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Dive into the research topics where Gregory D. Leonard is active.

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Featured researches published by Gregory D. Leonard.


Journal of Clinical Oncology | 2005

Neoadjuvant Chemotherapy Before Liver Resection for Patients With Unresectable Liver Metastases From Colorectal Carcinoma

Gregory D. Leonard; Baruch Brenner; Nancy E. Kemeny

Colorectal carcinoma is one of the most common cancers in the world, and more than 50% of these patients develop liver metastases. Despite recent advances, systemic chemotherapy for metastatic disease without the use of surgery is considered palliative, as there are rarely long-term survivors. However, patients who are candidates for surgical resection of their liver metastases can have a prolonged survival or possibly a cure. Consensus guidelines on criteria for resection and prognostic scores help facilitate patient selection, yet only 25% of patients with liver metastases are considered to have resectable metastases. Neoadjuvant chemotherapy has been explored in an attempt to render more patients candidates for resection. First reports using neoadjuvant systemic chemotherapy in patients with unresectable disease found that 13% to 16% of patients could be rendered resectable. Efforts to increase response rates using hepatic arterial infusion or biologic agents may increase resection rates. This review summarizes the current data on neoadjuvant chemotherapy, the rationale for this approach, potential complications, and future prospects.


Journal of Clinical Oncology | 2005

Phase I Trial of Systemic Oxaliplatin Combination Chemotherapy With Hepatic Arterial Infusion in Patients With Unresectable Liver Metastases From Colorectal Cancer

Nancy E. Kemeny; William R. Jarnagin; Philip B. Paty; Mithat Gonen; Lawrence H. Schwartz; Meroe Morse; Gregory D. Leonard; Michael I. D'Angelica; Ronald P. DeMatteo; Leslie H. Blumgart; Yuman Fong

PURPOSE To determine the maximum-tolerated dose (MTD) of concurrent systemic oxaliplatin (Oxal) combinations plus hepatic arterial infusion (HAI) in patients with unresectable hepatic metastases from colorectal cancer. PATIENTS AND METHODS Thirty-six patients (89% previously treated) with unresectable liver metastases were treated with concurrent HAI and systemic Oxal plus irinotecan (CPT-11; group A) or Oxal, fluorouracil (FU), and leucovorin (LV; group B). Systemic chemotherapy was administered every 2 weeks concurrent with 2 weeks of HAI floxuridine (FUDR) and dexamethasone (Dex) every 28 days. RESULTS The MTD for patients in group A was Oxal 100 mg/m(2), CPT-11 150 mg/m(2), and FUDR 0.12 mg/kg x 30 mL divided by pump flow rate. The MTD for group B was Oxal 100 mg/m(2), LV 400 mg/m(2), and FU 1,400 mg/m(2) by continuous infusion over 48 hours, with the same FUDR dose as in group A. Grade 3 or 4 toxicities in groups A and B included diarrhea (24% and 20%), neutropenia (10% and 7%), neurotoxicity (24% and 20%), and bilirubin more than 3 mg/mL (5% and 7%, respectively). The complete and partial response rate totaled 90% for group A and 87% for group B. Median survival time was 36 and 22 months for groups A and B, respectively. Seven patients in group A were ultimately able to undergo liver resection. CONCLUSION Combination therapy with HAI FUDR and Dex plus systemic Oxal combinations may be safely administered to patients with colorectal cancer. The high response rate (88%) and the possibility of conversion to resectability, despite disease progression on prior systemic regimens, suggest that these combinations should be evaluated in larger studies as first- or second-line therapy in patients with hepatic metastases from colorectal cancer.


