Dose-response relationship for breast cancer induction at radiotherapy dose

• Main Authors: Gruber Günther, Robotka Judith, Sumila Marcin, Schneider Uwe, Mack Andreas, Besserer Jürgen
• Format: Article
• Language: English
• Published: BMC 2011-06-01
• Series: Radiation Oncology
• Subjects: second cancer; breast cancer; carcinogenesis
• Online Access: http://www.ro-journal.com/content/6/1/67

<p>Abstract</p> <p>Purpose</p> <p>Cancer induction after radiation therapy is known as a severe side effect. It is therefore of interest to predict the probability of second cancer appearance for the patient to be treated including breast cancer.</p> <p>Materials and methods</p> <p>In this work a dose-response relationship for breast cancer is derived based on</p> <p>(i) the analysis of breast cancer induction after Hodgkin's disease,</p> <p>(ii) a cancer risk model developed for high doses including fractionation based on the linear quadratic model, and</p> <p>(iii) the reconstruction of treatment plans for Hodgkin's patients treated with radiotherapy,</p> <p>(iv) the breast cancer induction of the A-bomb survivor data.</p> <p>Results</p> <p>The fitted model parameters for an <it>α/β = 3 </it>Gy were <it>α = 0.067Gy</it>^{<it>-1 </it>}and <it>R = 0.62</it>. The risk for breast cancer is according to this model for small doses consistent with the finding of the A-bomb survivors, has a maximum at doses of around 20 Gy and drops off only slightly at larger doses. The predicted <it>EAR </it>for breast cancer after radiotherapy of Hodgkin's disease is 11.7/10000PY which can be compared to the findings of several epidemiological studies where EAR for breast cancer varies between 10.5 and 29.4/10000PY. The model was used to predict the impact of the reduction of radiation volume on breast cancer risk. It was estimated that mantle field irradiation is associated with a 3.2-fold increased risk compared with mediastinal irradiation alone, which is in agreement with a published value of 2.7. It was also shown that the modelled age dependency of breast cancer risk is in satisfying agreement with published data.</p> <p>Conclusions</p> <p>The dose-response relationship obtained in this report can be used for the prediction of radiation induced secondary breast cancer of radiotherapy patients.</p>