Marrow biopsy and survival in multiple myeloma

Pretreatment posterior iliac crest bone marrow biopsies were obtained from 26 multiple myeloma patients. Biopsies were processed in methacrylate. The percentage of myeloma tissue, myeloid tissue, and fat was estimated in each biopsy. In 20 patients who died there was a positive correlation between the percent of myeloid tissue in posterior iliac crest biopsies and survival time (r = 0.47, P less than 0.025), but no correlation could be demonstrated between percentage of myeloma tissue and survival time. The ratio of percentage of myeloid tissue to percentage of myeloma tissue also was related to survival. Six deceased patients with ratios greater than one had a median survival of 4.4 years, compared with 1.8 years in 12 deceased patients with ratios less than one. These medians differ significantly (P less than 0.05). Seven patients also had simultaneous biopsies of the posterior iliac crest and either or both the greater trochanter and the proximal tibia. All five greater trochanter biopsies showed extension of both myeloma tissue and myeloid tissue into the proximal appendicular skeleton.