David,
A bit more information is needed to make sense of your diagnosis and treatment plan. I am guessing that you already know the information, and it just seemed unimportant.
The majority of the people here have TCC Transitional Cell Carcinoma of the bladder. That cancer comes in two forms, papillary (think of mushrooms) and cancer in-situ (think velvet rash).
You, however included the words "undifferentiated urothelial". From this description, there is a ?strong? possibility that your diagnosis is NOT TCC, but MAY be small-cell (or another variant) carcinoma. The treatments are different for the two cancers.
The recommended treatment you describe may be entirely appropriate for your diagnosis. Only your doctor can confirm the diagnosis, and explain the need for a more aggressive initial treatment.
You can search on this site for "Small Cell" and read the comments of others. Again it is UNCLEAR (to me) what your diagnosis is.
I hope this helps explain that there are a range of standard treatments based on diagnosis. It is important that the treatment plan match the diagnosis.
Best
Jack