Correlation of KRAS and PIK3CA gene status between primary tumors and paired metastases in colorectal cancer / 临床与实验病理学杂志

ABSTRACT

Purpose To investigate the mutation status of KRAS and PIK3CA gene in colorectal cancer (CRC) primary lesions and corresponding liver metastasis and its clinical significance.Methods The gene mutations of KRAS and PIK3CA were detected in 58 cases of primary lesions of CRC and corresponding liver metastasis tissue by real-time PCR.Results The mutation rates of KRAS were 31.03％ (18/58) and 25.86％ (15/58) in primary lesions of CRC and corresponding liver metastasis tissue,respectively,in which G12D was most commonly detected.The mutation rates of PIK3CA were 8.62％ (5/58) and 10.34％ (6/58) respectively,in which the most common mutation site was E545K.Only one case carried simultaneously both mutations of KRAS (G12D) and PIK3CA (E545K).The mutation of KRAS and PIK3CA had a good consistency between primary lesions and liver metastasis.Univariate analysis showed that the mutation of KRAS was related to the primary lesion of tumor location,the quantity of metastasis and the types of tumor (P ＜ O.05),PIK3 CA mutation was associated with the synchronous/metachronous liver metastasis and the quantity of metastasis (P ＜ 0.05).Multivariate Cox regression analysis showed that synchronous/metachronous liver metastasis and the mutation of KRAS were influencing factors for prognosis of CRC.The overall survival of patients with CRC who had simultaneous liver metastases was longer than those with heterotopic liver metastases;the overall survival of KRAS wild-type mutant patients was longer than those of mutant patients (P ＜ 0.05).Conclusion The G12D site of KRAS gene has the highest mutation frequency in CRC,KRAS/PIK3CA mutation has a good consistency of the primary lesions of CRC and corresponding liver metastasis.Primary lesions can be as the source of molecular detection.To achieve individualized treatment,we need to reassess the genetic status of metastasis based on the choice of targeted therapy for precision medicine.