ABSTRACT
Background: The molecular testing of KRAS mutation status in metastatic colorectal cancer patients is mandatory to identify patients eligible for anti-epidermal growth factor receptor monoclonal antibody therapy. Aim: To report the frequency of KRAS gene mutations in Chilean patients with colorectal cancer (CRC). Material and Methods: A cohort of 262 Chilean patients with CRC aged 26 to 90 years (53% males), was studied. KRAS mutation status was analyzed by real-time polymerase chain reaction and correlated with clinicopathological data. Results: Ninety-eight patients (37%) were positive for KRAS mutations. G12D was the most common mutation with a frequency of 36.7%, followed by G12V (25.5%), G13D (17.3%), G12A (7.1%), G12C (6.1%), G12S (5.1%) and G12R (2%). The frequency of the mutation in left, right colon and rectal tumors was 37.8, 32.6 and 44.9%, respectively. Among tumors with mutations, 86.7% were well or moderately differentiated tumors and the rest were poorly differentiated. No significant associations between KRAS gene mutations and other clinicopathological features of the tumor were observed. Conclusions: The frequencies of KRAS mutations reported in this study are similar to frequencies reported for European and North-American populations, lower than in a Spanish study and higher than in a Peruvian study.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Colorectal Neoplasms/genetics , Mutation , Proto-Oncogene Proteins/genetics , ras Proteins/genetics , Age Factors , Chile/ethnology , Colorectal Neoplasms/ethnology , Colorectal Neoplasms/pathology , DNA Mutational Analysis , DNA, Neoplasm/genetics , Epidermal Growth Factor/genetics , Neoplasm Invasiveness/genetics , Prospective Studies , Real-Time Polymerase Chain Reaction , Sex FactorsABSTRACT
Introducción: En la actualidad hay consenso en la seguridad oncológica en la cirugía laparoscópica para el tratamiento del cáncer de colon, sin embargo, en el cáncer de recto (CR) los resultados a largo plazo, continúan siendo objeto de estudio. El objetivo de este trabajo es analizar la sobrevida a largo plazo en pacientes operados por adenocarcinoma de recto por vía laparoscópica. Material y Métodos: Desde la base de datos prospectiva de cirugía colorrectal laparoscópica se seleccionaron los pacientes operados por CR en el periodo entre octubre 2000 y diciembre 2009. Se excluyó a los pacientes con cáncer colorrectal hereditario. Se analizaron los datos de seguimiento los cuales son obtenidos mediante registros clínicos y datos del registro civil. Se realizó un análisis de sobrevida con el método de Kaplan-Meier. Resultados: En el periodo mencionado, 60 pacientes fueron operados por CR, 2 (3,4%) pacientes fallecieron en el postoperatorio temprano y fueron excluidos en el análisis de sobrevida, por tanto, 58 pacientes fueron incluidos en el seguimiento. El 41% eran sexo femenino y la edad promedio fue de 60 ± 11,6 años. Los tumores se encontraban localizados en el recto superior, medio e inferior en un 28%, 28% y 44% respectivamente. Las cirugías realizadas fueron resección abdominoperineal, resección anterior ultrabaja interesfintérica, resección anterior ultrabaja y resección anterior baja en un 8%, 28%, 5% y 59% de los pacientes, respectivamente. El 50% de los pacientes recibieron neoadyuvancia. Tras la estadificación postoperatoria 4% fueron clasificados estadio 0, 38% estadio I, 17% estadio II, 28% estadio III y 13% estadio IV. El recuento de linfonodos de la pieza operatoria fue de 12,3 en promedio. A un seguimiento de 42,6 meses (r: 17 a 103 meses) la sobrevida global estimada a 5 años es de 85%. Según estadios la sobrevida estimada a 5 años fue de 100% para el estadio 0 y I, 88% para el estadio II, 74% para el estadio III... (TRUNCADO)
Background: Currently there is a consensus in oncological safety for laparoscopic surgery for colon cancer; however, in rectal cancer long term outcomes are still a subject of debate. The aim is to analyze long term survival in patients who underwent laparoscopic surgery for rectal cancer. Material and Methods: From the prospective database of laparoscopic colorectal surgery, we selected patients operated on between October 2000 and December 2009. Patients with hereditary colorectal cancer were excluded. Follow-up data was obtained by medical records and national vital records. Survival was analyzed using the Kaplan-Meier method. Results: In this period, 60 patients were operated on for rectal cancer. Two died in the early postoperative period and were excluded from the analysis; therefore, 58 patients were included in follow-up. Forty-one percent were female and mean age was 60±11.6 years old. Tumors were localized in the upper, mid and lower rectum in 28%, 28% and 44%, respectively. Surgeries performed were abdominoperineal resection, ultra-low intersphincteric resection, ultralow anterior resection and low anterior resection in 8%, 28%, 5% and 59% of patients, respectively. Fifty percent received neoadjuvant treatment. After postoperative staging 4% were classified as stage 0,17% as stage I, 28% as stage II, 28% as stage III, and 13% as stage IV. At a mean 42.6 month follow-up (r: 17-103 months) estimated overall 5-year survival was 85%. When analyzed according to stage, estimated overall 5-year survival was 100% for stages 0 and I, 88% for stage II, 74% for stage III, and 57% for stage IV. Conclusion: Long term survival in patients undergoing laparoscopic surgery for rectal cancer is satisfactory and is within the values reported by international centers.