Citations

Abstract Background: The POSITIVE trial recently demonstrated that temporary interruption of ET to attempt pregnancy does not increase the short-term risk of recurrence in pts with hormone receptor-positive (HR+) BC. Yet, uncertainty exists regarding the safety of ovarian stimulation for embryo/oocyte cryopreservation to preserve fertility in these pts. In addition, very limited data exist regarding safety and efficiency of ART to achieve pregnancy after ET interruption. Methods: POSITIVE is an international, single-arm, prospective trial that enrolled pts ≤ 42 years with stage I-III HR+ BC who had already received 18-30 months of ET prior to enrollment. The use of ART was a predefined 2ry endpoint. We evaluated factors associated with time to pregnancy in a Fine and Gray competing risks model, which included chemotherapy (chemo) ± GnRH analogue (GnRHa), age, prior ET, prior birth, and menstrual status at enrollment. The cumulative incidence of pregnancy at 12 months from enrollment by age was estimated controlling for competing risks. We performed a logistic regression model to evaluate whether ART use was associated with achieving pregnancy, adjusting for age, receipt of chemo ± GnRHa. The cumulative incidence of BCFI events was estimated according to whether or not ovarian stimulation for cryopreservation was performed at diagnosis and prior to enrollment. BC-free interval (BCFI) was defined as the time from enrollment until the first BC event (invasive local, regional, or distant recurrence or contralateral disease). A 24-month landmark analysis was performed to investigate the safety of ART use after enrollment. Median follow-up was 41 months. Results: 497 out of 516 included pts (96%) were followed for at least 6 months and were evaluable for pregnancy status. 368 out of 497 evaluable pts (74%) reported at least one pregnancy. In a multivariable model, young age was the only factor associated with shorter time to pregnancy. The cumulative incidence of pregnancy at 12 months was 64%, 54% and 38% for pts aged < 35, 35-39 and 40-42 years, respectively. 179 pts (36.0%) had undergone ovarian stimulation for embryo/oocyte cryopreservation at diagnosis and prior to enrollment, of whom 68 (37.9%) reported cryopreserved embryo transfer after enrollment. 215 pts (43.3%) reported using any ART after enrollment, of whom 80 (37.2%) underwent ovarian stimulation for in-vitro fertilization (FIVET) or intracytoplasmic sperm injection (ICSI). Other ART used included clomiphene (n=19), intrauterine insemination (n=37) and egg donation (n=17). Pregnancy rates were 82.4% and 67.5% for women who underwent cryopreserved embryo transfer and FIVET/ICSI, respectively. In a multivariate model, cryopreserved embryo transfer was the only ART independently associated with a higher chance of pregnancy (OR:2.41, 95% CI: 1.75-4.95). The cumulative incidence of BCFI events at 3 years was similar for women who underwent ovarian stimulation for cryopreservation at diagnosis and before enrollment, 9.7% (95% CI: 6.0-15.4%), and those who did not, 8.7% (95% CI: 6.0-12.5%). A 24-month landmark analysis showed no impact of ovarian stimulation for FIVET/ICSI after enrollment on BCFI. Conclusions: This is the largest prospective study to investigate fertility preservation and ART in pts with HR+ BC. Young age was the main factor associated with shorter time to pregnancy. Embryo/oocyte cryopreservation at BC diagnosis followed by embryo transfer after ET interruption was the only approach associated with an increased chance of pregnancy. Ovarian stimulation either at BC diagnosis for embryo/oocyte cryopreservation or after enrollment to POSITIVE for FIVET/ICSI did not appear to impact prognosis in the short term. These data are of paramount importance for oncofertility counselling of young BC pts. Citation Format: Hatem Azim, Samuel Niman, Ann Partridge, Isabelle Demeestere, Monica Ruggeri, Marco Colleoni, Cristina Saura, Chikako Shimizu, Anna Saetersdal, Judith Kroep, Audrey Mailliez, Ellen Warner, Virginia Borges, Frédéric Amant, Andrea Gombos, Akemi Kataoka, Christine Rousset-Jablonski, Simona Borstnar, Junko Takei, Jeong Eon Lee, Janice Walshe, Manuel Ruíz - Borrego, Halle Moore, Christobel Saunders, Vesna Bjelic-Radisic, Snezana Susnjar, Fatima Cardoso, Natalie Klar, Tanya Spanic, Kathryn Ruddy, Martine Piccart, Larissa Korde, Aron Goldhirsch, Richard Gelber, Olivia Pagani, Fedro Alessandro Peccatori. Fertility preservation and assisted reproductive technologies (ART) in breast cancer (BC) patients (pts) interrupting endocrine therapy (ET) to attempt pregnancy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS02-11.

