Telomere function in colorectal cancer

Table 1 Summary of the relationship between telomere length and clinic-pathological parameters in CRC described by different authors

Authors	No. of CRC patients	Telomeres and clinic-pathological parameters
Engelhardt et al[46], 1997	100	Telomeres in early stage Dukes’ A and B tumours were significantly shorter than telomeres in late-stage Dukes’ C and D tumours
Gertler et al[43], 2004	57	Telomeres of UICC stage I tumours were significantly shorter than telomeres of UICC stages II-IV tumours. Telomere length ratio of cancer to no cancer tissue was shown to be an independent prognostic parameter for overall survival. Telomere length ratio > 0.90 implied a 3.3 times higher RR compared with patients who had telomere shortening
Garcia-Aranda et al[44], 2006	91	Telomeres of tumours of the right colon displayed significantly shorter telomeres compared with tumours located in other sites. A significantly poor clinical outcome in the group of patients who had tumours with longer telomeres was observed both in overall survival and disease-free survival. This parameter was found to be a significant prognostic factor independent of tumour stage. RR was 6.48 in patients who had tumours with longer telomeres

CRC: Colorectal cancer.

Table 2 Summary of the relationship between telomerase activity and clinic-pathological parameters in CRC described by different authors

Authors	No. of CRC patients	Telomerase and clinic-pathological parameters
Engelhardt et al[46], 1997	100	Lower rates of telomerase activity were detected in tumours at early stages
Okayasu et al[67], 1998	371	There is a correlation between positive telomerase activity and lymph node metastasis
Lukman et al[61], 2000	17	Lower rates of telomerase activity were detected in tumours at early stages. Telomerase activity detection is more frequent in colon than in rectal tumours
Shoji et al[60], 2000	30	TI increased significantly with depth of invasion. TI was higher in telomerase positive tumours with venous invasion
Tatsumoto et al[47], 2000	100	Lower rates of telomerase activity were detected in tumours at early stages. The overall survival and the disease-free survival of patients showing high telomerase activity was significantly worse than those for other patients. Telomerase activity was an independent prognosis-associated factor
Ghori et al[66], 2002	30/202	Lower rates of telomerase activity were detected in tumours at early stages
Kawanishi-Tabata et al[69], 2002	1221	Telomerase activity detection is more frequent in colon than in rectal tumours at stage II. Telomerase positive tumours at stage II were larger than telomerase negative tumours. Disease-free survival for patients with telomerase negative tumours was shorter than for patients with telomerase positive tumours
Maláska et al[65], 2004	41	There is a correlation between positive telomerase activity and lymph node metastasis
Sanz-Casla et al[64], 2005	103	Lower rates of telomerase activity were detected in tumours at early stages. Telomerase activity detection is more frequent in colon than in rectal tumours. Telomerase activity could be used to predict the risk of death or recurrence
Garcia-Aranda et al[44], 2006	91	Higher rates of telomerase activity were detected in patients older than 69 years-old. Patients who had tumours with telomerase activity and high telomere length ratios had a significantly shorter disease-free survival compared with patients whose tumours showed lower telomere length ratios
Bautista et al[72], 2007	108	Patients with low TI rectal tumours showed a higher recurrence-free survival and overall survival probability. TI was an independent prognostic factor for predicting the recurrence in the first two years after surgery and for survival in rectal cancer patients
Vidaurreta et al[62], 2007	97	Lower rates of telomerase activity were detected in tumours at early stages. The overall survival of patients with telomerase activity was significantly worse than those for other patients

¹Number of tumour samples;

²30 tumour samples and 20 adjacent normal mucosa samples.