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Biomedical subjects

Raphael E Pollock

Publications and source records attributed to Raphael E Pollock.

At least 37 records · Page 2Linked to original sources

Bilateral metastatic renal synovial sarcoma.

Synovial sarcoma is a malignant soft-tissue neoplasm, usually arising in close association with the joints and generally carrying a poor prognosis. We describe the first report of bilateral renal metastases from synovial sarcoma in a long-term survivor. Treatment consisted of systemic therapy with bilateral partial nephrectomies. The patient was disease free at 1 year of follow-up.

Amputation, Surgical↗

Gene therapy with E2F-1 up-regulates the protein kinase PKR and inhibits growth of leiomyosarcoma in vivo.

Overexpression of the transcription factor E2F-1 induces apoptosis in a variety of carcinoma cells and inactivates murine double minute protein 2, a factor associated with poor prognosis in soft tissue sarcomas. We have shown previously that the double-stranded RNA-activated protein kinase PKR plays an important role in mediating this apoptotic response in carcinoma cells to E2F-1. We sought to evaluate the potential of E2F-1 gene therapy in soft tissue sarcomas and to study the involvement of PKR in the response to E2F-1 overexpression in mesenchymal cells. A replication-deficient adenovirus carrying the E2F-1 gene (Ad5E2F) was used to induce E2F-1 overexpression in the p53 mutated leiomyosarcoma cell line, SKLMS-1. Western blot analysis confirmed E2F-1 overexpression and up-regulation of the antiapoptotic factor Bcl-2 48 hours following infection with Ad5E2F. Apoptosis in Ad5E2F-treated cells was confirmed by fluorescence-activated cell sorting analysis and by poly(ADP-ribose) polymerase cleavage and DNA fragmentation assays. Vector-dependent up-regulation of PKR correlated with the amount of Ad5E2F-induced apoptosis. In vivo treatment of SKLMS-1 tumor-bearing BALB/c mice with intratumoral injections of Ad5E2F at a dose of 2 x 10(10) viral particles resulted in significant inhibition in tumor growth compared with control-treated animals (P < 0.016). Complete disappearance of all tumors was seen in two of seven mice in the Ad5E2F-treated animals. Immunohistochemical analysis of tumor specimens showed overexpression of E2F-1 and up-regulation of PKR in Ad5E2F-treated tumors. These findings show that adenovirus-mediated overexpression of E2F-1 results in up-regulation of PKR and significant growth suppression of leiomyosarcomas in vivo. Taken together, these data suggest that E2F-1 gene therapy and PKR modulation might be a promising treatment strategy for these tumors that are highly resistant to conventional therapies.

Adenoviridae↗

Transcriptional repression of protein kinase Calpha via Sp1 by wild type p53 is involved in inhibition of multidrug resistance 1 P-glycoprotein phosphorylation.

The protein kinase C (PKC) family consists of serine/threonine protein kinases that play important roles in signal transduction, cell proliferation, and tumor formation. Recent studies found that PKCs are commonly overexpressed in human tumors, including soft tissue sarcoma (STS). Overexpression of PKCs contributes to invasion and migration of tumor cells and induction of angiogenesis. PKC can also phosphorylate the multidrug resistance (MDR) gene-encoded P-glycoprotein and induce MDR phenotype. Our previous studies showed that mutation of p53 enhanced STS metastasis and mediated the MDR phenotype. Restoring wild type (WT) p53 in STS cells containing mutant p53 sensitized the cells to chemotherapy. In the present study, we found that PKCalpha protein expression is inhibited by WT p53 partly due to reduced PKCalpha mRNA expression in STS cells, but p53 does not affect PKCalpha mRNA stability. Deletion and mutation analysis of the PKCalpha promoter fused to the luciferase reporter gene identified a Sp1 binding site (-244/-234) in the PKCalpha promoter that is required for p53-mediated inhibition of PKCalpha promoter activity. More importantly, PKCalpha phosphorylates and activates MDR1 P-glycoprotein, whereas inhibition of PKCalpha by p53 leads to decreased MDR1 phosphorylation in STS cells, which sensitizes STS cells to chemotherapeutic agents. These data indicate that WT p53 may resensitize STS to chemotherapeutic agents by reducing MDR1 phosphorylation via transcriptional repression of PKCalpha expression. Thus, molecular-based therapies targeting mutant p53 and PKCalpha may be an effective new strategy to improve chemotherapeutic efficacy in STS.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Cohort analysis of patients with localized, high-risk, extremity soft tissue sarcoma treated at two cancer centers: chemotherapy-associated outcomes.