Importance Among women diagnosed with primary breast cancer (BC) at or younger than age 40 years, prior data suggest that their risk of a second primary BC (SPBC) is higher than that of women who are older when they develop a first primary BC. Objective To estimate cumulative incidence and characterize risk factors of SPBC among young patients with BC. Design, Setting, and Participants Participants were enrolled in the Young Women’s Breast Cancer Study, a prospective study of 1297 women aged 40 years or younger who were diagnosed with stage 0 to III BC from August 2006 to June 2015. Demographic, genetic testing, treatment, and outcome data were collected by patient surveys and medical record review. A time-to-event analysis was used to account for competing risks when determining cumulative incidence of SPBC, and Fine-Gray subdistribution hazard models were used to evaluate associations between clinical factors and SPBC risk. Data were analyzed from January to May 2023. Main Outcomes and Measures The 5- and 10- year cumulative incidence of SPBC. Results In all, 685 women with stage 0 to III BC (mean [SD] age at primary BC diagnosis, 36 [4] years) who underwent unilateral mastectomy or lumpectomy as the primary surgery for BC were included in the analysis. Over a median (IQR) follow-up of 10.0 (7.4-12.1) years, 17 patients (2.5%) developed an SPBC; 2 of these patients had cancer in the ipsilateral breast after lumpectomy. The median (IQR) time from primary BC diagnosis to SPBC was 4.2 (3.3-5.6) years. Among 577 women who underwent genetic testing, the 10-year risk of SPBC was 2.2% for women who did not carry a pathogenic variant (12 of 544) and 8.9% for carriers of a pathogenic variant (3 of 33). In multivariate analyses, the risk of SPBC was higher among PV carriers vs noncarriers (subdistribution hazard ratio [sHR], 5.27; 95% CI, 1.43-19.43) and women with primary in situ BC vs invasive BC (sHR, 5.61; 95% CI, 1.52-20.70). Conclusions Findings of this cohort study suggest that young BC survivors without a germline pathogenic variant have a low risk of developing a SPBC in the first 10 years after diagnosis. Findings from germline genetic testing may inform treatment decision-making and follow-up care considerations in this population.

Abstract Glioblastoma remains difficult to treat with immunotherapy due to the immunosuppressive tumor microenvironment and the ability of glioma cells to invade diffusely into normal brain parenchyma. While it is known that glioblastoma-associated myeloid cells (GAMs) comprise a large proportion of the tumor microenvironment and can suppress adaptive and innate immune responses through various mechanisms, detailed mapping of myeloid lineages in glioblastoma is still missing. Further characterization of pro-tumoral myeloid-lineages in glioblastoma is important for identifying myeloid-based drug targets that may synergize with T cell-based therapies and produce a more meaningful anti-tumor immune response. Towards this end, we examined numerous scRNAseq datasets derived from glioblastoma patients and identified expression of TNFRSF12A, the gene encoding the TNF- family receptor, Fn14, in a subset of GAMs enriched for expression of cytokines such as CCL3, CCL5, IL-6, and IL-8. This result is intriguing since TWEAK (TNFSF12), the ligand for Fn14, is abundantly expressed within numerous patient-derived glioblastoma cell lines, namely GBM6, GBM8, GBM22, and GBM39. To validate Fn14 protein expression in GAMs, we isolated murine bone-marrow derived macrophages and treated them with glioma-conditioned media, which induced Fn14 gene expression. We then conducted in vitro experiments utilizing the human microglia line HMC3, the murine microglia line SIM-A9, and primary murine bone-marrow-derived macrophages to assess the effects of Fn14 activation in myeloid cells. We found that treatment of Fn14+ myeloid cells with TWEAK ligand upregulates CCL3, CCL5, IL-6, and IL-8 expression. We tested the conditioned media generated from TWEAK-treated Fn14+ myeloid cell lines and found that it promotes glioblastoma invasion in a CCL5-dependent manner. This aligns with previous reports demonstrating the CCL5-CCR5 signaling in glioma cells promotes invasion through calcium-dependent matrix metalloproteinase 2. To assess the spatial distribution of this myeloid subpopulation, we performed RNAscope hybridization against AIF1, TMEM119, CCR5, CCL5, and Fn14 