Published online Mar 7, 2015. doi: 10.3748/wjg.v21.i9.2629
Peer-review started: September 11, 2014
First decision: October 14, 2014
Revised: October 31, 2014
Accepted: December 1, 2014
Article in press: December 1, 2014
Published online: March 7, 2015
Processing time: 180 Days and 4.3 Hours
AIM: To investigate GATA5, SFRP2, and ITGA4 methylation in plasma DNA as noninvasive biomarkers for colorectal cancer (CRC) or adenomas.
METHODS: There were 57 CRC patients, 30 adenomas patients, and 47 control patients enrolled in this study. Methylation-specific polymerase chain reaction was used to determine the promoter methylation status of GATA5, SFRP2, and ITGA4 genes in plasma DNA, and their association with clinical outcome in CRC. The predictive ability of GATA5, SFRP2, and ITGA4 methylation, individually or in combination, to detect CRC or adenomas was further analyzed.
RESULTS: Hypermethylated GATA5 was detected in plasma in 61.4% (35/57) of CRC cases, 43.33% (13/30) of adenoma cases, and 21.28% (10/47) of control cases. The hypermethylation of SFRP2 was detected in 54.39% (31/57), 40.00% (12/30), and 27.66% (13/47) in plasma samples from CRC, adenomas, and controls, respectively. ITGA4 methylation was detected in 36.84% (21/57) of plasma samples of CRC patients and in 30.00% (9/30) of plasma samples from patients with colorectal adenomas, and the specificity of this individual biomarker was 80.85% (9/47). Moreover, GATA5 methylation in the plasma was significantly correlated with larger tumor size (P = 0.019), differentiation status (P = 0.038), TNM stage (P = 0.008), and lymph node metastasis (P = 0.008). SFRP2 and ITGA4 methylation in plasma significantly correlated with differentiation status (SFRP2, P = 0.012; ITGA4, P = 0.007), TNM stage (SFRP2, P = 0.034; ITGA4, P = 0.021), and lymph node metastasis (SFRP2, P = 0.034; ITGA4, P = 0.021). From the perspective of predictive power and cost-performance, using GATA5 and SFRP2 together as methylation markers seemed the most favorable predictor for CRC (OR = 8.06; 95%CI: 2.54-25.5; P < 0.01) and adenomas (OR = 3.35; 95%CI: 1.29-8.71; P = 0.012).
CONCLUSION: A combination of GATA5 and SFRP2 methylation could be promising as a marker for the detection and diagnosis of CRC and adenomas.
Core tip: Hypermethylated GATA5 was identified as a novel plasma gene in colorectal cancer (CRC) and adenomas, and it showed high potential as a biomarker in plasma-based DNA testing. Furthermore, this study suggests that a combination of GATA5 and SFRP2 methylation could be used as a promising marker for the detection, diagnosis, and prognosis of CRC and adenomas.