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Dive into the research topics where Denis H. Y. Leung is active.

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Featured researches published by Denis H. Y. Leung.


Annals of Surgery | 2000

Two Hundred Gastrointestinal Stromal Tumors: Recurrence Patterns and Prognostic Factors for Survival

Ronald P. DeMatteo; Jonathan J. Lewis; Denis H. Y. Leung; Satvinder S. Mudan; James M. Woodruff; Murray F. Brennan

OBJECTIVE To analyze the outcome of 200 patients with gastrointestinal stromal tumor (GIST) who were treated at a single institution and followed up prospectively. SUMMARY BACKGROUND DATA A GIST is a visceral sarcoma that arises from the gastrointestinal tract. Surgical resection is the mainstay of treatment because adjuvant therapy is unproven. METHODS Two hundred patients with malignant GIST were admitted and treated at Memorial Hospital during the past 16 years. Patient, tumor, and treatment variables were analyzed to identify patterns of tumor recurrence and factors that predict survival. RESULTS Of the 200 patients, 46% had primary disease without metastasis, 47% had metastasis, and 7% had isolated local recurrence. In patients with primary disease who underwent complete resection of gross disease (n = 80), the 5-year actuarial survival rate was 54%, and survival was predicted by tumor size but not microscopic margins of resection. Recurrence of disease after resection was predominantly intraabdominal and involved the original tumor site, peritoneum, and liver. CONCLUSIONS GISTs are uncommon sarcomas. Tumor size predicts disease-specific survival in patients with primary disease who undergo complete gross resection. Tumor recurrence tends to be intraabdominal. Investigational protocols are indicated to reduce the rate of recurrence after resection and to improve the outcome for patients with GIST.


Journal of Clinical Oncology | 1996

Analysis of prognostic factors in 1,041 patients with localized soft tissue sarcomas of the extremities

Peter W.T. Pisters; Denis H. Y. Leung; James M. Woodruff; Weiji Shi; Murray F. Brennan

PURPOSE To identify specific independent adverse clinicopathologic factors for event-free survival in a cohort of consecutively treated patients with extremity soft tissue sarcomas. PATIENTS AND METHODS Prospectively collected data from a population of 1,041 adult patients with localized (American Joint Committee on Cancer [AJCC] stage IA to IIIB) extremity soft tissue sarcomas were analyzed. Patients were treated at a single institution between 1982 and 1994. Patient, tumor, and pathologic factors were analyzed by univariate and multivariate techniques to identify independent prognostic factors for the end points of local recurrence, distant recurrence, disease-specific survival, and post-metastasis survival. RESULTS The 5-year survival rate for this cohort of patients was 76%, with a median follow-up time of 3.95 years. Significant independent adverse prognostic factors for local recurrence were age greater than 50 years, recurrent disease at presentation, microscopically positive surgical margins, and the histologic subtypes fibrosarcoma and malignant peripheral-nerve tumor. For distant recurrence, intermediate tumor size, high histologic grade, deep location, recurrent disease at presentation, leiomyosarcoma, and nonliposarcoma histology were independent adverse prognostic factors. For disease-specific survival, large tumor size, high grade, deep location, recurrent disease at presentation, the histologic subtypes leiomyosarcoma and malignant peripheral-nerve tumor, microscopically positive surgical margins, and lower extremity site were adverse factors. For post-metastasis survival, only large tumor size ( > 10 cm) was an adverse prognostic factor. CONCLUSION The independent adverse prognostic factors for distant recurrence and disease specific survival differ from those identified for subsequent local recurrence. Patients with microscopically positive surgical margins or patients who present with locally recurrent disease are at increased risk for subsequent local recurrence and tumor-related mortality. Specific histopathologic subtypes are associated with increased risks for local failure and tumor-related mortality.


Journal of Clinical Oncology | 1996

Long-term results of a prospective randomized trial of adjuvant brachytherapy in soft tissue sarcoma.