PURPOSE: Patients with American Joint Committee on Cancer stage III soft tissue sarcoma (STS) have high risks of distant recurrence and death. The role of chemotherapy for these patients remains controversial despite several randomized trials and a meta-analysis. METHODS: We reviewed the treatments and outcomes of 674 consecutive adult patients presenting with primary stage III extremity STS between 1984 and 1999. Pre- or postoperative doxorubicin-based chemotherapy was used in a nonrandomized fashion in approximately half of this high-risk population. The objective of this review was to evaluate the impact of chemotherapy while accounting for known prognostic variables. RESULTS: Among 674 patients, 338 (50%) were treated with local therapy only, and 336 (50%) were treated with local therapy plus chemotherapy. The median follow-up for survivors was 6.1 years. Five-year local and distant recurrence-free interval probabilities were 83% and 56%, respectively, for the two groups combined. The 5-year disease-specific survival (DSS) rate was 61%. Cox regression analyses showed a time-varying effect associated with chemotherapy. During the first year, the hazard ratio associated with DSS for patients treated with chemotherapy versus no chemotherapy was 0.37 (95% CI, 0.20 to 0.69; P = .002). Thereafter, this hazard ratio was 1.36 (95% CI, 1.02 to 1.81; P = .04). CONCLUSION: It seems that the clinical benefits associated with doxorubicin-based chemotherapy in patients with high-risk extremity STS are not sustained beyond 1 year. These results suggest that caution should be used in the interpretation of randomized clinical trials of adjuvant chemotherapy that seem to demonstrate clinical benefits with relatively short-term follow-up.

Adult↗

A missense mutation in KIT kinase domain 1 correlates with imatinib resistance in gastrointestinal stromal tumors.

KIT gain of function mutations play an important role in the pathogenesis of gastrointestinal stromal tumors (GISTs). Imatinib is a selective tyrosine kinase inhibitor of ABL, platelet-derived growth factor receptor (PDGFR), and KIT and represents a new paradigm of targeted therapy against GISTs. Here we report for the first time that, after imatinib treatment, an additional specific and novel KIT mutation occurs in GISTs as they develop resistance to the drug. We studied 12 GIST patients with initial near-complete response to imatinib. Seven harbored mutations in KIT exon 11, and 5 harbored mutations in exon 9. Within 31 months, six imatinib-resistant rapidly progressive peritoneal implants (metastatic foci) developed in five patients. Quiescent residual GISTs persisted in seven patients. All six rapidly progressive imatinib-resistant implants from five patients show an identical novel KIT missense mutation, 1982T-->C, that resulted in Val654Ala in KIT tyrosine kinase domain 1. This novel mutation has never been reported before, is not present in pre-imatinib or post-imatinib residual quiescent GISTs, and is strongly correlated with imatinib resistance. Allelic-specific sequencing data show that this new mutation occurs in the allele that harbors original activation mutation of KIT.

Alleles↗

Phase I trial of preoperative doxorubicin-based concurrent chemoradiation and surgical resection for localized extremity and body wall soft tissue sarcomas.

