OSMAR KENJI YAGI

(Fonte: Lattes)
Índice h a partir de 2011
10
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Faculdade de Medicina - Médico

Resultados de Busca

Agora exibindo 1 - 4 de 4
  • article 37 Citação(ões) na Scopus
    Surgical treatment of gastric cancer: a 10-year experience in a high-volume university hospital
    (2018) RAMOS, Marcus Fernando Kodama Pertille; PEREIRA, Marina Alessandra; YAGI, Osmar Kenji; DIAS, Andre Roncon; CHARRUF, Amir Zeide; OLIVEIRA, Rodrigo Jose de; ZAIDAN, Evelise Pelegrinelli; ZILBERSTEIN, Bruno; RIBEIRO-JÚNIOR, Ulysses; CECCONELLO, Ivan
    OBJECTIVES: Surgery remains the cornerstone treatment modality for gastric cancer, the fifth most common type of tumor in Brazil. The aim of this study was to analyze the surgical treatment outcomes of patients with gastric cancer who were referred to a high-volume university hospital. METHODS: We reviewed all consecutive patients who underwent any surgical procedure due to gastric cancer from a prospectively collected database. Clinicopathological characteristics, surgical and survival outcomes were evaluated, with emphasis on patients treated with curative intent. RESULTS: From 2008 to 2017, 934 patients with gastric tumors underwent surgical procedures in our center. Gastric adenocarcinoma accounted for the majority of cases. Of the 875 patients with gastric adenocarcinoma, resection with curative intent was performed in 63.5%, and palliative treatment was performed in 22.4%. The postoperative surgical mortality rate for resected cases was 5.3% and was related to D1 lymphadenectomy and the presence of comorbidities. Analysis of patients treated with curative intent showed that resection extent, pT category, pN category and final pTNM stage were related to disease-free survival (DFS) and overall survival (OS). The DFS rates for D1 and D2 lymphadenectomy were similar, but D2 lymphadenectomy significantly improved the OS rate. Additionally, clinical factors and the presence of comorbidities had influence on the OS. CONCLUSIONS: TNM stage and the type of lymphadenectomy were independent factors related to prognosis. Early diagnosis should be sought to offer the optimal surgical approach in patients with less-advanced disease.
  • article 54 Citação(ões) na Scopus
    Clinicopathological and prognostic features of Epstein-Barr virus infection, microsatellite instability, and PD-L1 expression in gastric cancer
    (2018) PEREIRA, Marina A.; RAMOS, Marcus F. K. P.; FARAJ, Sheila F.; DIAS, Andre R.; YAGI, Osmar K.; ZILBERSTEIN, Bruno; CECCONELLO, Ivan; ALVES, Venancio A. F.; MELLO, Evandro S. de; RIBEIRO JR., Ulysses
    Background and ObjectivesGastric cancer (GC) has recently been categorized in molecular subtypes, which include Epstein-Barr (EBV)-positive and microsatellite instability (MSI) tumors. This distinction may provide prognostic information and identifies therapeutic targets. The aim of this study was to evaluate EBV, MSI, and PD-L1 immunoexpression in GC and its relationship with clinicopathological characteristics and patient's prognosis. MethodsWe evaluated 287 GC patients who underwent D2-gastrectomy through immunohistochemistry for DNA mismatch repair proteins and PD-L1, and in situ hybridization for EBV detection utilizing tissue microarray. ResultsEBV-positive and MSI were identified in 10.5% and 27% of the GCs, respectively. EBV positivity was associated to male gender (P=0.032), proximal location (P<0.001), undetermined Lauren type (P<0.001), poorly differentiated histology (P=0.043) and severe inflammatory infiltrate (P<0.001). MSI-tumors were associated to older age (P=0.002), subtotal gastrectomy (P=0.004), pN0 (P=0.024) and earlier TNM stage (P=0.020). PD-L1-positive was seen in 8.8% of cases, with predominant expression in EBV-positive GC (P<0.001). MSI was associated to better survival outcomes. ConclusionEBV-positive GCs had increased PD-L1 expression, while MSI GC had better survival outcome. EBV and MSI subgroups are distinct GC entities, their recognition is feasible by conventional techniques, and it may help individualize follow-up and guide adjuvant therapy.
