Detection at diagnosis of tumor cells in bone marrow aspirates of patients with small-cell lung cancer (SCLC) and clinical correlations.

Background: Immunocytochemistry has often been used to identify tumor cells in bone marrow aspirate (BMA) of SCLC patients in order to improve the results of conventional histomorphology. However, whether the detection of bone marrow microlocalisation at diagnosis had implications for prognosis has not been clear.

Patients And Methods: Eighty-four slides (44 patients) and 66 bone marrow biopsies (from 42/44 patients) were evaluated. Cytospins of BMA were incubated with the monoclonal antibody (MAb) NCC-LU-243, recognising the cluster 1 antigen (NCAM) and then stained by the APAAP (alkaline phosphatase-anti-alkaline phosphatase) method. The relationship among BMA and PS (performance status), NSE (neuron-specific enolase), stage, survival was also studied.

Results: 33/84 (39%) BMA were positive for NCAM, compared with 8/66 (12%) bone marrow biopsies (p = 0.009), (17/44 and 6/42 patients, respectively). Moreover, BMA was positive for NCAM in 6/19 patients with limited disease. The presence of positive BMA did not correlate with PS, NSE or stage, but patients with positive BMA had shorter survivals than those with negative BMA (median survival: 7 and 12 months, respectively, p = 0.007).

Conclusions: Bone marrow involvement detected by immunocytochemistry appears to be related to survival but not to parameters of tumor burden (NSE, stage), suggesting that this technique might help to select patients with better prognoses for new therapeutic strategies.