Leo Mascarenhas

Prof. Leo Mascarenhas

orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 December 2021 in Journal of Clinical Oncology
Verified
Journal Article
Closed access
PLPatrick Leavey
Patrick Leavey
NLNadia Laack
Nadia Laack
MKMark D. Krailo
Mark D. Krailo
ABAllen Buxton
Allen Buxton
RRR. Lor Randall
R. Lor Randall
LMLeo Mascarenhas
Leo Mascarenhas
PURPOSE: The primary aim of this phase III randomized trial was to test whether the addition of vincristine, topotecan, and cyclophosphamide (VTC) to interval compressed chemotherapy improved survival outcomes for patients with previously untreated nonmetastatic Ewing sarcoma. METHODS: Patients were randomly assigned to receive standard five-drug interval compressed chemotherapy (regimen A) for 17 cycles or experimental therapy with five cycles of VTC within the 17 cycles (regimen B). Patients were stratified by age at diagnosis (< 18 years and ≥18 years) and tumor site (pelvic bone, nonpelvic bone, and extraosseous). Tumor volume at diagnosis was categorized as < 200 mL or ≥ 200 mL. Local control occurred following six cycles. Histologic response was categorized as no viable or any viable tumor. Event-free survival (EFS) and overall survival (OS) were compared between randomized groups with stratified log-rank tests. RESULTS: Of 642 enrolled patients, 309 eligible patients received standard and 320 received experimental therapy. The 5-year EFS and OS were 78% and 87%, respectively. There was no difference in survival outcomes between randomized groups (5-year EFS regimen A v regimen B, 78% v 79%; P = .192; 5-year OS 86% v 88%; P = .159). Age and primary site did not affect the risk of an EFS event. However, age ≥ 18 years was associated with an increased risk of death at 5 years (hazard ratio 1.84; 95% CI, 1.15 to 2.96; P = .009). The 5-year EFS rates for patients with pelvic, nonpelvic bone, and extraosseous primary tumors were 75%, 78%, and 85%, respectively. Tumor volume ≥ 200 mL was significantly associated with lower EFS. CONCLUSION: While VTC added to five-drug interval compressed chemotherapy did not improve survival, these outcomes represent the best survival estimates to date for patients with previously untreated nonmetastatic Ewing sarcoma.

1 November 2019 in Journal of Clinical Oncology
Verified
Journal Article
Closed access
LMLeo Mascarenhas
Leo Mascarenhas
YCYueh-Yun Chi
Yueh-Yun Chi
PHPooja Hingorani
Pooja Hingorani
JAJames R. Anderson
James R. Anderson
ELElizabeth R. Lyden
Elizabeth R. Lyden
DHDouglas S. Hawkins
Douglas S. Hawkins
PURPOSE: The primary aim of this clinical trial was to prioritize bevacizumab or temsirolimus for additional investigation in rhabdomyosarcoma (RMS) when administered in combination with cytotoxic chemotherapy to patients with RMS in first relapse with unfavorable prognosis.PATIENTS AND METHODS: Patients were randomly assigned to receive bevacizumab on day 1 or temsirolimus on days 1, 8, and 15 of each 21-day treatment cycle, together with vinorelbine on days 1 and 8, and cyclophosphamide on day 1 for a maximum of 12 cycles. Local tumor control with surgery and/or radiation therapy was permitted after 6 weeks of treatment. The primary end point was event-free survival (EFS). Radiographic response was assessed at 6 weeks. The study had a phase II selection that was design to detect a 15% difference between the two regimens (α = .2; 1-β = 0.8; two sided test).RESULTS: Eighty-seven of 100 planned patients were enrolled when the trial was closed after the second interim analysis after 46 events occurred in 68 patients with sufficient follow-up. The O’Brien Fleming boundary at this analysis corresponded to a two-sided P value of .058 with an observed two-sided P value of .003 favoring temsirolimus. The 6-month EFS for the bevacizumab arm was 54.6% (95% CI, 39.8% to 69.3%) and 69.1% (95% CI, 55.1% to 83%) for the temsirolimus arm. Objective response rates were 28% (95% CI, 13.7% to 41.3%) and 47% (95% CI, 31.5% to 63.2%) for the bevacizumab and temsirolimus arms, respectively ( P = .12) and, 28% of patients on bevacizumab and 11% on temsirolimus had progressive disease at 6 weeks.CONCLUSION: Patients who received temsirolimus had a superior EFS compared with bevacizumab. Temsirolimus has been selected for additional investigation in newly diagnosed patients with intermediate-risk RMS.

