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Dive into the research topics where Laércio Gomes Lourenço is active.

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Featured researches published by Laércio Gomes Lourenço.


Gastric Cancer | 2012

How useful is preoperative imaging for tumor, node, metastasis (TNM) staging of gastric cancer? A meta-analysis

Rajini Seevaratnam; Roberta Cardoso; Caitlin Mcgregor; Laércio Gomes Lourenço; Alyson L. Mahar; Rinku Sutradhar; Calvin Law; Lawrence Paszat; Natalie G. Coburn

BackgroundSurgery is the fundamental curative option for gastric cancer patients. Imaging scans are routinely prescribed in an attempt to stage the disease prior to surgery. Consequently, the correlation between radiology exams and pathology is crucial for appropriate treatment planning.MethodsSystematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 1, 2009. We calculated the accuracy, overstaging rate, understaging rate, Kappa statistic, sensitivity, and specificity for abdominal ultrasound (AUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) with respect to the gold standard (pathology). We also compared the performance of CT by detector number and image type. A meta-analysis was performed.ResultsFor pre-operative T staging MRI scans had better performance accuracy than CT and AUS; CT scanners using ≥4 detectors and multi-planar reformatted (MPR) images had higher staging performances than scanners with <4 detectors and axial images only. For pre-operative N staging PET had the lowest sensitivity, but the highest specificity among modalities; CT performance did not significantly differ by detector number or addition of MPR images. For pre-operative M staging performance did not significantly differ by modality, detector number, or MPR images.ConclusionsThe agreement between pre-operative TNM staging by imaging scans and post-operative staging by pathology is not perfect and may affect treatment decisions. Operator dependence and heterogeneity of data may account for the variations in staging performance. Physicians should consider this discrepancy when creating their treatment plans.


Gastric Cancer | 2012

A systematic review of the accuracy and utility of peritoneal cytology in patients with gastric cancer

Pierre-Anthony Leake; Roberta Cardoso; Rajini Seevaratnam; Laércio Gomes Lourenço; Lucy Helyer; Alyson L. Mahar; Corwyn Rowsell; Natalie G. Coburn

BackgroundThere is lack of uniformity in the utilization of peritoneal cytology in gastric cancer management. The identification of intraperitoneal free cancer cells (IFCCs) is believed to confer poor prognosis. However, while some of these patients are palliated, others may undergo more aggressive therapies. In this review, we aimed to identify and synthesize findings on the use of peritoneal cytology in predicting peritoneal recurrence and overall survival in curative gastric cancer patients.MethodsElectronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 31, 2009. We determined the accuracy, sensitivity, and specificity of peritoneal cytology in predicting peritoneal recurrence based on four techniques—conventional cytology, immunoassay, immunohistochemistry, and reverse transcriptase-polymerase chain reaction. Recurrence rates and overall survival rates for curative patients were determined, based on positivity or negativity for IFCCs.ResultsTwenty-eight articles were included. All four techniques showed wide variations in accuracy, sensitivity, and specificity in predicting peritoneal recurrence. Recurrence rates for patients positive for IFCCs ranged from 11.1 to 100%, while those negative for IFCCs had recurrence rates of 0–51%. Overall survival was significantly reduced for patients with positive IFCCs. Short follow-up periods and possible duplication of results may limit result interpretation.ConclusionThe presence of IFCCs appears to increase the risk of peritoneal recurrence and is associated with worse overall survival in gastric cancer patients. Further incorporation of peritoneal cytology in clinical decision-making in gastric cancer depends on the development of a consistently accurate and rapid IFCC detection method.


Gastric Cancer | 2012

A systematic review of the accuracy and indications for diagnostic laparoscopy prior to curative-intent resection of gastric cancer

Pierre-Anthony Leake; Roberta Cardoso; Rajini Seevaratnam; Laércio Gomes Lourenço; Lucy Helyer; Alyson L. Mahar; Calvin Law; Natalie G. Coburn

