Real-world outcomes of Mantle Cell Lymphoma in Colombia: A multicenter cohort study

Abstract Introduction: Mantle cell lymphoma (MCL) remains understudied in Latin America, with limited data on clinical presentation, treatment patterns, and outcomes. This study characterizes disease features, treatment access, and survival in MCL patients in Bogotá, Colombia. Methods: We conducted a retrospective cohort study of 80 MCL patients diagnosed between 2010 and 2024 at two fourth-level hospitals in Bogotá. Data on baseline characteristics, treatment patterns, and survival outcomes were collected. The primary endpoint was 5-year overall survival (OS), analyzed using Kaplan-Meier estimates and log-rank tests. Cox regression identified variables associated with OS. Secondary endpoints included treatment patterns and response. Analyses were performed in Python 3.13.3 (p < 0.05). Results: The median age was 65 years (IQR: 56–73), and 72.5% (n = 58) were male. Most had advanced-stage disease (80.7%, n = 63, stage IV) and were classified as high-risk by MIPI (56.2%, n = 36) and MIPIb (68.7%, n = 44). The most common induction regimens were cytarabine-based, including Rituximab - cyclophosphamide - doxorrubicin - vincristin - prednisolone (R-CHOP)/ Rituximab - dexamethasone - citarabine - cisplatin (R-DHAP) (LYMA) (46.2%, n = 37) followed by the Nordic regimen (12%, n = 10) and Bendamustine-Rituximab (BR)(10.0%, n = 8). Other treatment regimens were R-CHOP/R-miniCHOP (10.0%, n = 8), and rituximab - bendamustine - cytarabine (R-BAC) (8.8%, n = 7). Seventeen patients (21.2%) had a complex karyotype, 27 (33.7%) had a MYC translocation detected by FISH, and 15 (18.7%) demonstrated MYC overexpression by immunohistochemistry. SOX11 expression was observed in 24 patients (36.3%). A TP53 mutation was identified by NGS in 15 patients (18.7%). The most common TP53 alterations included R248Q/W in 4 patients (5.0%), R175H in 3 patients (3.75%), and R273H/C in 2 patients (2.5%). Only 27 (34%) pts received Rituximab maintenance. The ORR to first-line therapy was 69%, with CR in 67.5%. Among 48 eligible for autologous stem cell transplantation (ASCT), only 30 (62.5%) underwent consolidation. Of 39 receiving second-line therapy, 31 (44%) were treated with BTK inhibitor ibrutinib, which remains approved only for relapsed/refractory disease in Colombia. With a median follow-up of 29 months, 5-year OS rate was 66.2% (95% CI: 52.9%–76.6%). The 5-year overall survival (OS) varied by histological subtype. Patients with classical MCL had the highest 5-year OS (76.2%), followed by blastoid (54.9%). Elegible patients who underwent ASCT had significantly better OS compared to those who did not undergo transplantation (log-rank p = 0.0053). In a Cox proportional hazards model adjusted for ECOG performance status, LDH levels, and leukocyte count, a high Ki-67 index (>50%) was the only variable independently associated with worse overall survival (HR: 3.67; p = 0.006). Conclusion: Our 5-year overall survival (OS) rate of 66.2% exceeded the 57.1% reported in a broader Latin American cohort (Pavlovsky et al., 2022), suggesting potential regional differences in outcomes. Despite the established survival benefit of autologous stem cell transplantation (ASCT), over one-third of eligible patients did not undergo transplant, highlighting ongoing barriers to access. In Colombia—where novel therapies such as CAR T-cell therapy and bispecific antibodies remain unavailable, and BTK inhibitors are not approved in the first-line setting—ASCT remains a cornerstone of treatment for transplant-eligible patients. These limitations underscore the need for thoughtful sequencing of available therapies and reinforce the importance of expanding access to molecular profiling, to improve risk stratification and guide therapeutic strategies.