Slager, Susan L.

Abstract BACKGROUND: Multiple Myeloma (MM) is an incurable disease with no known germline high penetrant risk gene. The higher risk of MM among affected relatives suggests a genetic contribution to the etiology. To date, 24 common risk variants with low effect sizes were identified using genome-wide association studies, which account for 17% of heritability. However, a systematic analysis of the known rare alleles in cancer predisposition genes has not been undertaken so far in MM. We collaborated with six other academic centers across the United States to identify and select cases for analysis of germline predisposition of MM. METHODS: We performed whole exome, next-generation sequencing of 2,387 familial or early onset germline MM cases from the myeloma sequencing consortium (MMSEQ). We called 1.5 million variants and performed standard quality control of the data. We also obtained exome data on 1,285 cases from UK Biobank (UKBB) and 344,513 non-cancer controls (total=3,672 cases). We analyzed the ultra-rare, coding variants in 90 clinically relevant or putative candidates for cancer predisposition. We then used the automated variant curator PathoMAN to annotate and assert pathogenicity of each variant. We contrasted our results with assertions of pathogenicity from ClinVar and tested for gene association with MM. RESULTS: Overall, we observed several pathogenic or likely pathogenic variants, both singleton and recurrent founder mutations. In the MMSEQ, 8.7% of MM cases harbored a pathogenic variant in these known/putative cancer predisposition genes. Predominant group of pathogenic variants were observed within CHEK2 (19%), TP53 (8%), and ATM (5%). A case-control analysis revealed strong association with TP53 and weakly with ATM. In the familial/early onset MMSEQ cases, TP53 mutations were enriched 68 times more than in the UKBB controls. Our preliminary results suggest that known genes of cancer susceptibility such as TP53 and ATM may also play a role in myeloma risk. CONCLUSION: In a large study of multi-center MM cases, we identified a significant proportion of individuals who are carriers of known (solid) cancer predisposition genes. This study suggests that these known cancer predisposition genes may be relevant in a subset of MM cases. Citation Format: Michael T. Conry, Nicola Camp, Celine Vachon, Michelle Hildebrandt, Elizabeth E. Brown, Steven M. Lipkin, Judy Garber, Susan L. Slager, Samantha Stokes, Aaron D. Norman, Aalin Izhar, Sita Dandiker, Kylee Maclachlan, Kenneth Offit, Saad Usmani, Vijai Joseph. Pathogenic germline mutations and risk of multiple myeloma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5229.

12057 Background: AlthoughCLL primarily affects older adults (median age 71 years), limited data exists about the outcomes of adults who are ≥80 years old because they are under-enrolled on clinical trials. Methods: The Mayo Clinic CLL Database was used to conduct a retrospective cohort study of adults ≥80 years at the time of frontline CLL treatment. Kaplan-Meier analysis was used to plot OS, and cumulative incidence was used to plot TTNT, accounting for competing risk of death. The Mayo Clinic IRB approved the study. Results: Our study included 216 patients with CLL who were age ≥80 years at the time of frontline CLL therapy between 1/1995 and 11/2022 (Table). The median time from CLL diagnosis to initiation of frontline therapy was 3.1 years. The median OS after start of frontline therapy was 3.9 years. The median OS was 3.3 years (95% CI 2.6–4.2) for patients who received alkylating agents (e.g., chlorambucil, n=96), 3.8 years (95% CI 2.8–not reached [NR]) for purine analogues (e.g., fludarabine, n=11), 3.9 years (95% CI 3.2–4.9) for anti-CD20 monoclonal antibody monotherapy (e.g., obinutuzumab, n=64), and not reached (95% CI 3.3-NR) for novel agents (n=43) (P=0.02). The types of novel agents included ibrutinib (n=19), acalabrutinib (n=16), venetoclax (n=7), and orelabrutinib (n=1). There was no difference in OS between 36 patients who received a BTKi compared to the 7 patients who received venetoclax-based therapy. At a median follow-up time of 6.7 years from the first visit, 143 patients died from the following: progressive CLL (n=63), infections (n=12), other cancer (n=11), non-CLL reasons (n=21). Cause of death was unavailable for 36 patients. On multivariable analyses, older age (i.e., any 5-year increase in age) was associated with a 50% increased risk of death (HR 1.5, 95% CI 1.2-1.9, p=0.001), and treatment with non-novel agents was associated with 3.2 times increased risk of death (HR 3.2, 95% CI 1.2-8.9, p=0.02). Of the 216 patients, 76 patients required second-line therapy; the median TTNT was 4.2 years (95% CI 2.9-NE). The most used second-line agents were monoclonal antibodies alone (20/76, 26%) and single-agent alkylators (18/76, 24%). Conclusions: When compared to all other CLL treatments, novel agents such as BTKi and venetoclax-based treatments are associated with significantly improved OS in patients with CLL ≥80 years old when used in the frontline setting. [Table: see text]

