Prognostic impact of telomeric repeat containing RNA expressing on long-term oncologic outcomes in colorectal cancer

Abstract

Purpose: Telomere shortening is associated with colorectal carcinogenesis and transcription from subtelomeres produces telomeric repeat containing RNA (TERRA), a natural inhibitor of telomerase activity (TA). Previous studies on TERRA expression demonstrated downregulation in advanced stages of human tumors.

Materials and Methods: We evaluated the 2p TERRA expression and telomere length using quantitative real-time PCR in 60 patients who underwent surgical resection for colorectal cancer between June 2008 and November 2010.

Results: Patients were grouped according to 2p TERRA expression, with 27 (45%) and 33 (55%) in the low and high TERRA expression groups, respectively. The median follow-up period was 80 months (range 2-103). 2p TERRA expression was marginally significantly associated with preoperative CEA (P = 0.082) and significantly associated with telomere length (P < 0.05). Five-year overall survival rates in the high 2p TERRA expression group and the low expression group were 73.6% and 78.2%, respectively (p = 0.322), and five-year disease-free survival rates in the high 2p TERRA expression group and the low expression group were 66.1% and 75.1%, respectively (p = 0.317).

Conclusions: 2p TERRA expression was marginally significantly associated with preoperative CEA and significantly associated with telomere length; however, it was not prognostic on long-term oncologic outcomes in colorectal cancer.