i am so sorry that you are going through this again. Especially after having been clear for so long... ;o( the good news is treatments are always changing. So hopefully this road won't be so hard to travel and hopefully they'll have something else in mind that will help.
I always wonder if it is something we are eating, some kind of imbalance in our body, some dental filler they are using or exposure to something that causes this kind of thing to recur. I changed my diet big time after my diagnosis and treatment. I was a veg head before but wasn't the healthiest eater, and I now take vitamin d, b12 and circumen. I know the area where I had my tumor had been a problem area for some time. And two caps to my molars in that area which caused a major increase in pain.
I guess we'll never know so we do what we can and hope for the best. I am not sure if you smoke. I am assuming not... but I never smoked a day in my life, don't drink, and stay away from second hand smoke, so I have no idea.
Best of luck... and hugs. this is a great support group here.
The good news - if there is such a thing that includes the word CA is that there are a few here that have been through the same scenario. Pandora had a second primary tumor 3 years after her first and she is doing really well.