The non-pCR group had a greater incidence of tumor cells in the primary biopsy than the pCR group after NACRT (pCR group [0 %] vs non-pCR group [15.9 %]; p = 0.014) and greater CEA values after NACRT (pCR group median [1.7 ng/mL] vs non-pCR group median [2.7 ng/mL]; p = 0.004). Here, CEACAM5 is linked to neoplasm.