There is no evidence that milk has an effect on estrogen levels in the body, which can affect the prognosis of breast cancer. Therefore, breast cancer patients who are not lactose intolerant can consume small amounts of milk as appropriate, but it is not recommended for breast cancer patients to consume large amounts. Breast cancer patients are advised to choose the appropriate food and consumption amount according to their physical condition and illness under the guidance of their doctors to avoid any impact on breast cancer recovery. Breast cancer patients may suffer from nutritional deficiencies, such as low calcium and low protein, and milk has a large amount of nutrients, which is good for breast cancer patients to replenish their nutrition. Besides, whey protein, calcium, vitamin D and butyric acid in milk are helpful for cancer recovery, and a high protein diet helps to restore and maintain the sound immune function of the body, so it is beneficial for breast cancer patients to drink milk in moderation.