Xrcc1 Gene Polymorphisms and Side Effect with Whole Breast Radiotherapy: a Meta-analysis

Breast cancer is the most common type of cancer among women with an incidence rate of 13% worldwide (Bray et al., 2004; Boyle et al., 2005; Héry et al., 2008). Whole breast radiotherapy, which is widely used after breast-conserving surgery, has been shown to reduce the risk of loco-regional recurrence of breast cancer by approximately 70% and to be as effective as radical mastectomy (Fisher et al., 2002). However, radiationinduced skin reaction is the most common side effect in breast cancer patients and can affect the therapeutic program and worsen the quality of life of patients (Schnur et al., 2011). Acute and late normal tissue effects are known to vary considerably, even between patients treated with identical schedules, ranging from negligible to severe. There is increasing evidence that the heterogeneity of normal tissue reactions in cancer patients treated with radiotherapy may be related to their genetic predisposition,