Bone marrow metastases in small cell carcinoma of the lung: Frequency, description, and influence on chemotherapeutic toxicity and prognosis

The frequency pathologic features, and clinical implications of bone marrow metastases were reviewed in 73 previously untreated patients with small cell carcinoma of the lung given intensive combination chemotherapy. After unilateral posterior iliac crest marrow examination and other staging procedures, 26 patients (36%) proved to have limited disease (confined to one hemithorax and regional lymph nodes); the 47 patients with more extensive tumor included 14 (19%) with marrow involvement and 33 (45%) without it. Patients with marrow metastases had tumor documented in more extrathoracic sites than did other patients with extensive disease; the marrow was the sole site of metastatic tumor in only one instance. No patient with a negative marrow biopsy had cancer detected in touch preparation or aspirate. Marked bone remodeling and myelofibrosis were associated with tumor infiltration in 9 of 14 cases. During intensive induction chemotherapy, patients with positive bone marrows had more severe infections and required more red blood cell transfusions (both trends of borderline significance), but leukopenia, thrombocytopenia, and the need for platelet transfusions did not differ in the three groups. Limited disease patients had significantly superior complete response rates to treatment and longer survival than those with extensive disease, but the results of therapy in patients with marrow involvement were not significantly worse than in other patients with extrathoracic metastatic tumor.