Background: Abiraterone acetate (AA) is a selective oral inhibitor of Steroid-17α-Hydroxylase, for patients with castration-resistant prostate cancer. Not all patients respond to therapy, however, there are no biomarkers predicting response to AA therapy. The aim of the present study was the identification of a biomarker for patients who are likely to respond to AA therapy.
Patients and methods: We measured thyroid parameters in a collective of 30 patients before and during AA therapy. For statistical analyses, paired and unpaired t-tests were used.
Results: During AA therapy, responders developed a significant increase in thyroid stimulating hormone (TSH) compared to non-responders (p=0.03). In the subgroup of responders, 16 out of 21 patients (76.1%) had a significant increase in TSH level (p=0.001), suggesting that TSH increase is predictive of therapy response. Non-responders showed no change in TSH level during AA therapy.
Conclusion: Hypothyreosis may serve as a simple predictive biomarker for therapy response under AA therapy.
Keywords: Abiraterone acetate; biomarker; castration-resistant prostate cancer; hypothyreosis.