I had stage 3c colon cancer in 2008 and I was a semi-frequent poster here. A few years after my diagnosis, I had genetic testing done and there was no sign of Lynch syndrome or any other known genetic abnormality.
Last week I was diagnosed with endometrial cancer and I just met with the gyn oncologist for the first time today. She said that testing was done on the tumor that showed Lynch syndrome, but then there was an addendum to the report saying they retested and there was no Lynch syndrome?! My doctor said that (especially given that I've had both colon and endometrial cancer) she is highly suspicious of the second, negative result. She referred me to a geneticist.
I'll be having surgery for this new cancer in the next couple of weeks (surgery is not scheduled yet), and I'll know my stage a week or two after that. The tumor is grade 1 (low grade), which is really good news and ups my odds for the cancer being early stage (but of course we won't know till we know).