transcripts on sections of murine gliomas generated using the RCAS/tv-a model of human glioblastoma. We found an abundance of Fn14+ plus AIF1+ as well as Fn14+plus TMEM119+ myeloid cells throughout the tumor core and rim of murine tumors and identified CCL5 expression in pseudo-palisades bordering necrotic regions. Our results to date suggest that Fn14 expression in GAMs can promote the invasion of tumor cells into normal brain parenchyma by release of CCL5. Currently, we are utilizing orthotopic patient-derived xenograft models co-implanted with Fn14+/- myeloid cells to test the hypothesis that TWEAK-Fn14 signaling in GAMs provides strong pro-tumoral signals in the glioblastoma microenvironment. Citation Format: Angad Beniwal, Matthew Dufault, Pranjali Kanvinde, David Nascari, Ryan Eghlimi, Adarsha Malla, Dolores Hambardzumyan, Henrique Borges da Silva, Graeme Woodworth, Jeffrey Winkles, Nhan Tran. TWEAK-Fn14 signaling in glioblastoma-associated myeloid cells promotes tumor invasion via CCL5-CCR5 axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6867.

Abstract Multiple myeloma (MM) is an incurable plasma cell (PC) cancer in which all patients are expected to relapse. Cytotoxic agents such as high-dose melphalan (HDM), which is used as a myeloablative agent prior to autologous stem cell transplant (ASCT) in MM, drive therapy-induced senescence (TIS) in non-cancerous tissues. We hypothesized that HDM similarly activates TIS pathways in surviving MM cells and this response may correlate with patient outcomes post-ASCT. To test this, we developed an in vitro model in which 5TGM1 mouse MM cells are cultured with 10uM melphalan (HDM) or vehicle (Veh) for 6 hours, followed by co-culture in normal media with primary mouse bone marrow stromal cells. Cultures were maintained for 10 days and imaged to quantify cumulative population doublings (CPDs). 5TGM1 were then isolated by FACS to measure telomere-associated DNA damage foci (TAFs), sensitivity to senolytic drugs, and senescence gene expression (RT-qPCR and scRNA-seq). To translate these studies, scRNA-seq was used to analyze CD138+ PCs from MM patient bone marrow post-ASCT. Additionally, longitudinal bone biopsies from MM patients at diagnosis and post-ASCT were stained for CD138+ PCs; PC burden was quantified using artificial intelligence assisted histology (HALO). HDM-5TGM1 exhibited stable growth arrest (decreased CPDs) and sustained DNA damage (increased TAFs) compared to Veh-5TGM1. HDM-5TGM1 were also significantly more sensitive to senolytic ablation (Dasatinib+Quercetin or Fisetin). HDM-5TGM1 showed increased senescence (Cdkn1a, Cdkn1c, Glb1), anti-apoptosis (Bcl2l1), and senescence associated secretory phenotype (Ccl5, Icam1, Mmp13) genes, as well as myeloid markers found to be increased in MM dormancy (Axl, Fcer1g, Mpeg1). Analysis by scRNA-seq revealed that HDM-5TGM1 were G0/G1 arrested, and gene set enrichment analysis (GSEA) confirmed upregulation of senescence pathways with downregulation of DNA replication and cell cycle pathways. Consistent with RT-qPCR results, these cells exhibited myeloid gene expression. Analysis of patient CD138+ PCs post-ASCT by scRNA-seq also revealed a myeloid-like cluster. Of interest, of the 491 genes upregulated in this cluster, 268 were also upregulated in HDM-5TGM1. CD138+ PCs could also be detected in patient bone biopsies post-ASCT, although PC burden was significantly reduced post-ASCT. Surprisingly, the percent reduction in PC burden post-ASCT was greater in relapsed (≤3 years) vs non-relapsed patients. Further, in relapsed patients, PC burden post-ASCT positively correlated with time in remission. Altogether, these findings demonstrate that HDM can induce senescence features and a myeloid-dormancy signature in surviving MM cells. This phenotype is associated with longer durable response, suggesting that activation of TIS may be a strategy to extend PFS. Further, senolytic therapy may be a novel approach to eliminate dormant MM cells and prevent relapse. Citation Format: Angelo Jose Guilatco, Marta Diaz-del-Castillo, Gabriel Alvares Borges, Neal I. Sannuli, Megan L. Ritting, Syed Mohammed Aalam, Nagarajan Kannan, Tamar Tchkonia, James L. Kirkland, Yi Lin, Taxiarchis Kourelis, Matthew T. Drake, Thomas Levin Andersen, Megan Weivoda. Melphalan-treated multiple myeloma cells exhibit a senescent-like dormancy phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2958.

