I too fell into the non-smoker, casual drinker, HPV- category. My RO at Beth Israel did say that there are false negatives and he thought there was a good posibility that I fell into that. I also had a false negative result from my fine needle aspiration from my (malignant) lymph node. I don't have great trust in lab-work results.

6-05, Left Tonsil-T1N2bM0 stageIVA, chemo(Cisplatin), radiation(6660cGy), neck disection, no PEG. HPV negative. (Doc suspects posit)
3-9-09 last of 30 HBO treatments.