BackgroundDespite improved preoperative imaging techniques, patients with incurable or unresectable gastric cancer are still subjected to non-therapeutic laparotomy. Diagnostic laparoscopy (DL) has been advocated by some to be essential in decision-making in gastric cancer. We aimed to identify and synthesize findings on the value of DL for patients with gastric cancer, in this era of improved preoperative imaging.MethodsElectronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 31, 2009. We calculated the change in management and avoidance of laparotomy based on the addition of DL and laparoscopic ultrasound (LUS). The accuracy, agreement (kappa), sensitivity, and specificity of DL in assessing tumor extent, nodal involvement, and the presence of metastases with respect to the gold standard (pathology) were also calculated.ResultsTwenty-one articles were included. DL showed moderate to substantial agreement with final pathology for T stage, but only fair agreement for N stage. For M staging, DL had an overall accuracy, sensitivity, and specificity ranging from 85–98.9%, 64.3–94%, and 80–100%, respectively. The use of DL altered treatment in 8.5–59.6% of cases, avoiding laparotomy in 8.5–43.8% of cases. LUS provided additional benefit in 5.8–7.2% of cases.ConclusionsDespite evolving preoperative imaging techniques, diagnostic laparoscopy continues to be of substantial value in staging patients with gastric cancer and in avoiding unnecessary laparotomy. The current data support DL for all patients with advanced gastric cancer.


Annals of Surgery | 2014

Optimal management of gastric cancer: results from an international RAND/UCLA expert panel.

Natalie G. Coburn; Rajini Seevaratnam; Lawrence Paszat; Lucy Helyer; Calvin Law; Carol J. Swallow; Roberta Cardosa; Alyson L. Mahar; Laércio Gomes Lourenço; Matthew Dixon; Tanios Bekaii-Saab; Ian Chau; Neal Church; Daniel G. Coit; Christopher H. Crane; Craig C. Earle; Paul F. Mansfield; Norman E. Marcon; Thomas J. Miner; Sung Hoon Noh; Geoff Porter; Mitchell C. Posner; Vivek Prachand; Takeshi Sano; Cornelis J. H. van de Velde; Sandra L. Wong; Robin S. McLeod

Objective:Defining processes of care, which are appropriate and necessary for management of gastric cancer (GC), is an important step toward improving outcomes. Methods:Using a RAND/UCLA Appropriateness Method, an international multidisciplinary expert panel created 22 statements reflecting optimal management. All statements were scored for appropriateness and necessity. Results:The following tenets were scored appropriate and necessary: (1) preoperative staging by computed tomography of abdomen/pelvis; (2) positron-emission tomographic scans not routinely indicated; (3) consideration for adjuvant therapy; (4) further clinical trials; (5) multidisciplinary decision making; (6) sufficient support at hospitals; (7) assessment of 16 or more lymph nodes (LNs); (8) in metastatic disease, surgery only for palliation of major symptoms; (9) surgeons experienced in GC management; (10) and surgeons experienced in both GC management and advanced laparoscopic surgery for laparoscopic resection. The following were scored appropriate, but of indeterminate necessity: (1) diagnostic laparoscopy before treatment; (2) a multidisciplinary approach to linitis plastica; (3) genetic assessment for diffuse GC and family history, or age less than 45 years; (4) endoscopic removal of select T1aN0 lesions; (5) D2 LN dissection in curative intent cases; (6) D1 LN dissection for early GC or patients with comorbidities; (7) frozen section analysis of margins; (8) nonemergent cases performed in a hospital with a volume of more than 15 resections per year; and (9) by a surgeon with more than 6 resection per year. Conclusions:The expert panel has created 22 statements for the perioperative management of GC patients, to provide guidance to clinicians and improve the care received by patients.


Revista Da Associacao Medica Brasileira | 1999

Resultados tardios da operação de Heller associada à fundoplicatura no tratamento do megaesôfago: análise de 83 casos

F. A. M. Herbella; J. C. Del Grande; Laércio Gomes Lourenço; Nacime Salomäo Mansur; C. M Haddad

BACKGROUND: Retrospective study of the late results of the Hellers cardiomyotomy and fundoplication for the treatment of the megaesophagus. MATERIAL AND METHODS: Were studied 83 patients with a follow-up from one to 186 months (average 40.0±47.4 months). The fundoplications used were in three plans in 15.7% and posterior in 83.1%. The main pre-operatory complain was disphagia followed by regurgitation and loss of weight. Chagas, Disease as the etiology was confirmed in 72.3% of the patients. RESULTS: In the follow-up 55.4 % of the patients were assymptomatic, 34.9% complained of sporadic dysphagia, 14.4% of heartburn, 8.4% of regurgitation and 2.4% did not changed the dysphagia, these being re-operated and had improvement the symptoms. Gastro-esophageal reflux was noted in 8.4% of the patients. Other late complications were par-esophageal hernia, sliping of the fundoplication, Barrett esophagus and cancer. CONCLUSIONS: The necessity of a long-term clinical and endoscopical follow-up, even after surgery, owing to the possibility of late complications, especially cancer was emphasized. The late results are good in relation to the dysphagia. Myotomy is proposed as an alternative to patients with advanced megaesophagus with bad clinical conditions who can not be submitted to an esophagectomy.