e19507 Background: Patients (pts) with CLL are at elevated risk of developing non-hematologic malignancies. Radiation therapy (RT) is a critical component of management in localized solid organ malignancies. Novel agents (NA) are widely used in CLL treatment; however, safety data are lacking to guide treatment of pts requiring concurrent RT and NA. Methods: We identified pts treated concurrently with NA for CLL and RT for second primary malignancy (SPM) at Mayo Clinic from 2014-2022. Adverse events within 3 months of RT were evaluated using the International Workshop on Chronic Lymphocytic Leukemia (iwCLL) criteria for hematological toxicity and the Common Terminology Criteria for Adverse Events (CTCAE) version 5 for non-hematological toxicity. Patients without seamless, concurrent treatment with NA and RT were excluded. Results: Twenty-six pts were included. NA therapy consisted of ibrutinib (n = 23), acalabrutinib (n = 2), and venetoclax (n = 1). Median follow up time since RT completion was 1.5 years. The median age at NA initiation was 67 years (range:46-85) and at RT start was 68 years (range: 51-85); 92% of pts were male. NA was first treatment in 23% of pts; the median number of prior lines of therapy was 1 (range: 0-4). IGHV was unmutated in 82% and TP53 aberration was present in 24% of evaluable patients. SPM sites included prostate (n = 9), head/neck (n = 8), lung (n = 3), and brain, breast, bone, skin, kidney, and thymus (n = 1 each). The most common conventionally fractionated prescriptions (cGy/fx) were 6000/30 (n = 6) and > 6000-7020/20-33 (n = 7). SBRT ranged from 3300/5 to 5400/3 (n = 8). Five pts received other, varied RT prescriptions. Overall, 3 (12%) pts experienced at least one grade 3/4 toxicity. Grade 3/4 thrombocytopenia was observed in 2 (8%) pts and grade 3/4 neutropenia was observed in 2 pts per iwCLL criteria. Grade ≥3 non-hematological toxicities occurred in two pts that required hospitalization for critical illness, including 1 pt with grade 5 respiratory failure within 6 weeks after RT. Dose de-escalation of ibrutinib was reported in one case for pancytopenia attributed to use of a radiosensitizing agent. There were no cases of RT dose modification. Conclusions: Continuing NA CLL therapy during RT did not result in unexpected toxicities. This approach may maintain CLL disease control without compromising management of the SPM. [Table: see text]

7577 Background: Prior research has consistently shown that patients with chronic lymphocytic leukemia (CLL) have an ~2-fold increased risk of developing melanoma compared to controls. MBL is a common condition affecting 8-10 million adults over the age of 40 years in the United States and is a precursor to CLL. Little is known about the association between MBL and melanoma. Herein, we evaluated the risk of incident melanoma in a large cohort of individuals screened for MBL. Methods: Participants from the Mayo Clinic Biobank who had no prior history of hematologic malignancy, were 40 years or older, were residents of counties surrounding Mayo Clinic, and who provided blood samples between 7/2009 and 4/2022 were included in the study. Peripheral blood mononuclear cells were screened for MBL using highly sensitive eight-color flow cytometry. Individuals with MBL were classified as CLL-like MBL (CD5+, CD20dim) or atypical MBL (CD5+, CD20+) based on immunophenotypes, and also classified as low-count MBL (LCMBL) or high-count MBL (HCMBL) based on whether the percent clonal B-cell count was < 85% or ≥85%, respectively. Diagnosis of melanoma was ascertained using ICD codes and review of the electronic health records. All individuals were followed from date of sample upon which MBL screening was performed to the earliest of incident melanoma, loss to follow-up, withdrawal from the study, or September 30, 2022. We used Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI), adjusting for age, sex, and history of melanoma in previous 5 years. Results: A total of 7,334 participants were screened for MBL, of which 1,151 (16%) individuals had MBL. Among those with MBL, 1,107 (96.2%) had CLL-like MBL and 1098 (95.4%) had LC MBL. The median age at entry into the MBL screening cohort was 67 years (range 40-101) and 37% were male; individuals with MBL were older (median age 72 vs 65 years) and male (49% vs 35%). After a median follow-up of 2.9 years (range 0-13.2), 121 of the 7,334 (1.6%) participants developed incident melanoma after the date of MBL screening. The 10-year cumulative incidence of melanoma among individuals with MBL was 7.8% (95% CI 4.5-13.5%) compared to 3.4% (2.7-4.4%) in those who screened negative for MBL. After adjusting for age, sex, and history of prior melanoma, we found a 1.81-fold increased risk of incident melanoma (95% CI 1.19-2.76) among individuals with MBL. The increased risk of melanoma persisted when the analysis was restricted to individuals with LCMBL (HR = 1.84; 95% CI 1.21-2.82). Conclusions: In the largest MBL screening cohort to date, we found that LCMBL, a common condition, was associated with an 84% elevated risk of melanoma, similar to the ~2-fold increased risk observed in patients with CLL. These data, together with our prior findings of a heightened risk of serious infections and lymphoid malignancies, suggest that individuals with LCMBL are at increased risk for adverse health outcomes.

