SERGIO CARLOS NAHAS
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Gastroenterologia, Faculdade de Medicina - Docente
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Faculdade de Medicina - Médico
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Faculdade de Medicina - Médico
3 resultados
Resultados de Busca
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- Understanding the factors associated with reduction in the number of lymph nodes in rectal cancer patients treated by neoadjuvant treatment(2017) BUSTAMANTE-LOPEZ, L.; NAHAS, C. S.; NAHAS, S. C.; RIBEIRO JR., U.; MARQUES, C. F.; COTTI, G.; ROCCO, A.; CECCONELLO, I.Introduction Rectal cancer patients frequently present with locally advanced disease for which the standard of care includes neoadjuvant chemoradiotherapy followed by total mesorectal excision. Positive lymph nodes are one of the most powerful risk factors for recurrence and survival in colorectal cancer. In the absence of specific rectal guidelines, the literature recommends to the pathologist to optimize the number of rectal lymph nodes (LN) retrieved. We made a literature review in order to identify factors that could potentially affect the number of LN retrieved in specimens of patients with rectal cancer treated by chemoradiotherapy (CRT) followed by total mesorectal excision (TME). Results Age did not have a significant effect on LN yield. The effect of sex on LN number is not consistent in the literature. Most of the papers did not find a relationship between lower LN obtained and gender. Laparoscopy for primary rectal cancer is associated with a greater number of LN as well as shortterm benefits. Tumors in the upper rectum are associated with a higher number of LN than those in the mid and lower rectum. The type of surgery had no effect on lymph node yield either. Tumors with complete or almost complete pathologic regression were exactly the ones with lower number of lymph nodes detected. Approximately one-third of patients with neoadjuvant treatment had less than 12 LN yield. Conclusion The tumor regression grade is the most important factor for the decrease in the number of lymph nodes.
- One-level step section histological analysis is insufficient to confirm complete pathological response after neoadjuvant chemoradiation for rectal cancer(2017) PEREIRA, M. A.; DIAS, A. R.; FARAJ, S. F.; NAHAS, C. S. R.; IMPERIALE, A. R.; MARQUES, C. F. S.; COTTI, G. C.; AZEVEDO, B. C.; NAHAS, S. C.; MELLO, E. S. de; RIBEIRO JR., U.Neoadjuvant chemoradiation therapy (nCRT) for rectal cancer may lead to cure. As we currently lack reliable methods to clinically confirm the absence of disease, some patients undergo radical resection and have pathological complete response (pCR) still undergo surgery. Furthermore, it is uncertain if conventional one-level histopathological analysis is accurate enough to determine complete response. Confirming pCR is essential to determine the prognosis and to consider the patient's inclusion in trials of adjuvant therapy. The aim of this study was to determine whether the current 1-level approach is sufficient to confirm pCR. Four hundred and thirty-five patients with rectal cancer who received nCRT followed by radical resection were analyzed. All cases identified as pCR by 1-level step section histological evaluation were reassessed with 3-level step sections and immunohistochemical analysis to verify the presence of residual disease. Out of 435 patients, 75 (17.2%) were staged as ypT0. Of these, 6 had lymph node involvement and 1 had distant metastasis, leaving 68 (15.6%) who had pCR. After the additional step sections, residual tumor was detected in 12 (17.6%) of these 68. The final pCR rate was 12.9%. Distant recurrence was detected in 7.1% of real-pCR patients compared to 16.7% in the false-pCR group (p = 0.291). Sensitivity of clinical assessment for detecting pCR was 35.7%, and the accuracy of 1-section histological evaluation to identify pCR was 82.4%. Histopathological analysis with 1-level step section is insufficient to determine complete tumor eradication. The 3-level sections methodology revealed residual tumor cells in patients initially classified as ypT0. Further studies with larger sample size are required to verify the clinical relevance of these residual tumor cells. Caution should continue to be applied to watch and wait strategies following nCRT.
- Clinical relevance of positron emission tomography/computed tomography-positive inguinal nodes in rectal cancer after neoadjuvant chemoradiation(2013) PEREZ, R. O.; HABR-GAMA, A.; JULIAO, G. P. Sao; PROSCURSHIM, I.; ONO, C. R.; LYNN, P.; AGUILAR, P. Bailao; NAHAS, S. C.; GAMA-RODRIGUES, J.; BUCHPIGUEL, C. A.Aim Inguinal nodes may be a possible route for lymphatic spread in patients with distal rectal cancer. The outcome was examined for patients with distal rectal cancer undergoing neoadjuvant chemoradiation (CRT) and having 2-fluorine-18-fluoro-2-deoxy-d-glucose (FDG)-avid inguinal nodes using positron emission tomography/computed tomography (PET/CT) imaging. Method Ninety-nine consecutive patients with cT2-4N0-2M0 distal rectal adenocarcinoma were enrolled in a clinical trial (NCT00254683) and underwent baseline PET/CT followed by 54Gy and 5-fluorouracil-based CRT. After CRT, patients underwent 6- and 12-week PET/CT. Patients with positive inguinal node uptake were compared with patients with negative uptake. The inguinal region was not included in the field of radiation therapy. Results Seventeen (17%) patients had baseline positive inguinal node FDG uptake. They were more likely to have the tumour closer to the anal verge (2.0 vs 4.2cm; P=0.001). Of these, eight (47%) demonstrated a positive inguinal uptake at PET/CT after 12weeks from CRT. Patients with inguinal node FDG uptake after CRT (positive PET at baseline and 12weeks) had a significantly worse 3-year overall and disease-free survival (P=0.02 and P=0.03). After a median follow-up period of 22months, none of these patients had developed inguinal recurrence. Conclusion Uptake of inguinal nodes at PET/CT may be present in up to 17% of patients with distal rectal cancer, particularly with ultra-low tumours. Nearly half of these nodes no longer show uptake after CRT despite the groin area not being included in the radiation field. Persistence of inguinal node uptake 12weeks after CRT completion may be a marker for worse oncological outcome.