MCL is a rare subtype of hematological malignant disease that comprise 2.5–6% non-Hodgkin’s lymphomas. The incidence of MCL has been increasing over these years, especially among elderly patients17. Moreover, the complexity of its clinical presentations, variety in disease pathophysiological and high incidence of disease progression/recurrence pose a major challenge to developing personalized precise therapeutic strategy8,17. Although kinds of chemotherapeutic regimens show significant activity in MCL patients, no regimen has been found to be superior, and no standard treatment has been identified for 4,18. Over the years, the therapeutic options has been gradually evolving from combination chemotherapy to combination novel treatment options4. A number of targeted therapies are approved for R/R MCL patients in a surprisingly short time, including immunomodulatory agent, proteasome inhibitor and Bruton kinase inhibitors11,19,20. Despite currently available therapies show significant activity in MCL patients, prognosis remains poor after progression on these novel agents21. Treating aggressive variants of this disease is remain a serious challenge for clinicians and researchers18. Therefore, there is an urgent need to explore new individual prognostic and risk-stratified biomarkers to better distinguish the prognostic subsets of MCL with the potential to guide therapeutic decisions.
In this study, we summarized 979 cases of MCL from nine medical centers of China, which is a largest retrospective study on MCL in China. The present study presented similar clinical outcome as in previous reports13,15. The proportion POD-24 patients with Low/intermediate MIPI was significantly lower (66% vs. 82%), and the POD-24 patients more likely to have a worse performance status. Also, POD24 could be used as a prognostic predictor of MCL patients has been proposed by previous works13,15. Consistent with these results, our study demonstrated that the median OS for Non-POD24 patients was significantly longer than those of POD24 patients ((122 months vs 24 months), which displayed that POD24 was significantly associated with inferior survival of MCL patients. Besides, there was nonlinear dose-response relationship between POD and survival outcome of MCL, with POD was highly prognostic with a cut-off around 24 months. POD24 with markedly reduced OS with a hazard ratio (HR) of 5.32 (95% CI, 4.05–6.70) in multivariable cox regression analysis and POD24 was most powerful factor associated with an elevated risk of death than age, LDH level, MIPI score, splenomegaly, Ki67 expression and ASCT. These results indicated that POD24 was related with worse prognosis outcome for MCL patients.
MCL patient risk stratification and prognosis remain a challenge for clinicians. Mantle cell lymphoma international prognostic index (MIPI) score was established as the first prognostic stratification tool to identify clinical prognostic factors and patient with different risk groups22. The MIPI discriminated three groups of low, intermediate and high risk groups and has been validated by numerous studies10,22,23. However, the MIPI was derived from patients with advanced stage disease primarily in the pre-rituximab era and therefore presumably do not represent the general patient population of a new era10. Several studies have demonstrated that Ki-67 proliferation index is a strong biologic prognostic factor independent of MIPI score24,25. Thus, a combined biologic index (MIPI-b) that integrated MIPI and the Ki-67 proliferation index was developed and confirmed the prognostic value for patients with MCL10. MIPI-b model discriminates the high-risk group well, but a small low-risk group that overlapping with the intermediate-risk group in overall survival curves10. Therefore, MIPI-b does not adequately reflect the heterogeneity clinical outcome of MCL13. Similarly, our results also confirmed that MIPI and Ki67 do not show a promising performance in 3-years survival prediction with the AUC was 0.626 and 0.572, respectively. Thus, it is essential to establish novel strategies for risk assessment that include clinically relevant biomarkers to develop precision medicine treatment strategies.
Kinds of prognostic factors are markedly associated with survival outcome in MCL patients, including TP53 mutation, epigenetic profile variance, SOX11 gene expression profile and POD244,11,26. Several prognostic tools currently allow for risk stratification at diagnosis, but do not truly define the complexity of the heterogeneity of MCL disease12,13. Our findings are consistent with some results of the previously studies from western countries, which have confirmed the impact of POD24 as a prognostic and predictive marker both at diagnosis and at time of relapse in the 2 prospective Nordic MCL trials13. Furthermore, we constructed an encompassed prognostic nomogram combining POD24 with OS-related clinical factors. This nomogram (AUC = 0.869) was superior than the POD24 single factor and other clinical factors. This novel developed model greatly improved the prognostic predictive accuracy, which could be used to individualize the survival outcomes of patients and has the potential translation into clinical practice in the future.
Additionally, the level of healthcare resources and available treatments in China vary from one country/region to another27–29. While some areas may have only basic access to oncology care, some highly urbanized areas may have world-class expertise and newer therapies, some areas may have only basic treatments after being diagnosed with MCL27. Additionally, many Chinese patients common have different comorbidities, for example hepatitis B virus or tuberculosis infection. Although, our results not found the clinically relevant or statistically significant of active hepatitis B virus infection in univariate analysis, chemotherapy may increase threat with hepatitis B virus reactivation and the spread of tuberculosis. So, these should be considered as a serious consideration for the treatment of MCL patients in China27.
While our study has several limitations including its retrospective design, limited quality of the captured data and a heterogeneous patient population. On the other hand, it truly represents a real-world cohort experience, which is considered extremely important for understanding trends in day to day practice.
In summary, we confirm the prognostic impact of the POD24 and highlight the relevance of other known prognostic biomarkers in a retrospective analysis of a real-world cohort in Chinese patients, including a nomogram model of POD24-Clinical was established. To the best of our knowledge, our study is the first to identify and validate POD24-based prognostic model comprising with clinical prognostic factors in patients with MCL, which might serve as a prognosis stratification tool for facilitating patient counseling, decision- making regarding individualized adjuvant treatment, and follow-up scheduling.