Clinicopathological profiles and ki67 expression of luminal B breast cancer in Hospital Pakar Universiti Sains Malaysia
Abstract
Objective Breast cancer has a growing incidence among Malaysian women. It’s molecular classification, based on immunohistochemical (IHC) staining, has been widely used as a guide for therapeutic decision making. Luminal B is an aggressive molecular subtype with poor outcomes. This study aimed to determine the prevalence, prognostic parameters, and outcomes of luminal B, distinguished from luminal A subtype by a nuclear marker, Ki67, in the female breast cancer population in Hospital Pakar Universiti Sains Malaysia (HPUSM). Materials and methods A retrospective study included 165 female patients with luminal breast cancer (ER/PR+, HER2− and HER2+) treated at HPUSM from years 2009-2018. Quantitative analysis of stained luminal A slides via Ki67 antigen was performed. Positive slides (cut-off level >20%) were termed luminal B HER2− subtype, and the clinicopathological features recorded. Cross-tabulated statistics of recorded data were performed for the luminal B subtypes. Statistical significance was measured using Chi Square test, Fisher’s exact test and Mann-Whitney U t-test, where appropriate. Statistical analysis was done using SPSS version 26. Results and Discussion 85 luminal B cases were reported. Among the stained luminal A cases, 19% were positive, and termed luminal B HER2−. Luminal B cancers were prevalent in premenopausal women (52%), with parity >3 (62%); associated with high grade (46% grade 2) and stage (44% stage 4). 34% patients had recurrence within 5 years of diagnosis. 70% had lymph node involvement and 45% had lympho-vascular invasion. Lung and bone were the most common sites of metastasis, while nodular metastasis was strongly linked to recurrence (34.5% patients). Conclusion Luminal B was shown to have high grade, stage, metastasis, and recurrence, while differentiating from luminal A via the ki67 index. Owing to its disease course, early diagnosis and management are essential in improving patient outcomes. Bangladesh Journal of Medical Science Vol. 25 No. 04 October’26 Page: 1154-1161