Mushrooms have been used since ages for various medical reasons, nearly for all of our well known medical conditions.
Many of them have been used for cancer treatment,at least for support, especailly in Japan and Korea
.One compound, Active Hexose Correlated Compound (AHCC)[found in shiitake] have shown beneficial in many cases for all kind of the most common cancers and also to alleviate many of the side effects of chemotherapy [nausea,less liver toxicity,leucopenia, less hairloss? etc

Why would every oncological patient not be given this compound which-pricewise-is totally insignificant compared to extremely expensive chemotherapy?
You can order it yourself if you wish:[all good brands, I think]

https://www.betterlife.com/product/ahcc-500-mg/planetary-herbals/38967

https://www.betterlife.com/product/ahcc-500-mg-vegetarian-capsule/source-naturals/39350

https://www.betterlife.com/product/ahcc-500-mg/aor-advanced-orthomolecular-research/53167

https://www.iherb.com/pr/Quality-of-Life-Labs-Kinoko-Platinum-AHCC-750-mg-60-Vegicaps/72288 out of stock at this moment