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Biomedical subjects

P F Mansfield

Publications and source records attributed to P F Mansfield.

At least 19 recordsLinked to original sources
PubMed2003

Induction of neuropilin-1 and vascular endothelial growth factor by epidermal growth factor in human gastric cancer cells.

The epidermal growth factor receptor (EGF-R) pathway plays a pivotal role in the progression of human gastric cancer. The angiogenic factor vascular endothelial growth factor (VEGF) has been shown to be induced by EGF in various cancer cell lines. Neuropilin-1 (NRP-1) acts as a coreceptor for VEGF-165 and increases its affinity for VEGF receptor 2 (VEGFR-2) in endothelial cells. Furthermore, NRP-1 has been found to be expressed by tumour cells and has been shown to enhance tumour angiogenesis and growth in preclinical models. We examined the expression of NRP-1 mRNA and EGF-R protein in seven human gastric cancer cell lines. NRP-1 expression was expressed in five of seven cell lines, and EGF-R expression closely mirrored NRP-1 expression. Moreover, in EGF-R-positive NCI-N87 and ST-2 cells, EGF induced both NRP-1 and VEGF mRNA expression. C225, a monoclonal antibody to EGF-R, blocked EGF-induced NRP-1 and VEGF expression in NCI-N87 cells in a dose-dependent manner. The treatment of NCI-N87 cells with EGF resulted in increases in phosphorylation of Erk1/2, Akt, and P38. Blockade of the Erk, phosphatidylinositol-3 kinase/Akt, or P38 pathways in this cell line prevented EGF induction of NRP-1 and VEGF. These results suggest that regulation of NRP-1 expression in human gastric cancer is intimately associated with the EGF/EGF-R system. Activation of EGF-R might contribute to gastric cancer angiogenesis by a mechanism that involves upregulation of VEGF and NRP-1 expression via multiple signalling pathways.

Base Sequence↗
PubMed2002

Effects of combination anti-vascular endothelial growth factor receptor and anti-epidermal growth factor receptor therapies on the growth of gastric cancer in a nude mouse model.

We hypothesised that the combination of anti-angiogenic and anti-epidermal growth factor (EFG)-receptor (R) therapies would more effectively inhibit gastric cancer growth than single-agent therapy. TMK-1 gastric cancer cells were injected into the gastric wall of nude mice to generate tumours. After 4 days, mice were randomly assigned to the following groups: control, DC101 ([vascular endothelial growth factor (VEGF)-receptor (R)-2 antibody], C225 (EGF-R antibody), or a combination of DC101 and C225. The combination therapy significantly inhibited gastric tumour growth compared with the control group, whereas the decrease in tumour growth in mice treated with DC101 or C225 alone did not reach statistical significance. All mice administered DC101 demonstrated decreased tumour vascularity and increased endothelial cell apoptosis. C225 alone did not affect angiogenesis, but inhibited tumour cell proliferation. The combination therapy led to a further decrease in tumour cell proliferation. The combination of anti-VEGF-R and anti-EGF-R therapies was effective in inhibiting gastric cancer growth. These findings support the hypothesis that inhibiting multiple biological pathways that mediate tumour growth may be an effective therapeutic strategy.

Animals↗
PubMed2001

Significance of plasma cytokine levels in melanoma patients with histologically negative sentinel lymph nodes.