AbstractAge‐related comorbid conditions are exceedingly common in patients with chronic lymphocytic leukemia (CLL). As the prevalence of type 2 diabetes (T2D) is predicted to double during the next two decades, a better understanding of the interplay between CLL and T2D is of increasing importance. In this study, analyses were performed in parallel in two separate cohorts, based on Danish national registers and the Mayo Clinic CLL Resource. The primary outcomes were overall survival (OS) from time of CLL diagnosis, OS from time of treatment, and time to first treatment (TTFT), studied using Cox proportional hazard regression analysis and Fine‐Gray regression analysis. In the Danish CLL cohort, the prevalence of T2D was 11%, in the Mayo CLL cohort, it was 12%. Patients with CLL and T2D had shorter OS both from time of diagnosis and from first‐line treatment for were less likely to receive treatment for CLL compared with patients with CLL and without T2D. The increased mortality was largely driven by an increased risk of death due to infections, especially in the Danish cohort. The findings of this study emphasize a substantial subgroup of CLL patients with co‐occurring T2D with an inferior prognosis and a possible unmet treatment need requiring additional interventions and further research.

Chronic lymphocytic leukemia (CLL) is the most common leukemia among adults worldwide. Although genome-wide association studies (GWAS) have uncovered the germline genetic component underlying CLL susceptibility, the potential use of GWAS-identified risk variants to predict disease progression and patient survival remains unexplored. Here, we evaluated whether 41 GWAS-identified risk variants for CLL could influence overall survival (OS) and disease progression, defined as time to first treatment (TTFT) in a cohort of 1039 CLL cases ascertained through the CRuCIAL consortium. Although this is the largest study assessing the effect of GWAS-identified susceptibility variants for CLL on OS, we only found a weak association of ten single nucleotide polymorphisms (SNPs) with OS (p < 0.05) that did not remain significant after correction for multiple testing. In line with these results, polygenic risk scores (PRSs) built with these SNPs in the CRuCIAL cohort showed a modest association with OS and a low capacity to predict patient survival, with an area under the receiver operating characteristic curve (AUROC) of 0.57. Similarly, seven SNPs were associated with TTFT (p < 0.05); however, these did not reach the multiple testing significance threshold, and the meta-analysis with previous published data did not confirm any of the associations. As expected, PRSs built with these SNPs showed reduced accuracy in prediction of disease progression (AUROC = 0.62). These results suggest that susceptibility variants for CLL do not impact overall survival and disease progression in CLL patients.

