André Mattar

Dr. André Mattar

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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20 March 2025 in Journal of Clinical Oncology
Verified
Journal Article
Open access
CMChristian Marth
Christian Marth
RMRichard G Moore
Richard G Moore
MBMariusz Bidziński
Mariusz Bidziński
SPSandro Pignata
Sandro Pignata
AAAli Ayhan
Ali Ayhan
EIENGOT-en9/LEAP-001 Investigators
ENGOT-en9/LEAP-001 Investigators
PURPOSE: Lenvatinib plus pembrolizumab (len + pembro) significantly improved progression-free survival (PFS) and overall survival (OS) versus chemotherapy in previously treated advanced or recurrent endometrial cancer (aEC) in the phase III Study 309/KEYNOTE-775. We report results from the phase III, randomized, open-label European Network of Gynaecological Oncological Trial-en9/LEAP-001 study (ClinicalTrials.gov identifier: NCT03884101 ) that evaluated len + pembro versus chemotherapy in first-line aEC. METHODS: Patients with stage III to IV or recurrent, radiographically apparent EC and no previous chemotherapy or disease progression ≥6 months after neo/adjuvant platinum-based chemotherapy were randomly assigned 1:1 to lenvatinib 20 mg once daily plus pembrolizumab 200 mg once every 3 weeks or paclitaxel 175 mg/m 2 plus carboplatin AUC 6 mg/mL/min once every 3 weeks. Primary end points were PFS and OS, evaluated in the mismatch repair-proficient (pMMR) and all-comers populations. Noninferiority was assessed for OS at final analysis (FA) for len + pembro versus chemotherapy (multiplicity-adjusted, one-sided nominal alpha, .0159; null hypothesis–tested hazard ratio [HR], 1.1). RESULTS: Eight hundred forty-two patients were randomly assigned (len + pembro, n = 420 [pMMR population, n = 320]; chemotherapy, n = 422 [pMMR population, n = 322]). At FA (data cutoff, October 2, 2023), median PFS (95% CI) in the pMMR population was 9.6 (8.2 to 11.9) versus 10.2 (8.4 to 10.5) months with len + pembro versus chemotherapy (hazard ratio [HR], 0.99 [95% CI, 0.82 to 1.21]) and among all-comers was 12.5 (10.3 to 15.1) versus 10.2 (8.4 to 10.4) months (HR, 0.91 [95% CI, 0.76 to 1.09]; descriptive analyses). Median OS (95% CI) in the pMMR population was 30.9 (25.4 to 37.7) versus 29.4 (26.2 to 35.4) months with len + pembro versus chemotherapy (HR, 1.02 [95% CI, 0.83 to 1.26]; noninferiority P = .246, not statistically significant per multiplicity control strategy) and among all-comers was 37.7 (32.2 to 43.6) versus 32.1 (27.2 to 35.7) months (HR, 0.93 [95% CI, 0.77 to 1.12]). Grade ≥3 treatment-related adverse events occurred in 331/420 (79%) versus 274/411 (67%) treated patients. CONCLUSION: First-line len + pembro did not meet prespecified statistical criteria for PFS or OS versus chemotherapy in pMMR aEC.

18 September 2013 in BMC Cancer
Verified
Journal Article
Open access
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MMMarcelo Madeira
Marcelo Madeira
André MattarAndré Mattar
André Mattar
ÂLÂngela Flávia Logullo
Ângela Flávia Logullo
FSFernando Augusto Soares
Fernando Augusto Soares
LGLuiz Henrique Gebrim
Luiz Henrique Gebrim
The role of estrogen receptor beta (ER-β) in breast cancer (BC) remains unclear. Some studies have suggested that ER-β may oppose the actions of estrogen receptor alpha (ER-α), and clinical evidence has indicated that the loss of ER-β expression is associated with a poor prognosis and resistance to endocrine therapy. The objective of the present study was to determine the role of ER-β and the ER-α/ER-β ratio in predicting the response to endocrine therapy and whether different regimens have any effect on ER-β expression levels. Ninety postmenopausal patients with primary BC were recruited for a short-term double-blinded randomized prospective controlled study. To determine tumor cell proliferation, we measured the expression of Ki67 in tumor biopsy samples taken before and after 26 days of treatment with anastrozole 1 mg/day (N = 25), tamoxifen 20 mg/day (N = 24) or placebo (N = 29) of 78 participants. The pre- and post-samples were placed in tissue microarray blocks and submitted for immunohistochemical assay. Biomarker statuses (ER-β, ER-α and Ki67) were obtained by comparing each immunohistochemical evaluation of the pre- and post-surgery samples using the semi-quantitative Allred’s method. Statistical analyses were performed using an ANOVA and Spearman’s correlation coefficient tests, with significance at p ≤ 0.05. The frequency of ER-β expression did not change after treatment (p = 0.33). There were no significant changes in Ki67 levels in ER-β-negative cases (p = 0.45), but in the ER-β-positive cases, the anastrozole (p = 0.01) and tamoxifen groups (p = 0.04) presented a significant reduction in post-treatment Ki67 scores. There was a weak but positive correlation between the ER-α and ER-β expression levels. Only patients with an ER-α/ER-β expression ratio between 1 and 1.5 demonstrated significant differences in Ki67 levels after treatment with anastrozole (p = 0.005) and tamoxifen (p = 0.026). Our results provide additional data that indicate that the measurement of ER-β in BC patients may help predict tamoxifen and anastrozole responsiveness in the neoadjuvant setting. These effects of hormonal treatment appear to be dependent on the ratio of ER-α/ER-β expression. Current Controlled Trials ISRCTN89801719


