MKI67 and Hereditary breast and ovarian cancer syndrome: Studies show that tumors related to HBOC syndrome are often larger, less poorly differentiated, with high cell proliferation markers, predominance of the invasive ductal histological type, and triple-negative subtype, leading to a more aggressive form of the disease.22, 23, 24, 25, 26This study corroborates these results, as there was a higher prevalence of advanced ductal carcinomas, tumor size greater than 2 cm, lymph nodes involvement, poorly differentiated tumors, Ki-67 ≥ 25%, and triple-negative subtype in the increased risk group.