Among patients with diffuse large B cell lymphoma (DLBCL), undergoing autologous hematopoietic stem cell transplantation (AHSCT) with hypomagnesemia increases the risk of failure, according to research published in Blood Cancer Journal.
While the standard of care in the first line for patients with DLBCL is a combination of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), patients who remain uncured – generally expected to be approximately 40% of those treated with R-CHOP in the first line – may undergo AHSCT, which can induce long-term remission.
It is, however, unclear exactly what patient and disease characteristics predict optimal AHSCT results. Previous research suggests that magnesium levels may be predictive of overall survival in Burkitt lymphoma and may be involved in some cases of immunodeficiency, although it was not previously clear whether hypomagnesemia has any impact on outcomes in DLBCL.
For this retrospective study, researchers evaluated for any relationship between magnesium levels and outcomes among patients with DLBCL undergoing AHSCT, hypothesizing that hypomagnesemia before transplant would predict relapse risk at day 100, and further that magnesium levels would predict lymphocyte recovery at day 15 and thereafter.
Data from 581 patients with DLBCL were included in this study. The median patient age was 62 years (range, 19-78), 60.8% of patients were male, 91.2% of patients were white, and the median magnesium level was 1.9 mg/dL (range, 1.0-2.6).
Overall, 82 (14.1%) patients had hypomagnesemia, defined as less than 1.7 mg/dL. In this group, patients had worse event-free survival (median, 3.9 years vs 6.29 years among those without hypomagnesemia; hazard ratio, 1.63; P = .017) and overall survival (median, 7.3 years vs 9.7 years among those without hypomagnesemia; hazard ratio, 1.9; P =.005).
Magnesium levels did not, however, predict absolute lymphocyte counts at day 15 (P =.591) or thereafter.
“Although we have demonstrated the importance of low magnesium with respect to outcome, the key next question is whether magnesium replacement in this subset (14%) of relapsed DLBCL patients with hypomagnesemia will actually improve outcome,” the authors wrote. “A low magnesium level may simply be another biomarker of illness and replacement of magnesium to the reference range levels prior to AHSCT may not improve outcomes.”
Gile JJ, Lopez CL, Ruan GJ, et al. Hypomagnesemia at the time of autologous stem cell transplantation for patients with diffuse large B-cell lymphoma is associated with an increased risk of failure. Blood Cancer J. 2021;11(3):65. doi:10.1038/s41408-021-00452-0