Journal of Surgical Oncology | 2010

Management of gastric cancer in Ontario.

Natalie G. Coburn; Laércio Gomes Lourenço; Seana E. Rossi; Nadia Gunraj; Alyson L. Mahar; Lucy Helyer; Calvin Law; Linda Rabeneck; Lawrence Paszat

To describe the processes of care for gastric cancer in Ontario and identify areas in which care and possibly survival can be improved.


Arquivos De Gastroenterologia | 2009

Ki67 and p53 in gastrointestinal stromal tumors - GIST

Lúcio Roberto de Oliveira das Neves; Celina Tizuko Fujiyama Oshima; Ricardo Artigiani-Neto; Gianni Yanaguibashi; Laércio Gomes Lourenço; Nora Manoukian Forones

CONTEXT Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor. Cellular proliferation and apoptosis is gaining importance for predicting prognosis in several cancers. OBJECTIVE To investigate the Ki67 and p53 immunostaining in GISTs. METHODS Specimens from 40 patients with GIST were assessed for immunohistochemical expression of Ki67 and p53. The tumors were divided according the risk of recurrence in two groups: I with high or intermediate risk and; II with low or very low risk. RESULTS Among the 40 patients, 21 were men, the mean age was 56 years, 16 occurred in the small intestine and 13 in the stomach, 5 in the retroperitonium, 4 in the colon or rectum and 2 in the mesenterium. Thirty two tumors were from group I and 8 from group II. Half of the patients developed recurrence, being 90% of the group I (P = 0.114). The tumor Ki67 labelling index ranged from 0.02 to 0.35 (mean level 0.12). This index was marginally higher in the group I patients with recurrence (P = 0.09) compared to the patients of the same group without recurrence. p53 staining was expressed in 65% of the GISTs. A higher frequency of p53 and Ki67 had been found in the group I tumors when compared to the other group (P = 0.022; OR = 8.00 - IC 95%: 1.32-48.65). CONCLUSION The most common site was the small intestine and 80% had a malignant potential justifying the high recurrence observed. No significant correlation was found between p53 and overall outcome of the patients. In group I patients, the evaluation Ki67LI may be a marker of prognosis. The positivity of both markers is higher among the patients with worst prognosis than in the others.


Journal of The American College of Surgeons | 2013

Defining Surgical Quality in Gastric Cancer: A RAND/UCLA Appropriateness Study

Savtaj S. Brar; Calvin Law; Robin S. McLeod; Lucy Helyer; Carol J. Swallow; Lawrence Paszat; Rajini Seevaratnam; Roberta Cardoso; Matthew Dixon; Alyson L. Mahar; Laércio Gomes Lourenço; Lavanya Yohanathan; Alina Bocicariu; Tanios Bekaii-Saab; Ian Chau; Neal Church; Daniel G. Coit; Christopher H. Crane; Craig C. Earle; Paul F. Mansfield; Norman E. Marcon; Thomas J. Miner; Sung Hoon Noh; Geoff Porter; Mitchell C. Posner; Vivek Prachand; Takeshi Sano; Cornelis J. H. van de Velde; Sandra L. Wong; Natalie G. Coburn

Savtaj Brar, MD, MSc, Calvin Law, MD, MPH, Robin McLeod, MD, FACS, Lucy Helyer, MD, MSc, Carol Swallow, MD, PhD, FACS, Lawrence Paszat, MD, MSc, Rajini Seevaratnam, MSc, Roberta Cardoso, RN, PhD, Matthew Dixon, MD, Alyson Mahar, MSc, Laercio G Lourenco, MD, Lavanya Yohanathan, MD, Alina Bocicariu, MD, Tanios Bekaii-Saab, MD, Ian Chau, MD, Neal Church, MD, Daniel Coit, MD, FACS, Christopher H Crane, MD, Craig Earle, MD, MSc, Paul Mansfield, MD, FACS, Norman Marcon, MD, Thomas Miner, MD, FACS, Sung Hoon Noh, MD, Geoff Porter, MD, MSc, FACS, Mitchell C Posner, MD, FACS, Vivek Prachand, MD, FACS, Takeshi Sano, MD, PhD, Cornelis van de Velde, MD, PhD, FACS, Sandra Wong, MD, FACS, Natalie Coburn, MD, MPH, FACS


Arquivos De Gastroenterologia | 2005

Cell proliferation and apoptosis in gastric cancer and intestinal metaplasia.

