Hyphomycetes, a class of fungi that includes several genera such as Cordyceps and Trichoderma, have been studied for their potential benefits in cancer treatment, particularly in reducing side effects of chemotherapy and radiotherapy. Among the Hyphomycetes, the most well-documented are medicinal mushrooms like Cordyceps sinensis and related species. These fungi are rich in bioactive compounds such as polysaccharides, cordycepin, and nucleoside derivatives, which have demonstrated immunomodulatory, anti-inflammatory, and antioxidant effects in both in vitro and in vivo studies.

Some clinical trials and animal studies suggest that extracts from these fungi can help mitigate chemotherapy-induced myelosuppression, fatigue, and other toxicities by enhancing immune function (e.g., stimulating NK cell activity and improving cytokine profiles). For example, a few randomized controlled trials (RCTs) in China have reported that Cordyceps supplementation may improve quality of life and reduce hematological toxicity in cancer patients undergoing treatment. However, the quality of clinical evidence is moderate; studies often have small sample sizes, methodological limitations, and sometimes lack rigorous controls.

Overall, while there is a growing body of preclinical and limited clinical evidence supporting the use of certain Hyphomycetes in reducing cancer treatment side effects, more large-scale, high-quality RCTs are needed to confirm efficacy and safety. The evidence rating is therefore moderate (3/5).