Treatment patterns and oncological outcomes of older adults with metastatic prostate cancer in real-world setting

Abstract

Background: The landscape of systemic therapies for metastatic hormone-sensitive (mHSPC) and castration resistant prostate cancer (mCRPC) extensively improved within the last decades resulting in a significantly prolonged overall survival. However, subgroup analyses of phase III trials suggest potentially different overall survival outcomes for older adults.

Methods: We relied on our institutional metastatic prostate cancer database to identify mHSPC and subsequently mCRPC patients. Older adults were stratified according to age groups 70-74 versus ≥75-79 versus ≥80 years at metastatic occurrence. Subsequently, uni- and multivariable time to mCRPC and overall survival analyses were performed.

Results: Of 494 older adults, 217 (44%) were 70-74 versus 180 (36%) 75-79 versus 97 (20%) ≥80 years old. Rates of local prostate cancer treatment differed significantly between all three groups (p < 0.01). Regarding mHSPC treatment, androgen receptor signaling inhibitors (ARSI) were administered in 30-39% of patients and docetaxel with 9% in age group 70-74 years and 6% and 3% in age groups 75-79 years and ≥80 years. Regarding mCRPC treatment, significant differences between treatment proportions were observed (p < 0.01). Most common treatment was ARSI for all three groups. Conversely, chemotherapy was more frequently administered in patients aged 70-74 (16%), relative to 4% and 3% in 75-79 year and ≥80 year aged patients. In univariable and multivariable time to mCRPC analyses, overall survival in mHSPC and OS in mCRPC analyses, no significant differences between all three age groups were observed (all p ≥ 0.3).

Conclusions: Treatment patterns differ significantly between older adults with metastatic prostate cancer. However, these differences may not result in differences of overall life expectancy.

Keywords: De novo; mCRPC; mCSPC, survival; mHSPC; metastatic prostate cancer.