Mantle cell lymphoma (MCL) is a rare peripheral B-cell lymphoma characterised by eventual relapse and progression towards a more aggressive disease biology. With the introduction of rituximab-and cytarabine-based immunochemotherapy regimens, the prognosis of the disease has changed dramatically over the last two decades. To assess the real-world survival of patients with MCL, we used a population-based cohort of 564 patients with MCL who were diagnosed and treated between 2000 and 2020. Patient data were collected from seven Finnish treatment centres and one Spanish treatment centre. For the entire patient population, we report a 2-year overall survival (OS) rate of 77%, a 5-year OS of 58%, and a 10-year OS of 32%. The estimated median OS was 80 months after diagnosis. MCL is associated with increased mortality across the entire patient population. Additionally, we assessed the survival of patients after MCL relapse with the aim of establishing a cut-off point of prognostic significance. Based on our statistical analysis of survival after the first relapse, disease progression within 24 months of the initial diagnosis should be considered as a strong indicator of poor prognosis.

SUPPLEMENT ABSTRACTS 85 (15.5 %). A total of 362 (66.1%) of patients had died from MCL and 166 (30.3%) from other causes. The median number of treatment lines received both at 10 and 20 years of follow-up was three. Conclusions:In this study, we estimated the number of treatment lines patients with MCL receive during a 20-year follow-up. The estimation we provide serves as a tool to determine the number of MCL patients that could potentially receive novel therapies during each stage of follow-up. This would contribute to the accuracy of evaluation of health economical costs, thus, allocation of the new, expensive cancer treatments.

BackgroundVenous thromboembolic events (VTEs) remain a major cause of mortality and morbidity among lymphoma patients. Accurate risk-prediction models are lacking, however, especially in the high VTE risk subgroup of diffuse large B-cell lymphoma (DLBCL). The relationship between patient-, disease- and treatment-related factors and the VTE risk is yet incompletely defined in this disease entity. MethodsIn this retrospective study, we analyzed the risk factors for VTEs in DLBCL patients treated with first-line (1L) chemoimmunotherapy in Kuopio and Oulu University Hospitals (2010-2019). Univariate and multivariate analysis (Cox regression) of VTE risk factors was performed. Two novel VTE risk scores were developed and compared by ROC (receiver operating characteristic) analysis.ResultsVTE occurred in 17.2% (n=59) in the whole population, of which seven cases occurred during anticoagulant therapy. Statistically significant risk factors for VTE included age >65 years, ECOG (Eastern Cooperative Oncology Group) >1, thrombophilia, bulky disease, LDH > ULN (lactate dehydrogenase; upper limit of normal) and IPI (International Prognostic Index) 4-5. In a multivariate Cox regression model, previous history of thrombophilia and bulky disease were independent risk factors for VTE (p=0.000 and p=0.032, respectively). VTE at 1L had no significant effect on survival (overall survival, progression-free survival or disease-specific survival) at 2 or 5 years of follow-up. Two different VTE risk scores were tested in DLBCL patients treated in 1L. ROC analysis was used to assess the ability of the score to classify VTE risk. A risk score 2 (age >65/LDH > ULN/ ECOG>1/thrombophilia = 1 p., bulky disease 2 p.) received a higher ROC value (0.680) than risk score 1. In the “high risk” group (5 p., according to risk score 2), VTE risk was increased, at 35.3%. ConclusionsThrombophilia and bulky disease were independent risk factors for VTE in 1L-treated DLBCL patients. A novel VTE risk score was developed, to be further qualified.

Venous thromboembolic events (VTEs) remain a major cause of mortality and morbidity among lymphoma patients. In this retrospective study, we analyzed the risk factors for VTEs in DLBCL (diffuse large B-cell lymphoma) patients treated with first-line (1L) chemoimmunotherapy in Kuopio and Oulu University Hospitals (2010–2019).VTE occurred in 17.2% (n = 59) in the whole population, and seven VTEs occurred during anticoagulant therapy. Statistically significant risk factors for VTE included age > 65 years, ECOG (Eastern Cooperative Oncology Group) > 1, thrombophilia, bulky disease, LDH > ULN (lactate dehydrogenase; upper limit of normal) and IPI (International Prognostic Index) 4–5. In a multivariate Cox regression model, history of thrombophilia and bulky disease were independent risk factors for VTE (p = 0.000 and p = 0.032, respectively). VTE at 1L had no significant effect on survival at 2 or 5 years of follow-up. Two different VTE risk scores were tested in DLBCL patients treated in 1L. A risk score 2 (age > 65/LDH > ULN/ ECOG > 1/thrombophilia = 1 p., bulky disease 2 p.) received a higher ROC value (0.680) than risk score 1. In the “high risk” group (5 p., according to risk score 2), VTE risk was increased, at 35.3%.