduce costs and resource utilization, while maintaining or improving patient care. However, there is little data to support their use in more complex surgery. The objective of this study was to determine the effects of clinical pathway implementation in patients undergoing elective pancreaticoduodenectomy (PD) on cost and resource utilization. METHODS: Outcome data from before and after the development of a clinical pathway were analyzed. The clinical pathway standardized the preoperative outpatient care, critical care, and postoperative floor care of patients who underwent PD. An independent department determined total costs for each patient, which included all hospital and physician costs, in a blinded review. Outcomes that were examined included perioperative mortality, postoperative morbidity, length of stay, readmissions, and postoperative clinic visits. RESULTS: From January, 1996 to December, 1998, 148 consecutive patients underwent PD or total pancreatectomy; 68 before pathway development (PrePath) and 80 after pathway implementation (PostPath). There were no significant differences in patient demographics, comorbid conditions, underlying diagnosis, or use of neoadjuvant therapy between the two groups. Mean total costs were significantly reduced in PostPath patients compared with PrePath patients ($36,627 vs. $47,515; P = .003). Similarly, mean length of hospital stay was also significantly reduced in PostPath patients (13.5 vs. 16.4 days; P = .001). The total cost differences could not be attributed solely to differences in room and board costs. Cost and length-of-stay differences remained when outliers were excluded from the analysis. Despite these findings, there were no significant differences between PrePath and PostPath patients in terms of perioperative mortality (3% vs. 1%), readmissions within 1 month of discharge (15% vs. 11%), or mean number of clinic visits within 90 days of discharge (3.3 vs. 3.4 visits). CONCLUSIONS: The establishment of a clinical pathway for PD patients dramatically reduced costs and resource utilization without any apparent detrimental effect on quality of patient care. These findings support the implementation of clinical pathways for PD patients, as well as investigation into pathway care for other complex surgical procedures.

Aged↗
PubMed2000

Significance and management of local recurrences and limited metastatic disease in the abdomen.

The management of patients with synchronous or metachronous metastatic carcinoma, sarcoma, or melanoma in the abdomen requires a knowledge of the natural history of the disease and of the available treatment options. Patients with advanced malignant disease may be of marginal performance status yet may require large surgical procedures or combined modality therapy; the most challenging therapeutic decisions involve such patients. The authors highlight the role of surgery in selected patients with metastatic or recurrent malignancy as it is practiced at The University of Texas M. D. Anderson Cancer Center.

Abdominal Neoplasms↗
PubMed2000

Current approaches and future strategies for pancreatic carcinoma.

Pancreatic cancer is a lethal disease characterized by local invasion and early dissemination. It is resistant to conventional surgical, radiotherapeutic, and chemotherapeutic modalities. These interventions have had minimal impact on overall survival with very few patients enjoying long term survival. Over the past few years, 2'difluoro-2'deoxycytidine (gemcitabine) has demonstrated modest activity in this disease and investigations are proceeding to expand its role in combination with radiotherapy and other chemotherapeutic agents. In addition, the identification of the molecular defects underlying this disease has suggested molecular targets for the design of rational systemic therapy. These targets include matrix metalloproteinases, K-ras, HER2/neu, p53, and the epidermal growth factor receptor. Current and future clinical trials designed to improve the survival of patients with pancreatic cancer will be discussed.

Animals↗
PubMed2000

Preoperative chemoradiation for patients with pancreatic cancer: toxicity of endobiliary stents.

PURPOSE: A recent multicenter study of preoperative chemoradiation and pancreaticoduodenectomy for localized pancreatic adenocarcinoma suggested that biliary stent-related complications are frequent and severe and may prevent the delivery of all components of multimodality therapy in many patients. The present study was designed to evaluate the rates of hepatic toxicity and biliary stent-related complications and to evaluate the impact of this morbidity on the delivery of preoperative chemoradiation for pancreatic cancer at a tertiary care cancer center. PATIENTS AND METHODS: Preoperative chemoradiation was used in 154 patients with resectable pancreatic adenocarcinoma (142 patients, 92%) or other periampullary tumors (12 patients, 8%). Patients were treated with preoperative fluorouracil (115 patients), paclitaxel (37 patients), or gemcitabine (two patients) plus concurrent rapid-fractionation (30 Gy; 123 patients) or standard-fractionation (50.4 Gy; 31 patients) radiation therapy. The incidences of hepatic toxicity and biliary stent-related complications were evaluated during chemoradiation and the immediate 3- to 4-week postchemoradiation preoperative period. RESULTS: Nonoperative biliary decompression was performed in 101 (66%) of 154 patients (endobiliary stent placement in 77 patients and percutaneous transhepatic catheter placement in 24 patients). Stent-related complications (occlusion or migration) occurred in 15 patients. Inpatient hospitalization for antibiotics and stent exchange was necessary in seven of 15 patients (median hospital stay, 3 days). No patient experienced uncontrolled biliary sepsis, hepatic abscess, or stent-related death. CONCLUSION: Preoperative chemoradiation for pancreatic cancer is associated with low rates of hepatic toxicity and biliary stent-related complications. The need for biliary decompression is not a clinically significant concern in the delivery of preoperative therapy to patients with localized pancreatic cancer.