INTRODUCTION: Although sentinel lymph node (SLN) status is the most powerful predictor of prognosis in patients with clinically localized melanoma, a proportion of melanoma patients with histologically negative SLNs will still recur. It is hypothesized that tumor response may be altered or mediated by specific cytokines. We therefore investigated whether levels of IL-4, IL-6, IL-10, TNF-alpha, or IFN-gamma would predict disease recurrence in melanoma patients with histologically negative SLNs. METHODS: This prospective cohort study involved 218 patients with clinically localized melanoma who underwent a histologically negative SLN biopsy. Preoperative plasma cytokine levels were determined by enzyme-linked immunosorbent assay on these patients, as well as on 90 healthy controls. Kaplan-Meier life tables were constructed, and Cox proportional hazards analyses were performed to assess predictors of disease-free survival (DFS). RESULTS: At a median follow-up of 43 months, 33 of 218 patients (15%) had suffered disease recurrence. Melanoma patients had significant elevations of IL-4, IL-6, and IL-10 compared to healthy controls; levels of IFN-gamma were less elevated in melanoma patients compared to controls. Despite this, melanoma patients with detectable IFN-gamma levels were at significantly higher risk for recurrence compared to patients with undetectable levels (5-year DFS 70% vs. 86%, P = .03). On multivariate analysis including standard melanoma prognostic factors, only tumor thickness (P = .004) and the presence of detectable IFN-gamma levels (P = .05) were significant independent prognostic factors for disease-free survival. CONCLUSIONS: Among melanoma patients with clinically localized disease who have undergone a histologically negative SLN biopsy, presence of a detectable plasma level of IFN-gamma is an independent predictor of disease recurrence. Elevated levels of IFN-gamma may identify a group of early-stage melanoma patients who are more likely to have recurrence of disease and who may benefit from adjuvant therapies, including immunotherapies.

Adolescent↗
PubMed2001

A pilot study of preoperative chemoradiotherapy for resectable gastric cancer.

BACKGROUND: The goals of this study were to assess the feasibility and toxicity of a regimen of preoperative chemoradiotherapy, surgery, and intraoperative radiotherapy in the treatment of patients with potentially resectable gastric cancer. A secondary objective was to assess pathologic response to chemoradiotherapy in the treated tumors. METHODS: Twenty-four patients were entered in the protocol. Treatment regimen consisted of 45 Gy of external beam radiotherapy with concurrent 5-FU given as a continuous infusion at a dose of 300 mg/m2. Patients were restaged 4-6 weeks after chemoradiotherapy and then underwent surgical resection and intraoperative radiotherapy to a dose of 10 Gy. RESULTS: Twenty-three patients (96%) completed chemoradiotherapy in accordance with the study protocol. Nineteen (83%) of 23 patients who completed chemoradiotherapy underwent surgical resection with D2 lymphadenectomy. Four patients (17%) had progressive disease and were not resected. The morbidity and mortality rates were 32% and 5%, respectively. Of the resected patients, two (11%) had complete pathologic responses while 12 (63%) had pathologic evidence of significant treatment effect. CONCLUSIONS: Preoperative chemoradiotherapy for gastric cancer can be delivered safely and is well tolerated. The rate of surgical complications is consistent with that of other recently reported prospective trials of gastrectomy alone. Preoperative chemoradiotherapy resulted in significant pathologic responses in the majority of treated tumors, and complete pathologic responses were achieved in some patients.

Adenocarcinoma↗
PubMed2001

A caution regarding lymphatic mapping in patients with colon cancer.

BACKGROUND: The value of lymphatic mapping and sentinel lymph node biopsy in the treatment of colon cancer is controversial. The purpose of this study was to determine the accuracy of lymphatic mapping in patients with colon cancer. METHODS: Forty-eight patients with colon cancer underwent lymphatic mapping and sentinel lymph node biopsy using isosulfan blue dye followed by standard surgical resection. The sentinel lymph nodes underwent thin sectioning as will as immunohistochemical staining for cytokeratin, in addition to standard hematoxylin and eosin staining. RESULTS: In 47 (98%) patients, a sentinel lymph node was identified. Sixteen patients had lymph nodes containing metastatic disease, and in 6 patients the sentinel lymph node was positive for disease. In no patient was the sentinel lymph node the only site of metastatic disease. In 10 patients the sentinel lymph node was negative for disease, whereas the nonsentinel lymph nodes contained metastatic disease (false negative rate = 38%). CONCLUSIONS: The role of lymphatic mapping and sentinel lymph node biopsy in colon cancer is not as clear as its role in other tumors. Further large prospective studies are needed to evaluate the accuracy and potential benefit of this procedure in patients with colon cancer.

Aged↗
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

Regional nodal basin control is not compromised by previous sentinel lymph node biopsy in patients with melanoma.

