Treatment for peritoneal cancer

Hi, my aunt was just diagnosed with primary peritoneal carcinoma stage IV and Ive been doing alot of reading since.  Her docter is putting her on chemo every 3 weeks but hasnt mentioned surgery yet. He wants to shrink many of the tumors first.  Ive yet to read a post where its done in this order, does this seem strange? Does it mean it has spread too much for surgery to be effective?  Any input or thoughts would be greaty appreciated, im so concerned.