More than half of patients with metastatic castration-sensitive prostate cancer (mCSPC) did not receive androgen deprivation therapy (ADT) plus docetaxel or ADT plus novel hormonal therapies as first-line treatment in 2019, even though these regimens are associated with improved survival compared to ADT alone, according to a study presented at the virtual 2021 ASCO Annual Meeting.

These findings were presented by Daniel J. George, MD, FASCO, Duke Cancer Institute Center for Prostate and Urologic Cancers, Duke University, NC.

“ADT has served as the standard of care for patients with mCSPC for decades, but recent clinical trials have shown that combining ADT with either docetaxel or novel hormonal therapy leads to improved survival compared to ADT alone,” explained Dr George during his presentation.

“Given the limited insight on the potential impact of these new this new evidence and guidelines on real-world treatment selection in mCSPC, we evaluated treatment trends in US real-world oncology practice predominantly in the community practice,” he continued.

Dr George and colleagues used the electronic medical record (EMR) data from a network of US oncology practices in the ConcertAI Oncology Dataset to evaluate treatment patterns in mCSPC patients who initiated first-line therapy between 2014–2019.

A total of 858 patients (70% White, 16% Black, 3% Hispanic, and 11% other race/unknown) were included in this study. Patients had a median age of 69 years at mCSPC diagnosis, and 63% had de novo metastases.

The most common first-line regimens were ADT plus nonsteroidal anti-androgen therapy (primarily bicalutamide, 26.3%), ADT monotherapy (20.5%), ADT plus nonhormonal therapy with or without anti-androgen therapy (19.2%), and ADT plus docetaxel with or without anti-androgen therapy (16.4%). The remaining patients (17.55%) received other therapies, including anti-androgen monotherapy (5.9%) or nonhormonal therapy with or without anti-androgen therapy (5.5%)

Nonhormonal therapy included abiraterone, apalutamide, and enzalutamide.

ADT plus nonhormonal therapy with or without anti-androgen treatment increased each year. ADT plus or minus anti-androgen treatment reached peak use in 2017 and then decreased in 2018 and 2019. In 2014, treating patients with ADT plus anti-androgen therapy was the most common treatment method, but use has since declined.

While median duration until initiation of a subsequent regimen was 14.3 months for ADT plus nonhormonal therapy with or without anti-androgen therapy, it was 10.8 months for ADT plus docetaxel and plus anti-androgen therapy.

More than half of patients with mCSPC treated in a recent real-world setting did not receive first-line therapy even though it is associated with improved survival compared to ADT alone, and those who did received shorter durations of treatment than recommended in trials.

“The disconnect between clinical trial evidence and real-world practice could be due to patient disease characteristics causing access issues or lack of physician awareness of the survival advantages seen with treatment intensification in the mCSPC setting,” said Dr George.

“A better understanding these contributing factors is worthy of further study thank you for your interest,” he concluded.—Marta Rybczynski

George DJ, Agarwal N, Rider JR, et al. Real-world treatment patterns among patients diagnosed with metastatic castration-sensitive prostate cancer (mCSPC) in community oncology settings. Presented at: the 2021 ASCO Annual Meeting; June 4-8, 2021; virtual. Abstract 5074.