Maybe, but site says:

"Stimulates the production of inflammatory signal proteins such as
interleukin-1"

IL-1 is required for cancer invasivness & angiogenesis [Voronov, et al.
Many other studies.]

IL-1 stimulation sems to be a bad idea for PC.  However, I suppose it
is possible for beta glucan to be beneficial because of other effects.

In any event, a cure for cancer is unlikely to be found in a single
supplement.  McCarty has papers explaining why cancer will only be
successfully attacked when we address the multiple cellular protection
mechanisms that have been subverted or silenced.

-pc55