BACKGROUND: Regional nodal basin control is an important goal of lymphadenectomy in the management of melanoma patients with nodal disease. The purpose of this study was to determine if previous sentinel lymph node (SLN) biopsy compromises the ultimate regional nodal control achieved by subsequent therapeutic lymph node dissection in melanoma patients with microscopic lymph node metastases. METHODS: A surgical melanoma database and hospital records were reviewed for 602 patients with primary cutaneous melanoma who underwent successful lymphatic mapping and SLN biopsy between 1991 and 1997. RESULTS: A total of 105 (17%) of 602 patients had histologically positive SLNs and were offered therapeutic lymphadenectomy; 101 (96%) underwent this procedure. Thirty-six patients (36%) developed recurrent melanoma at one or more sites. The median follow-up period was 30 months. Recurrence in the previously dissected nodal basin was observed in 10 patients (10%); none had recurrence at only that site. Nodal basin disease appeared after local/in-transit (n = 6) or distant (n = 1) failure in seven patients and, as a component of the first site of failure, simultaneously with local/in-transit (n = 2) or distant (n = 1) recurrence in three patients. CONCLUSIONS: Nodal basin failure after lymphadenectomy in patients who underwent previous biopsy of a histologically positive SLN is primarily a function of aggressive locoregional disease rather than of contamination from previous surgery. Because regional nodal control was comparable with that in other series, we conclude that SLN biopsy with selective lymphadenectomy does not compromise regional nodal basin control.

Adolescent↗
PubMed2000

Role for lymphatic mapping and sentinel lymph node biopsy in patients with thick (> or = 4 mm) primary melanoma.

BACKGROUND: Historically, patients with thick (> or =4 mm) primary melanoma have not been considered candidates for elective lymph node dissection, because their risk for occult distant disease is significant. Sentinel lymph node (SLN) biopsy offers an alternative approach to assess disease in the regional nodal basin, but no studies have specifically addressed the role for this technique in patients with thick melanoma. Although adjuvant therapy benefits patients who develop nodal metastases, data that supports its routine use in all patients with thick melanoma is both limited and controversial. This study was performed to determine whether pathological status of the SLN is an important risk factor in this heterogeneous group and, thus, provides a rationale for SLN biopsy. METHODS: The records of 131 patients with primary cutaneous melanoma whose primary tumors were at least 4 mm thick and who underwent lymphatic mapping and SLN biopsy were reviewed. Several known prognostic factors, i.e., tumor thickness, ulceration, Clark level, location, sex, as well as SLN pathological status were analyzed with respect to disease-free and overall survival. RESULTS: Lymphatic mapping and SLN biopsy was successful in 126 (96%) of 131 patients who underwent the procedure. In 49 patients (39%), the SLN biopsy was positive by conventional histology, although it was negative in 77 patients (61%). The median follow-up was 3 years. Although presence of ulceration and SLN status were independent prognostic factors with respect to disease-free and overall survival, SLN status was the most powerful predictor of overall survival by univariate and multivariate analyses. CONCLUSIONS: Lymphatic mapping and SLN biopsy is a highly accurate method of staging lymph node basins at risk for regional metastases in patients with thick melanoma and identifies those patients who may benefit from earlier lymphadenectomy as well as patients with a more favorable prognosis. Pathological status of the SLN in these patients with clinically negative nodes is the most important prognostic factor for survival and is essential to establish stratification criteria for future adjuvant trials in this high-risk group.

Adolescent↗
PubMed2000

Significance of multiple nodal basin drainage in truncal melanoma patients undergoing sentinel lymph node biopsy.

