Benjamin K Yang

Duke University Medical Center, Durham, NC, United States

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Publications (6)30.57 Total impact

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    ABSTRACT: To compare the perioperative outcomes of severely obese and nonobese patients undergoing radical perineal prostatectomy (RPP). A cohort of 71 severely obese patients, as defined by a body mass index of 35 kg/m2 or more, who underwent RPP between 1992 and 2003 was retrospectively identified. These patients were matched by age, American Society of Anesthesiologists class, and year of surgery to a cohort of 71 nonobese patients (body mass index less than 25 kg/m2). Statistical testing was performed to compare the estimated blood loss, transfusion requirements, and complication rates (primary endpoints), as well as the length of surgery, intraoperative anesthesia requirements, postoperative hematocrit level, length of stay, and surgical margin status (secondary endpoints). The mean body mass index +/- standard deviation of patients in the obese and nonobese group was 38.9 +/- 4.7 and 22.9 +/- 1.6 kg/m2 (P = 0.001), respectively. Patients were similar with regard to baseline characteristics. Obese and nonobese patients did not demonstrate significant differences in mean estimated blood loss (571 +/- 391 and 494 +/- 317 mL, respectively; P = 0.06), transfusion rates (2.8% and 7.0%, respectively; P = 0.45), or positive surgical margin rates (14.1% and 9.9%, respectively; P = 0.22). The overall complication rates were significantly different at 16.9% and 7.0% (P = 0.03). Severely obese patients undergoing RPP had blood transfusion rates similar to those of the nonobese patients. Obese RPP patients were at increased risk of surgical and anesthesia-related perioperative complications, many of which might be avoidable. Specifically, efforts should be directed toward preventing the development of lower extremity neurapraxia by minimizing the operative time and optimizing patient positioning.
    Urology 06/2006; 67(5):990-5. · 2.42 Impact Factor
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    ABSTRACT: In this study, we investigated whether elimination of CD4+/CD25+ Tregs using the recombinant IL-2 diphtheria toxin conjugate DAB(389)IL-2 (also known as denileukin diftitox and ONTAK) is capable of enhancing the immunostimulatory efficacy of tumor RNA-transfected DC vaccines. We show that DAB(389)IL-2 is capable of selectively eliminating CD25-expressing Tregs from the PBMCs of cancer patients without inducing toxicity on other cellular subsets with intermediate or low expression of CD25. DAB(389)IL-2-mediated Treg depletion resulted in enhanced stimulation of proliferative and cytotoxic T cell responses in vitro but only when DAB(389)IL-2 was omitted during T cell priming. DAB(389)IL-2 significantly reduced the number of Tregs present in the peripheral blood of metastatic renal cell carcinoma (RCC) patients and abrogated Treg-mediated immunosuppressive activity in vivo. Moreover, DAB(389)IL-2-mediated elimination of Tregs followed by vaccination with RNA-transfected DCs significantly improved the stimulation of tumor-specific T cell responses in RCC patients when compared with vaccination alone. Our findings may have implications in the design of immune-based strategies that may incorporate the Treg depletion strategy to achieve potent antitumor immunity with therapeutic impact.
    Journal of Clinical Investigation 01/2006; 115(12):3623-33. · 12.81 Impact Factor
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    ABSTRACT: We assessed the feasibility of radical perineal prostatectomy (RPP) in morbidly obese patients with clinically organ confined prostate cancer. Of 1,265 consecutive patients who underwent RPP at our institution from 1992 to 2003 we identified 18 with a body mass index (BMI) of 40 kg/m or greater. Demographic and clinical patient characteristics were obtained from the medical records, which were further reviewed to identify the perioperative incidence of surgical and anesthesia related complications. Median BMI was 41.7 kg/m (range 40.2 to 62.6). Five patients had a BMI of 45.0 kg/m or greater. No intraoperative or anesthesia related complication occurred. Mean operative time +/- SD was 188 +/- 32 minutes and estimated blood loss was 573 +/- 285 ml. None of the 18 patients received blood transfusions. During the immediate postoperative period 4 complications occurred in the form of lower extremity neuropraxia in 2 patients, local skin bleeding in 1 and early sepsis in 1 requiring rehospitalization for intravenous antibiotics. Mean operative time and estimated blood loss were significantly lower when surgery was performed by a highly experienced surgeon compared with experienced surgeons (174 +/- 21 vs 235 +/- 10 minutes and 485 +/- 258 vs 838 +/- 197 ml, p = 0.001 and 0.027, respectively). RPP in morbidly obese patients is feasible and it is associated with acceptable perioperative morbidity. The perineal approach should be considered in morbidly obese patients seeking surgical treatment for clinically localized prostate cancer.
    The Journal of Urology 08/2005; 174(1):131-4. · 3.70 Impact Factor
