DISCUSSION
RP, fatigue, anxiety, cancer, cognitive impairments, reduced depression, insomnia, depression, prostate cancer
CANCER, SECONDARY, PROSTATE CANCER
The goal of this planned secondary analysis of a one‐year phase IIb RCT was to evaluate the effects of MAG‐EPA supplementation as compared to those of a placebo (HOSO) on depression and other psychological symptoms that are prevalent in men with prostate cancer. Findings revealed significant changes over time of several variables, that is depression (assessed with HADS‐D but not PHQ‐9), anxiety, FCR, insomnia, fatigue (number of days), and cognitive functioning (impact), mainly at the beginning of the study. However, patients who received MAG‐EPA did not show significantly greater changes than those on placebo on any variable and at any time point. Omega‐3 supplementation does not appear to improve depression and other patient‐reported outcomes in men with prostate cancer treated with RP.Comparing results with the previous literature is challenging given significant differences in populations studied, and the dosage and composition of the n‐3 PUFA used (e.g., proportion and dosage of EPA and DHA). Yet, results of this trial contradict prior evidence showing reduced depression with n‐3 supplementation in the general population despite the fact that our supplements contained a larger amount of EPA and a greater EPA:DHA ratio than most prior studies.Prior evidence on effects of n‐3 supplementation on other symptoms was rather sparse and equivocal. Consistent with RCTs conducted in individuals without cancer,It is noteworthy that RP took place between V0 and V2 when most of the significant reductions were found. Longitudinal studies have shown that depression, FCR, and symptoms such as insomnia and perceived cognitive impairments are at their highest point around the time of cancer diagnosis and improve afterwards.This study has several strengths. Patients were recruited in routine cancer care thus increasing the study's external validity. Symptoms were measured using validated self‐report scales. The one‐year follow‐up with multiple time points and the use of placebo capsules identical in appearance to MAG‐EPA capsules are other strengths. On the other hand, our participants had a circulating n‐6/n‐3 ratio in red blood cell membranes of 3.7 ± 0.68 (Western diet is typically around 16:1In conclusion, results of this trial did not support the efficacy of n‐3 supplementation in alleviating depression, anxiety, FCR, insomnia, fatigue, and subjectively assessed cognitive impairments in men treated for prostate cancer with RP. RCTs that specifically include patients with clinical levels of depression and other symptoms are warranted.