Henry Becerra

Genotyping Non-small Cell Lung Cancer (NSCLC) in Latin America

Introduction: Frequency of mutations in EGFR and KRAS in non-small cell lung cancer (NSCLC) is different between ethnic groups; however, there is no information in Latin-American population. Methods: A total of 1150 biopsies of NSCLC patients from Latin America (Argentina, Colombia, Peru, and Mexico) were used extracting genomic DNA to perform direct sequencing of EGFR gene (exons 18 and 21) and KRAS gene in 650 samples. In Mexico, Scorpions ARMS was also used to obtain a genetic profile. Results: We report the frequency of mutations in EGFR and KRAS genes in four Latin-American countries (n = 1150). Frequency of EGFR mutations in NSCLC was 33.2% (95% confidence interval [CI] 30.5–35.9) (Argentina 19.3%, Colombia 24.8%, Mexico 31.2%, and Peru 67%). The frequency of KRAS mutations was 16.6% (95% CI 13.8–19.4). EGFR mutations were independently associated with adenocarcinoma histology, older age, nonsmokers, and absence of KRAS mutations. Overall response rate to tyrosine kinase inhibitors in EGFR-mutated patients (n = 56) was 62.5% (95% CI 50–75) with a median overall survival of 16.5 months (95% CI 12.4–20.6). Conclusions: Our findings suggest that the frequency of EGFR mutations in Latin America lies between that of Asian and Caucasian populations and therefore support the genetic heterogeneity of NSCLC around the world.

Stem Cells in Brain Tumorigenesis and their Impact on Therapy

The concept that the genesis of new cells in the adult mammalian brain is negligible has long influenced our perception and understanding of the origin and development of central nervous system (CNS) tumors. The discovery that neurons and glia are produced throughout life from neural stem cells provides new possibilities for candidate precursor cells of CNS neoplasms. The emerging hypothesis is that alterations in the cellular and genetic mechanisms that control adult neurogenesis might contribute to brain tumorigenesis. As such, opportunities become available to identify new therapeutic strategies.

Morbilidad y mortalidad en una serie de pacientes con neoplasias del peritoneo, tratados con citorreducción peritoneal más quimioterapia hipertérmica intraperitoneal en el Hospital Universitario de la Fundación Santa Fe de Bogotá (ONCOLGroup - estudio ATIA)

BACKGROUND The procedure of radical peritonectomy followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is considered the standard treatment for peritoneal cancers. AIMS To evaluate various outcomes in a cohort of patients with peritoneal tumors treated with HIPEC. METHODS Twenty-four patients consecutively treated with radical peritonectomy plus HIPEC within the time frame of November 2007 to July 2010 were enrolled; 15 (62%) had tumors of appendicular origin, 4 (16.7%) had primary peritoneal tumors, 2 had ovarian carcinomas and there was one case of colon cancer, one carcinosarcoma and one hemangioendothelioma. Mean age was 53 years (range: 26-68) and median follow-up was 14.2 months (range: 1-32). Demographic data, histology, peritoneal cancer index (PCI), surgical procedure characteristics, recurrence-free survival (RFS), and overall survival (OS) were all evaluated. Short-term morbidity and mortality were also determined. RESULTS Complete cytoreduction was achieved in 18 patients (75%). Mean PCI was 15 (<10: 41% and >10: 58%), and the median (range) for surgery duration, length of stay in the Intensive Care Unit, parenteral nutritional support, and hospital stay were 12,5 (7-20) hours, 11,4 (2-74) days, 13,8 (12-65) days, and 29,1 (10-90) days, respectively. One patient (4%) died 6 months after the procedure, due to multiple associated complications. Considerable morbidity was seen in 52% of cases, including thromboembolic events (41%), catheter-related bacteremia (29%), fistulas (29%), and nephrotoxicity (25%). Six patients (25%) recurred after a median of 21 months of RFS. CONCLUSIONS Cytoreductive surgery plus HIPEC in well-selected patients presenting with tumors that affect the peritoneum is a procedure that can be carried out in Colombia with an adequate safety and effectiveness profile. Mortality was similar to that reported in the international literature.