MKI67 and invasive ductal breast carcinoma: In the study cohort, a lower percentage of invasive ductal carcinoma (P = 0.026) and a higher frequency of unknown tumor grade (P = 0.003) was seen in the carboplatin treatment group than in the non-carboplatin treatment group, whereas Ki67 levels were higher in the carboplatin treatment group than in the non-carboplatin treatment group (P < 0.001).