Anterior Fatty Fibrosis - Race next week

I have been having severe knee pain on my runs over the last two months. I was hoping everything under the sun, but it never got better. I finally got a MRI last week, and he said there was no tear. He did say it had Anterior Fatty Fibrosis (scar tissue) under the knee cap. 

So my question is, I am supposed to do St Croix 70.3 next week, but there is no way I can complete the run. What do I do...do I try to tough it out and try to make it through the pain? Just do the swim and bike and stop? Save myself and rehab for another event?

What is everyones opinions?