Hematologic findings in cases of mammary cancer metastatic to bone marrow

The hematologic findings in 22 cases of mammary cancer metastatic to bone marrow are presented. Cancer of the breast was the most frequent neoplasm metastatic in bone marrow in this study of 2,878 bone-marrow examinations. All 22 patients who had carcinoma of the breast metastatic to bone marrow had clinical, radiographic, or hematologic evidence of widespread metastatic disease. Peripheral blood was abnormal in 58% of the cases, and in most of these cases two or more abnormalities were present. Bone-marrow biopsies were superior to particle sections and aspirates in identifying tumor, but correlations among all modalities were necessary for proper interpretation. Although the morphologic features of tumor cells in sections and smears were quite characteristic for carcinoma of the breast, pitfalls in interpretation were numerous and should be recognized. The mean survival time of these patients was only 6.9 months after identification of bone-marrow metastases. The significant response to chemotherapy obtained with some individuals, however, should encourage aggressive therapy of this disorder.