Clinical value of circulating tumor cell typing and RAS/RAF gene detection in colorectal cancer / 中国医师杂志

ABSTRACT

Objective:To investigate the correlation between circulating tumor cell (CTC) detection, RAS/RAF gene mutation and clinicopathological characteristics in patients with colorectal cancer (CRC).Methods:The Amplification Refractory Mutation System (ARMS)-polymerase chain reaction (PCR) were used to detect the gene mutation in the tumor tissues of 138 CRC patients in the Third Affiliated Hospital of Sun Yat-sen University from May 2017 to May 2020. At the same time, the venous blood of 138 patients was collected and enriched for CTC genotyping by mRNA in situ hybridization. The correlation between CTC, RAS/RAF gene mutation and clinicopathological features of CRC patients was analyzed.Results:The mutation rates of KRAS, NRAS and BRAF genes were 48.6%(67/138), 5.1%(7/138) and 1.4%(2/138), respectively; The overall positive rate of CTC was 84.1%(116/138). The positive rates of different CTC types were 23.1%(32/138) in epithelial type, 71.7%(99/138) in mixed type and 12.3%(17/138) in interstitial type respectively. The positive rate of CTC in CRC patients with clinical stage Ⅲ-Ⅳ, lymph node metastasis (N1-N3) and distant metastasis (M1) was significantly higher than that in CRC patients with stage Ⅰ-Ⅱ, no lymph node metastasis (N0) and no distant metastasis (M0) (all P<0.05). The total number of CTC, mixed CTC and interstitial CTC were positively correlated with clinical stage, lymph node metastasis and distant metastasis (all P<0.05). RAS/RAF gene mutation, gender, age, tumor location and tumor differentiation did not affect the positive rate of CTC (all P>0.05). Conclusions:The results of CTC typing are of great research significance for comprehensive treatment, prognosis assessment and stratified management of CRC, among which the interstitial type of CTC may be a high risk factor for the recurrence and metastasis of CRC.