BMC Cancer | 2005

Survey of oxaliplatin-associated neurotoxicity using an interview-based questionnaire in patients with metastatic colorectal cancer

Gregory D. Leonard; Maurice A. Wright; Mary G. Quinn; Suzanne Fioravanti; Nancy Harold; Barbara Schuler; Rebecca R. Thomas; Jean L. Grem

BackgroundNew chemotherapy regimens for patients with colorectal cancer have improved survival, but at the cost of clinical toxicity. Oxaliplatin, an agent used in first-line therapy for metastatic colorectal cancer, causes acute and chronic neurotoxicity. This study was performed to carefully assess the incidence, type and duration of oxaliplatin neurotoxicity.MethodsA detailed questionnaire was completed after each chemotherapy cycle for patients with metastatic colorectal cancer enrolled in a phase I trial of oxaliplatin and capecitabine. An oxaliplatin specific neurotoxicity scale was used to grade toxicity.ResultsEighty-six adult patients with colorectal cancer were evaluated. Acute neuropathy symptoms included voice changes, visual alterations, pharyngo-laryngeal dysesthesia (lack of awareness of breathing); peri-oral or oral numbness, pain and symptoms due to muscle contraction (spasm, cramps, tremors). When the worst neurotoxicity per patient was considered, grade 1/2/3/4 dysesthesias and paresthesias were seen in 71/12/5/0 and 66/20/7/1 percent of patients. By cycles 3, 6, 9, and 12, oxaliplatin dose reduction or discontinuation was needed in 2.7%, 20%, 37.5% and 62.5% of patients.ConclusionOxaliplatin-associated acute neuropathy causes a variety of distressing, but transient, symptoms due to peripheral sensory and motor nerve hyperexcitability. Chronic neuropathy may be debilitating and often necessitates dose reductions or discontinuation of oxaliplatin. Patients should be warned of the possible spectrum of symptoms and re-assured about the transient nature of acute neurotoxicity. Ongoing studies are addressing the treatment and prophylaxis of oxaliplatin neurotoxicity.


Breast Journal | 2004

CA 125 Elevation in Breast Cancer: A Case Report and Review of the Literature

Gregory D. Leonard; Jennifer A. Low; Arlene Berman; Sandra M. Swain

Abstract:   A 69‐year‐old postmenopausal woman with newly diagnosed inflammatory breast cancer was evaluated for a pelvic mass found incidentally during staging computed tomography (CT) scans. Her serum cancer antigen (CA) 125 was greater than 900 U/ml, but laparoscopic examination of the ovaries was normal. Her breast cancer was deemed metastatic by virtue of a supraclavicular lymph node, but she had no visceral or bone metastasis. She was begun on primary chemotherapy and her CA 125 normalized. CA 125 is a tumor‐associated antigen that is most commonly seen in advanced ovarian cancer. It is predominantly derived from coelomic epithelium, which explains elevations in benign conditions or other malignancies. The significance of CA 125 elevations in breast cancer is uncertain. Although CA 125 production has been demonstrated in the normal breast, it has been reported most often as a marker of pleural involvement with metastatic breast cancer. Further information on CA 125 in breast cancer is required to delineate its role in the management of this disease. 


Journal of Clinical Oncology | 2004

Liver resection after hepatic arterial infusion (HAI) plus systemic oxaliplatin (Oxal) combinations in pretreated patients with extensive unresectable colorectal liver metastases

Gregory D. Leonard; Y. Fong; W. Jarnagin; R. Harris; Larry Schwartz; Michael I. D'Angelica; Philip B. Paty; Ronald P. DeMatteo; Leslie H. Blumgart; Nancy E. Kemeny

