Citations

Abstract Introduction: The binding of Programmed Death-Ligand 1 (PD-L1) on the surface of tumor cells to PD-1 on T cells prevents T-cell-mediated anti-cancer immune responses. Immune checkpoint blockades that target the PD-L1/PD-1 interaction have improved survival rates but have several critical limitations. Post-translational modifications (PTMs) of PD-L1, such as glycosylation, are crucial for its stability and engagement with PD-1. Thus, targeting PD-L1 PTMs may be a novel method to improve immune checkpoint blockade efficacy. The mevalonate pathway (MVP) generates various substances involved in PTMs process. Here, we explore the effect of MVP in altering the PTMs of PD-L1 and its impacts on cell surface PD-L1 function. Methods: The triple-negative human breast cancer (TNBC) cell lines MDA-MB-231 and BT549 were treated with the HMG-CoA reductase inhibitor lovastatin (LOV) with or without the addition of IFN-γ and/or MVP intermediates for 48 hours. PD-L1 transcription was evaluated by qPCR. Alterations in PD-L1 size were detected by Western blotting. PD-L1 surface levels were measured by flow cytometry. HMG-CoA reductase (HMGCR) knockdown was performed to validate the non-off-target effect of LOV. The binding of PD-1 protein to the cell surface PD-L1 was measured by PD-1/PD-L1 binding assay. PD-L1 glycosylation levels were measured by Concanavalin A (Con A) lectin binding assay with immunoprecipitated PD-L1 protein. Results: LOV treatment caused a significant molecular weight shift of PD-L1 from approximately 45 kDa to 40 kDa and reduced the cell surface PD-L1 levels. However, PD-L1 transcription was not affected by LOV. HMGCR knockdown produced similar changes, indicating LOV's impact on PD-L1 was not due to off-target effects. The addition of MVP intermediates mevalonate (MEV) or geranylgeraniol, but not farnesol prevented LOV-induced changes in PD-L1 molecular weight and surface levels. Interestingly, the addition of 25-hydroxycholesterol, but not dolichol, partially prevented LOV-induced decreases in PD-L1 surface levels. Geranylgeranyl transferase inhibitor GGTI-286, which prevents protein geranylgeranylation, also altered PD-L1 molecular weight and decreased surface levels. In addition, LOV impaired the binding of PD-1 protein to tumor cells' surface PD-L1, which was reversed by the addition of MVP substrate MEV. Con A lectin-binding of immunoprecipitated PD-L1 showed that the LOV did not reduce the N-glycosylation level of PD-L1. Conclusions: This study reveals the involvement of the MVP in regulating PD-L1 PTMs and highlights the MVP as a potential therapeutic target to modulate PD-L1’s molecular weight and function and improve the efficacy of immunotherapy interventions, presenting a promising avenue for further investigation. Citation Format: Ruoheng Zhang, Emily J. Koubek, Jessie L. Reed, Jeffrey D. Neighbors, Joel M. Reid, Raymond J. Hohl. The role of the mevalonate pathway in post-translational modifications of PD-L1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4265.

Abstract Background and Objective: Bladder cancer is the 9th most diagnosed cancer worldwide with high incidences reported in Europe and the United States. Here, we evaluated the real-world performance of a commercially available multiplex immunoassay Oncuria-Detect that detects bladder cancer by simultaneously measuring a panel of 10 biomarker proteins in naturally voided urine samples. Methods: We tested prospectively collected urine samples from a real-world cohort of 1, 002 patients presenting to five USA centers, one European center and one Japanese center with hematuria. Assay results were collated with patient clinical data and a cancer diagnosis was defined by biopsy and pathology. The prevalence of bladder cancer in the cohort was 15.9%. Results: In a training set (n=684), the Oncuria-Detect assay correctly identified bladder cancer in 94/109 cases, representing a sensitivity of 91.8%, specificity of 71.6% (AUC 0.885; 95% CI 0.843 - 0.927) and with improved performance for high-grade bladder cancer and muscle-invasive bladder cancer (sensitivity 93.6% and 92.1%, respectively). In a test cohort of n =339 the AUC for detecting bladder cancer was 0.850 (95% CI 0.779-0.920). Conclusions and Implications: The multiplex Oncuria-Detect assay identified bladder cancer with high sensitivity and NPV, for low-grade and high-grade tumors alike. Oncuria-Detect’s high NPV could effectively rule out 66% of patients from requiring subsequent cystoscopy. Citation Format: Ian Pagano, Zhen Zhang, Sergei Tikhonenkov, Florence Le Calvez-Kelm, Steve Goodison, Toru Sakatani, Kaoru Murakami, Takashi Kobayashi, Howard Kim, Riko Lee, Sunao Tanaka, Charles J. Rosser, Hideki Furuya. Performance of the Oncuria-detect bladder cancer test for evaluating patients presenting with hematuria: results from a real-world clinical setting [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5919.

