Cancer cannot be cured with selenium supplementation. Selenium is a kind of trace element needed by human body, selenium supplementation helps to maintain the normal physiological function of the immune system, but selenium supplementation can not treat cancer, nor can it make cancer cured. Cancer requires “early detection, early diagnosis and early treatment”, and some tumor patients can be cured after positive and correct treatments, such as surgery, radiotherapy and chemotherapy, etc. If you are diagnosed with cancer, you should take selenium supplementation to help maintain the normal physiological function of the immune system. If you are diagnosed with cancer, you should pay attention to rest, avoid staying up all night and exertion, and do physical exercise according to your own situation to enhance your immunity. Normally, one should avoid too much depression, sadness and other bad emotions. Diet can be based on protein, vitamins and other nutritious food, which can help maintain the normal physiological function of the body. Cancer patients should follow the doctor’s instructions to go to the hospital for regular follow-ups, and if there are other abnormalities in the body, they should inform the doctor in time to avoid adverse effects.