Clinical Significance of Bone Marrow Microinvolvement in Nonsmall Cell Lung Carcinoma

BACKGROUND. The divergences in the clinical significance of bone marrow microinvolvement (BMM) in patients with nonsmall cell lung carcinoma (NSCLC) necessitated a long-term large series study. METHODS. Between March 1997 and June 2001, the authors analyzed 212 bone marrow specimens (from the posterior iliac crest) taken from patients with NSCLC before surgery. The degree of tumor differentiation included well differentiated carcinoma in 12 Patients, moderately differentiated carcinoma in 112 Patients, and poorly differentiated carcinoma in 68 Patients. The pTNM staging (according the the criteria of the American Joint Committee on Cancer) included Stage IA in 8 patients, Stage IB in 70 patients, Stage IIB in 36 patients, Stage IIIA in 54 patients, Stage IIIB in 14 patients, and Stage IV in 10 patients. The specimens were evaluated by immunohistochemical staining with antihuman cytokeratin AE1/AE3, Ber-EP4, and clone MNF116 mixed solution to detect the presence of malignant epithelial cells in the bone marrow. RESULTS. Positive results were observed in 66 patients (34.4%). The occurrence of BMM was not found to be related to patient age, gender, cell type, or TNM status. The 5-year disease-free survival rates were 44.9% and 40.5% in BMM-negative and BMM-positive patients, respectively (P = 0.3797). The 5-year cumulative survival rates were 43.5% and 44.0% in BMM-negative and BMM-positive patients, respectively (P = 0.4262). Multivariate analysis failed to demonstrate BMM as an independent prognostic factor (P = 0.1817). CONCLUSIONS. The results of the current study showed that although BMM was observed frequently in patients with NSCLC, regardless of tumor stage and pathologic types, its occurrence was not a good predictor of long-term prognosis.