Treatment Intensity in Diffuse Large B-Cell Lymphoma with Cardiac Involvement: A Case Report and Literature Review

Diffuse large B-cell lymphoma (DLBCL) with cardiac involvement poses a therapeutic dilemma because rapid tumor regression may precipitate early cardiac complications, whereas prolonged attenuation of curative chemotherapy may compromise disease control. We report a 61-year-old man with stage IVB non-germinal-center B-cell-like DLBCL and a 6.5 cm right atrial mass. He received a chemotherapy-free pre-phase of rituximab, zanubrutinib, and dexamethasone, followed by five cycles of modified polatuzumab vedotin-based immunochemotherapy incorporating liposomal doxorubicin, a mobilization cycle, and autologous stem cell transplantation (ASCT). The cardiac mass decreased during pre-phase without major cardiac complications, and complete metabolic response was achieved and maintained six months after ASCT. To contextualize this approach, we reviewed 65 publications reporting 81 patients with cardiac-involved DLBCL; inclusion of the present case yielded 82 patients. Among 61 patients with extractable curative-intent treatment sequences, 42 received standard-dose therapy from the first cycle, eight received persistent dose reduction, and 11 received initial dose reduction followed by standard- or near-standard-dose therapy. Reported overall response rates were 92.9% in the standard-dose group and 94.7% across the two dose-reduction groups. Relapse-related mortality occurred in 7.1%, 37.5%, and 9.1% of the standard-dose, persistent dose-reduction, and initial dose-reduction groups, respectively. These findings suggest that temporary attenuation confined to the early high-risk period may permit transition to definitive treatment without an obvious loss of initial response, whereas persistent dose reduction, particularly of anthracyclines, may be associated with less durable disease control. However, these findings are exploratory given the small sample sizes and heterogeneous follow-up. A targeted pre-phase followed by definitive polatuzumab-based immunochemotherapy and ASCT may be a feasible risk-adapted strategy for selected patients.