Background and aims: The CpG island methylator phenotype (CIMP) is found in approximately 30% of colorectal cancer (CRC) cases. However, the role of CIMP status in predicting oncologic outcomes in curatively resected CRC is still unclear.
Study: Between January 2006 and December 2006, we retrospectively reviewed 157 consecutive patients who underwent curative surgery for CRC. Prognostic significance of CIMP status was evaluated using reverse transcriptase-polymerase chain reaction.
Results: CIMP-high (H) and CIMP-none/low (N/L) tumors were found in 50 cases (31.8%) and 107 cases (68.2%), respectively. CIMP-H tumors were significantly associated with female sex, colonic location, poorly/mucinous histologic type, higher T category, perineural invasion, and MSI-high status (P = 0.001). During a median of 64.5 months, tumor recurrence developed in 47 (29.9%) patients. The 5-year disease-free survival for CIMP-H and CIMP-N/L was 61.4% and 76.3% (P = 0.018). In addition, multivariate analysis showed that CIMP-H was also a significant prognostic factor (P = 0.042). When analysis was performed according to anatomical location, more marked survival differences were observed in patients with colon cancer (P = 0.026) than in patients with rectal cancer (P = 0.210). Similarly, the role of CIMP status as a prognostic indicator was more prominent in patients with stage I/II (P = 0.006) than in patients with stage III/IV CRC (P = 0.65).
Conclusions: DNA methylation status can be considered as a useful predictor of survival after CRC surgery, particularly for patients with stage I/II disease or colon cancer.
Keywords: CpG island methylator phenotype; colorectal cancer; prognosis.
© 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.