Medicinal mushrooms have been increasingly studied for their potential role in oncology, particularly as adjunctive therapies alongside conventional cancer treatments such as chemotherapy and radiation. Several types of medicinal mushrooms are believed to have immune-modulating, anti-cancer, and anti-inflammatory properties that may benefit cancer patients.

Several medicinal mushrooms are approved for cancer care in various Asian countries, especially in Japan, China, and South Korea. These mushrooms are primarily used as adjuvants to conventional cancer treatments. Their use is often based on their ability to modulate the immune system, enhance the efficacy of treatments, and improve the overall well-being of patients.

Here's a look at some of the most researched medicinal mushrooms and their possible effects in oncology:

1. Reishi (Ganoderma lucidum)

Key Compounds: Polysaccharides (beta-glucans), triterpenoids.

Potential Effects in Oncology:

• Immunomodulation: Reishi is believed to enhance the immune system by stimulating the activity of natural killer (NK) cells, T-cells, and macrophages, which are crucial for fighting tumors.
• Antitumor Activity: Some studies suggest that Reishi extracts may inhibit cancer cell proliferation and induce apoptosis (programmed cell death) in certain cancer types.
• Quality of Life: Reishi is often used to improve the overall well-being of cancer patients, helping with fatigue and emotional stress.

2. Turkey Tail (Trametes versicolor)

Key Compounds: Polysaccharopeptides (PSP) and polysaccharide-K (PSK).

Potential Effects in Oncology:

• Immunostimulant: PSP, a compound in Turkey Tail, is used as an approved adjuvant in cancer therapy in China, particularly for gastric and colorectal cancers. It enhances immune responses, including increasing NK cell activity.
• Adjunct to Chemotherapy: Turkey Tail extracts have been shown to improve survival rates in some cancers, such as breast, lung, and colorectal cancer, when used alongside chemotherapy.
• Clinical Research: Ongoing clinical trials are investigating its role in improving outcomes for patients with cancers like breast cancer.

3. Chaga (Inonotus obliquus)

Key Compounds: Betulinic acid, inotodiol, polysaccharides.

Potential Effects in Oncology:

• Antioxidant and Anti-inflammatory Properties: Chaga is rich in antioxidants, which help reduce inflammation and oxidative stress—factors that can contribute to cancer development.
• Antitumor Effects: Preliminary studies suggest that Chaga extracts may slow the growth of certain cancer cells, such as liver and colorectal cancer cells, though more research is needed.

5. Maitake (Grifola frondosa)

Key Compounds: Beta-glucans (especially the D-fraction).

Potential Effects in Oncology:

• Immune Activation: Maitake D-fraction has been shown to stimulate the immune system, particularly NK cells and T-cells, which are involved in combating cancer cells.
• Synergistic Effects with Chemotherapy: Some research suggests that Maitake can enhance the effects of chemotherapy drugs, such as doxorubicin and paclitaxel, improving treatment outcomes.
• Anti-metastatic Potential: Maitake may help inhibit the spread of cancer to other parts of the body, though more human studies are needed to confirm this.

6. Cordyceps (Cordyceps sinensis)

Key Compounds: Cordycepin, polysaccharides.

Potential Effects in Oncology:

• Apoptosis Induction: Cordyceps has been shown to induce apoptosis in cancer cells, particularly in lung, colon, and breast cancers.
• Immunomodulatory Properties: Cordyceps is believed to boost the activity of immune cells, particularly NK cells, which help target and eliminate cancer cells.
• Energy and Recovery: It is often used by cancer patients to improve energy levels and reduce fatigue, particularly during chemotherapy.

7. Agaricus blazei Murill (Agaricus subrufescens)

Region of Approval: Used widely in Asia and also in some South American countries

Clinical Use:

• Known as Himematsutake in Japan, this mushroom is used as a complementary cancer therapy.
• Although not officially approved as a standalone cancer treatment, Agaricus blazei is widely prescribed in Japan to support conventional cancer treatments, especially for breast, gastrointestinal and lung cancers.
• It is believed to enhance the immune system's capacity to target cancer cells, reduce chemotherapy side effects, and improve overall patient outcomes.

Mechanisms of Action

Beta-glucans: Many medicinal mushrooms contain beta-glucans, which are polysaccharides that enhance immune function. Beta-glucans are known to stimulate the innate immune system, improving the body’s ability to recognize and destroy tumor cells.

Triterpenoids, Polysaccharides and other secondary metabolites: These compounds, found in various mushrooms like Reishi, have shown potential in reducing inflammation, preventing cancer cell proliferation, and inducing apoptosis in tumors.

Clinical Application

In countries like Japan and China, medicinal mushrooms are often integrated into cancer treatment protocols, primarily as immunotherapeutic agents to boost the body's natural defenses. Their primary roles are to:

• Support immune health during and after chemotherapy.
• Improve the efficacy of conventional treatments.
• Reduce the side effects associated with chemotherapy and radiation.
• Potentially improve survival rates and quality of life in cancer patients.

Limitations and Considerations

• While promising, many studies on medicinal mushrooms and cancer are still in early stages or have been conducted in vitro or on animals. More high-quality clinical trials are needed to establish their efficacy and safety in human cancer patients.
• Patients should consult their healthcare provider before using medicinal mushrooms, as some mushrooms may interact with conventional cancer therapies or medications.

Conclusion

Medicinal mushrooms hold promise in oncology, particularly for their immune-boosting and anti-cancer properties. They are often used as complementary therapies alongside conventional cancer treatments, with the potential to enhance immune function, reduce treatment side effects, and improve patient outcomes.