Peter W.T. Pisters; Louis B. Harrison; Denis H. Y. Leung; James M. Woodruff; Ephraim S. Casper; Murray F. Brennan

PURPOSE This trial was performed to evaluate the impact of adjuvant brachytherapy on local and systemic recurrence rates in patients with soft tissue sarcoma. PATIENTS AND METHODS In a single-institution prospective randomized trial, 164 patients were randomized intraoperatively to receive either adjuvant brachytherapy (BRT) or no further therapy (no BRT) after complete resection of soft tissue sarcomas of the extremity or superficial trunk. The adjuvant radiation was administered by iridium-192 implant, which delivered 42 to 45 Gy over 4 to 6 days. The two study groups had comparable distributions of patient and tumor factors, including age, sex, tumor site, tumor size, and histologic type and grade. RESULTS With a median follow-up time of 76 months, the 5-year actuarial local control rates were 82% and 69% in the BRT and no BRT groups (P = .04), respectively. Patients with high-grade lesions had local control rates of 89% (BRT) and 66% (no BRT) (P = .0025). BRT had no impact on local control in patients with low-grade lesions (P = .49). The 5-year freedom-from-distant-recurrence rates were 83% and 76% in the BRT and no BRT groups (P = .60), respectively. Analysis by histologic grade did not demonstrate an impact of BRT on the development of distant metastasis, despite the improvement in local control noted in patients with high-grade lesions. The 5-year disease-specific survival rates for the BRT and no BRT groups were 84% and 81% (P = .65), respectively, with no impact of BRT regardless of tumor grade. CONCLUSION Adjuvant brachytherapy improves local control after complete resection of soft tissue sarcomas. This improvement in local control is limited to patients with high-grade histopathology. The reduction in local recurrence in patients with high-grade lesions is not associated with a significant reduction in distant metastasis or improvement in disease-specific survival.


Annals of Surgery | 1998

Retroperitoneal soft-tissue sarcoma : analysis of 500 patients treated and followed at a single institution

Jonathan J. Lewis; Denis H. Y. Leung; James M. Woodruff; Murray F. Brennan

OBJECTIVE To analyze treatment and survival of a large cohort of patients with retroperitoneal soft-tissue sarcomas (STS) treated and prospectively followed at a single institution. SUMMARY BACKGROUND DATA Retroperitoneal STS are relatively uncommon and constitute a difficult management problem. Although surgical resection is often difficult or impossible, current chemotherapy is not effective and radiation is limited by toxicity to adjacent structures. Thus, complete surgical resection remains the most effective modality for selected primary and recurrent disease. METHODS Five hundred patients with retroperitoneal STS were admitted and treated between July 1, 1982, and September 30, 1997, and prospectively followed. Patient, tumor, and treatment variables were analyzed for disease-specific and disease-free survival. Survival was determined with the Kaplan-Meier method. Statistical significance was evaluated using the logrank test for univariate influence and Cox model stepwise regression for multivariate influence. RESULTS Two hundred seventy-eight patients (56%) had primary disease and 222 (44%) recurrent disease. Median follow-up was 28 months (range 1 to 172 months), 40 months for survivors. Median survival was 72 months for patients with primary disease, 28 months for those with local recurrence, and 10 months for those with metastasis. For patients with primary or locally recurrent tumors, unresectable disease, incomplete resection, and high-grade tumors significantly reduced survival time. CONCLUSIONS In this study of patients with retroperitoneal STS, stage at presentation, high histologic grade, unresectable primary tumor, and positive gross margin are strongly associated with the tumor mortality rate. Patients approached with curative intent should undergo aggressive attempts at complete surgical resection. Incomplete resection should be undertaken only for symptom relief.