BACKGROUND: Although previous studies have demonstrated that truncal site is associated with an adverse prognosis, explanations for such risk are lacking. In addition, the number of nodal basins as well as the number of lymph nodes containing regional metastases are important prognostic factors in these patients. Because the lymphatic drainage pattern of truncal melanoma often includes more than one basin, we designed a study to evaluate (1) whether patients with multiple nodal basin drainage (MNBD) were at an increased risk of lymph node metastases identified by sentinel lymph node (SLN) biopsy, and (2) whether the histological status of an individual basin reliably predicted the status of the other draining basins in patients with MNBD. METHODS: The records of 295 consecutive truncal melanoma patients who were managed primarily with intraoperative lymphatic mapping and SLN biopsy, between 1991 and 1997, were reviewed. All patients underwent preoperative lymphoscintigraphy, which established the number and location of draining nodal basins. Univariate and multivariate analyses of relevant clinicopathological factors were performed to assess which factors may predict the presence of a pathologically positive SLN. RESULTS: At least one SLN was identified in 281 patients. MNBD was present in 86 (31%) patients, and a pathologically positive SLN was found in 56 (20%) patients. By multivariate analysis, the presence of MNBD (relative risk = 1.9; P = .03), tumor thickness (P = .007), and tumor ulceration (relative risk = 2.4; P = .01) were significant independent risk factors for the presence of at least one pathologically positive SLN. SLN pathology in one basin did not predict the histology of other basins in 19 (22%) of 86 patients with MNBD. CONCLUSIONS: MNBD is independently associated with an increased risk of nodal metastases in truncal melanoma patients. Because the histological status of an individual basin did not reliably predict the status of the other draining basins in patients with MNBD, it is important to adequately identify and completely assess all nodal basins at risk, as defined by lymphoscintigraphy, in truncal melanoma patients.

Biopsy↗
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

How many lymph nodes are enough during sentinel lymphadenectomy for primary melanoma?

BACKGROUND: Sentinel lymph node (SLN) biopsy has been shown to reliably identify nodal metastases and the subsequent need for further surgical and adjuvant therapy in patients with cutaneous melanoma. Although SLN identification rates have improved with the addition of radioactive colloid to the blue dye technique, it remains unclear how many lymph nodes should be removed to accurately determine the histologic status of the nodal basin. The objective of this study was to determine the optimal extent of SLN biopsy in these patients. METHODS: The records of 633 consecutive patients with melanoma (765 nodal basins) whose primary treatment included SLN biopsy with the use of a combination of blue dye and technetium Tc 99 labeled sulfur colloid were reviewed. SLN biopsy consisted of the removal of all of the blue-stained nodes and all nodes with radiotracer uptake activity of at least twice background. RESULTS: SLN biopsy was successful in 765 of 772 basins (99%). A mean of 1.9 SLNs (median, 2 SLNs) per basin were excised. At least 3 SLNs were removed in 176 basins (23%). The overall histologic status of a basin was always established by the first or second SLN harvested (ie, in no patient was the third or subsequent SLN positive when 1 of the first 2 was not). Of the 124 basins containing lymphatic metastases, the SLN that contained the maximal radiotracer uptake (hottest) and/or stained blue was pathologically positive in 118 basins (95%). In only 6 of the 124 positive basins (5%) was the sole evidence of occult nodal metastases identified in an SLN that was neither blue-stained nor the hottest. All but 1 of these SLNs had counts that were at least 66% of the hottest node in the basin. CONCLUSIONS: With a combined modality approach to SLN biopsy, removal of more than 2 SLNs did not provide information that upstaged any patient with primary melanoma. Removal of additional nonblue SLN(s) that contained radioactive counts of at least twice background but lower than two thirds of the SLNs with maximal radiotracer uptake affected patient management in less than 0.2% of all cases. These findings may be helpful in minimizing the extent of surgery and perhaps in reducing the costs and resource use associated with operating room time and pathologic examination.

Biopsy↗
PubMed1999

Port site recurrences after laparoscopy for malignant disease.

Reports of recurrent malignant disease developing at laparoscopic port sites has created considerable controversy among surgeons. Many have implicated the technique of laparoscopy as a cause of metastases and this has led to condemnation of laparoscopy in malignant disease by many surgeons. A review of the case reports, as well as animal studies, reveals the problem to be considerably more complex. Based on experimental models, reported cases, and our experience at the University of Texas M. D. Anderson Cancer Center, we have arrived at some substantive conclusions regarding this phenomenon. Port site recurrences (PSRs) after laparoscopy for malignant disease can occur as the only site of recurrence, but this is an extremely rare event, and the incidence does not appear to be significantly different from the development of wound recurrences after open laparotomy for malignancy. It is likely that port site recurrences reflect the underlying biology of the malignant disease, rather than an effect of the technique of laparoscopy.

