Colorectal cancer DNA methylation patterns from patients in Manaus, Brazil

BACKGROUND: DNA methylation is commonly linked with the silencing of the gene expression for many tumor suppressor genes. As such, determining DNA methylation patterns should aid, in times to come, in the diagnosis and personal treatment for various types of cancers. Here, we analyzed the methylation pattern from five colorectal cancer patients from the Amazon state in Brazil for four tumor suppressor genes, viz.: DAPK, CDH1, CDKN2A, and TIMP2 by employing a polymerase chain reaction (PCR) specific to methylation. Efforts in the study of colorectal cancer are fundamental as it is the third most of highest incidence in the world. RESULTS: Tumor biopsies were methylated in 1/5 (20 %), 2/5 (40 %), 4/5 (80 %), and 4/5 (80 %) for CDH1, CDKN2A, DAPK, and TIMP2 genes, respectively. The margin biopsies were methylated in 3/7 (43 %), 2/7 (28 %), 7/7 (100 %), and 6/7 (86 %) for CDH1, CDKN2A, DAPK, and TIMP2, respectively. CONCLUSIONS: Our findings showed DAPK and TIMP2 to be methylated in most samples from both tumor tissues and adjacent non-neoplastic margins; thus presenting distinct methylation patterns. This emphasizes the importance of better understanding of the relation of these patterns with cancer in the context of different populations.

Análise de 5 anos de seguimento de hepatectomias em portadores de turmor hepático / Analysis of 5 years following hepatectomy in patients with liver tumor

Introdução: os tumores hepáticos malignos são muito mais comuns do que os benignos, sendo os metastáticos ou secundários 20 vezes mais frequentes do que os primários. A hepatectomia permanece como o principal e mais utilizado método de tratamento dos tumores hepáticos. Infelizmente, esse método é aplicável apenas em cerca de 10% dos casos. Analisar a sobrevida dos pacientes portadores de tumor hepático submetidos a ressecções hepáticas no Estado do Amazonas, assim como as principais complicações pós-operatórias e índice de recidiva tumoral. Métodos: estudo retrospectivo, analisando os prontuários e laudos anatomopatológicos dos pacientes submetidos à ressecção hepática na Fundação Centro de Controle de Oncologia do Amazonas (FCECON), entre janeiro de 2006 a dezembro de 2010. Resultados: foram realizadas 34 ressecções hepáticas, sendo 55,9% tumores malignos primários do fígado, 26,5% doença metastática e 17,6% tumores benignos. Houve 17,64% de complicações pós-operatórias, sendo as mais graves o abscesso subfrênico e a hemorragia intra-abdominal. A taxa de reoperação foi de 2,94%. Não houve mortalidade operatória. O índice de recidiva tumoral foi de 23,5%, com óbito ocorrendo em 75% destes casos. A taxa de sobrevida em um, três e cinco anos foi respectivamente 96%, 89% e 68%. Conclusão: a cirurgia hepática tem se tornado cada vez mais factível e as complicações pós-operatórias, sob maior controle clínico, tem diminuído consideravelmente a mortalidade.

Introduction: malignant Hepatic tumors are much more common than the benign ones, being the metastatics 20 times more frequent than the primaries. Hepatectomy remains as the more common and used method in its treatment. Unfortunately this method can be applied in around 10% of cases. To analyze the overall survival of malignant liver tumors patients who underwent a hepatic resection in the state of Amazonas, as well as the post-operative complications and recurrence rate. Methods: retrospective study, analysing the patient records and anatomopathologic reports of patients who underwent liver resection in Fundação Centro de Controle de Oncologia do Amazonas (FCECON), between january 2006 and december 2010. Results: a total amount of 34 liver resections were done, being 55,9% liver primary malignant tumors, 26,5% metastatic disease e 17,6% benign tumors. There were 17,64% of post-operative complications, being the more serious diaphragmatic abscess and intra-abdominal bleeding. Reoperation rate was of 2,94%. There were no preoperative mortality. Tumor recurrence was 23,5%, with death happening in 75% of these cases. Overall survival in one, three and five years were respectively 96%, 89% e 68%. Conclusion: hepatic surgery has been increasingly more appliable and post-operative complications, under strict clinical care, has considerably diminished mortality.