γ-H2AX as a protein biomarker for radiation exposure response in ductal carcinoma breast tumors: Experimental evidence and literature review

Radiotherapy is an effective cancer treatment, but, there are individualized variable responses and also even with highly conformal treatment planning, associated radiation toxicities in neighboring normal tissues remain the major limiting factor for delivering tumoricidal doses. Clear differences exist between patients regarding their individual tissue responses after radiotherapy. Even after strictly identical treatment modalities, some patients seem to have different responses even in their normal tissues; some tolerate the treatment well, whereas others develop severe radiation induced side effects. There is increasing evidence that the patient‐to‐patient variability in tissue response is caused primarily by their genetic predisposition, by subtle mutations, or polymorphisms in genes involved in cellular responses to radiation (1‐3). The study of damage to cellular DNA is essential for the understanding of cell apoptosis and mutation that may lead to serious disease including * and H. Mozdarani M. Salimi