Medication-based Comorbidity Measures and Prostate Cancer Treatment Selection

Introduction: We aimed to assess the association between comorbidities and prostate cancer management. 

Patients and methods: We studied 12,603 South Australian men diagnosed with prostate cancer between 2003 and 2019. Comorbidity was measured one year prior to prostate cancer diagnosis using a medication-based comorbidity index (Rx-Risk). Binomial logistic regression analyses were used to assess the association between comorbidities and primary treatment selection (active surveillance, radical prostatectomy (RP), external beam radiotherapy (EBRT) with or without androgen deprivation therapy (ADT), brachytherapy, ADT alone, and watchful waiting (WW)). Certain common comorbidities within Rx-Risk (cardiac disorders, diabetes, chronic airway diseases, depression and anxiety, thrombosis, and chronic pain) were also assessed. All models were adjusted for sociodemographic and tumor characteristics. 

Results: Likelihood of receiving RP was lower among men with Rx-Risk score ≥3 (odds ratio (OR) 0.62, 95%CI:0.56-0.69) and Rx-Risk 2 (OR 0.80, 95%CI:0.70-0.92) compared with no comorbidity (Rx-Risk ≤0). Men with high comorbidity (Rx-Risk ≥3) were more likely to have received ADT alone (OR 1.76, 95%CI:1.40-2.21), EBRT (OR 1.30, 95%CI:1.17-1.45) or WW (OR 1.49, 95%CI:1.19-1.88) compared with Rx-Risk ≤0. Pre-existing cardiac and respiratory disorders, thrombosis, diabetes, depression and anxiety, and chronic pain were associated with lower likelihood of selecting RP and higher likelihood of EBRT (except chronic airway disease) or WW (except diabetes and depression and anxiety). Cardiac disorders and thrombosis were associated with higher likelihood of selecting ADT alone. Furthermore, age had greater effect on treatment choice than the level of comorbidity. 

Conclusion: High comorbidity burden was associated with primary treatment choice, with significantly less RP and more EBRT, WW and ADT alone among men with higher levels of comorbidity. Each of the individual comorbid conditions also influenced treatment selection.