Effect of neoadjuvant chemotherapy for lymph node micrometastasis and tumor cell microinvolvement in the patients with esophageal carcinoma

Micrometastasis (MM) and tumor cell microinvolvement (TCM) in the lymph node were immunohistochemically evaluated using the cytokeratin (CK) antibody between a surgery group (n=20; 929 lymph nodes) and a chemotherapy group (n=20; 1052 lymph nodes). The incidence of MM+/-TCM in the surgery and chemotherapy groups was 50.0 (10/20) and 55.0% (11/20), respectively. Limiting the analysis to TCM alone revealed that the incidence in the chemotherapy group (10.0%; 2/20) was significantly lower than that in the surgery group (40.0%; 8/20; P=0.032). Preoperative chemotherapy in this regime was not effective, except for some patients with TCM alone.