Abstract Low count (LC) MBL is characterized by a circulating population of clonal B-cells and is a precursor state to CLL. Most individuals with LC MBL do not progress to CLL and never come to clinical attention. An active area of research is to identify factors that distinguish those individuals with MBL who progress from those who do not. Currently, 41 single nucleotide polymorphisms (SNPs) are known to be associated with CLL risk, and a portion of these SNPs have also been found to be associated with MBL risk. We hypothesize that these CLL-susceptibility SNPs associated with both MBL and CLL risk are SNPs associated with developing a B-cell clone; whereas the remaining SNPs found not to be associated with MBL risk are associated with progression of the B-cell clone (i.e., progression from MBL to CLL). To test this hypothesis, we evaluated the association of these 41 SNPs with risk of progression to CLL using a case-control study of 1,911 CLL cases and 1,579 individuals with MBL from Mayo Clinic. Individuals with MBL were identified through screening using 8-color flow cytometry assay. Individuals with LC MBL (defined by having a clonal B-cell population with the percent clonal B-cells out of total B-cell count &lt;85%) who had an immunophenotype consistent with CLL were included as controls. CLL cases were obtained through the Mayo Clinic hematology practice. DNA was genotyped from whole blood. We analyzed the 41 CLL susceptibility SNPs with risk of progression to CLL using logistic regression and estimated odds ratio (OR) and 95% confidence interval (CI), adjusting for sex and age. We evaluated the CLL polygenic risk score (CLL-PRS), comprised of a weighted average of the 41 SNPs, with risk of CLL. Out of the 41 established CLL susceptibility SNPs, 15 were associated with CLL progression from MBL to CLL (all P&lt;0.05). Nine of these 15 significant SNPs were not previously found to be associated with risk of MBL. The most significant SNPs were rs9880772 (OR=1.23, CI: 1.11-1.36, P=6.1 × 10−5), rs888096 (OR=1.25, CI: 1.12-1.38, P=3.0 × 10−5), and rs305065 (OR=1.28, CI: 1.14-1.43, P=1.5 × 10−5). One SNP (rs77551289) had a suggestive association (OR=1.21, P=0.069). The remaining 25 SNPs had no evidence of association with progression (ORs ranging between 0.9-1.1 and all P&gt;0.1). The CLL-PRS was also associated with CLL risk (continuous OR = 1.25, CI: 1.15 - 1.35, P = 6.7 × 10−8). In our study accounting for the presence of B-cell clonal population, we identified 15 out of 41 CLL-susceptibility SNPs to be significantly associated with progression from LC MBL to CLL. The remaining 25 non-significant CLL-SNPs were not associated with progression and may instead be associated with development or initiation of the B-cell clone. These findings suggest that the established CLL susceptibility SNPs may play differing role (i.e., development or progression of the clone) in the etiology of CLL. Citation Format: Raphael Mwangi, Geffen Kleinstern, Sara J. Achenbach, Dennis Robinson, Aaron D. Norman, Kari G. Rabe, Janet E. Olson, Neil E. Kay, Rosalie G. Waller, Nicholas J. Boddicker, James R. Cerhan, Esteban Braggio, Sameer A. Parikh, Curtis A. Hanson, Celine M. Vachon, Tait Shanafelt, Susan L. Slager. Genetic variants associated with progression from monoclonal B-cell lymphocytosis (MBL) to chronic lymphocytic leukemia (CLL). [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5222.

Abstract Multiple studies including ours have shown that the interaction of chronic lymphocytic leukemia (CLL) B cells with the bone marrow (BM) microenvironment promotes cell survival and protects these cells from the cytotoxic effects of therapy. A detailed understanding of this interaction will help better understand CLL leukemic cell survival and drug resistance mechanisms. We performed RNA-seq in paired CLL B cells isolated from untreated blood and BM (n=6) and in untreated CLL B cells (n=4) cultured alone or co-cultured with bone marrow stromal cells (BMSCs) derived from either normal individuals (n=2) or CLL patients (n=2). We found upregulation of 232 and 917 genes in CLL B cells from BM and in co-cultured CLL B cells compared to the CLL B cells from the same patient’s blood and CLL B cells cultured alone respectively (p&lt;0.05, fold change &gt;1.5). However we found only 13 genes overlapped between BM CLL B cells and co-cultured CLL B cells. To explore the functional importance of these 13 genes, we analyzed the expression of these genes in CLL blood B cells from an additional 169 untreated patients by RNA-seq and found a positive relationship between 5 of these 13 genes (MKI67, PNP, C16orf54, MOB3A, CDK2AP2) with CLL patient’s clinical outcome including overall survival (OS), progression free survival (PFS), and time to first treatment (TTFT) [univariate Cox regressions analysis (UCRA) p&lt;0.05]. Out of 5 genes, purine nucleotide phosphorylase (PNP) which is an enzyme in the purine salvage pathway, showed the significant association for patient’s OS, PFS, and TTFT using UCRA [hazard ratio (HR) {95% CI}: 2.8 {1.8-4.3}, 2.7 {1.9-3.8}, 2.9 {2.0-4.2}, respectively, p&lt;.0001], suggesting purine metabolism plays an important role in BM induced CLL B cell survival. We also observed an increase in PNP protein levels in CLL B cells co-cultured with BMSCs or from BM using Western blot analysis. Untargeted metabolomic profiling (LC-MS+GC-MS) showed an increased level of purine salvage pathway metabolites adenosine, inosine, and hypoxanthine in co-cultured CLL B cells. Consistent with this altered nucleotide metabolism data, we also found increased pyrimidine pathway enzyme thymidylate synthase (TYMS) at RNA and protein levels in co-cultured CLL B cells and in BM CLL B cells. We further analyzed the RNA-seq data generated from the 169 CLL patients and it also showed a positive association of TYMS gene with their OS, PFS and TTFT using UCRA [HR (95% CI): 1.35 (1.0-1.8), 1.3 (1.0-1.6), 1.63 (1.3-2.1) respectively, p&lt;0.05]. In conclusion, these results indicate that active purine/pyrimidine metabolism in CLL B cells may be augmented by the BM environment to support CLL B cell survival. Future studies to understand the exact mechanism of PNP and TYMS mediated CLL B cell survival for both untreated and treated CLL B cells will uncover unique approaches for therapy. Citation Format: Sutapa Sinha, Zhiquan Wang, Weiguo Han, Kari G. Rabe, Susan L. Slager, Chantal E. McCabe, Daniel R. O'Brien, Sameer A. Parikh, Esteban Braggio, Neil E. Kay. Role of purine and pyrimidine metabolism in CLL B cell survival and drug resistance mediated via interaction with bone marrow microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1252.

