--might be indicated if serological tests indicated a possibility of cancer; otherwise it probably wouldn't reveal anything that one wouldn't already know.
There are some cases of neuropathy due to such "paraneoplastic syndromes", but they are not common and they usually are traceable to a definite cancerous process.

An exception may be neuronopathy due to Anti-hu antibodies, which are associated with lung cancers for the most part (especially small cell lung cancers), and which may show up well before a tumor is discovered; have you had that serological test?

In general, I still recommend the Liza Jaen spreadsheets as a pretty exhaustive guide to testing for neurological conditions--www.lizajane.org--you should look that over to see what testing you've had and not had. (It's also a good way to track tests results over time to discern patterns.)