PURPOSE: The primary objective of this phase I trial was to define the maximum-tolerated dose of continuous-infusion doxorubicin administered with standard preoperative radiation for patients with localized, potentially resectable soft tissue sarcomas of the extremities or body wall. PATIENTS AND METHODS: Twenty-seven patients with radiographically resectable intermediate- or high-grade soft tissue sarcomas were treated. Preoperative external-beam radiation was administered in 25 2-Gy fractions (total dose, 50 Gy). Concurrent continuous-infusion doxorubicin was administered by an initial bolus (4 mg/m(2)) and subsequent 4-day continuous infusion (12.5, 15.0, 17.5, or 20.0 mg/m(2)/wk). Radiographic restaging was performed 4 to 7 weeks after chemoradiation, and patients with localized disease underwent surgical resection. RESULTS: Chemoradiation was completed as an outpatient procedure in 25 patients (93%). The maximum-tolerated dose of continuous-infusion doxorubicin combined with standard preoperative radiation was 17.5 mg/m(2)/wk; at this dose level, seven (30%) of 23 patients had grade 3 dermatologic toxicity. Macroscopically complete resection (R0 or R1) was performed in all 26 patients who underwent surgery. Among 22 patients who were treated with doxorubicin 17.5/mg/m(2)/wk with concurrent radiation and subsequent surgery, 11 patients (50%) had 90% or greater tumor necrosis, including two patients who had complete pathologic responses. CONCLUSION: Preoperative doxorubicin-based chemoradiation appears safe and feasible. The maximum-tolerated dose of continuous-infusion doxorubicin with standard preoperative radiation was 17.5 mg/m(2)/wk. Pathologic response rates with this regimen are encouraging.

Adolescent↗

Cost-effectiveness of pulmonary resection and systemic chemotherapy in the management of metastatic soft tissue sarcoma: a combined analysis from the University of Texas M. D. Anderson and Memorial Sloan-Kettering Cancer Centers.

BACKGROUND: We sought to determine the cost-effectiveness of different treatment strategies for patients with pulmonary metastases from soft tissue sarcoma. METHODS: We constructed a decision tree to model the outcomes of 4 treatment strategies for patients with pulmonary metastases from soft tissue sarcoma: pulmonary resection, systemic chemotherapy, pulmonary resection and systemic chemotherapy, and no treatment. Data from 1124 patients with pulmonary metastases from soft tissue sarcoma were used to estimate disease-specific survival for pulmonary resection and no treatment. Outcomes of systemic chemotherapy and pulmonary resection and of systemic chemotherapy were estimated by assuming a 12-month improvement in disease-specific survival with chemotherapy; this was done on the basis of the widely held but unproven assumption that chemotherapy provides a survival benefit in patients with metastatic soft tissue sarcoma. Direct costs were examined for a series of patients who underwent protocol-based pulmonary resection or doxorubicin/ifosfamide-based chemotherapy. RESULTS: The mean cost of pulmonary resection was 20,339 dollars per patient; the mean cost of 6 cycles of chemotherapy was 99,033 dollars. Compared with no treatment and assuming a 12-month survival advantage with chemotherapy, the incremental cost-effectiveness ratio was 14,357 dollars per life-year gained for pulmonary resection, 104,210 dollars per life-year gained for systemic chemotherapy, and 51,159 dollars per life-year gained for pulmonary resection and systemic chemotherapy. Compared with pulmonary resection, the incremental cost-effectiveness ratio of pulmonary resection and systemic chemotherapy was 108,036 dollars per life-year gained. Sensitivity analyses showed that certain patient and tumor features, as well as the assumed benefit of chemotherapy, affected cost-effectiveness. CONCLUSIONS: For patients with pulmonary metastases from soft tissue sarcoma who were surgical candidates, pulmonary resection was the most cost-effective treatment strategy evaluated. Even with favorable assumptions regarding its clinical benefit, systemic chemotherapy alone, compared with no treatment, was not a cost-effective treatment strategy for these patients.

Antineoplastic Agents↗

Platelet kinetics and decreased transfusion requirements after splenectomy for hematologic malignancy.