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    ABSTRACT: Telomerase reverse transcriptase (hTERT) represents an attractive target for cancer immunotherapy because hTERT is reactivated in most human tumors. A clinical trial was initiated in which hTERT mRNA-transfected dendritic cells (DC) were administered to 20 patients with metastatic prostate cancer. Nine of these subjects received DC transfected with mRNA encoding a chimeric lysosome-associated membrane protein-1 (LAMP) hTERT protein, allowing for concomitant induction of hTERT-specific CD8+ and CD4+ T cell responses. Treatment was well tolerated. Intense infiltrates of hTERT-specific T cells were noted at intradermal injection sites after repeated vaccination. In 19 of 20 subjects, expansion of hTERT-specific CD8+ T cells was measured in the peripheral blood of study subjects, with 0.9-1.8% of CD8+ T cells exhibiting Ag specificity. Patients immunized with the chimeric LAMP hTERT vaccine developed significantly higher frequencies of hTERT-specific CD4+ T cells than subjects receiving DC transfected with the unmodified hTERT template. Moreover, CTL-mediated killing of hTERT targets was enhanced in the LAMP hTERT group, suggesting that an improved CD4+ response could augment a CTL response. Vaccination was further associated with a reduction of prostate-specific Ag velocity and molecular clearance of circulating micrometastases. Our findings provide a rationale for further development of hTERT-transfected DC vaccines in the treatment of prostate and other cancers.
    The Journal of Immunology 04/2005; 174(6):3798-807. · 5.52 Impact Factor
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    ABSTRACT: To evaluate the late health-related quality of life (HRQOL) after radical perineal prostatectomy (RPP) and identify the predictors of outcome. We performed a cross-sectional study of 266 consecutive patients who underwent RPP for clinically localized prostate cancer between July 1998 and December 2000. Of the 236 patients successfully contacted, 187 (79.2%) returned a validated patient self-assessment questionnaire, the Expanded Prostate Cancer Index Composite, a mean of 42.1 months (range 29 to 64) months after surgery. The median HRQOL scores were calculated in four disease-specific domains: urinary, bowel, sexual, and hormonal. Preoperative baseline information from a separate group of 144 consecutive RPP candidates from January 2002 to May 2003 was used for comparison. Univariate and multivariate logistic regression analyses were used to identify predictors of more favorable long-term HRQOL outcomes. No statistically significant differences were found in any of the domain-specific summary scores between the study and reference groups, except in the sexual domain (median score 19.2 versus 56.4; P = 0.001). The number of medical comorbidities was a statistically significant predictor of HRQOL summary scores in all domains (P <0.05). In addition, the urinary summary score was statistically significantly associated with income (P = 0.03), sexual summary with the use of erectile aids (P = 0.003), bowel summary with secondary radiotherapy (P = 0.001) and income (P = 0.002), and hormonal summary with androgen ablation (P = 0.004). The results of this study have shown that the long-term HRQOL of RPP patients in the urinary, bowel, and hormonal domains is favorable. HRQOL outcomes depend on a spectrum of factors, including the presence of comorbid disease, socioeconomic status, and secondary cancer treatments. Future studies should seek to address the efficacy of preserving the sexual domain HRQOL in patients undergoing bilateral nerve-sparing RPP.
    Urology 02/2005; 65(1):120-5. · 2.42 Impact Factor
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    ABSTRACT: We provide a comprehensive, longitudinal assessment of health related quality of life (HRQOL) following radical perineal prostatectomy (RPP). We report the results of a prospective cohort study of 109 patients with at least 3 months of followup who underwent RPP between January 2001 and July 2003. A validated patient self-assessment questionnaire, the Expanded Prostate Cancer Index Composite, was administered preoperatively, and 1, 3, 6, 9, 12 and 18 months postoperatively. Mean domain specific HRQOL scores were calculated as well as the proportion of patients achieving an individual baseline by each interval. The Cox proportional hazards model was used to identify predictors of a successful return to baseline of disease specific HRQOL scores. HRQOL scores were lowest 1 month postoperatively and they increased with time. By 6 months a majority of patients had recovered baseline summary scores in urinary (65.1%), bowel (93.6%) and hormonal (91.7%) domains at a median of 5.8 (95% CI 3.6 to 6.2), 1.3 (95% CI 1.1 to 1.5) and 1.3 (95% CI 1.2 to 1.8) months, respectively. One in 4 patients recovered the sexual summary score by 18 months. Significant independent predictors for the recovery of domain summary scores were younger age in urinary (p = 0.001), individual surgeon in bowel (p = 0.022), and older age (p = 0.017) and absent medical comorbidities (p = 0.012) in hormonal domains. A majority of patients undergoing RRP experience an early recovery of individual urinary, bowel and hormonal HRQOL. Future studies should establish the benefit of bilateral nerve sparing RPP on the recovery of sexual domain HRQOL.
    The Journal of Urology 08/2004; 172(1):264-8. · 3.70 Impact Factor