pT3N0Mx may belong to stage II colon cancer or stage IV colon cancer because Mx stands for distant metastasis cannot be assessed, if there is no distant metastasis, i.e., pT3N0M0 is stage II colon cancer, if there is distant metastasis, i.e., pT3N0M1, it is stage IV colon cancer.
The p in pT3N0Mx represents the pathological stage after surgery, T3 represents tumor invasion through the intrinsic muscular layer into the perirectal tissues, N0 represents no regional lymph node metastasis, and Mx represents distant metastasis that cannot be assessed, which may be no distant metastasis, M0, or may be distant metastasis, M1.
According to AJCC TNM staging of colon cancer (8th edition), pT3N0M0 is stage II colon cancer, and pT3N0M1 is stage IV colon cancer, so pT3N0Mx may belong to stage IV colon cancer or stage IV colon cancer. If distant metastasis is suspected it can be determined by further perfecting the pathological examination of the suspicious lesions at the distant site.
It is recommended that patients with colon cancer should seek medical treatment in time and follow the doctor’s instructions for active diagnosis and treatment.