MKI67 and breast carcinoma: In literature, the criteria for determining Ki-67, p 53 and ER immunopositivity in breast cancer vary between 5 and 80% of cancer cells (Seymour et al, 1990; Jackson et al, 1990; Barnes and Millis, 1995; Goulding et al, 1995; Wishart et al, 2002).