Animals↗
PubMed1999

Laparoscopic splenectomy in patients with hematologic malignancies.

BACKGROUND: Although laparoscopic splenectomy (LS) for benign hematologic disease is well accepted, its role in hematologic malignancies is not clearly defined. This study examined the efficacy and feasibility of LS for hematologic malignancies. METHODS: Records were reviewed from patients who underwent LS at two university hospitals. Charts from 77 open splenectomies for malignancy (OM) during the same period were also reviewed. RESULTS: Fifty-three patients underwent LS, 22 for hematologic malignancies (LM) and 31 for benign hematologic disorders (LB). Median splenic weight was greater in the LM group (930 g) than in the LB group (164 g, P = 0.001). LM was associated with longer operations and greater blood loss than was LB. LM had a 41% conversion rate. Morbidity, mortality, and transfusion rates were similar. Median hospital stay was shorter for LM (4 days) than for OM (6 days, P = 0.001). CONCLUSIONS: LS is feasible in hematologic malignancies but is associated with increased operative time and blood loss and a high conversion rate. Morbidity and mortality, however, was similar. Shorter hospital stays for LM compared with OM may translate into earlier recovery and initiation of antineoplastic therapy.

Adult↗
PubMed1999

Response to neoadjuvant chemotherapy best predicts survival after curative resection of gastric cancer.

OBJECTIVE: In Western populations, long-term survival rates after curative resection of gastric cancer remain extremely poor. The lack of effective adjuvant therapy has prompted the evaluation of neoadjuvant approaches. Since 1988, we have conducted three separate phase II trials using neoadjuvant chemotherapy to treat patients with potentially resectable gastric cancer. The present study was conducted to evaluate whether response to neoadjuvant chemotherapy is predictive of survival in patients with resectable gastric cancer. METHODS: Eighty-three patients with pathologically confirmed gastric adenocarcinoma were treated with neoadjuvant chemotherapy before planned surgical resection. Response was assessed by upper gastrointestinal series, endoscopy, computed tomography scan, and pathologic examination. RESULTS: For the three phase II trials, clinical response rates ranged from 24% to 38%. Three patients (4%) had a complete pathologic response. Sixty-one patients (73%) underwent a curative resection. Median follow-up was 26 months. Univariate analysis revealed T stage, number of positive nodes, and response to chemotherapy to be significant predictors of overall survival. However, on multivariate analysis, response to chemotherapy was found to be the only independent prognostic factor. CONCLUSIONS: Response to neoadjuvant chemotherapy is the single most important predictor of overall survival after neoadjuvant chemotherapy for gastric cancer. These findings support further evaluation of neoadjuvant approaches in the treatment of this disease.

Adenocarcinoma↗
PubMed1999

Multi-institutional melanoma lymphatic mapping experience: the prognostic value of sentinel lymph node status in 612 stage I or II melanoma patients.

PURPOSE: To compare the effect of pathologic sentinel lymph node (SLN) status with that of other known prognostic factors on recurrence and survival in patients with stage I or II cutaneous melanoma. PATIENTS AND METHODS: We reviewed the records of 612 patients with primary cutaneous melanoma who underwent lymphatic mapping and SLN biopsy between January 1991 and May 1995 to determine the effects of tumor thickness, ulceration, Clark level, location, sex, and SLN pathologic status on disease-free and disease-specific survival. RESULTS: In the 580 patients in whom lymphatic mapping and SLN biopsy were successful, the SLN was positive by conventional histology in 85 patients (15%) but negative in 495 patients (85%). SLN status was the most significant prognostic factor with respect to disease-free and disease-specific survival by univariate and multiple covariate analyses. Although tumor thickness and ulceration influenced survival in SLN-negative patients, they provided no additional prognostic information in SLN-positive patients. CONCLUSION: Lymphatic mapping and SLN biopsy is highly accurate in staging nodal basins at risk for regional metastases in primary melanoma patients and identifies those who may benefit from earlier lymphadenectomy. Furthermore, pathologic status of the SLN in these patients with clinically negative nodes is the most important prognostic factor for recurrence. The information from SLN biopsy is particularly helpful in establishing stratification criteria for future adjuvant trials.

Biopsy↗