Published online Feb 7, 2018. doi: 10.3748/wjg.v24.i5.631
Peer-review started: November 13, 2017
First decision: December 3, 2017
Revised: December 13, 2017
Accepted: December 19, 2017
Article in press: December 19, 2017
Published online: February 7, 2018
Processing time: 78 Days and 16.9 Hours
To investigate the predictive value of PIK3CA and TP53 mutation status in colorectal cancer (CRC) patients treated with 5-fluorouracil-based chemotherapy.
In this study, a total of 315 patients with histologically proven CRC were enrolled from Yangpu Hospital affiliated to Shanghai Tongji University between 2007 and 2011. Of these patients, 241 with stage II/III CRC received 5-fluorouracil-based adjuvant chemotherapy. Formalin-fixed paraffin-embedded lesion samples of the patients with curatively resected CRC were collected. Next-generation sequencing was performed to identify somatic gene mutations. The correlation of PIK3CA and TP53 mutation status with overall survival (OS) was analyzed using a Cox proportional hazard model and the Kaplan-Meier method.
Among the 241 patients with stage II/III in this cohort, the PIK3CA and/or TP53 mutation was detected in 177 patients, among which 54 patients had PIK3CA and TP53 double mutations. The PIK3CA or TP53 mutation was not significantly correlated with OS in univariate and multivariate analyses. Compared with patients without PIK3CA and TP53 mutations, those with double PIK3CA-TP53 mutations showed a significantly worse survival (univariate HR = 2.21; 95%CI: 1.15-4.24; multivariate HR = 2.02; 95%CI: 1.04-3.91). The PIK3CA mutation located in the kinase domain showed a trend toward a shorter OS compared with wild-type tumors (multivariate HR = 1.56; 95%CI: 1.00-2.44; P = 0.052). The Kaplan-Meier curve showed that patients harboring the PIK3CA mutation located in the kinase domain had a worse clinical outcome than those with wild-type status (Log-rank P = 0.041)
Double mutation of PIK3CA and TP53 is correlated with a shorter OS in stage II/III CRC patients treated with 5-fluorouracil-based therapy.
Core tip: Targeted next-generation sequencing was used to detect gene mutations rather than mutational hotspots in the present study. This manuscript is by far the first to report the predictive value of the combined mutation status of PIK3CA and TP53 in colorectal cancer patients receiving 5-FU-based adjuvant chemotherapy. Our data revealed that the double mutation of PIK3CA and TP53 is an independent predictive factor for overall survival in stage II/III patients receiving 5-FU-based chemotherapy.