Cyclin D1 expression in ductal carcinoma breast and its correlation with other prognostic markers

Objectives: In the past few decades, alarmingly, there has been a substantial increase in the incidence of breast cancer in India. Triple-negative tumors are among the various molecular types that are associated with a dismal prognosis. Expression of Cyclin D1 in tumors has been associated with tumorigenesis, suggesting its potential role as a prognostic marker of clinical significance. The study aims to evaluate cyclin D1 expression in invasive mammary cancer and its relationship to various clinicopathological and histologic parameters. Material and Methods: This is a retrospective observational study conducted on 110 cases of breast cancer specimens received in the department of pathology over 4 years. Clinicopathological data were collected. Immunohistochemistry (IHC) for Cyclin D1 was performed and statistically analyzed with other histopathological parameters. Results: One hundred and ten cases were studied. The mean age was 54.56 ± 9.85 years. The most common molecular subtype was Luminal B (44.2%), followed by triple-negative breast cancer (TNBC) (31%) and Luminal A (21.2%). The HER2neu subtype was observed in 3.6% of cases. TNBC cases exhibited significantly higher Ki-67% expression compared to non-TNBC cases. Cyclin D1 expression was observed in 53% of breast cancers and absent in 46% of the cases; however, no significant correlation was observed between expression of Cyclin D1, tumor grade, stage, and molecular subtypes. Conclusion: No significant correlation was observed between Cyclin D1 expression by immunohistochemistry and other prognostic markers. Further large-scale molecular studies are necessary to evaluate the potential of Cyclin D1 as a target, particularly in TNBC, which is linked to a poor prognosis.