Poly(ADP-ribose) polymerase-1 Overexpression as A Predictive Factor for Poor Chemotherapy Outcome in Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC), is paradoxical breast cancer subtype. Some TNBC response well to chemotherapy but TNCB with remaining tumor mass after neoadjuvant chemotherapy have worse prognosis. Most TNBCs have defects in DNA repair pathway. To survive they activate alternative DNA repair pathway involving poly(ADP-ribose)polymerase-1 (PARP1), reflected by PARP1 overexpression. The aim of this study was to prove PARP1 overexpression as a predictive factor for poor chemotherapy outcome in TNBC. This study was conducted in retrospective case-control method. The PARP1 expressions immunohistochemically evaluated in 25 patients with positive chemotherapy clinical response and 25 patients with negative chemotherapy clinical response. The results were analyzed by Chi square and Odds ratio (OR) with significance at p<0.05. The results showed that PARP1 overexpression significantly correlated with poor chemotherapy clinical response (?2=6.522, OR=4.57, 95% IK=1.38-15.11, p=0.011). In conclusion TNBC with PARP1 overexpression have the possibility of showing poor chemotherapy clinical response 4.6 times higher than non-overexpression TNBC. Examination of PARP1 expression is important as predictive factors for chemotherapy outcome and consideration for utilization PARP1 inhibitor as targeted therapy in TNBC.