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.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
30
The activity of the oncology Department of the North Hospital ensures the quick and easy recruitment of 30 patients over the 10-month inclusion period. The collection of samples will be done in a forward-looking manner during chemotherapy and at different times. The patients will have 4 blood samples of 10 mL carried out during their chemotherapy with a sampling at T0 (before the initiation of chemotherapy), then to T1 (after the first 3 cures), to T2 (after the 6th cure) and to T3 is 5 weeks after the end of the chemo And before the onset of radiation therapy. The samples will be carried out within the Medical Oncology Department of the hospital Nord of Marseille. We will also perform micronuclei testing on Binucleate lymphocytes in culture. The lymphocyte Micronuclei test reveals structure and number chromosomal damage and allows to reveal clastogenic or eugènes exposures.
: Service de Gynécologie Obstétrique Hôpital Nord
Marseille, Marseille Cedex 20, France
RECRUITINGanalysis of the frequency of reticulocytes PIG-A mutated
The analyzes will be applied at T0 to determine the intra-assay reproducibility. The frequency distributions of mutated cells will be compared: * Between the two groups of patients at T0 then, * Within each group between T0 (before exposure), T1 (in process), T2 (end of treatment) and T3 (in therapeutic monitoring post) using non-parametric tests on paired and unpaired.
Time frame: 24 months
analysis of the binucleated cell micronuclei frequency in culture
Determining the frequency of micronucleated binucleate cells in culture will be performed on the samples at T0 and T3 each patient of both groups. The frequency distribution of micronucleated cells will be compared within each group between T0 and T3 using non-parametric tests on paired series. A difference shall be considered significant if p \<0.05.
Time frame: 24 months
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