OBJECTIVE: Thrombocytopenia is a significant and morbid problem in patients with hematologic malignancy, resulting in frequent platelet transfusions and significant resource consumption. We undertook this study to determine the impact of splenectomy on transfusion requirements in patients with chronic leukemia, acute leukemia, myelodysplastic syndrome, and lymphoma. METHODS: Records of 134 patients with hematologic malignancies who underwent splenectomy were reviewed. Results are reported as mean +/- standard error of the mean. RESULTS: Mean preoperative (preop) platelet count was 97 +/- 8 K/microL. A significant rise in platelets, compared with preop, was observed starting on postsplenectomy day 1 (141 +/- 8 K/microL, P < 0.001 versus preop) and persisted through day 7. Counts remained significantly elevated at 3 and 6 months and years 1-5. In profoundly thrombocytopenic patients (preop levels < 20 K/microL), preop count was 11 +/- 1 K/microL. A significant postsplenectomy platelet rise persisted for at least 1 year (137 +/- 52 K/microL, P < 0.05 versus preop). An increased platelet level was observed in all hematologic subgroups; in the chronic leukemias (n = 58, P < 0.01) and in lymphoma (n = 59, P < 0.001), this reached significance. Mean platelet transfusions were significantly decreased from preop (3 months preop: 8.6 +/- 2 units) compared with postsplenectomy (3 months postsplenectomy: 5.0 +/- 1 unit, P = 0.03). This decrease was even more pronounced in profoundly thrombocytopenic patients (31.6 +/- 10.6 units preop versus 8.9 +/- 4.8 units postoperative, P = 0.01). CONCLUSIONS: In the hematologic malignancies, splenectomy produces a significant and longlasting restoration of platelet levels and a resultant decrease in platelet transfusion requirements. These beneficial effects of splenectomy hold true even for the most profoundly thrombocytopenic patients.

Adolescent↗

Upper extremity reconstruction following resection of soft tissue sarcomas: a functional outcomes analysis.

BACKGROUND: Treatment for soft tissue sarcoma of the upper extremity has evolved to include limb salvage techniques. We reviewed our experience with limb salvage therapy for upper extremity sarcomas with an emphasis on functional outcomes following the reconstructive surgery. METHODS: A retrospective analysis was performed of 81 consecutive patients with soft tissue sarcoma of the upper extremity who had limb salvage therapy with reconstruction by a plastic surgeon. Univariate and multivariate regression analyses of relevant outcome variables were performed. Enneking functional scores were obtained from 43 patients. RESULTS: The study included 16 microvascular reconstructions and 67 non-microvascular reconstructions for a total of 83 reconstructions in 81 patients. The mean defect size was 129 cm(2) (standard deviation: 106 cm(2)). The mean total functional score was 23.1 (range, 9 to 30). Any reconstruction-related complication and preoperative chemotherapy use were associated with a 7.3 point (P = .03) and 4.7 point (P = .01) decrease in total functional score, respectively. Kaplan-Meier product-limit analysis showed 82% 5-year overall survival and 67% 5-year disease-free survival rates. CONCLUSIONS: For soft tissue sarcoma of the upper extremity, limb salvage with good functional outcome is possible with a judicious approach to reconstruction.

Adult↗

Prognostic factors for disease-specific survival after first relapse of soft-tissue sarcoma: analysis of 402 patients with disease relapse after initial conservative surgery and radiotherapy.

PURPOSE: To document the prognostic factors for survival of patients with soft-tissue sarcoma sustaining a first relapse after definitive treatment. METHODS AND MATERIALS: The clinicopathologic features, relapse patterns, and disease-specific survival rates for 402 consecutive patients sustaining a first relapse of sarcoma after combined surgery and radiotherapy were retrospectively reviewed. Factors affecting disease-specific survival after relapse were evaluated with univariate and multivariate techniques. RESULTS: The median follow-up after relapse was 6.8 years. The overall disease-specific survival rate was 25%, 19%, and 16% at 5, 10, and 15 years, respectively, after the first relapse. The median survival duration was 21 months. Patients with an isolated local recurrence had a 5- and 10-year disease-specific survival rate of 48% and 46%, respectively, and those with an initial metastatic relapse had a disease-specific survival rate of 16% and 10%, respectively (p < 0.001). For isolated local recurrences, the independent determinants of survival were (favorable feature first) the primary tumor site (extremity and superficial trunk vs. head and neck and deep trunk); tumor grade (low and intermediate vs. high); time to recurrence (>12 vs. 5 cm). Although the development of subsequent metastasis was the major cause of death, a significant fraction of patients died of uncontrolled primary tumor. For patients presenting with metastasis as the first relapse, the time to metastasis was the major determinant of survival (>12 vs. < or =12 months). Long-term salvage was largely confined to patients who could and did undergo resection of relapsed disease, either local or metastatic. CONCLUSION: On the whole, patients whose sarcoma relapses fare poorly. However, select subgroups are potentially salvageable. Patients with an isolated local recurrence at sites other than the head and neck and deep trunk have a reasonable prospect for satisfactory outcome. Surgical resection of recurrences and metastases appears to play a major role in potential salvage.

