I am so sorry you are worsening.

There is a thing called paraneoplasia. This is where a cancer is causing the nerve problems...along with other things:

This link lists some chemo agents and the potential for causing another cancer:
cancerresearchuk.org/cancer-help/type/hodgkins-lymphoma/treatment/chemotherapy/chemotherapy-drugs-for-hodgkins-lymphoma-and-their-side-effects

http://www.mayoclinic.org/diseases-c...n/CON-20028459

Blood work is called a paraneoplastic panel.

Some of the chemo agents are also triggers for Charcot Marie Tooth patients. Some CMT patients luck out and can be latent with it, until a round of chemo sets it off. This is due to the drugs but not the same as paraneoplasia.

I'd try to get into the doctor sooner. See if you can get on a cancellation list.