The Use of New Therapies for Metastatic Castrate Resistant Prostate Cancer in the North of Portugal

Abstract

Introduction:
New drugs such as abiraterone (Abi), enzalutamide (Enz), cabazitaxel (Cab) and radium 223 (Rad) were recently approved for metastatic castrate resistant prostate cancer (mCRPC) patients. However, their use in clinical practice is largely unknown, so the objective of this research is to describe their use in mCRPC patients in public hospitals in the north of Portugal.

Methods:
All mCRPC patients treated with these drugs in Centro Hospitalar de Vila Nova Gaia/Espinho, Centro Hospitalar de Trás-os-Montes e Alto, Centro Hospitalar Universitário S. João, Instituto Português de Oncologia do Porto Francisco Gentil, Hospital de Braga and in Centro Hospitalar Universitário do Porto were included. After obtaining the respective authorizations from all hospitals involved, data were retrospectively and standardized collected from the digital clinical records.

Results:
A total of 1075 treatments were included. From these, 368 (34.2%) patients were treated with Abi and 524 (48.7%) patients with Enz. These drugs were mainly prescribed in 2nd line (post-docetaxel) until 2016 and afterwards in 1st line (pre-docetaxel). Cab was used in 147 (13.7%) patients, mostly in 2nd line (post-docetaxel) or in 3rd line. Patients treated with Cab were younger (p<0.001), were more likely to have undifferentiated neoplasms (p=0.007) and have visceral metastasis (p<0.001). Only 36 (3.3%) patients were treated with Rad, usually in the 3rd line and none of them had visceral metastasis and 97.2% had more than 3 bone metastases.

Conclusion:
The use of these drugs replicated their respective therapeutic approvals. This study is limited by the retrospective and observational design and might not represent the entire country but is based on a multicentric big sample of the six biggest hospitals in the north of Portugal and reflects the reality experienced by patients.