title: Radiation-induced stress response in peripheral blood of breast cancer patients differs between patients with severe acute skin reactions and patients with no side effects to radiotherapy.
abstract: The aim of the study was to compare the radiation-induced oxidative stress response in blood samples from breast cancer patients that developed severe acute skin reactions during the radiotherapy, with the response in blood samples from patients with no side effects. Peripheral blood was collected from 12 breast cancer patients showing no early skin reactions after radiotherapy (RTOG grade 0) and from 14 breast cancer patients who developed acute severe skin reactions (RTOG grade 3-4). Whole blood was irradiated with 0, 5 and 2000mGy γ-radiation and serum was isolated. The biomarker for oxidative stress, 8-oxo-dG, was analyzed in the serum by a modified ELISA. While a significant radiation-induced increase of serum 8-oxo-dG levels was observed in serum of the RTOG 0 patients, no increase was seen in serum of the RTOG 3-4 patients. The radiation induced increase in serum 8-oxo-dG levels after 5mGy did not differ significantly from the increase observed for 2000mGy in the RTOG 3-4 cohort, thus no dose response relation was observed. A receiver operating characteristic (ROC) value of 0.97 was obtained from the radiation-induced increase in 8-oxo-dG indicating that the assay could be used to identify patients with severe acute adverse reactions to radiotherapy. The results show that samples of whole blood from patients, classified as highly radiosensitive (RTOG 3-4) based on their skin reactions to radiotherapy, differ significantly in their oxidative stress response to ionizing radiation compared to samples of whole blood from patients with no skin reactions (RTOG 0). Extracellular 8-oxo-dG is primarily a biomarker of nucleotide damage and the results indicate that the patients with severe acute skin reactions differ in their cellular response to ionizing radiation at the level of induction of oxidative stress or at the level of repair or both.
authors: Centre for Radiation Protection Research, Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE 10691 Stockholm, Sweden.
authors: Sara
authors: S
authors: Skiöld
authors: Ingemar
authors: I
authors: Naslund
authors: Karl
authors: K
authors: Brehwens
authors: Arja
authors: A
authors: Andersson
authors: Peter
authors: P
authors: Wersall
authors: Elisabet
authors: E
authors: Lidbrink
authors: Mats
authors: M
authors: Harms-Ringdahl
authors: Andrzej
authors: A
authors: Wojcik
authors: Siamak
authors: S
authors: Haghdoost
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000208:Acute Disease; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001773:Blood Cells / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000097:blood / Q000150:complications / Q000473:pathology* / Q000532:radiotherapy; D015331:Cohort Studies; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000097:blood; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005720:Gamma Rays / Q000009:adverse effects*; D006801:Humans; D008875:Middle Aged; D018384:Oxidative Stress / Q000528:radiation effects*; D011836:Radiation Tolerance / Q000528:radiation effects; D012871:Skin Diseases / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*
chemical_list: D015415:Biomarkers; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine
keywords: 8-Oxo-dG; Breast cancer; Oxidative stress; Predictive assay; Radiosensitivity; Radiotherapy