Abstract Background and Objective: Glioblastoma (GBM) is most common primary brain tumor with dire need of novel therapeutics. Studies with intracranial tumors are required for robust characterization and development of novel drugs for brain cancer. Tumor harvest and processing is an important aspect to study pharmacokinetics, pharmacodynamics, drug delivery, and tumor evolution. Typically, delineating and dissecting tumor from surrounding brain for varied downstream processes is dependent on the distinct morphology of the tumor and/or expression of fluorescent marker. However, genetic modification of the tumor cells for the expression of fluorescent protein is not always possible, especially for patient-derived xenograft (PDX) tumor models. Thus, we have developed a dye-based staining method to confidently visualize tumor in the brain and assessed usability of isolated tumors for drug and DNA analysis. Methodology: Whole brains were harvested from mice with intracranial Mayo GBM PDX tumors and stored at -80oC freezer. Few days prior to staining, brains were transferred to -20oC freezer. Brain was cut into 1 mm thick coronal sections and transferred onto glass slides. Slices were covered with toluidine blue (TB) solution (0.05 to 10 mg/mL) for 45 s. Excess stain solution was removed, and slices were observed under white light. Regions of tumor became more transparent, while normal brain remained opaque. This enabled dissection of tumor from normal brain for downstream analyses. Results: TB concentration (0.05 to 10 mg/mL) was optimized to stain 1 mm thick sections of fresh frozen brain, and the best contrast between tumor to normal brain was observed at 0.1-0.3 mg/mL. TB aided differential visualization of tumors in several PDX models - GBM12, GBM43, GBM39 and GBM108 - suggesting broad applicability. To evaluate the accuracy of TB staining, brain with PDX tumor transduced with pSINeGFP/fLuc2 was observed by both TB staining and eGFP fluorescence. This analysis demonstrated excellent concordance across 6 animals with three distinct PDX models. Genomic DNA was isolated from tumor dissected under TB guidance and analyzed by PCR for primers specific for murine vs human PTGER2. 50-70% of the DNA in tumor samples was detected to be of human origin while normal brain tissue had 90-95% of the mouse DNA highlighting the specificity of TB stain for tumor detection. Tumors from drug treated GBM108 PDX were isolated under TB guidance and comparable drug levels were detected by LC-MS/MS as analyzed in GFP-assisted tumor samples. Conclusion: Staining fresh frozen thick brain sections with toluidine blue enables visualization of tumor from normal brain regions that is compatible with varied downstream processes. Development of such staining assays can help faster and easier tumor processing and is not dependent on genetic modification of tumor cells prior to experimentation. Citation Format: Sonia Jain, Anders Herfindahl-Quint, Caroline D. Doherty, Wenjuan Zhang, Danielle M. Burgenske, Jann N. Sarkaria. Novel staining method for visualization, isolation and processing of intracranial brain tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2531.

