449P - The study of androgen receptor status in triple negative breast cancer patients at Medical Oncology Department, Yangon General Hospital (YGH)

Background

Breast cancer is the most common malignant tumor in women worldwide. Among the molecular subtypes of breast cancer, triple negative breast cancer (TNBC) is associated with worse prognosis and it lacks targetable hormonal receptor. In TNBC, androgen receptor (AR) positivity is about 25%-75% and would get potential benefit from anti-androgen therapy. The aims of this study are to know the occurrence of TNBC cases at Medical Oncology Department, YGH, and to know the AR status in TNBC cases.

Methods

This is a hospital-based, cross sectional descriptive study. All TNBC cases attending Medical Oncology Department, YGH, were collected from January 2019 to December 2019. Immunohistochemistry (IHC) for androgen receptor was done by peroxidase anti-peroxidase method.

Results

Among 808 breast cancer patients attended during study period, 515 patients were available for IHC testing and 88 patients were TNBC subtype. In those patients, 61 TNBC cases were included in this study; 22 patients were AR positive and 39 patients were AR negative. In TNBC, the youngest was 33, the eldest was 73 and median age was 53. Nine patients were <40 years of age. In histology, invasive ductal carcinoma was the commonest (91.8%). Regarding staging, unlike developed countries, advanced stage (64%) was the most common stage. Among AR positive patients, 23% were <40 years of age and 77% were ≥40 years. sixty eight percents of patients presented in advanced stage. In patients with negative AR status, 10% were <40 years of age and 90% were ≥40 years of age. Regarding the stage, 38% were early stage and 62% were advanced stage.

Conclusions

Although the risk of breast cancer increases with age, many younger patients were included in this study, reflecting that the trend is changing. Most patients presented at late stage and this points out that our population have limited knowledge about breast cancer. In this study, AR negativity (64%) is much more than that of positivity (36%), there were much younger patients in AR positive subgroup and not much association was seen between AR and histology. This study shows fundamental knowledge regarding AR status in TNBC in Myanmar.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Ministry of Health.

Funding

Ministry of Health.

Disclosure

All authors have declared no conflicts of interest.