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Featured researches published by Andrew Chung.


Journal of Clinical Oncology | 2004

Pathologic Variables and Recurrence Rates As Related to Obesity and Race in Men With Prostate Cancer Undergoing Radical Prostatectomy

Christopher L. Amling; Robert H Riffenburgh; Leon Sun; Judd W. Moul; Raymond S. Lance; Leo Kusuda; Wade J. Sexton; Douglas W. Soderdahl; Timothy F. Donahue; John P. Foley; Andrew Chung; David G. McLeod

PURPOSE To determine if obesity is associated with higher prostate specific antigen recurrence rates after radical prostatectomy (RP), and to explore racial differences in body mass index (BMI) as a potential explanation for the disparity in outcome between black and white men. PATIENTS AND METHODS A retrospective, multi-institutional pooled analysis of 3,162 men undergoing RP was conducted at nine US military medical centers between 1987 and 2002. Patients were initially categorized as obese (BMI > or = 30 kg/m(2)), overweight (BMI 25 to 30 kg/m(2)), or normal (BMI < or = 25 kg/m(2)). For analysis, normal and overweight groups were combined (BMI < 30 kg/m(2)) and compared with the obese group (BMI > or = 30 kg/m(2)) with regard to biochemical recurrence (prostate-specific antigen > or = 0.2 ng/mL) after RP. RESULTS Of 3,162 patients, 600 (19.0%) were obese and 2,562 (81%) were not obese. BMI was an independent predictor of higher Gleason grade cancer (P <.001) and was associated with a higher risk of biochemical recurrence (P =.027). Blacks had higher BMI (P <.001) and higher recurrence rates (P =.003) than whites. Both BMI (P =.028) and black race (P =.002) predicted higher prostate specific antigen recurrence rates. In multivariate analysis of race, BMI, and pathologic factors, black race (P =.021) remained a significant independent predictor of recurrence. CONCLUSION Obesity is associated with higher grade cancer and higher recurrence rates after RP. Black men have higher recurrence rates and greater BMI than white men. These findings support the hypothesis that obesity is associated with progression of latent to clinically significant prostate cancer (PC) and suggest that BMI may account, in part, for the racial variability in PC risk.


The Journal of Urology | 2004

Early versus delayed hormonal therapy for prostate specific antigen only recurrence of prostate cancer after radical prostatectomy

Judd W. Moul; Hongyu Wu; Leon Sun; David G. McLeod; Christopher L. Amling; Timothy R. Donahue; Leo Kusuda; Wade J. Sexton; Keith J. O'Reilly; Javier Hernandez; Andrew Chung; Douglas W. Soderdahl

PURPOSE Hormonal therapy (HT) is the current mainstay of systemic treatment for prostate specific antigen (PSA) only recurrence (PSAR), however, there is virtually no published literature comparing HT to observation in the clinical setting. The goal of this study was to examine the Department of Defense Center for Prostate Disease Research observational database to compare clinical outcomes in men who experienced PSAR after radical prostatectomy by early versus delayed use of HT and by a risk stratified approach. MATERIALS AND METHODS Of 5,382 men in the database who underwent primary radical prostatectomy (RP), 4,967 patients were treated in the PSA-era between 1988 and December 2002. Of those patients 1,352 men who had PSAR (PSA after surgery greater than 0.2 ng/ml) and had postoperative followup greater than 6 months were used as the study cohort. These patients were further divided into an early HT group in which patients (355) received HT after PSA only recurrence but before clinical metastasis and a late HT group for patients (997) who received no HT before clinical metastasis or by current followup. The primary end point was the development of clinical metastases. Of the 1,352 patients with PSAR clinical metastases developed in 103 (7.6%). Patients were also stratified by surgical Gleason sum, PSA doubling time and timing of recurrence. Univariate and multivariate Cox proportional hazard models were used to evaluate the effect of early and late HT on clinical outcome. RESULTS Early HT was associated with delayed clinical metastasis in patients with a pathological Gleason sum greater than 7 or PSA doubling time of 12 months or less (Hazards ratio = 2.12, p = 0.01). However, in the overall cohort early HT did not impact clinical metastases. Race, age at RP and PSA at diagnosis had no effect on metastasis-free survival (p >0.05). CONCLUSIONS The retrospective observational multicenter database analysis demonstrated that early HT administered for PSAR after prior RP was an independent predictor of delayed clinical metastases only for high-risk cases at the current followup. Further study with longer followup and randomized trials are needed to address this important issue.