Abstract Introduction: Breast cancer genome-wide association studies (GWAS) have identified over 200 susceptibility loci, many replicated in diverse populations. However, cross-ancestry evaluation of breast cancer genetic architecture remains limited. We examined breast cancer genetic architecture using GWAS summary results from European (EUR; cases (ca) = 188,474, controls (co) = 96,201), East Asian (EAS; ca = 20,393, co = 86,329), African American (AA; ca = 9,235, co = 10,184), and US Hispanic/Latina and Latin American (H/L; ca = 2,396, co =7,468) studies. Methods: GWAS results were derived from the Breast Cancer Association Consortium, the African Ancestry Breast Cancer Genetics Consortium (AABCG), Biobank Japan, and a meta-analysis of five studies of H/L women with breast cancer. Linkage disequilibrium (LD) scores were generated for EUR, EAS, and AMR using the 1000 Genomes Project, while AA LD scores were derived from a subset of AABCG controls. Heritability was estimated for each ancestry group using LD score regression. Genetic correlations between populations were assessed via Popcorn. Polygenicity was analyzed using GENESIS; however, due to the limited sample size in the H/L studies, these estimates were restricted to AA, EAS, and EUR. Enrichment of heritability across regulatory elements was evaluated using stratified LD score regression across all populations. Results: The logit-scale heritability and corresponding standard error (SE) were 0.466 (0.066) for EAS, 0.501 (0.050) for EUR, 0.588 (0.360) for H/L, and 0.614 (0.095) for AA. The estimated number of independent susceptibility loci was 4,446 for EAS, 5,235 for EUR, and 8,308 for AA. Using a clumping and thresholding approach, an optimal set of common variants were projected to explain 38.6% (EUR), 39.4% (EAS), and 26.2% (AA) of genetic variance for samples of 100,000 cases and 100,000 controls with AUCs from corresponding estimated polygenic risk scores (PRSs) of 0.621 (EUR), 0.634 (EAS), and 0.611 (AA). Genetic correlations were strongest between EUR and EAS (ρ = 0.79, SE = 0.08) and EUR and H/L (ρ = 0.68, SE = 0.21), and weakest between AA and EAS (ρ = 0.42, SE = 0.14) and AA and H/L (ρ = 0.26, SE = 0.24). Among 73 genomic features, we found significant (P < 0.05/73) enrichment in heritability in EUR for ‘ancient promoter’ regions, transcription factor binding sites, H3K4me3, ‘super-enhancers’, H3K4me1, H3K27ac; in EAS for ‘super-enhancers’; and in AA for H3K27ac. No genomic features were significantly enriched in H/L, likely due to limited power. Conclusion: These findings suggest a shared breast cancer genetic architecture across diverse populations, as well as the potential for a similar level of breast cancer risk stratification by PRS in these populations. Expanding GWAS in underrepresented populations is essential to improve genetic risk predictions and foster equitable cancer prevention. Citation Format: James L. Li, Maria Zanti, Jacob Williams, Om Jahagirdar, Guochong Jia, Qiang Hu, Jean-Tristan Brandenburg, Li Yan, Weang-Kee Ho, Jingmei Li, José P. Miranda, Devika Godbole, Julie-Alexia Dias, Leila Dorling, Wenlong C. Chen, Nicholas Boddicker, Ying Wang, Alicia Martin, Martin J. Zhang, Yan Zhang, Joe Dennis, Esther M. John, Gabriela Torres-Mejia, Larry Kushi, Jeffrey Weitzel, Susan L. Neuhausen, Luis Carvajal-Carmona, Christopher Haiman, Elad Ziv, Laura Fejerman, Wei Zheng, Dezheng Huo, Douglas Easton, Nilanjan Chatterjee, Peter Kraft, Montserrat Garcia-Closas, Wendy Wong, Kyriaki Michailidou, Qianqian Zhu, Diptavo Dutta, Thomas U. Ahearn, Haoyu Zhang. Genetic architecture of breast cancer across diverse populations: Assessing heritability, genetic correlation, and polygenicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2282.

Abstract Approximately two-thirds of hypopharyngeal squamous cell carcinoma (HPSCC) are diagnosed in advanced stage, with the worst prognosis among head and neck squamous cell carcinomas (HNSCCs). Identifying biomarkers for high-risk patients who need aggressive treatment is crucial. We present mutational, transcriptomic and proteomic studies of 103 Chinese HPSCC patients, observing a higher prevalence and poorer prognosis in males comparing to females. Genes in estrogen response pathways are up-regulated and proteins phosphorylated by protein kinase C (PKC) and Cyclin-dependent kinases (CDKs) are aberrantly regulated. We identify aberrant copy number regions including SOX2 (3q26.33), FGFR (8p11.23), CCND1 (11q13.3), CDKN2A/2B (9p21.3), and MYC (8q24.21). HPV status combined with highly mutated genes as predictive markers was assessed, including SYNE1 in HPV(-), MUC4 in HPV(+) patients. We confirm the presence of four known gene expression (GE) subtypes of HNSCC in our HPSCC cohort and present the genomic alterations, patient characteristics and survival status of each subtype. A predictive model involving clinical factors and transcriptomic expression of six genes was established and cross-site validated. The findings open new opportunities for stratifying high-risk patients and molecular targets for novel therapeutic strategies. Citation Format: Yanxin Ren, Wei Xiong, Chun Feng, Dan Yu, Xiaoyan Wang, Qing Yang, Siting Yu, Hongjiang Zhang, Bangyun Huo, Honglu Jiang, Zuli Li, Junlin Wang, Yu-Xiong Su, Ping Yang, Yong Liao, Qi Zhong, Junwen Wang. Multi-omics insights into the molecular signature and prognosis of hypopharyngeal squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4999.