  • article 24 Citação(ões) na Scopus
    Risk Factors for Lymph Node Metastasis in Western Early Gastric Cancer After Optimal Surgical Treatment
    (2018) PEREIRA, Marina Alessandra; RAMOS, Marcus Fernando Kodama Pertille; DIAS, Andre Roncon; FARAJ, Sheila Friedrich; YAGI, Osmar Kenji; SAFATLE-RIBEIRO, Adriana Vaz; MALUF-FILHO, Fauze; ZILBERSTEIN, Bruno; CECCONELLO, Ivan; MELLO, Evandro Sobroza de; RIBEIRO JR., Ulysses
    Lymph node metastasis (LNM) has a strong influence on the prognosis of patients with early gastric cancer (EGC). As minimally invasive treatments are considered appropriate for EGC, and lymphadenectomy may be restricted or even eliminated in some cases; it is imperative to identify the main risk factors for LNM to individualize the therapeutic approach. This study aims to evaluate the risk factors for LNM in EGC and to determine the adequacy of the endoscopic resection criteria in a western population. EGC patients who underwent gastrectomy with lymphadenectomy were retrospectively analyzed utilizing a prospective database. The clinicopathological variables were assessed to determine which factors were associated to LNM. Among 474 enrolled patients, 105 had EGC (22.1%). LNM occurred in 13.3% of all EGC (10% T1a; 15.4% T1b). Tumor size, venous, lymphatic, and perineural invasions were confirmed as independent predictors of LNM by multivariate analysis. Expanded criteria were safely adopted only in selected cases, and 13.6% of patients who matched expanded indication had LNM. Tumor size, venous, lymphatic, and perineural invasions were associated with LNM and should be considered as surrogate markers for surgical treatment of EGC. Expanded criteria for endoscopic resection can be safely adopted only in selected cases.
  • article 25 Citação(ões) na Scopus
    Duodenal fistula: The most lethal surgical complication in a case series of radical gastrectomy
    (2018) RAMOS, Marcus Fernando Kodama Pertille; PEREIRA, Marina Alessandra; BARCHI, Leandro Cardoso; YAGI, Osmar Kenji; DIAS, Andre Roncon; SZOR, Daniel Jose; ZILBERSTEIN, Bruno; RIBEIRO-JUNIOR, Ulysses; CECCONELLO, Ivan
    Background: Despite all advances regarding the surgical treatment of gastric cancer (GC), duodenal stump fistula (DF) continues to negatively affect postoperative outcomes. This study aimed to assess DF regarding its incidence, risk factors, management and impact on overall survival. Methods: We retrospectively analyzed 562 consecutive patients who underwent gastrectomy for GC between 2009 and 2017. Clinicopathological characteristics analysis was performed comparing DF, other surgical fistulas and patients with uneventful postoperative course. Results: DF occurred in 15 (2.7%) cases, and 51 (9%) patients had other surgical fistulas. Tumor located in the lower third of the stomach (p=0.021) and subtotal gastrectomy (p=0.002) were associated with occurrence of DF. The overall mortality rate was 40% for DF and 15.7% for others surgical fistulas (p=0.043). The median time of DF onset was on postoperative day 9 (range 1-75). Conservative approach was performed in 8 patients and surgical intervention in 7 cases. Age (OR 7.41, p=0.012) and DF (OR 9.06, p=0.020) were found to be independent risk factors for surgical mortality. Furthermore, patients without fistula had better long-term survival outcomes comparing to patients with any type of fistulas (p=0.006). Conclusion: DF is related with distal tumors and patients submitted to subtotal gastrectomy. It affects not only the postoperative period with high morbidity and mortality rates, but may also have a negative impact on long-term survival.