Högskolan i Skövde

Introduction: Accurate assessment and monitoring of the therapeutic efficacy of locally advanced prostate cancer remains a major clinical challenge. Contrary to prostate biopsies, circulating tumor cells (CTCs) are a cellular source repeatedly obtainable by blood sampling and could serve as a surrogate marker for treatment efficacy. In this study, we used size-based filtration to isolate and enumerate CTCs from the blood of 20 patients with high-risk (any one of cT3, Gleason 810, or prostate-specific antigen>20 ng/ml), nonmetastatic, and treatment-naive prostate cancer before and after androgen deprivation therapy (ADT) and radiation therapy (RT).

Materials and methods: We performed 3D telomere-specific quantitative fluorescence in situ hybridization on isolated CTCs to determine 3D telomere profiles for each patient before and throughout the course of both ADT and RT.

Results: Based on the distinct 3D telomere signatures of CTC before treatment, patients were divided into 3 groups. ADT and RT resulted in distinct changes in 3D telomere signatures of CTCs, which were unique for each of the 3 patient groups.

Conclusion: The ability of 3D telomere analysis of CTCs to identify disease heterogeneity among a clinically homogeneous group of patients, which reveals differences in therapeutic responses, provides a new opportunity for better treatment monitoring and management of patients with high-risk prostate cancer.