Telomere length is a prognostic factor for overall survival in colorectal cancer

Aim The aim of this study was to determine whether telomere length is an independent prognostic factor for the prevention and survival of colorectal cancer. Method Terminal restriction fragment (TRF) length was determined by Southern blot in tumours and paired normal tissue samples from 147 patients with sporadic colorectal cancer who had undergone surgery. The TRF length ratio (TRFLR) was determined as the ratio between the length of the patient's tumour and normal tissue. The classification and regression tree technique was used to determine optimal cut-off values (<= 1 or > 1). Results Mean TRF length was 6.79 Kbp (1.19-13.99) in tumour tissue and 7.81 Kbp (3.63-15.70) in normal mucosa (P < 0.001). Mean TRFLR was 0.88. Telomere length and telomere length ratio were not correlated with any clinicopathological factors. In univariate analysis, overall survival was related to N stage (lymph node +/-; P = 0.002), TNM classification (P = 0.019) and TRFLR (<= 1 or > 1; P = 0.014). In multivariate analysis, overall survival was significantly associated with TRFLR and N stage. Colorectal cancer patients with TRFLR <= 1 and negative lymph node involvement had a higher overall survival rate. Conclusion Telomere length ratio is an independent prognostic factor for survival in colorectal cancer patients, and the telomere lengths in the normal and tumour mucosa of the same patient present with parallel behaviour.