3542 Background: Metastatic colorectal cancer has a 5-year survival < 5% but increases to 30% in patients (pts) who undergo complete resection. Neoadjuvant systemic (SYS) chemotherapy may increase the proportion of patients suitable for resection, but this is unlikely to occur after first line chemotherapy failure, given the 10 - 15% response rates of second line SYS Oxal (Rothenberg et al, J Clin Oncol 2003:21;2059, Tournigand et al, Proc Am Soc Clin Oncol 2001;20:abstr 494). HAI plus SYS Oxal may be more effective in this regard, especially in previously treated patients. METHODS Forty-four patients with liver only metastatic colorectal cancer were deemed unresectable by experienced hepatobiliary surgeons. They were treated on either of two phase I trials consisting of HAI (floxuridine and dexamethasone) plus either SYS Oxal with irinotecan (CPT-11) or SYS Oxal with fluorouracil and leucovorin. Responding pts proceeded to surgery if deemed resectable. RESULTS The overall response rate using HAI plus SYS Oxal was 82% in the 44 unresectable patients despite 70% of pts having progressed on prior SYS CPT-11. Sixteen pts (36%) had minimal residual disease post HAI plus SYS Oxal, 9 pts (20%) have already had complete gross resection of liver metastases while the other 7 are being considered for resection. To illustrate the extent of disease in the 44 pts in this study, the characteristics of these pts are compared with the largest study in the literature that used SYS neoadjuvant chemotherapy alone in mostly chemotherapy naïve pts (Table 1). CONCLUSIONS HAI plus SYS Oxal combinations achieved a high response rate which allowed resection in at least 20% (to potentially 36%) of pts, who have already progressed on the latest generation of SYS chemotherapy and who have extensive liver metastases. [Figure: see text] No significant financial relationships to disclose.


Clinical Cancer Research | 2005

A Phase I Pharmacologic and Pharmacogenetic Trial of Sequential 24-Hour Infusion of Irinotecan Followed by Leucovorin and a 48-Hour Infusion of Fluorouracil in Adult Patients with Solid Tumors

Maurice A. Wright; Geraldine Morrison; Pengxin Lin; Gregory D. Leonard; Dat Nguyen; Xaiodu Guo; Eva Szabo; Jon L. Hopkins; Jorge P. Leguizamo; Nancy Harold; Suzanne Fioravanti; Barbara Schuler; Brian P. Monahan; M. Wasif Saif; Mary G. Quinn; Janet Pang; Jean L. Grem

Purpose: In preclinical studies, sequential exposure to irinotecan (CPT-11) then fluorouracil (5-FU) is superior to concurrent exposure or the reverse sequence; a 24-hour infusion of CPT-11 may be better tolerated than shorter infusions. Experimental Design: CPT-11 was first given at four levels (70-140 mg/m2/24 hours), followed by leucovorin 500 mg/m2/0.5 hours and 5-FU 2,000 mg/m2/48 hours on days 1 and 15 of a 4-week cycle. 5-FU was then increased in three cohorts up to 3,900 mg/m2/48 hours. Results: Two patients had dose-limiting toxicity during cycle 1 at 140/3,900 of CPT-11/5-FU (2-week delay for neutrophil recovery; grade 3 nausea despite antiemetics); one of six patients at 140/3,120 had dose-limiting toxicity (grade 3 diarrhea, grade 4 neutropenia). Four of 22 patients with colorectal cancer had partial responses, two of which had prior bolus CPT-11/5-FU. The mean 5-FU plasma concentration was 5.1 μmol/L at 3,900 mg/m2/48 hours. The end of infusion CPT-11 plasma concentration averaged 519 nmol/L at 140 mg/m2/24 hours. Patients with UDP-glucuronosyltransferase (UGT1A1; TA)6/6 promoter genotype had a lower ratio of free to glucuronide form of SN-38 than in patients with ≥1 (TA)7 allele. Thymidylate synthase genotypes for the 28-base promoter repeat were 2/2 (13%), 2/3 (74%), 3/3 (13%); all four responders had a 2/3 genotype. Conclusions: Doses (mg/m2) of CPT-11 140/24 hours, leucovorin 500/0.5 hours and 5-FU 3,120/48 hours were well tolerated.


