Frequency of KRAS mutations in female colorectal cancer (CRC) patients: Findings of a Brazilian cohort of 8,234 cases.
2012; Lippincott Williams & Wilkins; Volume: 30; Issue: 15_suppl Linguagem: Inglês
10.1200/jco.2012.30.15_suppl.e14101
ISSN1527-7755
AutoresCarlos Gil Ferreira, Mariano Zalis, Ilana Zalcberg-Renault, Martín Bonamino, Marcos Barcelos de Pinho, R. C. Helal, Jonas Hauben Salem, Ana Paula Ornelas Victorino, Fernando Meton de Alencar Câmara Vieira,
Tópico(s)Cancer Genomics and Diagnostics
Resumoe14101 Background: Although major advances in the last decades, there are still important gaps in our understanding of CRC carcinogenesis, particularly whether sex-linked factors play any role. Some groups, including ours, observed that KRAS mutation may be more frequent in female than male (Ferreira C.G. et al. J Clin Oncol 28: 2010 suppl abstr 3614; Uetake H. et al. J Clin Oncol 29: 2011 suppl abstr 3605). Methods: Between July 2008 and July 2011, we analyzed 8,234 consecutive patient samples sent to a reference laboratory for KRAS genotyping as a screening for cetuximab use. DNA was extracted from paraffin-embedded tissue, exon 1 was amplified by PCR and submitted to direct sequencing. Codons 12 and 13 were analyzed. Results: The median age was 59 years and well balanced according to gender with 51.9% of male and 48.1% female patients. The percentage of wild-type and mutated KRAS was 66.4 and 33.6%, respectively. Corroborating previous findings a significant difference in the percentage of mutated KRAS patients was observed between female and male (34.8% versus 32.5%, p = 0.03). However there were no differences in the distribution of any specific KRAS mutation according to gender. Among the 2,626 mutated cases, 83% were in codon 12 versus 17% in codon 13. Mutation Gly12Asp was the most common being detected in 36% of the mutated cases. Conclusions: This is one of the largest cohorts of KRAS genotyping in CRC patients. In line with previous data our present findings indicate that KRAS-mutations are more frequent in female than male. Further research is required to better address the impact of gender differences and/or hormones as potential drivers of CRC carcinogenesis.
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