Thomas E. Witzig

In myeloma, the bone marrow plasma cell percentage (BMPC%) is usually estimated independently on the aspirate, core biopsy, and plasma cell labeling index (PCLI) samples. This study was done to determine which of the 3 individual estimates correlates best with complete response (CR) and survival. Seventy-five consecutive patients who underwent SCT for relapsed myeloma were studied. The median BMPC% on the marrow aspirate, core biopsy, and PCLI studies were 20, 25, and 20, respectively. There was a significant correlation between the three methods, rho > 0.65, P < 0.001. However, in 8% of patients the BMPC% was different by an absolute value of 50% between methods. No individual method was predictive for CR. However, the highest estimate of the BMPC% among the three methods was a significant predictor of CR (P = 0.02). Survival following SCT was longer among patients with a low BMPC% (< or =60) by the PCLI method compared to those with higher values, median survival 23 versus 7 months, respectively, P = 0.02. PFS was also different, with survival times of 11 and 5 months, respectively, P = 0.003. Similar results were obtained when the highest estimate of the BMPC% was used in survival analysis (P = 0.02 and 0.004, respectively). Statistical significance was lower when the BMPC% on the aspirate or biopsy used in survival analysis. Compared to any individual method of estimating BMPC%, the highest estimate of the BMPC% is the best predictor of CR in myeloma. It is also prognostic for poor survival and PFS following SCT for myeloma. We recommend that all three methods of estimating BMPC% be routinely performed and that the highest value be used for prognostic purposes.

The most common chromosomal translocation in multiple myeloma (MM) is t(11;14)(q13;q32). Here, we describe the clinical characteristics of patients with MM who have this translocation. We have identified 24 patients at our institution who had t(11;14)(q13;q32) as determined by standard cytogenetic analysis (CC). Seven patients had the translocation detected at the time of original diagnosis and 17 at the time of relapse. Median survival in all patients after original diagnosis was 43 months; median survival after the translocation was detected was 11.9 months. Four patients had a clinical diagnosis of plasma cell leukemia. Most patients had an elevated beta2-microglobulin (13/20 had >4 microg/ml). The bone marrow (BM) labeling index (LI) of patients, at the time of translocation detection, was elevated in most (median 1.4%, 17/23 patients had BMLI > or = 1%). Of the 24 patients, 19 (79%) died of disease progression and 5 (21%) were alive with disease at last follow-up. Lytic lesions, bone pain, or compression fractures eventually developed in all patients. Patients with MM who have t(11;14)(q13;q32) detected by standard cytogenetics seem to have an aggressive clinical course.