Welcome @melw. I can imagine that you are shocked and scared to find out that you have stage 1 or 2 rectal cancer after the transanal endoscopic microsurgery (TEM). In stage 1 and 2, it has been determined that the cancer has not spread beyond the colon or rectal wall. But, if I understand you correctly, you are questioning how they would know since no lymph nodes were removed or tested at the time of surgery. Is that correct?

Here is some information about typical followup care.
- Colorectal Cancer: Follow-Up Care https://www.cancer.net/cancer-types/colorectal-cancer/follow-care

Do you think that a second opinion might be warranted?