Clinical and prognostic evaluation of bone marrow infiltration (biopsy versus aspirate) in early chronic lymphocytic leukemia. A single center study

Abstract

BACKGROUND AND OBJECTIVE: Recently published studies dealing with chronic lymphocytic leukemia (CLL) patients in early clinical stage reported that bone marrow (BM) biopsies and aspirates can be considered complementary methods of evaluating the extent of BM involvement. Consequently, we designed the present study to investigate the clinical and prognostic implications of BM biopsies and aspirates in a series of stage A CLL patients followed-up in a single center. PATIENTS AND METHODS: BM biopsy sections and aspirate smears obtained at the time of diagnosis from 102 CLL stage A patients were retrospectively evaluated. Results were correlated with clinical and hematological features as well as with survival and disease-progression risk. RESULTS: Diffuse (D) BM histology was detected in 10 patients (9.8%) while 21 (20.5%) displayed lymphocyte infiltration (LI) > 80%. Twenty-six patients (25.4%) died with a 5- and 10-year survival probability of 85% and 50%, respectively. The survival of patients with D-BM histology was significantly shorter than that of patients with non-diffuse (non-D) histology (p < 0.05). Interestingly, when considering only CLL-related deaths (i.e. leukemia progression, infections) were considered, there was an increase in the statistical significance of BM histology (p = 0.01). There was no difference in life expectancy in cases with LI either using different cut-off levels (i.e. 70% and 80%) or excluding non-CLL related deaths. According to our experience, disease progression could only be predicted by BM histology (p = 0.008), while LI was not useful for forecasting progression to more advanced stages (p = NS). INTERPRETATION AND CONCLUSIONS: In patients with early CLL, BM histology provides more reliable information regarding the clinical outcome of the disease than LI.