| Patients with late-stage prostate cancer often face a variety of treatment decisions. Interventions like androgen deprivation therapy (ADT) are not only associated with physiological side effects, but are also accompanied by effects on Quality of Life (QOL). This experimental study recruited 73 men aged 50 and older with stage IV prostate cancer assigned to either continuous or intermittent ADT to evaluate whether these treatment modalities, which reduce biologically available levels of testosterone (BioT), result in differential impacts with regard to QOL. Participants in this study were followed prospectively and assessed at three timepoints over the course of 24 to 32 months. A MANCOVA using data from timepoint 3 on nine dependent variables associated with QOL in prostate cancer patients undergoing ADT included: Physical Functioning, Role Limitations Due to Physical Health, Pain, General Health, Emotional Wellbeing, Role Limitations Due to Emotional Health, Energy, Social Functioning, and Depression. Adjustments were made for eight covariates: age, education, presence of diabetes, body mass index, time since diagnosis, processing speed, verbal learning, and verbal fluency. Group membership predicted differences in overall QOL (F(9) = 4.61, p < .01). Specifically, individuals in the continuous ADT treatment group experienced lower levels of Physical Functioning (F(1) = 12.08, p < .01) and more Role Limitations Due to Physical Health (F(1) = 6.78, p < .05). Significant multilevel correlations between levels of BioT with Physical Functioning and depressive symptoms were found after adjusting for multiple observations among participants. Other trends for non-significant associations and limitations of this study are discussed. Understanding the impact of intermittent and continuous ADT on a variety of domains associated with QOL could inform health care decisions in the future and may help to devise strategies for support and supplemental intervention approaches to improve overall treatment outcomes in late-stage prostate cancer patients undergoing ADT. |
