International Journal of Clinical Oncology

, Volume 18, Issue 6, pp 1042–1048

Prognostic relevance of KRAS and BRAF mutations in Japanese patients with colorectal cancer

  • Ryota Nakanishi
  • Jun Harada
  • Munkhbold Tuul
  • Yan Zhao
  • Koji Ando
  • Hiroshi Saeki
  • Eiji Oki
  • Takefumi Ohga
  • Hiroyuki Kitao
  • Yoshihiro Kakeji
  • Yoshihiko Maehara
Original Article

DOI: 10.1007/s10147-012-0501-x

Cite this article as:
Nakanishi, R., Harada, J., Tuul, M. et al. Int J Clin Oncol (2013) 18: 1042. doi:10.1007/s10147-012-0501-x

Abstract

Background

Mutations of the KRAS or BRAF genes are now recognized as prognostic markers for colorectal cancer (CRC). They are also important predictive markers for resistance to the monoclonal antibodies that target the epidermal growth factor receptor.

Methods

In this retrospective study, KRAS and BRAF mutations were analyzed using a direct sequence method in 254 Japanese CRC patients, and the associations between KRAS or BRAF mutations and clinicopathological characteristics or outcome were evaluated.

Results

KRAS and BRAF mutations were detected in 33.5 and 6.7 % of all patients, respectively. Consistent with previous reports, BRAF mutations were significantly correlated with the anatomical site of the tumor (P < 0.001), tumor grade (P = 0.001) and high frequency of microsatellite instability (P < 0.001). BRAF mutations were correlated with poor overall survival in the full patient cohort (P = 0.009). KRAS mutations were significantly correlated with poor recurrence-free survival (P = 0.03), particularly in patients with stage II CRC (P = 0.007). Cox regression analysis showed that KRAS mutations were a negative predictor of recurrence-free survival in patients with stage II CRC.

Conclusion

KRAS mutation status could be a novel biomarker for predicting disease recurrence in Japanese patients with stage II CRC.

Keywords

KRAS and BRAF mutationsColorectal cancerPrognostic factor

Copyright information

© Japan Society of Clinical Oncology 2012

Authors and Affiliations

  • Ryota Nakanishi
    • 1
    • 2
  • Jun Harada
    • 1
  • Munkhbold Tuul
    • 1
    • 2
  • Yan Zhao
    • 1
  • Koji Ando
    • 1
  • Hiroshi Saeki
    • 1
  • Eiji Oki
    • 1
  • Takefumi Ohga
    • 1
  • Hiroyuki Kitao
    • 2
  • Yoshihiro Kakeji
    • 1
  • Yoshihiko Maehara
    • 1
  1. 1.Department of Surgery and Science, Graduate School of Medical SciencesKyushu UniversityFukuokaJapan
  2. 2.Department of Molecular Oncology, Graduate School of Medical SciencesKyushu UniversityFukuokaJapan