Adolescent↗

Phase I trial of preoperative concurrent doxorubicin and radiation therapy, surgical resection, and intraoperative electron-beam radiation therapy for patients with localized retroperitoneal sarcoma.

PURPOSE: The primary objective of this phase I trial was to define the maximum-tolerated dose of external-beam radiation with concurrent fixed-dose continuous-infusion doxorubicin followed by surgical resection and electron-beam intraoperative radiation therapy (EB-IORT) for patients with localized, potentially resectable retroperitoneal sarcomas (RPS). PATIENTS AND METHODS: Thirty-five patients with radiographically resectable primary or recurrent intermediate- or high-grade RPS were treated. Doxorubicin was administered each week for 4 or 5 weeks as an initial bolus (4 mg/m2) followed by a 4-day continuous infusion (4 mg/m2/d). Concurrent radiation therapy was administered in escalating doses of 18.0, 30.6, 36.0, 41.4, 46.8, or 50.4 Gy in 1.8-Gy fractions. Radiographic restaging was performed 4 to 8 weeks after chemoradiation, and patients with localized disease underwent surgical resection with EB-IORT (15 Gy). RESULTS: Chemoradiation was completed as outpatient therapy in 31 patients (89%); four patients required hospital admission during chemoradiation or in the postchemoradiation preoperative period. At the highest radiation dose of 50.4 Gy, two (18%) of 11 patients had grade 3 or 4 nausea. Twenty-nine patients (83%) underwent laparotomy; six patients had interval disease progression and did not undergo surgery. Grossly complete resection (R0 or R1) was performed in 26 (90%) of 29 patients who had surgery. EB-IORT was feasible and successfully administered to 22 patients who had R0 or R1 resections. CONCLUSION: Preoperative chemoradiation, surgical resection, and EB-IORT are feasible for patients with RPS. Preoperative external-beam radiation can be administered to a total dose of 50.4 Gy with continuous-infusion doxorubicin.

Adult↗

Preoperative vs. postoperative radiation therapy for soft tissue sarcoma: a retrospective comparative evaluation of disease outcome.

PURPOSE: Radiation (XRT) is a proven component in the treatment of soft tissue sarcoma. However, there is little evidence regarding the relative effectiveness of preoperative vs. postoperative XRT. This retrospective study addresses the relative effectiveness of disease control by these two treatment sequences. METHODS AND MATERIALS: A total of 517 patients (246 treated with postoperative XRT, and 271 treated with preoperative XRT) with nonmetastatic sarcoma were evaluated for disease outcome and late complications using univariate and multivariate techniques. RESULTS: With a median follow-up of 6 years, overall local control was 81% and 78% at 5 and 10 years, respectively. Although local control appeared superior with preoperative XRT (83% at 10 years) compared with postoperative XRT (72%), multivariate analysis revealed that this difference could be entirely explained by the unequal distribution of prognostic factors between the two groups, and there was no evidence that treatment sequence independently determined local control. There were no differences in nodal or metastatic relapse between the two treatments, and disease-specific survival was not significantly different. There was a slightly higher incidence of late XRT-related complications among those treated with postoperative XRT (10-year incidence of 9% vs. 5%, p = 0.03). CONCLUSIONS: This study found no evidence for differences in disease outcome attributable to the use of either pre- or postoperative XRT. There was a slight increase in long-term complications with postoperative XRT, likely due to the higher doses used in this sequence.

Adolescent↗

Prognostic factors for patients with localized soft-tissue sarcoma treated with conservation surgery and radiation therapy: an analysis of 1225 patients.

