VIDEO: Early measure could assist escalation, de-escalation of prostate cancer therapies
CHICAGO — In this Healio video exclusive, Silke Gillessen, MD, discusses how identification of early surrogate measures for long-term outcomes in prostate cancer could identify patients who require therapy escalation or can be de-escalated.
Gillessen, medical oncologist for the Oncology Institute of Southern Switzerland, spoke about the research by Praful Ravi, MD, and colleagues presented at ASCO Annual Meeting. The identification of early surrogate measures for long-term outcome measures such as prostate cancer-specific survival (PCSS), metastasis-free survival (MFS) and OS could expedite development of new systemic therapies added to radiotherapy (RT) plus androgen deprivation therapy (ADT), while also potentially identifying patients for therapy de-escalation, according to researchers.
In the presented study, researchers included 10,415 patients from 16 randomized controlled trials. Of those studied, 2,629 received only RT; 6,033 received RT plus short-term ADT (defined as 3 to 6 months); and 1,753 received RT plus long-term ADT (defined as 18 to 36 months).
“It’s important that we have this data now, but unfortunately, we cannot use it as a new surrogate marker for overall survival,” Gillessen said.
According to results, researchers linked prostate-specific antigen nadir (PSAn) 0.1 ng/mL with poorer PCSS, MFS and OS in patients allocated to RT plus short-term ADT. PSAn 0.1 ng/mL within 6 months after RT completion was a strong prognostic indicator for PCSS, MFS and OS in patients receiving RT plus ADT for localized prostate cancer.
“In the end, it did not demonstrate surrogacy. It cannot be used as a new trial endpoint, but it could be used as a criterion to select patients for escalation or de-escalation of treatment in trials,” Gillessen continued.
References:
- Ravi P, et al. Abstract 5002. Presented at: ASCO Annual Meeting; June 2-6, 2023; Chicago.