Sally,
I would not think anyone would recommend chemo to you considering your case, except for the long history of precancerous lesions you present. It's unfortunate that there are no "do-overs" on this. I was not to have chemo until my lymph node, which was small, was found to have extracapsular extension (microscopic, but it seems to make no difference). The chemo was supposed to give you a small but significant chance of not having a recurrence--can't remember how much, but more than 10%. In my case it was my surgical oncologist who lobbied for the radiation and then the chemo being tacked on was standard after the lab finding. But if your MO is not recommending it, I guess that is what I would go with too.
Anne

SCC tongue 9/2010, excised w/clear margins:8 X 4 mm, 1 mm deep
Neck Met, 10/2010, 1 cm lymph node; 12/21/'10: Neck Diss 30 nodes, 29 clear, micro ECE node, part tongue gloss, no residual scc
IMRT & 6 cisplatin 1/20/11-2/28/11 at MDA
GIST tumor sarcoma, removed 9/2011, no chemo needed
Clear on both counts as of Fall, 2021