BACKGROUND: Prognostic factors for patients with soft-tissue sarcoma who are treated with conservative surgery and radiation are documented poorly. METHODS: The clinicopathologic features and disease outcome for 1225 patients with localized sarcoma who were treated with conservative surgery and radiation were reviewed retrospectively. Actuarial univariate and multivariate statistical methods were used to determine significant prognostic factors for local control, metastatic recurrence, and disease specific survival. RESULTS: The median follow-up of surviving patients was 9.5 years. The respective local control rates at 5 years, 10 years, and 15 years were 83%, 80%, and 79%. Factors predictive of local recurrence were positive or uncertain resection margins; tumors located in the head and neck and the deep trunk; presentation with local recurrence; patient age > 64 years; malignant fibrous histiocytoma, neurogenic sarcoma. or epithelioid sarcoma histopathology; tumor measuring > 10 cm in greatest dimension; and high pathologic grade. Freedom from metastasis at 5 years, 10 years, and 15 years was 71%, 68%, and 66%, respectively. Factors that were predictive of metastatic recurrence were high tumor grade; large tumor size (> 5 cm); and leiomyosarcoma, rhabdomyosarcoma, synovial sarcoma, or epithelioid sarcoma. The respective disease specific survival rates at 5 years, 10 years, and 15 years were 73%, 68%, and 65%. Adverse factors for disease specific survival were high tumor grade; large tumor size (> 5 cm); tumors located in the head and neck and deep trunk; rhabdomyosarcoma, epithelioid sarcoma, or clear cell sarcoma; patient age > 64 years; and positive or uncertain resection margins. CONCLUSIONS: Soft-tissue sarcoma comprises a heterogeneous group of diseases. Prognostic factors for local recurrence, metastatic recurrence, lymph node recurrence, disease free survival, and disease specific survival are different, and optimal treatment strategies need to take this complexity into account.

Adolescent↗

Surgical margins and reresection in the management of patients with soft tissue sarcoma using conservative surgery and radiation therapy.

BACKGROUND: Patients with localized soft tissue sarcoma (STS) who present to specialist centers after undergoing apparent macroscopic total resection often have a significant incidence of residual tumor and may benefit from reresection of the tumor bed. The potential benefits of such reresection have not been documented adequately. METHODS: The clinicopathologic features and disease outcome for 666 consecutive patients with localized STS who presented after undergoing apparent macroscopic total tumor resection were analyzed to elucidate the relative merits of reresection. Actuarial univariate and multivariate methods were used to compare disease outcome of patients who presented with positive or uncertain microscopic resection margins according to whether they underwent reresection. All patients received adjuvant radiation therapy. RESULTS: Two hundred and ninety-five patients underwent reresection of their tumor bed, and residual tumor was found in 136 patients (46%), including macroscopic tumor in 73 patients (28%). Final resection margins among patients who underwent reresection were negative in 257 patients (87%), positive in 35 patients (12%), and uncertain in 3 patients (1%). Patients who did not undergo reresection had final margins that were negative in 117 patients (32%), positive in 47 patients (13%), and uncertain in 207 patients (56%). Local control rates at 5 years, 10 years, and 15 years for patients who underwent reresection were 85%, 85%, and 82%, respectively; for patients who did not undergo reresection, the respective local control rates were 78%, 73%, and 73% (P = 0.03). Reresection remained a significant determinant of local control when other prognostic factors were incorporated into a multivariate proportional hazards regression analysis. A similar beneficial effect of reresection was found for metastasis free survival and disease specific survival. CONCLUSIONS: Patients with localized STS who were referred to a specialist center after undergoing apparent macroscopic total resection of their tumor had a high incidence of residual tumor in their tumor bed and benefited from undergoing reresection, even if radiation was administered routinely.

Adolescent↗

Increasing the pool of academically oriented African-American medical and surgical oncologists.

BACKGROUND: In the United States, breast cancer mortality rates are significantly higher among African-American women than among women of other ethnic backgrounds. Research efforts to evaluate the socioeconomic, environmental, biologic, and genetic mechanisms explaining this disparity are needed. METHODS: Data regarding patterns in the ethnic distribution of physicians and oncologists were accumulated from a review of the literature and by contacting cancer-oriented professional societies. This information was evaluated by participants in a national meeting, "Summit Meeting Evaluating Research on Breast Cancer in African American Women." Results of the data collection and the conference discussion are summarized. RESULTS: Ethnic minority specialists are underrepresented in academic medicine in general, and in the field of oncology in particular. This fact is unfortunate because ethnic minority students are more likely to express a commitment to providing care to medically underserved communities and, thus, they need to be better represented in these professions. Correcting these patterns of underrepresentation may favorably influence the design and implementation of culturally and ethnically sensitive research. CONCLUSIONS: Efforts to improve the ethnic diversity of oncology specialists should begin at the level of recruiting an ethnically diverse premed and medical student population. These recruitment efforts should place an emphasis on the value of mentoring.

