Estrogen receptor profile of patients with breast cancer metastatic to bone marrow.

The estrogen receptor (ER) profile of patients with breast cancer metastatic to bone marrow (BM) has not been widely reported. The charts of all patients having a diagnosis of breast cancer and undergoing bone marrow aspiration or biopsy at the Cleveland Clinic during the period of January 1980 through September 1982 were reviewed. Thirty-nine patients were so identified; of these 39 patients, 28 had estrogen receptor determination performed on a primary or a metastatic tumor specimen. Of the 28 patients with known ER, ten (36%) had ER less than 5 fmoles/mg cytosol protein, three (11%) had ER or 5 to 10 fmoles/mg, and 15 (54%) had ER greater than 10 fmoles/mg. Of the 39 patients with BM involvement, 36 (92%) had cortical bone involvement documented on x-ray or isotopic bone scan. Liver involvement was documented in 6/34 (18%) patients, pulmonary involvement in 14/37 (38%) patients, CNS relapses in 3/39 (8%), and locoregional recurrences in 19/39 (49%). The most significant hematologic finding was a hemoglobin of less than 12 gm% in 21/37 (57%). The most frequent biochemical abnormality was an elevation of the alkaline phosphatase in 30/39 (77%). The majority of breast cancer patients have a positive ER and ER-positive breast cancer has a tendency to metastasize to cortical bone. Bone marrow involvement by breast cancer is closely associated with cortical bone involvement; accordingly, bone marrow metastases are often associated with a positive ER.