Association of DNA repair and steroid metabolism gene polymorphisms with clinical late toxicity in patients treated with conformal radiotherapy for prostate cancer.
OBJECTIVE
To explore the possible relationship between single nucleotide polymorphisms (SNP) in candidate genes encoding DNA damage recognition/repair/response and steroid metabolism proteins with respect to clinical radiation toxicity in a retrospective cohort of patients previously treated with three-dimensional conformal radiotherapy (3-DCRT) for prostate cancer.


METHODS
One hundred twenty-four patients with prostate cancer underwent 3-DCRT at our institution between September 1996 and December 2000. Of these, 83 consented for follow-up of blood sampling and SNP analysis. Twenty-eight patients were documented as having experienced grade >/=2 late bladder or rectal toxicity (scoring system of Radiation Therapy Oncology Group) on at least one follow-up visit. We analyzed 49 SNPs in BRCA1, BRCA2, ESR1, XRCC1, XRCC2, XRCC3, NBN, RAD51, RAD52, LIG4, ATM, BCL2, TGFB1, MSH6, ERCC2, XPF, NR3C1, CYP1A1, CYP2C9, CYP2C19, CYP3A5, CYP2D6, CYP11B2, and CYP17A1 genes using the Pyrosequencing technique.


RESULTS
Significant univariate associations with late rectal or bladder toxicity (grade >/=2) were found for XRCC3 (A>G 5' untranslated region NT 4541), LIG4 (T>C Asp(568)Asp), MLH1 (C>T, Val(219)Ile), CYP2D6*4 (G>A splicing defect), mean rectal and bladder dose, dose to 30% of rectum or bladder, and age <60 years. On Cox multivariate analysis, significant associations with toxicity were found for LIG4 (T>C, Asp(568)Asp), ERCC2 (G>A, Asp(711)Asp), CYP2D6*4 (G>A, splicing defect), mean bladder dose >60 Gy, and dose to 30% of rectal volume >75 Gy.


CONCLUSIONS
In this study, we identified SNPs in LIG4, ERCC2, and CYP2D6 genes as putative markers to predict individuals at risk for complications arising from radiation therapy in prostate cancer.
Damaraju
Sambasivarao
S
Cross Cancer Institute, Department of Oncology, University of Alberta, Edmonton, Alberta, Canada.
Murray
David
D
Dufour
Jennifer
J
Carandang
Diana
D
Myrehaug
Sten
S
Fallone
Gino
G
Field
Colin
C
Greiner
Russell
R
Hanson
John
J
Cass
Carol E
CE
Parliament
Matthew
M
D000368:Aged; D019313:BRCA1 Protein / Q000235:genetics; D024682:BRCA2 Protein / Q000235:genetics; D015331:Cohort Studies; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000235:genetics; D004260:DNA Repair / Q000235:genetics* / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000235:genetics; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods*; D012007:Rectum / Q000473:pathology / Q000528:radiation effects; D012189:Retrospective Studies; D013256:Steroids / Q000378:metabolism*; D001743:Urinary Bladder / Q000473:pathology / Q000528:radiation effects; D051759:Xeroderma Pigmentosum Group D Protein / Q000235:genetics
D019313:BRCA1 Protein; D024682:BRCA2 Protein; D004268:DNA-Binding Proteins; C094443:G-T mismatch-binding protein; C000607893:LIG4 protein, human; D013256:Steroids; D003577:Cytochrome P-450 Enzyme System; D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human; D011088:DNA Ligases; D000072481:DNA Ligase ATP