Biomedical subjects

David R Lucas

Publications and source records attributed to David R Lucas.

4 recordsLinked to original sources

PubMed2004

Adjuvant therapy of osteosarcoma--A Phase II trial: Southwest Oncology Group study 9139.

BACKGROUND: The objective of this study was to estimate the time to treatment failure and survival rate of the three-drug combination of doxorubicin, cisplatin, and ifosfamide as primary and postoperative, adjunctive treatment for teenagers and adults with osteosarcoma (OS). METHODS: Sixty-three eligible patients with nonmetastatic OS of the extremities were registered from 24 institutions from February, 1992 through December, 1996. Chemotherapy was comprised of doxorubicin at a dose of 75 mg/m2 and cisplatin at a dose of 120 mg/m2, alternating with doxorubicin at a dose of 50 mg/m2 and ifosfamide at a dose of 8 g/m2. Four cycles were given prior to surgical resection, and four cycles were given after surgery. Outcome measures included the time to treatment failure, overall survival, toxicity, and centralized assessment of tumor necrosis. RESULTS: Thirty-one of 63 eligible patients died, for a 5-year overall survival rate of 58% (95% confidence interval [95% CI], 46-71%). The median time to treatment failure was 19 months (95% CI, 12-41 months). A good pathologic response (> or = 90% necrosis) to neoadjuvant chemotherapy was observed in 48% of patients who underwent surgery. There was no correlation noted between response to neoadjuvant chemotherapy and patient outcome. Grade 4 hematologic toxicities were frequent (89%), although serious nonhematologic toxicities other than nausea and emesis were uncommon. CONCLUSIONS: The regimen and schedule used in the current study did not improve outcomes compared with prior trials of doxorubicin and cisplatin alone. New, more effective drugs are needed for the treatment of patients with OS. The identification and utilization of molecular markers to predict outcome and response to therapy would facilitate clinical management, limiting exposure to toxic therapies for patients with favorable molecular profiles and identifying those patients who may fail with current approaches as candidates for clinical trials.

Adolescent↗

PubMed2004

Disseminated malignant solitary fibrous tumor of the pleura.

Solitary fibrous tumor (SFT) of the pleura typically forms a localized pleura-based mass, and most are benign. A rare case of disseminated malignant SFT of the pleura is reported. The patient was a 71-year-old man who presented with complaints of shortness of breath to his primary care physician. A diagnosis of malignant mesothelioma was suspected, based on clinical, radiological and needle biopsy findings. He was referred to our institution for surgery. An extrapleural pneumonectomy, encompassing all pleural masses, was performed. Gross examination of the resected specimen was remarkable for numerous masses, ranging in size from 0.2 to 13.5 cm, covering the majority of the visceral pleura. Histologically, the tumor was composed of short spindle cells admixed with variable proportions of collagenous stroma. There were great intra- and intertumoral heterogeneity in tumor growth pattern, cellularity, pleomorphism and mitoses. Histologically malignant areas were present in all of the masses examined. The neoplastic cells were diffusely and intensely positive for bcl-2. Most tumor cells were also strongly stained for CD34 and CD99. Staining for cytokeratin was negative. The tumor also revealed p53 over-expression. Thus, the histological and immunohistochemical features of the tumor were consistent with a disseminated malignant SFT. This report shows that SFT rarely presents with disseminated pleural involvement, and a panel with CD34, bcl-2 and cytokeratin are valuable for differentiating SFT from malignant mesothelioma and other malignant spindle cell neoplasms of the pleura.

Aged↗

PubMed2003

c-Kit expression in desmoid fibromatosis. Comparative immunohistochemical evaluation of two commercial antibodies.

To determine the frequency of c-Kit staining in desmoids and optimize an assay for clinical use, we stained 19 desmoids from various sites at various dilutions with 2 commonly used rabbit polyclonal, anti-c-Kit antibodies (A4502, DAKO, Carpinteria, CA; C-19, Santa Cruz Biotechnology, Santa Cruz, CA), with and without heat-induced epitope retrieval (HIER) in citrate buffer. Approdpriate external and internal control samples were evaluated for each test condition. At dilutions of 1:50 both antibodies stained substantial numbers of desmoids: with/without HIER, A4502, 89%/63%; C-19, 37%/74%. The staining was cytoplasmic without cell membrane accentuation. However, background stromal staining and nonspecific staining of endothelium and smooth and striated muscle were problematic with both antibodies at 1:50. At higher dilutions, C-19 stained no desmoid; however, diminished staining of external and internal control samples made it unreliable. A4502 similarly stained many fewer desmoids at higher dilutions. However, it retained strong staining of both external and internal control samples and showed much less nonspecific staining. Best results were achieved at 1:250 without HIER; only weak focal staining was present in 1 desmoid. With a simple immunohistochemical method optimized for clinical use, desmoid can be regarded as a c-Kit-negative tumor.

Animals↗

PubMed2002

Osteosarcoma as a second malignant neoplasm.

PURPOSE: The aim of this study is to compare primary and secondary osteosarcomas using data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program. METHODS: Osteosarcoma cases were identified in the SEER Cancer Incidence Public-Use Database, 1973-96 (1,511 primary and 133 secondary osteosarcomas). Secondary osteosarcomas were further classified as occurring within or outside the previously irradiated field. Comparisons among groups were performed by nominal logistic regression. Survival analyses were performed using Kaplan-Meir and proportional hazards regression. RESULTS: Secondary osteosarcomas were more likely to have a non-extremity primary site and an older age at diagnosis (>40 years) (<0.0001 for both). Secondary osteosarcoma cases continued to be more likely to have a non-extremity site when excluding those occurring within the radiation field. Five-year overall survival was 50% lower for secondary osteosarcomas for both extremity and non-extremity sites. Primary malignancies associated with secondary osteosarcomas included 14 lymphomas/leukemias, six sarcomas, 54 carcinomas, and seven other cancers. Secondary osteosarcomas occurring within a field of radiation were more likely to occur at a younger age, have a malignancy with a primary morphology other than carcinoma, a non-limb site, and a longer duration between their primary malignant neoplasms and the development of osteosarcoma. No difference in the overall survival was noted between secondary osteosarcomas occurring within an irradiated field and those that did not. CONCLUSIONS: Secondary osteosarcomas are associated with carcinomas especially in the elderly. Although a 50% decreased 5-year survival was observed for secondary osteosarcomas in this study, this might not reflect the current outcomes with more aggressive therapy.

Adolescent↗