BACKGROUNDTo investigate the relationship between micrometastasis of bone marrow and neoadjuvant chemotherapy and prognosis in patients with stage III non-small cell lung cancer (NSCLC).

METHODSSixty-five patients with stage III NSCLC were randomly divided into group A (32 patients treated with preoperative neoadjuvant chemotherapy plus operation) and group B (33 patients treated with operation and postoperative chemotherapy as control group). Expression of CK19 mRNA and CEA mRNA was detected in bone marrow samples from the rib segments of all patients obtained from operation by RT-PCR. The relationship between survival duration and CK19 and CEA expression was analyzed.

RESULTSThe positive rates of CK19 mRNA expression were 18.8%(6/32) and 45.5%(15/33) in group A and B, respectively (P=0.033), and the positive rates of CEA were 25.0%(8/32) and 51.5% (17/33) in group A and B, respectively (P= 0.041). A significant positive correlation was observed between CK19 and CEA expression (r s=0.671,P < 0.001). The response rates of neoadjuvant chemotherapy were 0%(0/5) and 56.5%(13/23) in patients with CK19(+)/CEA(+) and CK19(-)/CEA(-), respectively (P=0.044), and the median survival duration were 11 and 27 months, respectively (P=0.000 6). Cox's model showed that the response to neoadjuvant chemotherapy and the expression of CK19 or CEA were significantly prognostic factors in group A.

CONCLUSIONSNeoadjuvant chemotherapy can reduce the possibility of bone marrow micrometastasis in stage III NSCLC patients. Bone marrow micrometastasis may indicate a poorer prognosis for NSCLC.