The following considers the results of Chemotherapy on Metastatic urothelial carcinoma.
"Patients with refractory advanced or metastatic urothelial carcinoma derive only minor benefit from chemotherapy".
Various studies have shown combination chemotherapy to have an effect. Treatment with chemotherapy and "infusion cisplatin and high-dose 5-fluorouracil/leucovorin (P-HDFL)" results in a median survival of 38 months.
Donald Kaufman worked on a study using a combination of gemcitabine and cisplatin, which resulted in a median survival of 14.3 months.
Generally speaking, treatment with chemotherapy will not with any amount of certainty, extend one's life.