Mechanisms underlying the effects of n-3 polyunsaturated fatty acids on fear memory processing and their hypothetical effects on fear of cancer recurrence in cancer survivors

Abstract Objectives Dysfunctional processing of fear memory may be involved in the pathophysiology of fear of cancer recurrence (FCR), which is cited as the major unmet psychological need of cancer survivors. Emerging evidence has shown that the microbiota-gut-brain (MGB) axis affects psychiatric disorders, including depressive and anxiety disorders, which are associated with fear memory (PMID: 29628046). We therefore hypothesized that the gut microbiota is associated with FCR in cancer survivors (PMID: 29628046). Methods This cross-sectional study enrolled women diagnosed with invasive breast cancer who were not currently undergoing chemotherapy. Fecal samples were obtained to assess the gut microbiota. FCR grade was assessed using the Concerns About Recurrence Scale (CARS). Results Mean age of the participants (n = 126) was 58 years; 47% had stage I disease. Multiple regression analysis with adjustment for possible confounders showed that the relative abundance of the Bacteroides genus (beta = 0.180, P = 0.03) was significantly and directly associated with FCR. In the 57 participants with a history of chemotherapy, higher FCR was associated with lower microbial diversity (P = 0.04), lower relative abundance of Firmicutes (P = 0.03) and higher relative abundance of Bacteroidetes (P = 0.04) at the phylum level, and higher relative abundance of Bacteroides (P < 0.01) and lower relative abundance of Lachnospiraceae.g (P = 0.03) and Ruminococcus (P = 0.02) at the genus level. Conclusions Our findings provide the first evidence of an association between the gut microbiota and FCR and suggest that chemotherapy-induced changes in gut microbiota can influence FCR. Further studies should examine the effects of the gut microbiota on FCR using a prospective design. Funding Sources This study was supported in-part by a donation from Morinaga Milk Industry Co. Ltd, grants from the Japan Society for the Promotion of Sciences and the Foundation for Promotion of Cancer Research.

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Perilla Oil and Bifidobacterium for Alleviating Fear of Cancer Recurrence in Breast Cancer Survivors: Study Protocol for a Three-Arm Phase II Randomized Controlled Study (POB Study)

Methods and Protocols ◽

10.3390/mps4030046 ◽

2021 ◽

Vol 4 (3) ◽

pp. 46

Author(s):

Yohei Sasaki ◽

Mina Honyashiki ◽

Takayuki Kinoshita ◽

Akira Matsui ◽

Ayako Nakashoji ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Survivors ◽

Phase Ii ◽

Study Protocol ◽

Breast Cancer Survivors ◽

Cancer Recurrence ◽

Fear Of Cancer Recurrence ◽

Randomized Controlled ◽

Perilla Oil ◽

Fear Of Cancer

The fear of cancer recurrence (FCR) is the most common and most severe unmet need among cancer survivors. Safe treatments for the FCR that are easily disseminated are greatly needed. Our primary aim is a preliminary evaluation of the efficacy and effect size of perilla oil, which is rich in omega-3 fatty acids, and Bifidobacterium, a probiotic, on FCR in breast cancer survivors after the completion of chemotherapy. This study has been planned as an exploratory clinical study (phase II) and will be conducted as a three-arm, 12-week parallel group, masked-rater randomized controlled trial. Fifteen participants will be randomized with 1:1:1 allocation to receive Bifidobacterium plus perilla oil, Bifidobacterium alone, or no intervention (control). Interventions will end within 12 weeks after the random allocation of each participant. The participants will be outpatients with invasive breast cancer aged 20 years or older whose chemotherapy was completed at least 6 months before registration; hormone therapy may be ongoing. The primary outcome will be severity of FCR at 12 weeks assessed by masked raters using the 4-item Concerns about Recurrence Scale concerning overall fear of recurrence. The study protocol for the current study is registered in the Japan Registry of Clinical Trials (jRCTs031200029).

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