If swelling of the legs is the only problem, then you will be fine. Some oncologist add mannitol to the GEM/Cis regimen for the purpose as a diuretic., but others don't.
Normally around the 6th or 8th doses of GEM/CIS, you will know whether you can continue the regimen or not since the accumulative toxicity of the regimen will tell whether your body can tolerate the regimen or not. if not, then GEMOX will be a less toxic regimen than GEM/CIS with regard to the kidney. GEMOX is a better tolerated regimen,but neuropathy is one of the side effects for GEMOX.
Please know that my personal opinion is not intended nor implied to be a substitute for professional medical advice. If provided, information are for educational purposes.Consult doctor is a MUST for changing of treatment plans.