MKI67 and neoplasm: The fourth CPRS was characterized by an age < 40 years (respectively 12 observed vs 9 expected and 48 observed vs 21 expected for the <35 years and 35–39 years subgroups), ≥4 lymph nodes involved (255 observed vs 105 expected) a tumor size >2 (250 observed vs 127 expected), ER < 50 (70 observed vs 45 expected), PGR < 20 (78 observed vs 52 expected), G3 (155 observed vs 106 expected), and a Ki-67 ≥ 26 (129 observed vs 83 expected) (Fig. 3c).