Nora Manoukianá Forones; Ana Paula Souza Carvalho; Oswaldo Giannotti-Filho; Laércio Gomes Lourenço; Celina Tizuko Fujiyama Oshima

BACKGROUND Higher proliferation is commonly observed in cancer cells. Apoptosis can be a useful measure of a tumor cell kinetic. Alteration of the balance between proliferation and apoptosis is associated with cancer. AIM To study proliferation and apoptosis on gastric cancer and in intestinal metaplasia. METHODOLOGY Twenty-two samples from gastric adenocarcinomas and 22 biopsies from intestinal metaplasia were studied. The apoptotic bodies in hematoxylin-eosin slides and the expression of p53, bcl-2 and Ki67 were determined by immunohistochemistry. RESULTS The number of the apoptotic cells was higher in cancer. Ki 67LI increased from intestinal metaplasia to gastric cancer. p53 was positive in 68% of the patients with cancer, more frequently in advanced stage and negative in samples of intestinal metaplasia. Although there was no significant difference between the groups, bcl-2 was positive in 45% of gastric cancer tissue and in 68% of metaplasia. In gastric cancer patients bcl-2 was expressed in early gastric cancer more frequently than in advanced stage. CONCLUSION The positivity of bcl-2 was higher in metaplasia and probably is involved in the progression of carcinogenesis. p53 was negative in metaplasia and positive in more than half of the gastric cancer, mostly in stage IV, suggesting a late event in gastric cancer.


JAMA Surgery | 2014

Processes of Care in the Multidisciplinary Treatment of Gastric Cancer Results of a RAND/UCLA Expert Panel

Savtaj S. Brar; Alyson L. Mahar; Lucy Helyer; Carol J. Swallow; Calvin Law; Lawrence Paszat; Rajini Seevaratnam; Roberta Cardoso; Robin S. McLeod; Matthew Dixon; Lavanya Yohanathan; Laércio Gomes Lourenço; Alina Bocicariu; Tanios Bekaii-Saab; Ian Chau; Neal Church; Daniel G. Coit; Christopher H. Crane; Craig C. Earle; Paul F. Mansfield; Norman E. Marcon; Thomas J. Miner; Sung Hoon Noh; Geoff Porter; Mitchell C. Posner; Vivek Prachand; Takeshi Sano; Cornelis J. H. van de Velde; Sandra L. Wong; Natalie G. Coburn

IMPORTANCE There is growing interest in reducing the variations and deficiencies in the multidisciplinary management of gastric cancer. OBJECTIVE To define optimal treatment strategies for gastric adenocarcinoma (GC). DESIGN, SETTING, AND PARTICIPANTS RAND/UCLA Appropriateness Method involving a multidisciplinary expert panel of 16 physicians from 6 countries. INTERVENTIONS Gastrectomy, perioperative chemotherapy, adjuvant chemoradiation, surveillance endoscopy, and best supportive care. MAIN OUTCOMES AND MEASURES Panelists scored 416 scenarios regarding treatment scenarios for appropriateness from 1 (highly inappropriate) to 9 (highly appropriate). Median appropriateness scores from 1 to 3 were considered inappropriate; 4 to 6, uncertain; and 7 to 9, appropriate. Agreement was reached when 12 of 16 panelists scored the scenario similarly. Appropriate scenarios agreed on were subsequently scored for necessity. RESULTS For patients with T1N0 disease, surgery alone was considered appropriate, while there was no agreement over surgery alone for patients T2N0 disease. Perioperative chemotherapy was appropriate for patients who had T1-2N2-3 or T3-4 GC without major symptoms. Adjuvant chemoradiotherapy was classified as appropriate for T1-2N1-3 or T3-4 proximal GC and necessary for T1-2N2-3 or T3-4 distal GC. There was no agreement regarding surveillance imaging and endoscopy following gastrectomy. Surveillance endoscopy was deemed to be appropriate after endoscopic resection. For patients with metastatic GC, surgical resection was considered inappropriate for those with no major symptoms, unless the disease was limited to positive cytology alone, in which case there was disagreement. CONCLUSIONS AND RELEVANCE Patients with GC being treated with curative intent should be considered for multimodal treatment. For patients with incurable disease, surgical interventions should be considered only for the management of major bleeding or obstruction.

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José Carlos Del Grande

Federal University of São Paulo

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Carolina Oliveira Gigek

Federal University of São Paulo

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Fernanda Wisnieski

Federal University of São Paulo

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Mariana Ferreira Leal

Federal University of São Paulo

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Calvin Law

Sunnybrook Health Sciences Centre

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Rajini Seevaratnam

Sunnybrook Health Sciences Centre

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