Most patients with tumors are single organ tumors, but sometimes we see patients with more than two tumors at the same time. These tumors are usually caused by exposure to the same carcinogens or by the same genetic changes, such as lung, throat and bladder cancer in patients who smoke. Bladder cancer in combination with prostate cancer is not uncommon, especially in older men. The incidence of prostate cancer in older men is higher, because many older men have prostate cancer that progresses slowly and is less harmful to their bodies, and the tumor is not detected until they die. In addition, the high malignancy of prostate cancer in some patients leads to the onset of the disease, and the use of prostate-specific antigen for patient screening makes it possible to diagnose bladder cancer and prostate cancer before surgery. The results of surgical treatment for patients with bladder cancer combined with prostate cancer are similar to those of surgery for bladder cancer alone, with only a small number of patients requiring postoperative prostate cancer-related treatment. For men with bladder cancer who choose to have prostatectomy, it is important to screen for possible prostate cancer before surgery.