Can patients with early-stage diffuse large B-cell lymphoma be treated without bone marrow biopsy?

Background: Data on the incidence of bone marrow (BM) involvement in early-stage diffuse large B-cell lymphoma (DLBCL) are lacking. Although BM biopsy is a safe procedure, it is often poorly tolerated. This analysis aims to assess the incidence of BM involvement and to identify parameters predicting BM involvement in early-stage DLBCL. Patients and methods: One hundred and ninety-two patients with radiological stages 1 and 2 disease were analysed. The data collected were age, sex, presence of B symptoms, white blood cell (WBC) count, platelet count, haemoglobin (Hb), serum lactate dehydrogenase level, serum β₂-microglobulin level, presence of extranodal disease, and the presence of bulky disease (defined as >7 cm). Results: Overall incidence of BM involvement was 3.6%. Hb < 10g/dl (P=0.02), WBC count <4 × 10⁹/l (P=0.007) and bulky disease (P=0.06) were found to be predictive of BM involvement. Among the 120 patients without any of these three factors, only one patient had BM involvement (0.83%; 95% confidence interval 0.02% to 4.6%). The absence of all three factors gave a negative predictive value of 99.2%. Overall 3-year survival for patients without all three risk factors was 80%. Conclusions: BM biopsy may be safely omitted in selected patients with early-stage DLBCL.