Black or African American↗

Is there a role for surgery in patients with "unresectable" cKIT+ gastrointestinal stromal tumors treated with imatinib mesylate?

BACKGROUND: Imatinib mesylate (Gleevec) is being studied as adjuvant chemotherapy for the treatment of cKIT+ gastrointestinal stromal tumors (GISTs). Early reports using Gleevec for the treatment of unresectable GISTs have shown 50% to 60% partial response rates based on radiographic evaluation alone. No study has yet correlated radiographic response with pathologic findings. This retrospective review of patients with cKIT+ GISTs who received Gleevec prior to surgical resection examines the pathologic response to therapy and the feasibility of surgical resection after treatment. METHODS: Patients with cKIT+ GISTs were identified from the institutional sarcoma database. Patients were included if they had pathologic confirmation of cKIT mutation and therapy with Gleevec. The pretreatment and preoperative radiographs, surgeons' operative notes, and pathology reports were reviewed for documentation of the extent of disease. RESULTS: Between January 2001 and Octorber 2002, 126 patients with unresectable cKIT + GISTs treated with Gleevec were identified. Of these 126 patients, 17 have subsequently undergone surgical resection after a median of 10 months (range 2 to 16) of treatment with Gleevec. Based on computed tomographic (CT) scanning, 1 (6%) patient had evidence of a complete tumor response, 12 (70%) patients had a partial response, 3 (24%) patients had stable disease, and 1 (6%) patient had progressive disease. Posttreatment/preoperative CT imaging documented an overall response rate of 76%. The pathologic review of the operative specimens showed that 2 (12%) patients had a complete response to therapy, 11 (65%) had a partial response to therapy, 3 (18%) patients had no evidence of treatment effect on the excised tumor, 1 patient had progressive disease. Sixteen patients (94%) underwent complete surgical resection of disease, including 3 patients with no pathologic evidence of response to therapy. One patient had progression of disease and was unresectable at surgical exploration. CONCLUSIONS: This series is the first to present pathologic data after the treatment of cKIT+ GISTs with Gleevec. In this series, the majority of responses were limited to partial responses, indicating that surgical resection remains a vital component of the treatment plan for patients with cKIT+ GISTs. This series is consistent with previous reports indicating that complete responses are extremely rare in response to treatment with Gleevec. Patients with advanced disease may benefit from a course of neoadjuvant therapy with Gleevec followed by resection, even when there is evidence of multifocal disease. A prospective evaluation of neoadjuvant Gleevec therapy for advanced cKIT+ GISTs is warranted.

Adult↗

Characterization of 11 human sarcoma cell strains: evaluation of cytogenetics, tumorigenicity, metastasis, and production of angiogenic factors.

BACKGROUND: Human sarcomas have a propensity for aggressive local invasion and early pulmonary metastasis. Frequently, deaths are due to uncontrolled pulmonary metastases. The purpose of the current study was to evaluate cytogenetics, tumorigenicity, metastatic potential, and production of angiogenic factors in human sarcoma cell strains. A secondary purpose was to establish low passage cell strains for studying new therapeutic approaches. METHODS: The authors established 11 cell strains from human sarcoma surgical specimens and characterized their in vitro tumor properties, including growth in soft agar, expression of angiogenic growth factors (vascular endothelial growth factor [VEGF] and basic-fibroblast growth factor [bFGF]), and cytogenetics. RESULTS: All of the cell strains remained diploid. All exhibited the ability to grow in soft agar and expressed both VEGF as well as bFGF. In addition, 6 of the 11 established sarcoma cell strains were tumorigenic, 5 of which spontaneously metastasized to the lungs in nude mice. Four of the five cell strains that yielded lung metastases were derived from lung metastases in patients. CONCLUSIONS: The 11 cell strains, which were derived from diverse sarcoma histologies, will provide a model for studying not only metastatic progression but also the in vitro and in vivo efficacy of new therapeutic modalities for human sarcomas.

Animals↗