The PIG-A gene (in humans)/Pig-a (in rodents) may be a useful reporter of acquired gene mutation. A simple and reproductive test based on flow cytometry allows detection of Pig-a mutants in a few minutes with low blood volumes. Many studies in rodents showed that detecting Pig-a mutations is useful for identifying genotoxic exposure, but studies are needed in humans to validate this biological marker. The investigators propose to carry out a study to assess the prevalence of PIG-A mutated reticulocytes among 30 patients exposed to genotoxic chemotherapy for breast cancer treatment. The investigators will prospectively collect, for each patient, 4 blood samples of 10mL during chemotherapy: the first one (T0) before chemotherapy (before genotoxic exposure), T1 during treatment (after the third cure), T2 (just at the end of chemotherapy) and T3 (five weeks after the end of chemotherapy). PIG-A mutated cells frequency distributions will be compared between T0, T1, T2 and T3. At the same time, the investigators will document the impact of such a genotoxic exposure using the micronuclei test on in vitro binucleate lymphocytes. The micronuclei test reveals structural or numerical chromosome aberrations caused by aneugenic or clastogenic exposure. This test will be done on T0 and T3 blood samples of each patient.
- paroxysmal nocturnal hemoglobinuria (PNH)