Androgen receptor expression in triple-negative breast cancer cases and its effect on prognosis

SUMMARY Androgen Receptor Expression in Triple-Negative Breast Cancer Cases and Its Effect on Prognosis Objective: Breast cancer is the most seen malignity in females and the second most common cause of cancer-related death. Triple-negative breast cancer has higher recurrence rates and risk of death due to its aggressive nature and lack of targeted therapies. The androgen receptor is a member of the nuclear hormone receptor family, like estrogen and progesterone receptors, which was reported as a good prognostic factor in triple-negative breast cancer. Determining the androgen receptor expression has an essential role in new therapeutic options for this cancer group, which lacks targeted therapies. In this study, we aimed to analyse the overall survival, disease-free survival, and the effect of androgen receptor expression on survival and its relationship with prognostic factors in triple-negative breast cancer. Materials and Methods: 75 patients were included in this study, diagnosed and followed at the outpatient clinic of the Medical Oncology Division of the Department of Internal Medicine, Karadeniz Technical University Faculty of Medicine, between 2010-2018. The pathology results of these patients diagnosed with triple negative breast cancer were analyzed. Overall and disease-free survival, androgen receptor expression and positivity, and clinical and pathological prognostic factors were analysed in all cases included in the study. Findings: All cases were female and over 18 years old. The mean age was 52,83 ± 13,2 (minimum 32 and maximum 84). The median body mass index was 26. While there was no family history in 80% of the cases, it was present in 13.3%. The width of the largest tumour was 10 cm, and the smallest one was 0,1 cm, with a median width of 2,8. While lymph node metastases were found in %43 of the cases, %57 of the cases were not. The one-year survival was %97,3 and three years of survival was %76. The overall and disease-free survival was statistically significant and longer for all who had no lymph node metastases detected at the time of diagnosis. While %41,3 cases were androgen receptor-positive, %58,7 of them were androgen receptor-negative. Overall survival and disease-free survival were longer in the androgen-positive group than in the negative group. However, no statistically significant difference was found between two groups (p=0,997, p=0,9). %41,3 of the androgen-positive cases developed metastases during the follow-up. The bone metastases were higher in the androgen-positive group compared with the androgen-negative group (p=0,039). All 5 cases diagnosed with invasive lobular carcinoma were in the androgen-positive group. A statistically significant difference was found between androgen-positive and androgen-negative groups considering histological groups. Overall survival and disease-free survival were longer for androgen receptor-positive patients with no lymph node metastases at the time of diagnosis, respectively, p= 0.038 and p=0,0076. Results: In this study, we found that the positivity of the androgen receptor positively affects overall and disease-free survival. By adding the androgen receptors into the routine histopathological evaluation, like estrogen and progesterone receptors, it is thought that treatments targeting the androgen receptor may be promising in the targeted therapy group, which is lacking in the triple-negative breast cancer group.