14 September 2023 in The Breast
Verified
Journal Article
Open access
MAMarcelo Antonini
Marcelo Antonini
André MattarAndré Mattar
André Mattar
FRFernanda Grace Bauk Richter
Fernanda Grace Bauk Richter
GPGabriel Duque Pannain
Gabriel Duque Pannain
MTMarina Diogenes Teixeira
Marina Diogenes Teixeira
JRJuliana Monte Real
Juliana Monte Real
We aimed to evaluate the pCR rate in patients receiving NAC for the treatment of breast cancer (BC) in a multicenter cohort in Brazil. Additionally, we aimed to use RWD to assess the impact of pCR on OS and DFS. This was a retrospective, multicenter cohort study that included female patients over 18 years of age who were diagnosed with nonmetastatic breast cancer and received NAC. OS and DFS at five years were estimated by the Kaplan‒Meier method. Additionally, we conducted a multivariate analysis to identify factors that were significantly associated with pCR and OS. From 2011 to 2020, 1891 patients were included in the study, and 421 (22,3%) achieved pCR (ypT0 ypN0). Considering the presence of residual DCIS, pCR was achieved in 467 patients (23,5%). The pCR rate varied between the subtypes: HER-2+ (p = 0,016) and clinical stage IIIA and IIIB (p < 0,001). Among HER-2+ patients, those who received trastuzumab had a significantly higher pCR rate than those who did not receive trastuzumab (p < 0.0001). Similarly, patients with TNBC who received treatment with platinum-based regimens also showed higher pCR rates (p < 0.0001). OS was grouped according to pCR status, and the OS rate was 88,3% in the pCR group and 58.1% in the non-pCR group (p < 0.0001). The five-year DFS was 92.2% in the pCR group and 64.3% in the non-pCR group (p < 0.0001). The pCR rate and its prognostic value varied across BC subtypes. In our study, pCR could be used as a surrogate of favorable clinical outcome, as it was associated with higher OS and DFS rates.

20 March 2025 in The Breast
Verified
Journal Article
Open access
André MattarAndré Mattar
André Mattar
MAMarcelo Antonini
Marcelo Antonini
FCFrancisco Pimentel Cavalcante
Francisco Pimentel Cavalcante
FZFelipe Zerwes
Felipe Zerwes
EMEduardo Camargo Millen
Eduardo Camargo Millen
JRJuliana Monte Real
Juliana Monte Real
Sentinel lymph node biopsy (SLNB) is the gold standard for the axillary evaluation of clinically node-negative early breast cancer. The ACOSOG Z0011 study demonstrated the safety of omitting axillary dissection for limited SLNB disease, with other trials confirming SLNB alone or with axillary radiotherapy (AR) as non-inferior. We followed PRISMA guidelines and registered at PROSPERO. Using Medline, Embase, and Cochrane, we reviewed randomized controlled trials (2010-2024). Outcomes, including 5-, 8-, and 10-year OS, DFS, recurrence rates, and lymphedema, were analyzed with R software and assessed for bias (Cochrane RoB) and evidence quality (GRADE). The focus was ALND vs. SLNB, alone or with AR, in cT1-T3 BC with 1-2 metastatic SLNs. Thirteen articles from seven randomized controlled trials (RCTs) were included, covering 7338 women with a follow-up period of 2.8-10 years. SLNB was associated with a 65 % lower risk of lymphedema than ALND, with no significant differences in the 5-, 8-, or 10-year OS, DFS, or recurrence rates. A meta-analysis comparing micrometastasis and macrometastasis showed no impact on outcomes, indicating that ALND may be unnecessary in either case. Recurrence rates also did not differ between SLNB and ALND, reinforcing SLNB's significantly lower lymphedema risk of SLNB. This systematic review and meta-analysis support SLNB as a safe and effective alternative to ALND in early-stage BC with 1-2 positive SLNs, providing comparable survival and recurrence outcomes, with fewer complications.

1 December 2021 in JCO Global Oncology
Verified
Journal Article
Open access
André MattarAndré Mattar
André Mattar
GFGuilherme R. Fonseca
Guilherme R. Fonseca
MRMurilo B. A. Romão
Murilo B. A. Romão
JSJorge Y. Shida
Jorge Y. Shida
VOVilmar Marques Oliveira
Vilmar Marques Oliveira
LGLuiz Henrique Gebrim
Luiz Henrique Gebrim
PURPOSEWe evaluated the impact of 21-gene test results on treatment decisions for patients with early-stage breast cancer treated under the public health care system in Brazil, Sistema Único de Saú...