The reason why bladder cancer is called happy cancer is for bladder cancer with early detection, low recurrence and metastasis rate and better prognosis, such as carcinoma in situ of the bladder, so it is jokingly called happy cancer, but if it is advanced bladder cancer, the prognosis is poorer, so it cannot be generalized. 1. Bladder carcinoma in situ: it belongs to the early stage of the disease, without infiltrating into the muscle layer, and hematuria is the most common symptom of bladder cancer, and most of the patients have painless hematuria throughout the whole course of the early stage of the disease, so the treatment is more timely, and the clinical cure of this stage of bladder cancer can reach more than 90% after the early surgical treatment and the recurrence rate is low, therefore, it is a relatively happy cancer comparing with other malignant cancers. 2. Advanced bladder cancer: it belongs to the advanced stage of the disease, and may invade the fat connective tissue around the bladder, lymph nodes, etc. The chance of recurrence and metastasis is higher in this case, and the prognosis is relatively poor, and the five-year survival rate of the patients is low, coupled with the fact that if it is combined with liver, lung and other metastases, then the five-year survival rate will be extremely low and the prognosis is extremely poor, so it will not be jokingly called as happy cancer. If cancer is found in the examination, patients should consult the doctor in time and be treated actively so as not to miss the condition.