Ki67 representing the proliferation of the cells for the active tumors. Moreover, a lot of studies performed to determine its prognostic role. This study evaluated the significance and prognostic role of Ki67 among molecular subtypes of breast cancer.
Methods: Ki67 was measured in 58 cases of primary breast cancers in pathology department of Zagazig University from 2016-2018. These patients were evaluated for Estrogen Receptor, Progesterone Receptor, and HER2. Ki67 was divided to high and low according to percentage levels: < 20% and ≥ 20%.
Result: Among 58 cases studied, the patients' age ranged from 22 to 72 years, (50%) cases were classified luminal A subtype, (24.1%) cases as luminal B, (15.5%) cases as HER2 enriched, and (10.3%) cases triple-negative. Luminal tumors featured a prevalence of lower tumor grades (grades 1and 2), whereas high tumor grade (grade 3) predominated among the HER2-enriched and triple-negative subtypes (66.7% for each). Triple-negative was significantly associated with younger ages. We observed that high expression of Ki67 appears to be associated with tumor size, high histological grade & stage, positive lymph node, distant metastasis, histological type, hormonal receptor negativity and poor Nottingham Prognostic Index. Conclusion: We concluded that Luminal A breast cancer is the most common molecular subtype in patients of Zagazig University Hospitals, similar to other international and local studies, triple-negative subtype is the most aggressive subtype associated with poorer prognostic parameters, and Ki67 may be considered as a valuable biomarker in breast cancer patients.
Key words: breast cancer, Ki67, molecular subtypes, prognosis