Journal of Clinical Oncology | 2002

Postoperative Nomogram for 12-Year Sarcoma-Specific Death

Michael W. Kattan; Denis H. Y. Leung; Murray F. Brennan

PURPOSE Few published studies have analyzed risk factors for sarcoma-specific death. We developed and internally validated a nomogram that combines the factors to predict the probability of 12-year sarcoma-specific death using a database of 2,136 prospectively followed adult patients treated at a single institution. PATIENTS AND METHODS Nomogram predictor variables included age at diagnosis, tumor size (< or = 5, 5 to 10, or > 10 cm), histologic grade (high or low), histologic subtype (fibrosarcoma, leiomyosarcoma, liposarcoma, malignant fibrous histiocytoma, malignant peripheral nerve tumor, synovial, or other), depth (superficial or deep), and site (upper extremity, lower extremity, visceral, thoracic or trunk, retrointraabdominal, or head or neck). Death from sarcoma or treatment complication was the predicted end point. Three prediction methods were compared, Kaplan-Meier analysis of all possible subsets, recursive partitioning, and Cox proportional hazards regression analysis. The concordance index was used as an accuracy measure with bootstrapping to correct for optimistic bias. RESULTS Sarcoma-specific death at 12 years was 36% (95% confidence interval, 33% to 39%). The bootstrap-corrected concordance indices were as follows: Kaplan-Meier, 0.69; recursive partitioning, 0.74; and Cox regression, 0.77. A nomogram was drawn on the basis of the Cox regression model. This nomogram was internally validated using bootstrapping and shown to have excellent calibration. CONCLUSION A nomogram has been developed to predict 12-year sarcoma-specific death. This tool may be useful for patient counseling, follow-up scheduling, and clinical trial eligibility determination.


Annals of Surgery | 2002

Analysis of the prognostic significance of microscopic margins in 2,084 localized primary adult soft tissue sarcomas.

Alexander Stojadinovic; Denis H. Y. Leung; Axel Hoos; David P. Jaques; Jonathan J. Lewis; Murray F. Brennan

ObjectiveTo define the significance of positive microscopic resection margins in a large cohort treated for soft tissue sarcoma. MethodsThe authors analyzed 2,084 patients with localized primary soft tissue sarcoma (all anatomic sites) treated from 1982 to 2000. Clinicopathologic variables studied included tumor site, size, depth, histologic type, grade, and resection margin status. Treatment other than resection was not analyzed. Study endpoints included local and distant recurrence-free and disease-specific survival rates, estimated by the Kaplan-Meier method. Univariate and multivariate analyses were performed using the log-rank test and the Cox proportional hazards model. ResultsMedian follow-up was 50 months. After primary resection, 1,624 (78%) patients had negative and 460 (22%) had positive resection margins. Having positive margins nearly doubled the risk of local recurrence and increased the risk of distant recurrence and disease-related death. Seventy-two percent of patients with positive margins had no recurrence. Resection margin did not predict local control for retroperitoneal sarcomas or fibrosarcomas. Resection margin remained significantly associated with distant recurrence-free survival and disease-specific survival across all subsets after adjusting for other prognostic variables. The overall 5-year disease-specific survival rates for negative and positive margins were 83% and 75%. ConclusionsPositive microscopic resection margins significantly decrease the local recurrence-free survival rate for other-than-primary fibrosarcoma and retroperitoneal sarcomas, and independently predict distant recurrence-free survival rates and disease-specific survival rates for all patient subsets. Adjuvant therapy should be considered in the management of soft tissue sarcoma to increase local control. Because 72% of positive margins did not equate with inevitable local recurrence, considerable clinical judgment is required in considering additional treatment. Microscopic resection margins should be considered for inclusion in staging systems and treatment algorithms that address local recurrence.


American Journal of Pathology | 2001

Validation of Tissue Microarrays for Immunohistochemical Profiling of Cancer Specimens Using the Example of Human Fibroblastic Tumors

Axel Hoos; Marshall J. Urist; Alexander Stojadinovic; Stephen Mastorides; Maria E. Dudas; Denis H. Y. Leung; David Kuo; Murray F. Brennan; Jonathan J. Lewis; Carlos Cordon-Cardo

