Predictive factors for late normal tissue complications following radiotherapy for breast cancer.
OBJECTIVE
Radiotherapy after breast-conserving surgery is commonly applied to reduce recurrence of breast cancer but may cause acute and late side effects. To identify prognostic factors for the development of late toxicity after radiotherapy, we conducted a prospective study of breast cancer patients.


METHODS
We assessed late complications of radiotherapy and collected information on epidemiologic factors in a cohort of breast cancer patients who had received radiotherapy after breast-conserving surgery. Among 416 patients with complete follow-up data, the association between possible risk factors and development of late complications was evaluated using multivariate logistic regression analysis.


RESULTS
After a median follow-up time of 51 months, 131 (31.4%) patients presented with telangiectasia and 28 (6.7%) patients with fibrosis. We observed a strong association between development of telangiectasia and fibrosis (p < 0.01). Increasing age of the patient was a risk factor for both telangiectasia and fibrosis (p-value for trend <0.01 and 0.03, respectively). Patients with acute skin toxicity (odds ratio (OR) 1.8, 95% confidence interval (CI) 1.0-3.1) were at higher risk to develop telangiectasia. Long-term smoking was associated with a significant increase in risk of telangiectasia compared to non-smokers (OR 2.3, 95% CI 1.2-4.6).


CONCLUSIONS
Our study revealed several factors other than radiation dose that may predispose to late complications following radiotherapy. Further understanding of differences in response to irradiation may advance individualized treatment and improve cosmetic outcome.
Lilla
Carmen
C
Division of Cancer Epidemiology, C020, German Cancer Research Center, im Neuenheimer Feld 280, 69120 , Heidelberg, Germany.
Ambrosone
Christine B
CB
Kropp
Silke
S
Helmbold
Irmgard
I
Schmezer
Peter
P
von Fournier
Dietrich
D
Haase
Wulf
W
Sautter-Bihl
Marie-Luise
ML
Wenz
Frederik
F
Chang-Claude
Jenny
J
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D005355:Fibrosis / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D011832:Radiation Injuries / Q000209:etiology*; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects; D040521:Subcutaneous Tissue / Q000473:pathology / Q000528:radiation effects; D011795:Surveys and Questionnaires; D013684:Telangiectasis / Q000209:etiology*; D013997:Time Factors; D016896:Treatment Outcome