Breast Cancer )BC) is the most Common malignancy in women in 2020, there were 2.3 million women diagnosed with breast cancer and 685.000 deaths globally. Breast cancer rates are 88% higher in developed countries compared to developing countries .
TNBC represents accounts for approximately 24% of all breast cancer in 2020 .While in Egypt it accounts for 11.05% according to Egyptian national BC (5). By gene expression profiling ,4 subtypes of TNBC emerged : luminal androgen receptor (LAR), mesenchymal stem-like (MSL), immunomodulatory (IM), basal-like (BL1 and BL2) . Most of cases are advanced with median survival about 14 months . Brain and visceral organs represent common sites of distant metastasis . So it is considered the worst prognosis . In addition , chemotherapy is only option in treatment with no available targeted options for decades. Now we have Immunotherapy (IO ) and PARP inhibitors in neoadjuvant (NAT) and metastatic setting For example : Key note 355 which add Pembrolizumab in NAT which lead to marked improvement in pathological complete response ( PCR ) And in high risk patient and have marked results in disease and event free survival(8) .Poly (ADP-ribase) poly merase -1 (PARP-1) inhibitors appear to particularly effective in BRCA 1/2 mutation carries (9) .As reviewed by rodleret al. emerging data suggest that BRCA 1/2 carriers with TNBC disease may respond favorably to cisplatin therapy .
