Hello @anchor2025.
That was certainly a hard hit to take when you are on the home stretch with the previous cancer. I have had the SCC from my external ear canal reappear as metastases in my lung twice, on the surface of a muscle, and in a kidney and lymph nodes this last time in 2020. Metastatic SCC has been incurable so far but we have tackled each met with surgery until this last time since it was in the lymphatics. I had 2 years on an immunotherapy drug Libtayo ( Cemiplimab) which so far has eradicated the cancer. All mets were the same tumor as original per pathology.
All we can do is to keep battling as these things reappear. It is success to make your cancer into a chronic disease instead of a death sentence. May not be what we hope for, but sometimes it is the best we can get.