Objective : To evaluate the long term prognostic significance of bone marrow micrometastasis at the time of complete surgical resection in a selected population of patients presenting with non-small cell lung carcinoma (NSCLC)
Methods : From February 1996 to December 1999, 99 patients undergoing surgical treatment for non-small cell lung carcinoma (NSCLC) were prospectively investigated for the presence of occult bone marrow micrometastasis. Tumor cells were detected with monoclonal primary antibodies directed against low molecular weight cytokeratins.
Results : Median follow-up time was 44 months (range 0.2-87.6mo). Overall prevalence of OM was 22.2% (22/99). The presence of OM was not correlated to pathology, T status or N status. In survival analysis, the only independent predictors of overall survival were pNodal status and pStage (p=0.03 and 0.02, respectively). The same variables were found to be predictor of disease-free survival (p=0.13 and 0.0003, respectively). Metastasis and locoregional recurrence were observed at follow-up in 18.2% (4/22) and 22.7% (5/22) of OM (+) patients and in 19.4% (15/77) and 18.2% (14/77) of OM (-) patients, respectively (p = not significant). Occult Micrometastasis was neither a predictor of overall survival nor of disease-free survival (p=0.27 and 0.99, respectively). In Stage I and Stage II patients, 5-year overall survival were 63.5% and 45.5% for OM (-) patients and 73% and 85% for OM (+) patients, respectively (p=0.45 and p=0.10).
Conclusions : Occult micrometastasis was present in >20% of surgically treated NSCLC patients and did not correlate to pathological variables. In contrast to previously published data, in this study the presence of OM had no influence on overall or disease-free survival for patients operated on for early stage NSCLC.