Tissue microarrays allow high-throughput molecular profiling of cancer specimens by immunohistochemistry. Phenotype information of sections from arrayed biopsies on a multitissue block needs to be representative of full sections, as protein expression varies throughout the entire tumor specimen. To validate the use of tissue microarrays for immunophenotyping, we studied a group of 59 fibroblastic tumors with variable protein expression patterns by immunohistochemistry for Ki-67, p53, and the retinoblastoma protein (pRB). Data on full tissue sections were compared to the results of one, two, and three 0.6-mm core biopsies per tumor on a tissue array. Ki-67 and p53 staining was read as two categories (positive or negative). Concordance for this staining between tissue arrays with triplicate cores per tumor and full sections were 96 and 98%, respectively. For pRB staining was read as three categories (high, moderate, or negative), where concordance was 91%. The use of three cores per tumor resulted in lower numbers of lost cases and lower nonconcordance with standard full sections as compared to one or two cores per tumor. Correlations between phenotypes and clinical outcome were not significantly different between full section and array-based analysis. Triplicate 0.6-mm core biopsies sampled on tissue arrays provide a reliable system for high-throughput expression profiling by immunohistochemistry when compared to standard full sections. Triplicate cores offer a higher rate of assessable cases and a lower rate of nonconcordant readings than one or two cores. Concordance of triplicate cores is high (96 to 98%) for two category distinction and decreases with the complexity of the phenotypes being analyzed (91%).


Annals of Surgery | 1999

Pulmonary Metastases from Soft Tissue Sarcoma: Analysis of Patterns of Disease and Postmetastasis Survival

Kevin G. Billingsley; Michael Burt; Ellen Jara; Robert J. Ginsberg; James M. Woodruff; Denis H. Y. Leung; Murray F. Brennan

OBJECTIVE To report the patterns of disease and postmetastasis survival for patients with pulmonary metastases from soft tissue sarcoma in a large group of patients treated at a single institution. Clinical factors that influence postmetastasis survival are analyzed. SUMMARY BACKGROUND DATA For patients with soft tissue sarcoma, the lungs are the most common site of metastatic disease. Although pulmonary metastases most commonly arise from primary tumors in the extremities, they may arise from almost any primary site or histology. To date, resection of disease has been the only effective therapy for metastatic sarcoma. METHODS From July 1982 to February 1997, 3149 adult patients with soft tissue sarcoma were admitted and treated at Memorial Sloan-Kettering Cancer Center. During this interval, 719 patients either developed or presented with lung metastases. Patients were treated with resection of metastatic disease whenever possible. Disease-specific survival was the endpoint of the study. Time to death was modeled using the method of Kaplan and Meier. The association of factors to time-to-event endpoints was analyzed using the log-rank test for univariate analysis and the Cox proportional hazards model for multivariate analysis. RESULTS The overall median survival from diagnosis of pulmonary metastasis for all patients was 15 months. The 3-year actuarial survival rate was 25%. The ability to resect all metastatic disease completely was the most important prognostic factor for survival. Patients treated with complete resection had a median survival of 33 months and a 3-year actuarial survival rate of 46%. For patients treated with nonoperative therapy, the median survival was 11 months. A disease-free interval of more than 12 months before the development of metastases was also a favorable prognostic factor. Unfavorable factors included the histologic variants of liposarcoma and malignant peripheral nerve tumors and patient age older than 50 years at the time of treatment of metastasis. CONCLUSIONS Resection of metastatic disease is the single most important factor that determines outcome in these patients. Long-term survival is possible in selected patients, particularly when recurrent pulmonary disease is resected. Surgical excision should remain the treatment of choice for metastases of soft tissue sarcoma to the lung.