20 October 2010 in Journal of Clinical Oncology
Verified
Journal Article
Closed access
LMLeo Mascarenhas
Leo Mascarenhas
ELElizabeth R. Lyden
Elizabeth R. Lyden
PBPhilip P. Breitfeld
Philip P. Breitfeld
DWDavid O. Walterhouse
David O. Walterhouse
SDSarah S. Donaldson
Sarah S. Donaldson
DHDouglas S. Hawkins
Douglas S. Hawkins
Purpose: To compare response rates for two schedules of irinotecan with vincristine in patients with rhabdomyosarcoma at first relapse or disease progression. Patients and Methods: Patients with first relapse or progression of rhabdomyosarcoma and an unfavorable prognosis were randomly assigned to one of two treatment schedules of irinotecan with vincristine: regimen 1A included irinotecan 20 mg/m2/d intravenously for 5 days at weeks 1, 2, 4, and 5 with vincristine 1.5 mg/m2 administered intravenously on day 1 of weeks 1, 2, 4, and 5; regimen 1B included irinotecan 50 mg/m2/d intravenously for 5 days at weeks 1 and 4 with vincristine as in regimen 1A. Disease response was assessed at week 6. Those with responsive disease continued to receive 44 weeks of multiagent chemotherapy that incorporated the assigned irinotecan-vincristine regimen. Results: Ninety-two eligible patients were randomly assigned (1A, 45; 1B, 47). Response could be assessed in 89 patients (1A, 42; 1B, 47). There were five complete responses and six partial responses on regimen 1A (response rate, 26%; 95% CI, 16% to 42%) and 17 partial responses on regimen 1B (response rate, 37%; 95% CI, 25% to 51%; P = .36). Neutropenia was less common on regimen 1A (P = .04). One-year failure-free and overall survival rates for regimen 1A were 37% (95% CI, 23% to 51%) and 55% (95% CI, 39% to 69%), respectively, and for 1B, they were 38% (95% CI, 25% to 53%) and 60% (95% CI, 44% to 72%). Conclusion: There was no difference in the response rates between the two irinotecan-vincristine schedules. We recommend the shorter, more convenient regimen (1B) for further investigation.

1 February 2015 in Pediatric Clinics of North America
Verified
Journal Article
Closed access
JHJosephine H. HaDuong
Josephine H. HaDuong
AMAndrew A. Martin
Andrew A. Martin
SSStephen X. Skapek
Stephen X. Skapek
LMLeo Mascarenhas
Leo Mascarenhas

17 February 2021 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
CHChristine Heske
Christine Heske
LMLeo Mascarenhas
Leo Mascarenhas
Relapsed rhabdomyosarcoma (RMS) represents a significant therapeutic challenge. Nearly one-third of patients diagnosed with localized RMS and over two-thirds of patients with metastatic RMS will experience disease recurrence following primary treatment, generally within three years. Clinical features at diagnosis, including primary site, tumor invasiveness, size, stage, and histology impact likelihood of relapse and prognosis post-relapse. Aspects of initial treatment, including extent of surgical resection, use of radiotherapy, and chemotherapy regimen, are also associated with post-relapse outcomes, as are features of the relapse itself, including time to relapse and extent of disease involvement. Although there is no standard treatment for patients with relapsed RMS, several general principles, including tissue biopsy confirmation of diagnosis, assessment of post-relapse prognosis, determination of the feasibility of additional local control measures, and discussion of patient goals, should all be part of the approach to care. Patients with features suggestive of a favorable prognosis, which include those with botryoid RMS or stage 1 or group I embryonal RMS (ERMS) who have had no prior treatment with cyclophosphamide, have the highest chance of achieving long-term cure when treated with a multiagent chemotherapy regimen at relapse. Unfortunately, patients who do not meet these criteria represent the majority and have poor outcomes when treated with such regimens. For this group, strong consideration should be given for enrollment on a clinical trial.

18 October 2007 in Cancer
Verified
Journal Article
Open access
PDF file
CMCatherine E. Madigan
Catherine E. Madigan
SASaro H. Armenian
Saro H. Armenian
MMMarcio H. Malogolowkin
Marcio H. Malogolowkin
LMLeo Mascarenhas
Leo Mascarenhas
BACKGROUND.: Extracranial malignant rhabdoid tumor (MRT) is a rare, aggressive, pediatric malignancy with a historically poor outcome. Recent efforts to intensify treatment for MRT have resulted in isolated reports of long‐term survival.METHODS.: The authors conducted a retrospective review of consecutive patients with MRT at Childrens Hospital Los Angeles over the 20 years from 1983 to 2003.RESULTS.: Fourteen children were diagnosed with MRT over the 20‐year study period. The median age at presentation was 22.5 months (range, 0.5–108 months). Five patients had renal primary tumors, and 9 patients had extrarenal tumors. Eleven of 14 patients had stage III or IV disease at diagnosis. Five patients (35.7%) were long‐term survivors. The time to disease progression was rapid (mean, 3.6 months). There were no recurrences or deaths beyond 10 months after diagnosis. All survivors received multimodal therapy, including both chemotherapy and surgery with or without radiation. In addition, 2 patients received high‐dose chemotherapy with hematopoietic stem cell rescue (HSCT) after neoadjuvant chemotherapy and local tumor control. Both of those patients were long‐term survivors. There were no survivors after disease recurrence or progression.CONCLUSIONS.: Patients with localized disease and complete surgical resection were most likely to survive long‐term. Consolidation with HSCT may benefit selected patients with advanced disease stage. International collaboration and further understanding of the biology of this disease is necessary to improve the survival of children with MRT. Cancer 2007. © 2007 American Cancer Society.