Journal of Clinical Oncology | 2003

Temporarily Deferred Therapy (watchful waiting) for Men Younger Than 70 Years and With Low-Risk Localized Prostate Cancer in the Prostate-Specific Antigen Era

Corey A. Carter; Timothy F. Donahue; Leon Sun; Hongyu Wu; David G. McLeod; Christopher L. Amling; Raymond S. Lance; John P. Foley; Wade J. Sexton; Leo Kusuda; Andrew Chung; Douglas W. Soderdahl; Stephen Jackman; Judd W. Moul

Purpose: Watchful waiting (WW) is an acceptable strategy for managing prostate cancer (PC) in older men. Prostate-specific antigen (PSA) testing has resulted in a stage migration, with diagnoses made in younger men. An analysis of the Department of Defense Center for Prostate Disease Research Database was undertaken to document younger men with low- or intermediate-grade PC who initially chose WW. Patients and Methods: We identified men choosing WW who were diagnosed between January 1991 and January 2002, were 70 years or younger, had a Gleason score ≤ 6 with no Gleason pattern 4, had no more than three positive cores on biopsy, and whose clinical stage was ≤ T2 and PSA level was ≤ 20. We analyzed their likelihood of remaining on WW, the factors associated with secondary treatment, and the influence of comorbidities. Results: Three hundred thirteen men were identified. Median follow-up time was 3.8 years. Median age was65.4 years (range, 41 to 70 years). Ninety-eight patients remained on WW; 215 proceeded...


International Journal of Radiation Oncology Biology Physics | 2003

Effect of age on biochemical disease-free outcome in patients with T1-T3 prostate cancer treated with definitive radiotherapy in an equal-access health care system: a radiation oncology report of the Department of Defense Center for Prostate Disease Research.

Peter A.S. Johnstone; Robert H. Riffenburgh; Judd W. Moul; Leon Sun; Hongyu Wu; David G. McLeod; Christopher J. Kane; Douglas Martin; Leo Kusuda; Raymond S. Lance; Robert Douglas; Timothy R. Donahue; Michael G. Beat; John P. Foley; Andrew Chung; Douglas W. Soderdahl; Jason Do; Christopher L. Amling

PURPOSE It has traditionally been a common perception that young age is a negative prognostic factor in prostate cancer (CaP). Furthermore, many urologists believe that younger patients are better suited to surgery rather than radiotherapy (RT) because of this perception. However, the data on the effect of age on outcome in patients with CaP are unclear. The records of the Department of Defense Center for Prostate Disease Research were queried for the biochemical disease-free results of patients after definitive RT and analyzed by age. MATERIALS AND METHODS The records of 1018 patients with T1-T3 CaP treated with definitive RT between 1988 and 2000 were reviewed. The records of patients receiving adjuvant hormonal therapy or adjuvant or salvage RT postoperatively were excluded. Biochemical failure was calculated by the American Society for Therapeutic Radiology and Oncology criteria. The median potential follow-up was 85.3 months as of December 31, 2001. RESULTS Age did not affect biochemical disease-free survival significantly when considered as <60 vs. >/=60 years (p = 0.646), by decade (p = 0.329), or as a continuous variable (correlation coefficient r = 0.017, regression slope = 0.007, with p = 0.588 and R(2) < 0.001). Using multiple regression analysis, age was still not significant (p = 0.408). Other variables analyzed were pretreatment prostate-specific antigen level (p < 0.001), Gleason sum (p = 0.023), stage (p = 0.828), and RT dose (p = 0.033). CONCLUSIONS Age and biochemical disease-free survival after RT for CaP are not related. Age may not be a valid factor in choosing between primary treatment options for CaP.


Urologic Oncology-seminars and Original Investigations | 2003

Factors associated with blood loss during radical prostatectomy for localized prostate cancer in the prostate-specific antigen (PSA)-era: an overview of the department of defense (DOD) Center for Prostate Disease Research (CPDR) national database

Judd W. Moul; Leon Sun; Hongyu Wu; David G. McLeod; Christopher L. Amling; Raymond S. Lance; John P. Foley; Wade J. Sexton; Leo Kusuda; Andrew Chung; Douglas W. Soderdahl; Timothy F. Donahue

Radical Prostatectomy (RP) has been traditionally associated with significant operative blood loss and high risk of transfusion. However, over the last few years, centers of excellence have reported less bleeding and transfusion. To verify and document changes in the epidemiology of bleeding and transfusion of men electing RP, we undertook an analysis of such cases in the Department of Defense (DoD) Center for Prostate Disease Research (CPDR) Multicenter Research Database. Using the Department of Defense Center for Prostate Disease Research (CPDR) Multicenter National Research Database, a query of all RPs performed between January 1, 1985 and December 31, 2000 was conducted revealing 2918 cases with blood-loss data available for analysis from nine hospital sites. These cases were analyzed over time (calendar year) and changes in the characteristics of the patients, disease severity, and surgical results were compared with estimated blood loss (EBL) and transfusion data. Among the 2918 evaluable men, 2399 (82%) underwent a retropubic RP, 97% had clinical T1-2 disease, and 77% had a PSA level > or =10.0 ng/mL. Overall median operation time was 3.8 h, and EBL was 1000 cc. Examining trends over time, there was a dramatic decline in median operative time, EBL, and transfusion rate. In multiple linear regression analysis, operative time, operative approach, surgery year, lymphadenectomy status, and neoadjuvant hormonal therapy were significant predictor of EBL. Blood loss difference between retropubic and perineal RP became insignificant in the latter years. Radical prostatectomy is being performed more commonly on men with earlier stage disease in the PSA-Era. The operation is now performed more rapidly with less blood loss and fewer transfusion requirements. In a broad practice experience represented here, autologous blood donation would appear to be unnecessary for the majority of men and the blood loss advantage traditionally associated with perineal RP is no longer evident.


