The effects of information and negative affect on severity of side effects from radiation therapy for prostate cancer

A randomized clinical trial with 152 patients was conducted to examine the effects of an informational intervention on the severity of side effects resulting from radiation therapy for prostate cancer. We also examined negative affect both as a predictor and as an outcome variable. The informational intervention, given to patients at the first and fifth treatments, was based upon self-regulation theory and provided patients with specific, objective information about what to expect during their radiation treatments. Patients in the comparison group received general information at the same point in time. Negative affect was measured using the Profile of Mood States (POMS) prior to the intervention and at the last treatment. The severity of side effects for each individual was assessed at their last treatment. The results showed that patients in the informational intervention group reported significantly fewer problems with sleep and less fatigue (marginally significant) than those in the comparison group. Negative affect was not influenced by group assignment. Baseline negative affect was not related to symptom development, although the development of side effects was associated with an increase in negative mood. The results suggest that patients could benefit from increased knowledge about what to expect during their radiation treatments.