In vivo versus in vitro individual radiosensitivity analysed in healthy donors and in prostate cancer patients with and without severe side effects after radiotherapy

Abstract

Background: A high cellular radiosensitivity may be connected with a risk for development of severe side effects after radiotherapy and indicate cancer susceptibility. Hence, a fast and robust in vitro test is desirable to identify radiosensitive individuals.

Materials and methods: The study included 25 prostate cancer patients with severe side effects (S) and 25 patients without severe side effects (0) after radiotherapy as well as 23 male healthy age-matched donors. Blood samples were exposed to 0.5 Gy or 1 Gy of γ-rays. The initial level of double-strand breaks (dsb) and repair kinetics measured by phosphorylation of histone H2A (γ-H2AX-assay), apoptosis (Annexin V-assay) and the induction of chromatid aberrations after irradiation in the G2-phase of the cell cycle (G2-assay) were analysed.

Results: A significant higher chromatid aberration yield was found in lymphocytes from prostate cancer patients when compared to healthy donors. We found no significant differences between patients S and patients 0.

Conclusions: There is no obvious correlation between clinical and cellular radiosensitivity in lymphocytes of prostate cancer patients when all chosen in vitro assays are considered. Although 25% of the patients showed both severe side effects and increased radiation-induced chromosomal sensitivity, predictive value of G2-assay is doubtful.

Keywords::

• Individual radiosensitivity
• chromatid aberrations
• predictive assays
• cancer susceptibility
• DNA damage
• prostate cancer

Acknowledgements

This work was supported by DAAD (German Academic Exchange Service) – Helmholtz and Dr Erich Schmitt foundation. The authors wish to thank all the patients and healthy donors for donations of blood.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.