Metastatic cancer means that the patient has entered the advanced stage of cancer. The exact length of life depends on the degree of metastasis of the tumor, the treatment method, the patient’s nutritional status and other factors. For lung cancer and breast cancer, if the metastasis reaches the brain and cannot be actively treated, the survival period is usually about 3 months. Meanwhile, if the patient can receive regular treatment and obtain better efficacy, he/she can survive for 2-3 years or even longer. In addition, if the patient’s nutritional status is poor or the cancer tumor spreads more and consumes more nutrition, it may also shorten the survival time of the patient. And factors such as the patient’s psychological state may also affect the survival time of advanced cancer patients. In conclusion, cancer emphasizes early detection, early diagnosis and early treatment. Patients should face the disease with a positive attitude, actively cooperate with the treatment and improve the quality of life.