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Survival for patients diagnosed with mantle cell lymphoma (MCL) has improved drastically in recent years. However, patients carrying mutations in tumour protein p53 (TP53) do not benefit from modern chemotherapy-based treatments and have poor prognosis. Thus, there is a clinical need to identify missense mutations through routine analysis to enable patient stratification. Sequencing is not widely implemented in clinical practice for MCL, and immunohistochemistry (IHC) is a feasible alternative to identify high-risk patients. The aim of the present study was to investigate the accuracy of p53 as a tool to identify patients with TP53 missense mutations and the prognostic impact of overexpression and mutations in a Swedish population-based cohort. In total, 317 cases were investigated using IHC and 255 cases were sequenced, enabling analysis of p53 and TP53 status among 137 cases divided over the two-cohort investigated. The accuracy of predicting missense mutations from protein expression was 82%, with sensitivity at 82% and specificity at 100% in paired samples. We further show the impact of p53 expression and TP53 mutations on survival (hazard ratio of 3·1 in univariate analysis for both), and the association to risk factors, such as high MCL International Prognostic Index, blastoid morphology and proliferation, in a population-based setting., (© 2020 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Unlabelled: The IGHV3-21 gene has been shown to be overrepresented in Scandinavian patients with chronic lymphocytic leukemia (CLL). By investigating a population-based cohort of 337 Swedish patients with CLL, a lower (6.5%)IGHV3-21 frequency was determined relative to our previous hospital-based studies (10.1%-12.7%), yet this frequency remained higher compared to other Western CLL cohorts (2.6%-4.1%). Furthermore, we confirmed the poor outcome for patients with IGHV3-21 to be independent of mutational and stereotypy status., Background: Scandinavian patients with CLL have shown an overrepresentation of the poor-prognostic IGHV3-21 gene. Furthermore, approximately 50% of patients with IGHV3-21 carry stereotyped B-cell receptors, which implicate antigen selection in leukemogenesis. These patients have also been reported to have shorter time to progression than patients with nonstereotyped IGHV3-21., Materials and Methods: To investigate the IGHV3-21 frequency and the clinical impact of IGHV3-21 stereotypy, 337 newly diagnosed Swedish CLL patients from a population-based cohort were analyzed., Results: Interestingly, the IGHV3-21 frequency was indeed lower (6.5%) in this indolent patient cohort than in our previous hospital-based cohort studies (10.1%-12.7%). Hence, a selection bias of more-aggressive cases rendered a higher proportion of IGHV3-21 cases in our original studies. Nevertheless, the Swedish IGHV3-21 frequency still remained higher when compared with other larger European or American studies (2.6%-4.1%). Finally, we confirmed the poor outcome for IGHV3-21 patients to be independent of mutational status and found stereotypy to have no impact on survival or time to treatment., Conclusion: The Swedish geographic bias in IGHV3-21 gene frequency was validated albeit at a lower frequency than previously reported. Moreover, no prognostic value could be attributed to IGHV3-21 stereotype status., (Copyright © 2012 Elsevier Inc. All rights reserved.)