Hi Marianne,
and welcome to the forum. I take it they are calling this a recurrence since it was in the original region? If this is a recurrence than prevention is not the issue - they need to kill this thing once and for all. You need to hit this with all they've got.

First, I need to ask did you have radiation and chemotherapy? Many consider that to be the "first-line" treatment for tongue cancer.

Secondly, are you being treated at a Comprehensive Cancer Center? I would take a recurrence in the original tumor bed very seriously, especially after five years.

Third, do you have a medical team- radiation oncologist, medical oncologist, surgeon, etc., and did they conduct a tumor board to thrash out your best treatment plan and options?

Statistically 25% of H&N patients had no environmental exposure such as tobacco and alcohol. They have also found that EBV and HPV can be causitive factors.