Mushroom Study | City of Hope

White button mushrooms could be a powerful tool against breast cancer

Breast surgeon Lisa D. Yee, M.D., professor in the Division of Breast Surgery at City of Hope, has received an “Awesome Games Done Quick” funding award from the Prevent Cancer Foundation to support her innovative research to prevent breast cancer in at-risk women by introducing a white button mushroom supplement to their diet. The research study will evaluate the effects of the supplement, given in tablet form, on inflammation and immune cells.  
Breast cancer affects 1 in 8 women in the United States, with more than 300,000 new cases diagnosed in 2021. Women who fit the profile in Yee’s research are postmenopausal and with a BMI (body mass index) of 30 or higher (considered obese), with a substantially increased chance of developing breast cancer.
Lisa Yee
Lisa Yee, M.D.
“My research will focus on how diet and nutrition affect the development of breast cancer and how changes to diet could be used to prevent cancer,” Yee said. “Despite advances in early diagnosis and novel, molecular, genomic based therapies, similar progress in defining evidence-based strategies for preventing breast cancer is lacking. Obesity, particularly in women who are postmenopausal, is an important target for novel breast cancer prevention strategies.”
Yee said that while weight loss in overweight individuals is associated with a lower risk of breast cancer, many who fall into the obese category find it difficult to initiate and maintain the diet and exercise required.
“Given the generally low, inconsistent uptake of increased exercise and dietary change as a prevention strategy, there is an urgent, unmet need for the development of novel lifestyle-based interventions that will enable safe and effective prevention of obesity-associated breast cancer,” she said.
Of particular interest to Yee and the research team, co-led by Shiuan Chen, Ph.D., the Lester M. and Irene C. Finkelstein Chair in Biology at City of Hope, are natural product interventions that contribute to reduced risk of obesity-associated disease, such as breast cancer. There is emerging epidemiologic data that indicate a role for white button mushrooms in reducing risk for the disease.
White button mushrooms are the most common type of mushroom consumed in the United States. They are a low-calorie, low-cholesterol, low-sodium food with a high fiber and protein content. Yee said they also offer a wide range of healthy ingredients, including vitamins, such as thiamin and niacin; minerals, such as iron, magnesium, manganese, zinc and selenium; and powerful antioxidants. Most studies demonstrating the inverse relationship with white button mushroom consumption and breast cancer risk have been conducted in Asian countries, where their consumption is higher.
Chemicals in mushrooms have been found to slow the production of estrogen, as well as DHT. The intake of mushrooms has also been found to reduce one type of negative regulation of immune function. By the latter mechanism, white button mushroom intake is thought to improve our immune function to fight cancer.

Success With Prostate Cancer

City of Hope has had success in applying the white button mushroom supplement in clinical trials in the treatment of prostate cancer. Research led by Chen is currently working on a Phase 2 clinical trial to test if consumption of white button mushroom tablets could reduce levels of prostate specific antigen in the blood, effectively preventing or slowing down the progression of prostate cancer. More on that here.
“Human clinical studies have shown anti-inflammatory and antioxidant effects in patients,” Yee said. “Preclinical studies by Dr. Chen and team at City of Hope have shown us that breast tumor development was inhibited when the white button mushroom powder was introduced. That leads us to the intriguing possibility that white button mushrooms may modulate the immune cell profile and specifically reduce what are called myeloid-deprived suppressor cells, which are elevated in incidences of obesity and breast cancer.” 
With the Prevent Cancer Foundation funding, Yee and her team are currently conducting a clinical trial of white button mushroom supplementation in the target cohort of postmenopausal women who are identified as obese.
“Our study team is uniquely well-positioned to investigate the immunomodulatory effects of white button mushrooms,” she explained. “We began last summer, and the findings of our correlative analyses will provide us a solid foundation for future studies of the mushrooms as a dietary strategy for the prevention of breast cancer.”
As a breast surgical oncologist, Yee said her interest in cancer research is fueled by the need for advances and innovation in clinical cancer care, from cancer screening and diagnosis to treatment and prevention.
“Taking care of women with breast cancer, as well as those at high risk of developing breast cancer, has motivated my research efforts to understand how diet and diet quality modulate breast cancer risk,” she said. “This research and the generosity of the Prevent Cancer Foundation allows us to further investigate the effects of the common white button mushroom on cellular changes that can lead to cancer.”