Abstract Diffuse large B-cell lymphoma (DLBCL) is clinically and biologically heterogenous. Based on gene expression profiling of the tumor, DLBCL is classified into two major molecular subtypes linked to cell-of-origin (COO): germinal center (GCB) and activated B-Cell (ABC). The GCB subtype is characterized by a high prevalence of somatic mutations, particularly in apoptosis genes (e.g., BCL2) which is characteristic of follicular lymphoma (FL, another GCB lymphoma). The development of the validated NanoString gene expression test as well as immunohistochemistry markers that work in formalin-fixed, paraffin-embedded tissue allows for the classification of DLBCL by COO in epidemiological studies. We hypothesized that integration of COO with germline genetics could provide insight into the underlying biology driving this heterogeneity, as well as insight into putative function of germline risk variants. Prior genome wide association studies (GWAS) have identified 7 SNPs in 6 susceptibility loci for DLBCL, including: 2p23.3 (rs79480871 NCOA1), 3q13.33 (rs9831894 CD86), 3p24.1 (rs6773363 EOMES), 6p21.33 (rs2523607 HLA-B), 6p25.3 (rs116446171 EXOC2), and 8q24.21 (rs13255292 and rs4733601 PVT1 and MYC). Two of these loci were also identified in FL GWAS (different lead SNPs): 6p21.33 (rs3130437) and 8q24.21 (rs13254990 PVT1). Additional published FL susceptibility loci include: 3q28 (rs6444305 LPP), 6p21.32 (rs9268839), 11q23.3 (rs4938573 CXCR5), 11q24.3 (rs4937362 ETS1), and 18q21.33 (rs17749561 BCL2). Here we evaluated whether the published DLBCL/FL loci differ by COO molecular subtypes. We evaluated each of the 14 DLBCL/FL SNPs by case-case (GCB vs. nonGCB DLBCL) and polytomous case-control (GCB, nonGCB, and FL vs. controls) analyses. DLBCL cases were classified into GCB vs. nonGCB based on best available data from NanoString, RNAseq, followed by the Hans algorithm. A total of 778 DLBCL cases (470 GCB and 308 nonGCB), 1,050 FL cases, and 1,383 controls were analyzed. Odds ratios (OR) based on ordinal encoding of each SNP and 95% CI were calculated for each of the comparison groups. The ORs for four GWAS SNPs were significantly elevated in GCB vs. nonGCB DLBCL as well as in FL; two were FL GWAS SNPs from the HLA region (6p21.32 and 6p21.33) and the other two (BCL2 and ETS1) are important in the germinal center program. In contrast, one SNP (EXOC2) was significantly elevated in nonGCB-DLBCL and was not associated with GCB-DLBCL or FL; this SNP is also near IRF4 (MUM1), a gene important in the ABC program. For the remaining SNPs, there were suggestive associations for GCB-DLBCL and FL versus nonGCB DLBCL (CD86, CXCR5); nonGCB-DLBCL vs. GCB-DLBCL and FL (NCOA1, PVT1); and associations that showed no pattern with COO (EOMES, LPP, HLA-B and MYC). These findings provide insight into the shared pathogenesis of FL and GCB-DLBCL to inform etiologic mechanisms and risk assessment. Citation Format: Rosalie Griffin Waller, Dennis P. Robinson, Anne J. Novak, Lisa M. Rimsza, Kerstin Wenzl, Rebecca L. King, Andrew L. Feldman, Matthew J. Maurer, Grzegorz S. Nowakowski, Brian K. Link, Thomas M. Habermann, Susan L. Slager, James R. Cerhan. Etiologic heterogeneity of genetic risk for DLBCL cell-of origin molecular subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1181.