Bone marrow involvement in anaplastic small cell lung cancer. Diagnosis, hematologic features, and prognostic implications.

The hematologic changes and prognostic implications of bone marrow involvement in small cell lung cancer (SCLC) were examined in 133 patients undergoing staging procedures including bone marrow aspiration and trephine biopsy. Bone marrow involvement was found to be present in 27 of 133 (20%) at diagnosis. In most instances bone marrow involvement was associated with the presence of other metastases but in five patients (4%) the bone marrow was the sole site of metastasis. Bone marrow biopsy proved superior (14%) to bone marrow aspiration (5%) in detecting marrow infiltration. Peripheral blood hematologic changes were infrequent even in patients with positive bone marrow biopsy results. Although patients with bone marrow involvement had a shorter median survival (9 weeks) than bone marrow-negative patients (33 weeks) the adverse effect on survival appears to have been mainly due to the presence of concomitant metastases at other sites. Intensive chemotherapy was tolerated to the same degree by bone marrow-positive and bone marrow-negative patients.