Prognostic relevance of ALT-associated markers in liposarcoma: a comparative analysis

Background: Most cancers maintain telomeres by activating telomerase but a significant minority, mainly of mesenchymal origin, utilize an alternative lengthening of telomeres (ALT) mechanism. Methods: In this study we comparatively analyzed the prognostic relevance of ALT in a monoinstitutional series of 85 liposarcoma patients as a function of the marker (ALT-associated promyelocytic leukemia bodies (APB) versus heterogeneous telomeres) used to classify the tumor. Results: Independently of the detection approach, ALT proved to be a prognostic discriminant of increased mortality, although the prognostic relevance of the two markers appeared at different follow-up intervals (at 10 years for APB and 15 years for telomeres). Conclusions: Overall, we confirmed ALT as an indicator of poor clinical outcome in this disease and provide the first evidence that the sensitivity of the ALT predictive power depends, at least in part, on the method used.