Background: Recognizing the early signs of cancer risk is vital for informing prevention, early detection, and survival. Methods: To investigate whether changes in circulating metabolites characterize the early stages of colorectal cancer (CRC) development, we examined the associations between a genetic risk score (GRS) associated with CRC liability (72 single-nucleotide polymorphisms) and 231 circulating metabolites measured by nuclear magnetic resonance spectroscopy in the Avon Longitudinal Study of Parents and Children (N = 6221). Linear regression models were applied to examine the associations between genetic liability to CRC and circulating metabolites measured in the same individuals at age 8 y, 16 y, 18 y, and 25 y. Results: The GRS for CRC was associated with up to 28% of the circulating metabolites at FDR-P < 0.05 across all time points, particularly with higher fatty acids and very-low- and low-density lipoprotein subclass lipids. Two-sample reverse Mendelian randomization (MR) analyses investigating CRC liability (52,775 cases, 45,940 controls) and metabolites measured in a random subset of UK Biobank participants (N = 118,466, median age 58 y) revealed broadly consistent effect estimates with the GRS analysis. In conventional (forward) MR analyses, genetically predicted polyunsaturated fatty acid concentrations were most strongly associated with higher CRC risk. Conclusions: These analyses suggest that higher genetic liability to CRC can cause early alterations in systemic metabolism and suggest that fatty acids may play an important role in CRC development. Funding: This work was supported by the Elizabeth Blackwell Institute for Health Research, University of Bristol, the Wellcome Trust, the Medical Research Council, Diabetes UK, the University of Bristol NIHR Biomedical Research Centre, and Cancer Research UK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This work used the computational facilities of the Advanced Computing Research Centre, University of Bristol - http://www.bristol.ac.uk/acrc/ .

Abstract CD8+ T-cell responses are influenced by ion abundance, which can widely vary within the tumor microenvironment. In this issue, Collier and colleagues investigated how intracellular versus extracellular potassium ion (K+) regulates intratumoral CD8+ T cells. They show that, while excessive extracellular K+ induces exhaustion, intracellular K+ is needed for protection from dysfunction. This work shows additional evidence that the regulation of CD8+ T-cell responses depends on a fine balance between intracellular and extracellular metabolite levels. See related article by Collier et al., p. 36 (2) .

Multiple myeloma (MM) is an incurable plasma cell malignancy. Despite therapeutic advances that have vastly improved survival, all patients are expected to relapse. One mechanism that may contribute to MM relapse is tumor dormancy. Dormant MM cells may persist in the bone marrow, where they exhibit reduced proliferative capacity and resistance to treatment. These cells may then exit dormancy following treatment to drive disease relapse. Dormancy shares many features with cellular senescence, a state of stable growth arrest induced by cell stress. Chemotherapies that produce genotoxic stress have been associated with therapy-induced senescence (TIS). One such genotoxic agent, melphalan (Mel), is routinely administered to MM patients for myeloablation prior to autologous bone marrow transplant. We hypothesized that High Dose Mel (HDM) induces a senescent-like dormant phenotype in surviving MM cells. To test our hypothesis, we developed an in vitro model for HDM. We identified 10µM Mel as a concentration to induce &gt;90% cell toxicity (HDM) in 5TGM1 mouse MM cells over 10 days. 5TGM1-GFP MM cells were cultured with HDM or vehicle (Veh) for 6 hours; cells were then cultured in normal growth medium in the presence of primary mouse (C57BL/6) bone marrow stromal cells (BMSCs). Co-cultures were imaged by fluorescent microscopy every other day to quantify cumulative population doublings (CPD) and cell morphology over the following 10 days. The effect of HDM on CPDs was also evaluated in the human RPMI-8226 MM cell line. 5TGM1-GFP cells were isolated by FACS on day 10 for evaluation of senescence histological characteristics