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Biomedical subjects

Steven C Campbell

Publications and source records attributed to Steven C Campbell.

23 records · Page 2Linked to original sources

Biochemical disease-free survival following adjuvant and salvage irradiation after radical prostatectomy.

PURPOSE: To present the biochemical cure rates (biochemically no evidence of disease) after external irradiation (RT) in patients with high-risk prostate cancer after radical prostatectomy. METHODS AND MATERIALS: Seventy-six patients who underwent radical prostatectomy and subsequent RT were included in this analysis. No patient received hormonal therapy. Adjuvant RT was administered in 35 patients (46%), and 41 patients (54%) underwent salvage RT. After prostatectomy, the Gleason score was <7 in 87%, and 24% had seminal vesicle invasion. The median RT dose in the adjuvant RT and salvage RT groups was 60 Gy and 65 Gy, respectively. The biochemical cure rate was defined as a serum prostate-specific antigen of < or =0.2 ng/mL. RESULTS: The overall 5-year Kaplan-Meier biochemical control rate from the end of RT was 70%. The 5-year biochemical cure rate for adjuvant RT was significantly superior to that after salvage RT (86% vs. 57%). The significant predictors of biochemical failure were seminal vesicle invasion in the adjuvant RT group and the presence of Gleason grade 4 or 5 in the salvage RT group. The clinical local control rate in the prostate bed was 100%. CONCLUSION: This report demonstrates the efficacy of RT in achieving high biochemical cure rates after radical prostatectomy. Additional clinical studies are required to determine the optimal treatment of patients at high risk of biochemical failure after postprostatectomy RT.

Aged↗

Inhibition of tumor growth by systemic treatment with thrombospondin-1 peptide mimetics.

Many normal human cells produce thrombospondin-1 (TSP-1), a potent antiangiogenic protein that promotes vascular quiescence. In various organ systems, including the brain, breast and bladder and in fibroblasts, TSP-1 secretion is reduced during tumorigenesis, thereby allowing induction of the vigorous neovascularization required for tumor growth and metastasis. Full-length and short TSP-1-derived peptides inhibit angiogenesis by inducing endothelial cell apoptosis and thus disrupting the vasculature of the growing tumor. CD36 expressed on the surface of endothelial cells functions as the primary antiangiogenic receptor for TSP-1. A D-isoleucyl enantiomer of a TSP-1 heptapeptide specifically inhibits the proliferation and migration of capillary endothelial cells. DI-TSP, an approximately 1 kDa capped version of this peptide, is also antiangiogenic in vitro, with a specific activity approaching that of the 450 kDa parental molecule. Here, we show that DI-TSP delivered systemically dose-dependently inhibits the growth of murine melanoma metastases in syngeneic animals and that its more soluble isomer, DI-TSPa, similarly blocks the progression of primary human bladder tumors in an orthotopic model in immune-deficient mice. Like intact TSP-1, these peptide mimetics had no effect on cancer cells growing in vitro but markedly suppressed the growth of endothelial cells by inducing receptor-dependent apoptosis. Antibodies raised against CD36 blocked the ability of peptides to induce apoptosis in endothelial cells but had no effect on tumor necrosis factor-alpha-induced apoptosis. In vivo, the peptide mimetics were associated with a significantly reduced microvessel density and increased apoptotic indices in both the endothelial and tumor cell compartments. Such short peptides targeted to a specific antiangiogenic receptor, potent and easy to synthesize, show great promise as lead compounds in clinical antiangiogenic strategies.

Animals↗

p53 and microvessel density in primary resection specimens of superficial bladder cancer.

PURPOSE: p53 Regulates angiogenesis in fibrosarcoma and correlative studies suggest a similar role for muscle invasive bladder cancer. We evaluated the associations of p53 status and microvessel density with pathological features and clinical outcomes in a large population of patients with superficial bladder cancer. In addition, we assessed the correlation of p53 status with microvessel density, which would suggest the regulation of angiogenesis by p53. MATERIALS AND METHODS: We stained 84 primary bladder resection specimens, including 55 stage pTa, 29 stage pT1, 27 grade 1, 35 grade 2 and 22 grade 3 samples, for p53, CD31 and CD34. The relationships of p53 or microvessel density and tumor stage-grade or clinical recurrence-progression were analyzed by analysis of variance and pairwise comparison analysis for least significant difference, and Pearson correlation coefficients. Only patients with no previous biopsy were included in analysis to preclude interference by granulation tissue related neovascularization. The 4 samples with significant inflammation were also excluded from study. RESULTS: At a mean followup of 33 months (range 1 to 93) 34 of 84 patients (40.4%) experienced 1 or more tumor recurrences and 10 (11.9%) had stage and/or grade progression. Statistically significant associations were observed of p53 immunostaining and microvessel density with tumor stage and grade (p <0.05). However, the association of p53 status with microvessel density was weak and not statistically significant. Similar results were observed for the CD31 and CD34 based estimates of microvessel density. Neither p53 status nor microvessel density correlated with recurrence or progression. CONCLUSIONS: Our study confirms the strong association of p53 and microvessel density with the well established prognostic factors of grade and stage in superficial bladder cancer, supporting other evidence of an important role for p53 and angiogenesis in the tumor biology of this disease. However, our data argue against a primary role of p53 in the regulation of angiogenesis in superficial bladder cancer. This study, which to our knowledge is the first to focus on primary resection specimens, suggests that other genetic or environmental factors may contribute to the regulation of angiogenesis in superficial bladder cancer.

Humans↗

Juxtaglomerular apparatus tumor: a rare, surgically correctable cause of hypertension.

Although uncommon, presentation of juxtaglomerular cell tumor is distinct and should allow a correct preoperative diagnosis in most patients. Typical clinical presentations include headaches, polyuria, or isolated, asymptomatic, severe hypertension. The diagnosis of a juxtaglomerular apparatus (JGA) tumor typically results from identification of plasma renin levels two- to sevenfold greater than the normal value. Although JGA tumors are considered benign, with no reports of metastases or recurrence, they are potentially lethal if left untreated. Surgical excision is curative.

Case Reports↗