Lancet Oncology | 2003

Extraocular muscle palsy from metastatic prostate cancer

Gregory D. Leonard; Minocher Battiwalla; John B Stockle; Robert A Harris; Brian P. Monahan; Jean L. Grem

THE LANCET Oncology Vol 4 June 2003 http://oncology.thelancet.com 358 68 Paz MF, Fraga MF, Avila S, et al. A systematic profile of DNA methylation in human cancer cell lines. Cancer Res 2003; 63: 1114–21. 69 Wijermans PW, Krulder JW, Huijgens PC, et al. Continuous infusion of low-dose 5-Aza-2’-deoxycytidine in elderly patients with high-risk myelodysplastic syndrome. Leukemia 1997; 11: 1–5. 70 Schwartsmann G, Fernandes MS, Schaan MD, et al. Decitabine (5-Aza-2’-deoxycytidine; DAC) plus daunorubicin as a first line treatment in patients with acute myeloid leukemia: preliminary observations. Leukemia 1997; 11 (suppl): S28–31. 71 Wijermans P, Lubbert M, Verhoef G, et al. Low-dose 5-aza-2’deoxycytidine, a DNA hypomethylating agent, for the treatment of high-risk myelodysplastic syndrome: a multicenter phase II study in elderly patients. J Clin Oncol 2000; 18: 956–62. 72 Cameron EE, Bachman KE, Myohanen S, et al. Synergy of demethylation and histone deacetylase inhibition in the reexpression of genes silenced in cancer. Nat Genet 1999; 21: 103–07. 73 Ballestar E, Esteller M. The impact of chromatin in human cancer: linking DNA methylation to gene silencing. Carcinogenesis 2002; 23: 1103–09. 74 Daskalakis M, Nguyen TT, Nguyen C, et al. Demethylation of a hypermethylated P15/INK4B gene in patients with myelodysplastic syndrome by 5-Aza-2’-deoxycytidine (decitabine) treatment. Blood 2002; 100: 2957–64. 75 Lo Coco F, Zelent A, Kimchi A, et al. Progress in differentiation induction as a treatment for acute promyelocytic leukemia and beyond. Cancer Res 2002; 62: 5618–21. 76 Soengas MS, Capodieci P, Polsky D, et al. Inactivation of the apoptosis effector Apaf-1 in melanoma. Nature 2001; 409: 207–11. Review DNA methylation


Cancer | 2018

Multicenter, randomized, double-blind phase 2 trial of FOLFIRI with regorafenib or placebo as second-line therapy for metastatic colorectal cancer: Folfiri ± Regorafenib as Second-Line Therapy

Hanna K. Sanoff; Richard M. Goldberg; Anastasia Ivanova; Seamus O'Reilly; Samer S. Kasbari; Richard D. Kim; Ray McDermott; Dominic T. Moore; William C. Zamboni; William Grogan; Allen Lee Cohn; Tanios Bekaii-Saab; Gregory D. Leonard; Theresa Ryan; Olugbenga Olowokure; Nishan H. Fernando; John McCaffrey; Bassel F. El-Rayes; Anne M. Horgan; Gary Bradley Sherrill; George Yacoub; Bert H. O'Neil

Regorafenib, a multikinase inhibitor that inhibits angiogenesis, growth, and proliferation, prolongs survival as monotherapy in patients with refractory colorectal cancer. This international, double‐blind, placebo‐controlled, multicenter trial assessed the efficacy of regorafenib with folinic acid, fluorouracil, and irinotecan (FOLFIRI) as a second‐line treatment for metastatic colorectal cancer.


Oncologist | 2003

The Role of ABC Transporters in Clinical Practice

Gregory D. Leonard; Tito Fojo; Susan E. Bates


Journal of the National Cancer Institute | 2004

Ductal Carcinoma In Situ, Complexities and Challenges

Gregory D. Leonard; Sandra M. Swain

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Nancy E. Kemeny

Memorial Sloan Kettering Cancer Center

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Jean L. Grem

National Institutes of Health

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Derek G. Power

Cork University Hospital

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Elaine S. Jaffe

National Institutes of Health

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Philip B. Paty

Memorial Sloan Kettering Cancer Center

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Sandra M. Swain

Georgetown University Medical Center

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Upendra P. Hegde

University of Connecticut Health Center

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Wyndham H. Wilson

National Institutes of Health

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