and gene expression. All studies represent n=3 independent experiments unless otherwise indicated. HDM-5TGM1 cells exhibited a significant reduction in mean CPDs over 10 days compared to Veh (HDM 0.32±0.31, Veh 6.72±0.69, p&lt;0.0001), indicating stable growth arrest in HDM treated cells consistent with senescence. HDM-5TGM1 cells were also significantly larger versus Veh (median size in pixels units: HDM 413.2±99.98, Veh 207±8.88, p&lt;0.05), consistent with classical enlarged morphology in senescent cells. Preliminary assessment (n=1) of HDM-RPMI-8226 cells showed similar growth arrest (mean cumulative doublings: HDM 0.058±0.101, Veh 4.185±0.358) and enlargement (mean size in pixel units: HDM 804.1±6.048, Veh 526.9±2.115), suggesting a translatable mechanism in humans. FACS-sorted 5TGM1-GFP cells were stained for telomere associated foci (TAF), a marker of persistent DNA damage characteristic of senescent cells. HDM-5TGM1 cells showed a higher percentage of TAF+ cells (Percent TAF+ cells: HDM 39.7%±9.1%, Veh 10.6%±0.8%, n=2). Sorted HDM-5TGM1 cells also exhibited significant increases over Veh (p&lt;0.001) in senescence markers ( Cdkn1a, Cdkn1c, Glb1), senescence cell anti-apoptosis pathway genes (SCAPs, Bcl2l1), and senescence associated secretory phenotype (SASP) genes ( Ccl5, Icam1, Mmp13). In addition, HDM-5TGM1 cells showed significant increases in myeloid markers that have previously been shown to be increased in dormant 5TGM1 ( Axl, Fcer1g, Mpeg1). Single cell RNA-sequencing was used to further evaluate senescence gene expression changes in growth arrested HDM-5TGM1 cells. Gene set enrichment analysis (GSEA) of genes differentially expressed in HDM-5TGM1 versus Veh cells was performed for custom senescence phenotyping gene sets (Senescence Up, SenUp; Senescence Growth Arrest, SenGA; Inflammatory SASP, iSASP; SCAPs; and Plasma Cell Senescence; PCSen) as well as mouse ortholog versions of a published senescence and biological aging gene set (SenMayo) and KEGG curated gene sets. GSEA of HDM-5TGM1 versus Veh cells confirmed significant (FDR&lt;0.25) upregulation of iSASP, MayoSen, PCSen, SenUp, SCAPs, and SenGA gene sets. Concurrently, GSEA revealed significant downregulation of KEGG DNA replication, cell cycle, and nucleotide excision repair gene sets, supporting our observations of proliferative arrest and persistent DNA damage TAF. Our findings demonstrate that HDM-MM cells exhibit multiple features of senescence, suggesting a potential mechanistic role for TIS in MM dormancy and highlight a novel therapeutic target that may be present in patients post-HDM. Thus, targeting senescence may be a novel approach to eliminate dormant MM cells and prevent relapse.

Multiple Myeloma (MM) progresses from monoclonal gammopathy of undetermined significance (MGUS) and/or smoldering MM (SMM). Despite similar primary genetic events as MM, MGUS and SMM PCs are non- or low-proliferative. Since oncogene activation and DNA damage drive senescence growth arrest to promote immune clearance of potentially malignant cells, we hypothesized that MGUS and SMM pre-malignant PCs exhibit senescence features. To test this, we performed gene set enrichment analysis (GSEA) of a published human PC gene array dataset (GSE5900) comparing normal, MGUS, and SMM PCs for custom senescence phenotyping gene sets (Senescence Up, SenUp; Senescent Cell Anti-Apoptosis Pathways, SCAPs; Senescence Growth Arrest, SenGA; Inflammatory Senescence Associated Secretory Phenotype, iSASP; Interferon SASP, IFN-SASP) versus biological aging gene sets (SenMayo; CellAge). MGUS and SMM PCs exhibited significant enrichment (NES&gt;1.5, q&lt;0.05) for senescence gene sets SenUp, SenGA, and SCAPs compared to normal PCs, with no enrichment for aging gene sets. MGUS PCs were also enriched for iSASP (NES=1.4, q=0.11), whereas SMM PCs were enriched for IFN-SASP (NES=2.3, q&lt;0.05), characteristic of late-senescence. Thus, both MGUS and SMM PCs show enrichment of senescence gene sets compared to normal PCs with differential SASP profiles. Next, we evaluated MGUS, SMM, and MM patient PCs isolated by magnetic sorting for histological senescence features. PCs were immunostained for LMNB1 and HMGB1, and fluorescent in situ hybridized for α-satellite. Cellular senescence was defined