Presacral Reccurence

[JohnFg11]

Hello everyone,

First, thank you all for this wonderful community. I really appreciate all of the materials on this forum! My story is that I was first diagnosed with Stage 3 colorectal cancer in 2015, and have not had any recurrence for close to 10 years. Last year (2023), a PET scan found two tumors that had moderate FDG in the presacral region. The scan, along with elevated CEA levels to around 9 and a positive CTDNA test result, prompted my doctors to advise surgical resection. It was a rough surgery but I was glad that the tumors were out. The surprising thing was that the pathology report couldn't find any cancer cells and labeled them abscesses. Around two months ago, I had the exact same tumor reappear in the PET scan. Same size and same FDG activity. I'm now confused if the pathology report was wrong or if abscesses can trigger the PET scans like this. Has anyone experienced anything similar? I'll be going for a biopsy soon, and most likely opt for radiation. Any advice or comments on my situation would be appreciated! Thanks!


-John

[Thedruid]

Hello, JohnFg11

I am not a technical expert on the subject, but as a patient I already made SEVERAL PET scans and other exams.

The answer to your question is "yes". Infection or inflammation areas will appear as "lit" areas in your PET. If you do a PET scan when you have some type of cold, it is normal to have some lymph nodes and other areas shown to have moderate FDG activity.

A biopsy can be a good way for you to correctly identify what is in this area. What sounds strange to me is to have the same FDG consumption in the same place some time after you removed the abscesses.

If I was in your situation I would raise a lot of questions to the doctor, just to be sure this is really nothing to worry about... maybe a deeper investigation could help to identify what this really is ?

[JohnFg11]

Thank you for your extremely helpful response Thedruid! I have an appointment coming up and will raise a lot of questions. The surgeon is sure they got everything of whatever was there so maybe the abscess has returned. I’ll be sure to ask a lot of questions to figure out what it is. Thanks again!

[jts]

I am suspect for having a pre-sacral recurrence, so your post really caught my eye.

I am really surprised that they would do such a major surgery without confirming it with a biopsy first. I though the presacral area would be relatively easy to access. They must have felt that, given the CEA and CTDNA, even if a biopsy was negative they would do the surgery anyway?

My impression with this so far is that, unlike lungs and liver where tumors are pretty easy to see, in the mishmash of stuff left over at the primary surgical site, it is difficult for the radiologists to distinguish what the various blobs are. I my case they cannot decide if there is a tumor, scar tissue, or .... whatever else?

BTW, when I did have a PET scan about a year after my primary tumor was removed, the whole primary surgical site was lit up like crazy. Apparently scar tissue does that too.

Sorry this is not really any help. Just commenting, since I have a similar concern.