A PubMed search for <cancer Lentinula edodes> returns 64 hits (& 56 for <cancer Lentinus edodes>}, but only one for PCa. Some of the studies specifically used Lentinan, a β-(1→6) branched β-(1→3)-glucan.
Shiitake mushrooms are popular enough that all of my local supermarkets carry them. Apart from the morel, which one can find hereabouts in the Spring, the shiitake is my favorite mushroom. It is classed as a medicinal mushroom, so I feel a little virtuous when I have some with my bacon & egg. LOL
No mention of cancer in the Wiki-page [1].
[2] (2002 - U.S.)
An unlikely human PCa study:
"A total of 62 men (mean age 73.2 years, range 53.6 to 85.5) with histologically proven prostate cancer who had two consecutive elevated PSA readings were accrued to the study during a 3-month period."
Why select the shiitake for this? & why expect a 50% drop in PSA when used as monotherapy?
"Thirty-eight patients had stable PSA levels after 6 months. Although not the primary endpoint of the study, in other studies these patients could have been included as responders."
Nice try!
"shiitake mushroom extract" "alone is ineffective in the treatment of clinical prostate cancer."
Presumably, the men would have been watchful waiting cases? GS=3+3? But with increasing PSA.
[3] (2016 - Japan) Not PCa but interesting.
"Improvement of QOL and Immunological Function With Lentinula Edodes Mycelia in Patients Undergoing Cancer Immunotherapy"
"The participants received either dendritic cell (DC)-based cancer vaccine therapy or CD3-activated T-lymphocyte (CAT) therapy as immunotherapy. They received the immunotherapy only for the first 4 wk of the study, and then oral LEM {extract of Lentinula edodes mycelia} (1800 mg/d) was added for the next 4 wk."
"Participants' QOL symptom scores increased (ie, worsened) by 5.1 ± 1.7 during the first 4 wk of treatment when they were receiving immunotherapy only, but it decreased (ie, improved) by -2.5 ± 1.6 during the next 4 wk when the immunotherapy was combined with the LEM"
"The measurement of the immunological parameters during the 4 wk of immunotherapy combined with LEM showed that the amount of interferon-γ (IFN-γ) produced in the peripheral blood tended to increase as compared with that during the first 4 wk of immunotherapy only. The rise in IFN-γ was correlated with changes in several regulatory T cells (Tregs) (ie, forkhead box P3 [FOXP3]+/cluster of differentiation 4 [CD4]+ and transforming growth factor beta [TGF-β])."
-Patrick
[1] en.wikipedia.org/wiki/Shiitake