Local tumor control and DNA-PK activity of peripheral blood lymphocytes in prostate cancer patients receiving radiotherapy

• Published in: Journal of radiation research 2017-03, Vol.58 (2), p.225-231
• Main Authors: Someya, Masanori, Hasegawa, Tomokazu, Hori, Masakazu, Matsumoto, Yoshihisa, Nakata, Kensei, Masumori, Naoya, Sakata, Koh-ichi
• Format: Article
• Language: English
• Subjects: Aged; DNA-Activated Protein Kinase - blood; Humans; Leukocytes, Mononuclear - enzymology; Male; Middle Aged; Multivariate Analysis; Oncology; Prostate-Specific Antigen - blood; Prostatic Neoplasms - blood; Prostatic Neoplasms - enzymology; Prostatic Neoplasms - radiotherapy; Prostatic Neoplasms - urine; Recurrence; Risk Factors
• ISSN: 0449-3060; 1349-9157
• DOI: 10.1093/jrr/rrw099

Abstract Repair of DNA damage is critical for genomic stability, and DNA-dependent protein kinase (DNA-PK) has an important role in repairing double-strand breaks. We examined whether the DNA-PK activity of peripheral blood lymphocytes (PBLs) was related to biochemical (prostate-specific antigen: PSA) relapse and radiation toxicity in prostate cancer patients who have received radiotherapy. A total of 69 patients with localized adenocarcinoma of the prostate participated in this study. Peripheral blood was collected 2 years or later after radiotherapy and centrifuged, then DNA-PK activity was measured by a filter binding assay. The high DNA-PK activity group had a significantly higher PSA relapse–free survival rate than the low DNA-PK activity group. The 10-year PSA relapse–free survival was 87.0% in the high DNA-PK activity group, whereas it was 52.7% in the low DNA-PK activity group. Multivariate analysis showed the Gleason score and the level of DNA-PK activity were significant predictors of PSA relapse after radiotherapy. In addition, the low DNA-PK activity group tended to have a higher incidence of Grade 1–2 urinary toxicity than the high DNA-PK activity group. Prostate cancer patients with low DNA-PK activity had a higher rate of PSA relapse and a higher incidence of urinary toxicity. DNA-PK activity in PBLs might be a useful marker for predicting PSA relapse and urinary toxicity, possibly contributing to personalized treatment of prostate cancer.