Annals of Surgery | 1997

A prospective, randomized trial of early enteral feeding after resection of upper gastrointestinal malignancy

Martin J. Heslin; Lianne Latkany; Denis H. Y. Leung; Ari D. Brooks; Steven N. Hochwald; Peter W.T. Pisters; Moshe Shike; Murray F. Brennan

OBJECTIVE The purpose of the study was to determine whether early postoperative enteral feeding with an immune-enhancing formula (IEF) decreases morbidity, mortality, and length of hospital stay in patients with upper gastrointestinal (GI) cancer. SUMMARY BACKGROUND DATA Early enteral feeding with an IEF has been associated with improved outcome in trauma and critical care patients. Evaluable data documenting reduced complications after major upper GI surgery for malignancy with early enteral feeding are limited. METHODS Between March 1994 and August 1996, 195 patients with a preoperative diagnosis of esophageal (n = 23), gastric (n = 75), peripancreatic (n = 86), or bile duct (n = 11) cancer underwent resection and were randomized to IEF via jejunostomy tube or control (CNTL). Tube feedings were supplemented with arginine, RNA, and omega-3 fatty acids, begun on postoperative 1, and advanced to a goal of 25 kcal/kg per day. The CNTL involved intravenous crystalloid solutions. Statistical analysis was by t test, chi square, or logistic regression. RESULTS Patient demographics, nutritional status, and operative factors were similar between the groups. Caloric intake was 61% and 22% of goal for the IEF and CNTL groups, respectively. The IEF group received significantly more protein, carbohydrate, lipids and immune-enhancing nutrients than did the CNTL group. There were no significant differences in the number of minor, major, or infectious wound complications between the groups. There was one bowel necrosis associated with IEF requiring reoperation. Hospital mortality was 2.5% and median length of hospital stay was 11 days, which was not different between the groups. CONCLUSION Early enteral feeding with an IEF was not beneficial and should not be used in a routine fashion after surgery for upper GI malignancies.


Journal of Clinical Oncology | 1997

Prognostic factors associated with long-term survival for retroperitoneal sarcoma: implications for management.

Martin J. Heslin; Jonathan J. Lewis; Evan Nadler; Elliot Newman; James M. Woodruff; Ephraim S. Casper; Denis H. Y. Leung; Murray F. Brennan

PURPOSE Retroperitoneal soft tissue sarcomas are rare tumors. Studies characterizing long-term follow-up and patterns of recurrence are limited. The purpose of this analysis is to identify patterns of recurrence and prognostic factors associated with long-term survival after resection of retroperitoneal soft tissue sarcomas. METHODS Between July 1, 1982, and June 30, 1990, 198 adult patients were identified from our prospective soft tissue sarcoma database carrying the diagnosis of retroperitoneal soft tissue sarcoma who were eligible for > or = 5 years of follow-up. Of these, 48 patients (25%) were documented to be alive > or = 5 years from the time of operation. Statistical analysis was by log-rank or Wilcoxon test for univariate analysis. Multivariate analysis was by the Cox model. RESULTS The recurrence rate during the follow-up period was approximately 5% per year from the time of initial operation. Of the patients who were disease-free for > or = 5 years from initial surgery, 40% recurred by 10 years. Radiation therapy was the only factor significant (P = .02) for a reduction in the risk of local recurrence. Age < or = 50 years and high-grade tumors were significant factors (P = .003 and .009, respectively) for an increased risk of distant metastasis. Incomplete gross resection was the only factor significant for an increased risk of tumor mortality (P = .003). CONCLUSION Complete surgical resection at the time of primary presentation is likely to afford the best chance for long-term survival. With long-term follow-up, it is clear that recurrence will continue to occur, and a 5-year disease-free interval is not a cure. Patients with an incomplete initial resection, age less than 50 years, and high-grade tumors are candidates for investigational adjuvant therapy.

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Murray F. Brennan

Memorial Sloan Kettering Cancer Center

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Jonathan J. Lewis

Memorial Sloan Kettering Cancer Center

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James M. Woodruff

Memorial Sloan Kettering Cancer Center

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You-Gan Wang

Queensland University of Technology

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Jing Qin

Memorial Sloan Kettering Cancer Center

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Cristina R. Antonescu

Memorial Sloan Kettering Cancer Center

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Alexander Stojadinovic

Uniformed Services University of the Health Sciences

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Hao Zhang

Memorial Sloan Kettering Cancer Center

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Robert J. Downey

Memorial Sloan Kettering Cancer Center

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