I dont really know, but would think that this is looking for genetic markers and also testing your tumour against various chemo agents to find out what treatment will work best for you. Especially since your cancer has recurred now on a number of occasions.
I really hope that this will benefit you Cindy. Good luck and let us know all the answers when you have spoken to your doc.
Tammy.

Caregiver/advocate to Husband Kris age 59@ diagnosis
DX Dec '10 SCC BOT T4aN2bM0 HPV+ve.Cisplatin x3 35 IMRT.
PET 6/11 clear.
R) level 2-4 neck dissection 8/1/11 to remove residual node - necrotic with NED
Feb '12 Ca back.. 3/8/12 total glossectomy/laryngectomy/bilat neck dissection/partial pharyngectomy etc. clear margins. All nodes negative for disease. PEG in.
March 2017 - 5 years disease free. Woohoo!