Telomere maintenance mechanism and survival probability for 5 cancer types. (A) The percentage of the four types of telomere maintenance mechanisms in tumor samples; TEL: telomerase, TEL+ALT: telomerase and alternative lengthening of telomere, NDTMM: non defined telomere maintenance mechanism, ALT: alternative lengthening of telomere. (B) Pie chart showing the frequency of four telomere maintenance mechanisms in primary tumors of 31 cancer types, TEL: 9%, TEL+ALT: 47%, NDTMM: 17%, and ALT: 27%. (C) Pie chart showing the frequency of the four telomere maintenance mechanisms in metastatic tumors of 11 cancer types, TEL: 8%, TEL+ALT: 50%, NDTMM: 13%, and ALT: 29%. (D) Kaplan–Meier plots showing the overall survival rates of patients classified according to the four telomere maintenance mechanisms. The p-value was calculated using the log-rank test. Five cancer types (ACC, GBM, HNSC, PAAD, and SARC) had significantly different prognoses. ACC, adrenocortical carcinoma; GBM, glioblastoma multiforme; HNSC, head and neck squamous cell carcinoma; PAAD, pancreatic adenocarcinoma; and SARC, sarcoma.