The value of routine bone marrow biopsy in patients with diffuse large B-cell lymphoma staged with PET/CT: A Danish-Canadian study

BACKGROUND: The added diagnostic and prognostic value of routine bone marrow biopsy (BMB) in patients with diffuse large B-cell lymphoma (DLBCL) undergoing PET/CT staging is controversial.

PATIENTS AND METHODS: Patients with newly-diagnosed DLBCL who underwent both staging PET/CT and BMB were retrospectively identified in British Columbia, Aalborg, and Copenhagen. Original written PET/CT and pathology reports were retrospectively reviewed to determine Ann Arbor stage and outcomes, with and without the contribution of BMB.

RESULTS: A total of 530 patients were identified: 146 (28%) had focal bone marrow (BM) lesions on PET/CT and 87 (16%) had positive BMB. 52 of 146 patients (36%) with positive PET/CT had a positive BMB (39 DLBCL, 13 indolent non-Hodgkin lymphoma [iNHL]), while 35 of 384 patients (9%) with negative PET/CT had positive BMB (12 DLBCL, 23 iNHL). BMB upstaged 12/209 (6%) of stage I/II patients to stage IV, although this was the case for only 3 (1%) patients with DLBCL in the BMB. PET/CT identified bone marrow involvement by BMB with sensitivity 60%, specificity 79%, positive predictive value 36%, and negative predictive value 91%. Concordant histological involvement of the bone marrow by DLBCL was associated with worse OS and PFS than discordant or no involvement in univariate and multivariate analyses.

CONCLUSIONS: In patients with DLBCL, staging PET/CT can miss BM involvement with concordant DLBCL (less common) or discordant iNHL (more common). Routine BMB does not add relevant diagnostic or prognostic value over PET/CT alone in the majority of patients with DLBCL.