Combination chemotherapy for breast cancer metastatic to bone marrow

Seventy‐nine patients with metastatic breast cancer underwent examination of their bone marrow as part of their staging workup. Thirty‐one (39%) showed no evidence of bone marrow involvement (BM–); 48 (61%) were found to have bone marrow metastases (BM+). Both groups of patients were treated with intensive chemotherapy with 5‐FU, Adriamycin, cyclophosphamide, methotrexate, and nonspecific immunotherapy with BCG, methanol extraction residue, or Levamisole. The groups were comparable in age, race, menopausal status, and disease‐free interval; however, the BM+ group had a higher proportion of patients with dominant osseous disease and a somewhat lower overall tumor burden. Ten of 21 patients in the BM+ group treated with 100% of the calculated dose of chemotherapy are still alive, compared with only three of 27 patients treated with lower doses. A similar dose response was observed in the BM– group. Myelosuppression was more common and more severe in the BM+ group. Hematologic support, i.e., packed erythrocytes and platelet transfusions, was required in 60% of BM+ patients, as opposed to 26% of BM–. Infectious complications were also higher in the BM+ group, in which five episodes of sepsis and two infectious deaths were observed. These results suggest that metastatic breast cancer patients with bone marrow invasion achieve excellent palliation with aggressive high‐dose chemotherapy. Higher morbidity requiring aggressive supportive care suggests that these patients should be treated by physicians and centers experienced in their management.