as loss of ≥50% nuclear membrane LMNB1, loss of HMGB1, and ≥2 senescence-associated distensions of satellite (SADS) per nuclei. PCs from MGUS patients (N=12) exhibited increased percentage of senescent PCs (26.9±4.1%, Mean±SEM, p&lt;0.0001) compared to SMM (11.0±1.9%, N=19, p&lt;0.0001) and MM (11.6±1.5%, N=11, p&lt;0.001). A subset analysis of SMM patients for which disease stability was known (≥2 years, N=6-8) showed no differences. These results demonstrate that the percentage of senescent PCs is increased in MGUS but not SMM PCs compared to proliferative disease. To assess PC senescence in the native bone marrow microenvironment (BMME), we evaluated trephine bone biopsies from MGUS and SMM patients that progressed or not to MM ≤10 years, as well as newly diagnosed MM. Biopsies were immunostained for CD138, LMNB1, and HMGB1. Whole biopsy images were analyzed using the artificial intelligence-based software HALO. Cells were classified as senescent if they were double negative and non-senescent if they were double positive for LMNB1 and HMGB1. The percentage of non-senescent PCs increased with progression to MM and positively correlated with total PC burden (R=0.52, p&lt;0.0001), reflective of proliferative disease. Senescent PCs correlated with total senescent BMME (R=0.87, p&lt;0.0001), consistent with a role for senescent cells to drive paracrine senescence. We performed proximity analysis to evaluate the cellular composition within 25um of senescent and non-senescent PCs. As expected, non-senescent PCs exhibited a significantly greater percentage of proximate non-senescent BMME in all groups (p&lt;0.0001). In contrast, senescent PCs in stable MGUS (N=16) and SMM (N=14) were equally surrounded by senescent and non-senescent BMME. In progressing MGUS (N=21) and SMM (N=20), as well as MM (N=18), senescent PCs exhibited significantly reduced senescent BMME in their proximate environment (p&lt;0.05). This suggests that senescent PCs in progressive disease, in contrast to stable disease, fail to drive local paracrine senescence responses. These data demonstrate that PCs from stable MGUS and SMM patients exhibit senescence features, with isolated PCs from stable MGUS showing increased senescence gene expression and histologic features. While stable SMM also exhibits senescence gene expression, they lose morphological features of senescence and show a preferential IFN SASP. Within the bone compartment, senescent PCs in stable MGUS and SMM exhibit the expected proximity to senescent BMME. In contrast, progressing MGUS and SMM, as well as NDMM, show a loss of proximate senescent BMME. Given the role of senescence to drive inflammation to clear potentially tumorigenic cells, these data support that failure to drive paracrine senescence may be key to the immune escape of pre-malignant cells in MGUS and SMM.

Immune escape is a prerequisite for tumor growth. We previously described a decline in intratumor activated cytotoxic T cells and T cell receptor (TCR) clonotype diversity in invasive breast carcinomas compared to ductal carcinoma in situ (DCIS), implying a central role of decreasing T cell responses in tumor progression. To determine potential associations between peripheral immunity and breast tumor progression, here, we assessed the peripheral blood TCR clonotype of 485 breast cancer patients diagnosed with either DCIS or de novo stage IV disease at younger (<45) or older (≥45) age. TCR clonotype diversity was significantly lower in older compared to younger breast cancer patients regardless of tumor stage at diagnosis. In the younger age group, TCR-α clonotype diversity was lower in patients diagnosed with de novo stage IV breast cancer compared to those diagnosed with DCIS. In the older age group, DCIS patients with higher TCR-α clonotype diversity were more likely to have a recurrence compared to those with lower diversity. Whole blood transcriptome profiles were distinct depending on the TCR-α Chao1 diversity score. There were more CD8 + T cells and a more active immune environment in DCIS tumors of young patients with higher peripheral blood TCR-α Chao1 diversity than in those with lower diversity. These results provide insights into the role that host immunity plays in breast cancer development across different age groups.