title: Oxaliplatin-based Chemotherapy Might Provide Longer Progression-Free Survival in KRAS Mutant Metastatic Colorectal Cancer.
abstract: The identification of better regimens in currently available chemotherapeutic agents is crucial for treating patients with KRAS mutant metastatic colorectal cancer (mCRC). Records of mCRC patients who received first-line oxaliplatin-based or irinotecan-based regimens were reviewed retrospectively. Clinicopathologic features and treatment outcome of patients with first-line progression-free survival (PFS) and overall survival (OS) in association with KRAS mutation status were analyzed using the Cox proportional hazard model. Between 2007 and 2010, a total of 118 mCRC patients were enrolled. Among them, 67 were males and 51 were females. In patients who received first-line oxaliplatin-based regimens, the PFS was significantly longer in KRAS mutant patients (N = 32) than that in KRAS wild-type patients (N = 51). The median PFS was 8.5 months in KRAS mutant versus 5.8 months in KRAS wild-type patients (P = .008). In contrast, in patients who received first-line irinotecan-based regimens, the PFS was shorter in KRAS mutant patients (N = 15) than that in KRAS wild-type patients (N = 20). Median PFS was 3.9 months in KRAS mutant versus 6.0 months in KRAS wild-type patients (P = .23). Median OS between KRAS mutant and wild-type patients was not significantly different in both oxaliplatin-based and irinotecan-based regimens. In multivariate analyses, KRAS mutation remains an independent predictive factor for longer PFS in first-line oxaliplatin-based regimens. In conclusion, oxaliplatin-based chemotherapy in KRAS mutant mCRC might result in longer PFS than in KRAS wild-type mCRC.
authors.affiliation: Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan ; Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Lin
authors.forename: Jau-Yu
authors.initials: JY
authors.lastname: Liau
authors.forename: Shan-Chi
authors.initials: SC
authors.lastname: Yu
authors.forename: Li-Hui
authors.initials: LH
authors.lastname: Tseng
authors.forename: Liang-In
authors.initials: LI
authors.lastname: Lin
authors.forename: Jin-Tung
authors.initials: JT
authors.lastname: Liang
authors.forename: Ben-Ren
authors.initials: BR
authors.lastname: Lin
authors.forename: Ji-Shiang
authors.initials: JS
authors.lastname: Hung
authors.forename: Yih-Leong
authors.initials: YL
authors.lastname: Chang
authors.forename: Kun-Huei
authors.initials: KH
authors.lastname: Yeh
authors.forename: Ann-Lii
authors.initials: AL
authors.lastname: Cheng