The Journal of Urology | 2006

Temporarily Deferred Therapy (Watchful Waiting) for Men Younger Than 70 Years and With Low-Risk Localized Prostate Cancer in the Prostate-Specific Antigen Era

Corey A. Carter; Timothy F. Donahue; Leon Sun; Hongyu Wu; David G. McLeod; G. Amling; Raymond S. Lance; John P. Foley; Wade J. Sexton; Leo Kusuda; Andrew Chung; Douglas W. Soderdahl; S. Jackmaan; Judd W. Moul

PURPOSE Watchful waiting (WW) is an acceptable strategy for managing prostate cancer (PC) in older men. Prostate-specific antigen (PSA) testing has resulted in a stage migration, with diagnoses made in younger men. An analysis of the Department of Defense Center for Prostate Disease Research Database was undertaken to document younger men with low- or intermediate-grade PC who initially chose WW. PATIENTS AND METHODS We identified men choosing WW who were diagnosed between January 1991 and January 2002, were 70 years or younger, had a Gleason score < or = 6 with no Gleason pattern 4, had no more than three positive cores on biopsy, and whose clinical stage was < or = T2 and PSA level was < or = 20. We analyzed their likelihood of remaining on WW, the factors associated with secondary treatment, and the influence of comorbidities. RESULTS Three hundred thirteen men were identified. Median follow-up time was 3.8 years. Median age was 65.4 years (range, 41 to 70 years). Ninety-eight patients remained on WW; 215 proceeded to treatment. A total of 57.3% and 73.2% chose treatment within the first 2 and 4 years, respectively. Median PSA doubling time (DT) was 2.5 years for those who underwent therapy; those remaining on WW had a median DT of 25.8 years. The type of secondary treatment was associated with the number of patients comorbidities (P =.012). CONCLUSION Younger patients who choose WW seemed more likely to receive secondary treatment than older patients. PSA DTs often predict the use of secondary treatment. The number of comorbidities a patient has influences the type of secondary therapy chosen. The WW strategy may better be termed temporarily deferred therapy.


The Journal of Urology | 2003

Pretreatment Total Testosterone Level Predicts Pathological Stage in Patients With Localized Prostate Cancer Treated With Radical Prostatectomy

Jason C. Massengill; Leon Sun; Judd W. Moul; Hongyu Wu; David G. McLeod; Christopher L. Amling; Raymond S. Lance; John P. Foley; Wade J. Sexton; Leo Kusuda; Andrew Chung; Douglas W. Soderdahl; Timothy F. Donahue


Surgery | 2002

Epidemiology of radical prostatectomy for localized prostate cancer in the era of prostate-specific antigen: An overview of the Department of Defense Center for Prostate Disease Research national database

Judd W. Moul; Hongyu Wu; Leon Sun; David G. McLeod; Christopher L. Amling; Raymond S. Lance; Leo Kusuda; Timothy R. Donahue; John P. Foley; Andrew Chung; Wade J. Sexton; Douglas W. Soderdahl; Norman M. Rich


The Journal of Urology | 2004

Watchful waiting and factors predictive of secondary treatment of localized prostate cancer.

Hongyan Wu; Leon Sun; Judd W. Moul; Hongyu Wu; David G. McLeod; Christopher L. Amling; Raymond S. Lance; Leo Kusuda; Timothy F. Donahue; John P. Foley; Andrew Chung; Wade J. Sexton; Douglas W. Soderdahl


The Journal of Urology | 2004

1184: How Long can Radical Prostatectomy (RP) Safely be Delayed? CPDR'S Experiences From 3324 Cases

Judd W. Moul; Christopher L. Amling; Yongmei Chen; David G. McLeod; Timothy F. Donahue; Leo Kusuda; Wade J. Sexton; Keith J. O'Reilly; Javier Hernandez; Andrew Chung; Karen Smith

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Leo Kusuda

Naval Medical Center Portsmouth

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Christopher L. Amling

Naval Medical Center San Diego

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David G. McLeod

Uniformed Services University of the Health Sciences

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Judd W. Moul

Walter Reed Army Medical Center

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Wade J. Sexton

University of Texas MD Anderson Cancer Center

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Timothy F. Donahue

Uniformed Services University of the Health Sciences

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John P. Foley

Uniformed Services University of the Health Sciences

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Hongyu Wu

Uniformed Services University of the Health Sciences

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