The late radiotherapy normal tissue injury phenotypes of telangiectasia, fibrosis and atrophy in breast cancer patients have distinct genotype-dependent causes.
Br J Cancer
; 96(6): 1001-7, 2007 Mar 26.
Article
in En
| MEDLINE
| ID: mdl-17325707
The relationship between late normal tissue radiation injury phenotypes in 167 breast cancer patients treated with radiotherapy and: (i) radiotherapy dose (boost); (ii) an early acute radiation reaction and (iii) genetic background was examined. Patients were genotyped at single nucleotide polymorphisms (SNPs) in eight candidate genes. An early acute reaction to radiation and/or the inheritance of the transforming growth factor-beta1 (TGFbeta1 -509T) SNP contributed to the risk of fibrosis. In contrast, an additional 15 Gy electron boost and/or the inheritance of X-ray repair cross-complementing 1 (XRCC1) (R399Q) SNP contributed to the risk of telangiectasia. Although fibrosis, telangiectasia and atrophy, all contribute to late radiation injury, the data suggest that they have distinct underlying genetic and radiobiological causes. Fibrosis risk is associated with an inflammatory response (an acute reaction and/or TGFbeta1), whereas telangiectasia is associated with vascular endothelial cell damage (boost and/or XRCC1). Atrophy is associated with an acute response, but the genetic predisposing factors that determine the risk of an acute response or atrophy have yet to be identified. A combined analysis of two UK breast cancer patient studies shows that 8% of patients are homozygous (TT) for the TGFbeta1 (C-509T) variant allele and have a 15-fold increased risk of fibrosis following radiotherapy (95% confidence interval: 3.76-60.3; P=0.000003) compared with (CC) homozygotes.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Radiation Injuries
/
Telangiectasis
/
Breast Neoplasms
/
Radiation Pneumonitis
Type of study:
Etiology_studies
/
Prognostic_studies
Limits:
Female
/
Humans
Language:
En
Journal:
Br J Cancer
Year:
2007
Document type:
Article