If a patient with prostate cancer has swelling in both lower extremities, the first step is to analyze the cause of the swelling or swelling in both lower extremities. If the swelling is due to venous thrombosis of both lower extremities, anticoagulation therapy should be performed. In advanced prostate cancer patients with general malnutrition and severe hypoproteinemia, adequate albumin and protein should be supplemented. If the swelling of the lower limbs is caused by the decline of kidney function or heart function, medical interventions including diuretic and cardiac interventions should be performed. If a pelvic mass compresses the veins and blood vessels of the lower extremities in the advanced stage of prostate cancer causing impaired blood and lymphatic return to the lower extremities, then anti-tumor therapy, including local radiotherapy, chemotherapy, and anti-androgen therapy for prostate cancer patients, should be performed. When the tumor is effectively controlled, the edema of both lower limbs will also be improved.