Adenocarcinoma↗
PubMed2000

Irinotecan and cisplatin in advanced gastric or gastroesophageal junction carcinoma.

Chemotherapy for advanced gastric and gastroesophageal junction carcinomas remains suboptimal. Both irinotecan (Camptosar) and cisplatin (Platinol) are active against this group of malignancies. This article focuses on the results of an ongoing phase II trial with this combination in patients with advanced gastric or gastroesophageal junction carcinoma. Data from this trial suggest that the combination of irinotecan and cisplatin is active in untreated as well as previously treated patients with gastric or gastroesophageal junction carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Phase I study of irinotecan and concurrent radiation therapy for upper GI tumors.

Irinotecan (Camptosar) is an active chemotherapeutic agent for lung, gastric, esophageal, and colorectal cancers and a potent radiosensitizer. This phase I study was designed to assess the maximum tolerated dose of weekly irinotecan combined with concurrent radiotherapy for patients with locally advanced, unresectable gastric, gastroesophageal junction, or esophageal cancer. Patients who received previous chemotherapy (excluding irinotecan) or who experienced recurrent cancer after surgery were eligible for this protocol. The total dose of radiation did not exceed 50.4 Gy (28 fractions of 1.8 Gy each). The starting dose level of irinotecan was 30 mg/m2 infused over 90 minutes given weekly for 5 weeks. Subsequent dose levels were increased in 10 mg/m2 increments to 40, 50, 60, and 70 mg/m2. Of 15 patients who have been enrolled to date, all are evaluable for toxicities and 12 for response. Major hematologic toxicities (grade 3/4) were neutropenia, chills, hemorrhage, and anemia. Grade 3/4 gastrointestinal toxicities included nausea, vomiting, dehydration, anorexia, and constipation. Other severe nonhematologic toxicities included fatigue, hypotension, and hypothermia, as well as cardiovascular toxicities. There was no severe diarrhea and no treatment-related deaths. Of the 12 evaluable patients, 7 (58%) responded, including 2 complete responses; 4 (30%) had no change and 1 had progressive disease. Survival ranged from 1 month to 15 months, with a median survival of 8 months. When the total dose of irinotecan given concurrently with radiotherapy was higher than 250 mg/m2, patients experienced significantly more severe grade 3/4 toxicities than with lower doses (P = .04), with no improvement in response rate. It was concluded that weekly doses of irinotecan of up to 60 mg/m2 with concurrent radiotherapy given over 5 weeks was feasible and demonstrated good response. This regimen did not cause severe diarrhea or pneumonitis, but neutropenia and fatigue were major toxicities. The study continues to accrue.

Adolescent↗
PubMed1999

Patterns of recurrence in extremity liposarcoma: implications for staging and follow-up.

BACKGROUND: Liposarcoma is one of the most common histologic types of soft tissue sarcoma and presents a wide spectrum of clinical behavior. The authors examined the correlation among histologic subtypes, outcomes, and patterns of recurrence among patients with extremity liposarcomas. METHODS. A retrospective review of all patients with intermediate and high grade extremity liposarcoma referred to the University of Texas M. D. Anderson Cancer Center from January 1, 1980, to December 31, 1992, was performed. Data on clinical presentation, treatment, patterns of treatment failure, and outcome were evaluated. RESULTS: During the 13-year study period, 122 patients with intermediate or high grade extremity liposarcoma were identified: 102 patients (84%) with myxoid subtype, 18 patients (15%) with pleomorphic subtype, and 2 patients (2%) with mixed histology. There were no differences between the myxoid and pleomorphic subtype groups in tumor size (T1 vs. T2), depth in relation to the muscular fascia, or anatomic site. The median follow-up was 70 months. The 5-year overall survival rate for all intermediate and high grade extremity liposarcoma patients presenting with primary disease (n=85) was 74%; the 5-year local recurrence free survival, distant recurrence free survival, and disease free survival rates were 93%, 78%, and 73%, respectively. Among the 102 patients with myxoid tumors, 33 had distant recurrences; 31 of these were to extrapulmonary soft tissue sites (e.g., the retroperitoneum, chest wall, pleura, pericardium, pelvic sidewall, and soft tissue of the back), and 2 were to the lung only. Among the 18 patients with pleomorphic tumors, 10 had distant recurrences; 3 occurred at extrapulmonary sites, and 7 occurred in the lung only (P < 0.05 for myxoid vs. pleomorphic subtypes). CONCLUSIONS: Myxoid liposarcomas often metastasized to extrapulmonary sites and did so significantly more frequently than pleomorphic tumors. Imaging of the abdomen, retroperitoneum, and extrapleural chest should be performed for accurate staging and posttreatment follow-up of patients with myxoid liposarcoma. Patients presenting with "primary" myxoid liposarcoma of the trunk should be carefully evaluated for an occult primary tumor in an extremity.

Adolescent↗