Polysaccharide extracts from Lentinula edodes, Grifola frondosa and Trametes versicolor have all been reported to be beneficial for breast cancer1.
Long term immunotherapy with PSK has been shown to significantly improve the survival rate of patients with breast cancer2,3, while a separate study in breast cancer patients with vascular invasion linked the effect of PSK supplementation to B40 antigen status (a known indicator of breast cancer survival) with 100% of B40-positive patients treated with PSK as well as chemotherapy surviving beyond 10 years, while for B40- negative patients the 10-year survival rate was approximately 50%4.
Symptomatic improvement or regression was also reported by Nanba for 11 out of 15 breast cancer patients treated with a combination of Maitake D-fraction and Maitake (G. frondosa) fruiting body5. Mizuno reported recovery in a breast cancer patient with lung metastases using Agaricus subrufescens polysaccharide extract6, while Phellinus linteus has traditionally been used to treat breast cancer in Korea and polysaccharide extracts show strong in vitro activity7.
Oestrogen-independent – The transcription factor NF-kB has been identified as a key component in the ability of breast cancer cells to multiply independently of oestrogen while resisting chemotherapy and avoiding apoptosis1.
Ganoderma lucidum has shown the most significant inhibitory effect on NF-kB in highly invasive breast cancer cells with the triterpenes particularly active. Triterpenes from G. lucidum have also been shown to inhibit aromatase activity, as well as the transcription factor AP1 (characteristic of highly metastatic breast cancer cells), while the clinical role of a triterpene-enriched G. lucidum extract in inhibiting NF-kB in a case of breast cancer is also reported in one paper8.
Other mushrooms which have demonstrated NF-kB inhibition in vitro include Phellinus linteus and Lentinula edodes.
1. Potential role of medicinal mushrooms in breast cancer treatment: current knowledge and future perspectives. Petrova RD, Wasser SP; Mahajna JA, Denchev CM, Neva E. Int J Med Mushrooms. 2005;7(1–2):141–146.
2. Hormone conditioned cancer chemotherapy for recurrent breast cancer prolongs survival. Sugimachi K, Inokuchi K, Matsuura H, Ueo H, Kumashiro R. Jpn J Surg. 1984;14(3):217–221.
3. Immunochemotherapies versus chemotherapy as adjuvant treatment after curative resection of operable breast cancer. Iino Y, Yokoe T, Maemura M, Horiguchi J, Takei H, Ohwada S, Morishita Y. Anticancer Res. 1995;15(6B):2907–2911.
4. HLA antigen as predictive index for the outcome of breast cancer patients with adjuvant immunochemotherapy with PSK. Yokoe T, Iino Y, Takei H, Horiguchi J, Koibuchi Y, Maemura M, Ohwada S, Morishita Y. Anticancer Res. 1997;17(4A):2815–2818.
5. Maitake D-fraction: healing and preventive potential for cancer. Nanba H. J Orthomol Med. 1997;12(1):43–49.
6. Medicinal properties and clinical effects of culinary-medicinal mushroom Agaricus blazei Murrill (Agaricomycetideae) (Review). Mizuno T. Int J Med Mushrooms. 2002;4(4):299–312.
7. Phellinus linteus suppresses growth, angiogenesis and invasive behaviour of breast cancer cells through the inhibition of AKT signalling. Sliva D, Jedinak A, Kawasaki J, Harvey K, Slivova V. Br J Cancer. 2008;98(8):1348–1356.
8. Potential benefits of Ling Zhi or Reishi mushroom Ganoderma lucidum (W. Curt.: Fr.) P. Karst. (Aphyllophoromycetideae) to breast cancer patients. Chen AW, Seleen J. Int J Med Mushrooms. 2007;9(1):29–38.