There IS a study done in

Israel with CIDP or PN patients and Cancers… The IVIG was given for the CIDP and PN and cancer was found later [I believe] This was done about 3+ years ago and it’d found that the IVIG seemed to result in smaller tumors…this was for BC tho.
Cancers can be ‘hatching’ for 5-7 years before they are detected, it is possible that these cancers can cause what are called ‘paraneoplastic’ neuropathies. Thing is, even if you have a solid family cancer history… if you aren’t tested at the right time? It won’t be detected. The paraneoplastic aspects are what can set off the whole immune action/reaction chain of events that result in CIDP, but Neuros and Ocons aren’t really talking about the cross-connections too often.
Ironically treatments usually don’t/aren’t changed for all the knowing about a connection that I know of. Symptoms are treated, and the rest is history.
BTW? I was found to have BC – 3 years after my CIDP onset. It was found very early for which I am grateful…I guess. And I couldn’t take steroids due to other issues. Hope this helps. Always ask if you need more info.