Can 8-oxo-dG be used as a predictor for individual radiosensitivity?
OBJECTIVE
To develop predictive tests for individual radiosensitivity of tumor patients.


METHODS
Acute skin reactions were clinically scored among 40 women after 46 Gy, given with 2 Gy fractions to breast and regional lymph nodes, adjuvant after surgery. The acute skin reactions were compared to the excretion of 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxo-dG) in urine, determined by high-performance liquid chromatography (HPLC) with electrochemical detector. Specimens of urine were collected before and during postoperative radiation treatment at given intervals. We compared a group of 9 patients with the most pronounced skin reactions with another group of 8 patients with almost no skin reactions at 46 Gy.


RESULTS
The level of 8-oxo-dG excreted in urine during 8 h was measured. After normalizing the excretion to irradiated volumes, dose per volume and excretion before irradiation, the 8-oxo-dG level in urine was significantly (p < 0.001) lower for the patients with pronounced skin reactions as compared to patients with minor skin reactions, at an accumulated dose of 12 Gy. In addition, the background level of 8-oxo-dG excreted before treatment started, was significantly (p = 0.043) lower for patients with minor skin reactions as compared to patients with pronounced skin reactions. The background level of 8-oxo-dG was corrected for body weight and normalized to BMI.


CONCLUSIONS
We suggest that the excretion of 8-oxo-dG into urine of breast cancer patients is a possible marker for acute radiosensitivity.
Haghdoost
S
S
Department of Radiotherapy, Radiumhemmet, Stockholm, Sweden. Siamak.haghdoost@ks.se
Svoboda
P
P
Näslund
I
I
Harms-Ringdahl
M
M
Tilikides
A
A
Skog
S
S
D000080242:8-Hydroxy-2'-Deoxyguanosine; D015415:Biomarkers / Q000652:urine; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery / Q000652:urine*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000652:urine*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D011237:Predictive Value of Tests; D011836:Radiation Tolerance / Q000502:physiology*; D011855:Radiodermatitis / Q000652:urine; D018714:Radiotherapy, Adjuvant; D012867:Skin / Q000528:radiation effects
D015415:Biomarkers; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine