What are the risks and benefits of using alternative chemotherapy approaches such as Carboplatin/Taxol or Gemcitabine/Taxol in the neoadjuvant setting – is it as effective?  Is it justified?

We dont have any evidence to use such combination in the neoadjuvent setting , The ABC meta analysis concluded Cisplatin based chemotherapy improved overall survival by 5% , the use of MVAC has been studied , CMV and Cis-Gem is also used but no evidence  from RCTs only extraploation from the metastatic trials.   Carboplatinum is not as effective as cisplatin , at least extrapolation from adjuvent lung trials where Carbo was inferior to Cisplatin.

What would we do if we found no response after 2 cycles of neoadjuvant chemotherapy with Gemcitabine/Cisplatin?  Switch to MVAC or proceed to cystectomy?

I will refer the pt to a cystectomy , likely the pt has resistant disease and no further indication to switch to another neoadjuvent chemotherapy.