Effects of yoga in men with prostate cancer on quality of life and immune response: a pilot randomized controlled trial

Abstract

Background: Diagnosis and treatment of prostate cancer is associated with anxiety, fear, and depression in up to one-third of men. Yoga improves health-related quality of life (QoL) in patients with several types of cancer, but evidence of its efficacy in enhancing QoL is lacking in prostate cancer.

Methods: In this randomized controlled study, 29 men newly diagnosed with localized prostate cancer were randomized to yoga for 6 weeks (n = 14) or standard-of-care (n = 15) before radical prostatectomy. The primary outcome was self-reported QoL, assessed by the Expanded Prostate Index Composite (EPIC), Functional Assessment of Cancer Therapy-Prostate (FACT-P), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Functional Assessment of Cancer Therapy-General (FACT-G) at baseline, preoperatively, and 6 weeks postoperatively. Secondary outcomes were changes in immune cell status and cytokine levels with yoga.

Results: The greatest benefit of yoga on QoL was seen in EPIC-sexual (mean difference, 8.5 points), FACIT-F (6.3 points), FACT-Functional wellbeing (8.6 points), FACT-physical wellbeing (5.5 points), and FACT-Social wellbeing (14.6 points). The yoga group showed increased numbers of circulating CD4+ and CD8+ T-cells, more production of interferon-gamma by natural killer cells, and increased Fc receptor III expression in natural killer cells. The yoga group also showed decreased numbers of regulatory T-cells, myeloid-derived suppressor cells, indicating antitumor activity, and reduction in inflammatory cytokine levels (granulocyte colony-stimulating factor [0.55 (0.05-1.05), p = 0.03], monocyte chemoattractant protein [0.22 (0.01-0.43), p = 0.04], and FMS-like tyrosine kinase-3 ligand [0.91 (-0.01, 1.82), p = 0.053].

Conclusions: Perioperative yoga exercise improved QoL, promoted an immune response, and attenuated inflammation in men with prostate cancer. Yoga is feasible in this setting and has benefits that require further investigation.

Trial registration: clinicaltrials.org (NCT02620033).

Fig. 1. CONSORT diagram.

Flowchart of patient enrollment process for the study.

Fig. 2. Effect size of the yoga intervention compared to the minimally important difference (MID) with 95% confidence interval.

The effect size was calculated as the difference between the postintervention score minus the preintervention score in the yoga group and the postintervention score minus the preintervention score in the control group. The MID was calculated as one-third of the overall standard deviation of the patient-reported scale item at baseline. The ⊗ mark on the graph indicates the MID for the scale item. EPIC Expanded Prostate Index Composite, FACIT Functional Assessment of Chronic Illness Therapy, FACIT-F FACIT-Fatigue, FACIT-G FACIT-General, FACT Functional Assessment of Chronic Illness Therapy, FFOM Five Facets of Mindfulness, TOI Trial Outcome Index.

Fig. 3. Analysis of immune cell data.

a A t-distributed stochastic neighbor embedding (tSNE map) showing differences in immune cell phenotypes between the yoga group and the control group. b Box and whiskers plot of immune markers (IFNγ+CD4+, IFNγ+CD8+, IFNγNK, CD16+, CD11b+CD33+, CD15-CD14+CD33+, perforin+CD8+) between samples obtained from 13 patients in the control group and those obtained from 6 patients in the yoga group at endpoint.

Fig. 4. Analysis of cytokine data.

Volcano plot showing the difference in increase in expression levels of granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein (MCP-1) and FMS-like tyrosine kinase-3 ligand (Flt-3 ligand) from baseline between the yoga group and the control group granulocyte colony-stimulating factor [0.55 (0.05–1.05), p = 0.03], monocyte chemoattractant protein [0.22 (0.01–0.43), p = 0.04], and FMS-like tyrosine kinase-3 ligand.