Background: Multicellular programs in the tumor microenvironment (TME) drive cancer pathogenesis and response to therapy but remain challenging to identify and profile clinically. Here, we present Spatial EcoTyper, a multimodal machine learning framework for large-scale profiling of spatially dependent cell states and multicellular ecosystems, termed spatial ecotypes (SEs). Methods and Findings: By integrating five million single-cell and spot-level spatial transcriptomes from 10 diverse human neoplasms, including carcinomas and melanomas, we identified a rich tapestry of conserved regional plasticity across nine TME cell types. We then applied Spatial EcoTyper to deeply dissect these data, revealing nine novel SEs with broad conservation - each with unique biology, TME cell states, geospatial features, and clinical outcome associations. SEs were linked to specific biogeographic domains, including the tumor core, margin, and adjacent stroma, and were remarkably well-validated in 235 held-out tumor samples profiled by either single-cell RNA sequencing, sequencing-based spatial transcriptomics (10x Visium), or high-resolution imaging-based spatial transcriptomics (Vizgen MERSCOPE and NanoString CosMx). By deconvolving SEs from over 1,200 bulk tumor RNA-seq profiles, we discovered striking associations between SE levels and response to immune checkpoint inhibitors (ICIs), outperforming nearly 40 potential correlates of ICI response, including previously described signatures of tertiary lymphoid structures and tumor tissue PD-L1 expression. Notably, baseline levels of a proinflammatory SE - localized to the tumor core and defined by a hub of unique T cell, macrophage, fibroblast, and endothelial cell states - strongly forecasted ICI benefit, while another SE - localized to the tumor margin and defined by myofibroblast and hypoxia-associated endothelial cell states - portended ICI resistance. Conclusion: Our data reveal fundamental units of TME organization and demonstrate a platform for large-scale profiling of spatial cellular ecosystems in any tissue, with implications for improved forecasting of immunotherapy response and the development of novel therapeutic strategies. Citation Format: Wubing Zhang,Erin L. Brown,Abul Usmani,Noah Earland,Hyun Soo Jeon,Irfan Alahi,Nicholas P. Semenkovich,Janella C. Schwab,Chloé B. Steen,Chloe M. Sachs,Bilge Gungoren,Faridi Qaium,Peter K. Harris,Jacqueline Mudd,Qingyuan Cai,Antonella Bacchiocchi,Ryan C. Fields,Mario Sznol,Ruth Halaban,David Y. Chen,Aadel A. Chaudhuri,Aaron M. Newman. High-resolution profiling of the tumor microenvironment with spatial ecotypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 153.

Background Severe alcohol-associated hepatitis (sAH) is a life-threatening condition with high mortality, where corticosteroid use is the only treatment that has shown short-term benefits. Pentoxifylline, an anti-tumour necrosis factor-alpha agent, has been proposed for its potential to improve outcomes, especially in patients with acute kidney injury (AKI). We aimed to evaluate the impact of pentoxifylline on mortality in patients with sAH and AKI in a well-characterised global cohort. Methods We conducted a retrospective, registry-based study including patients meeting the National Institute on Alcohol Abuse and Alcoholism clinical criteria for sAH and AKI. Mortality was the primary endpoint, with liver transplantation as a competing risk. Statistical analysis included Cox regression and Kaplan-Meier survival estimates. Results We included 525 patients from 20 centres across eight countries. The median age was 48 years, with 26.1% females, and 76.9% had a history of cirrhosis. Multivariable Cox regression models showed that pentoxifylline use was not associated with survival (HR 1.20, 95% CI 0.85 to 1.69, p=0.291). Factors associated with mortality included age (HR 1.23, 95% CI 1.10 to 1.36, p<0.001), Model for End-Stage Liver Disease score at admission (HR 1.06, 95% CI 1.04 to 1.08, p<0.001) and renal replacement therapy use (HR 1.39, 95% CI 1.05 to 1.84, p=0.019). The main causes of death were multiple organ failure (42%), infections (10%), oesophageal varices bleeding (7%) and renal failure (6%). Conclusion Pentoxifylline showed no significant benefit on mortality in patients with sAH and AKI. Further studies are needed to refine treatment strategies for this high-risk group.

ImportanceThe safety and effectiveness of combining surgical peripheral iridectomy (SPI) with goniosynechialysis (GSL) and goniotomy (GT) vs trabeculectomy for intraocular pressure (IOP) reduction remains unknown.ObjectiveTo investigate the safety and effectiveness at 1 year of SPI + GSL + GT vs trabeculectomy in advanced primary angle-closure glaucoma (PACG) without cataract.Design, Setting, and ParticipantsThis noninferiority randomized clinical trial was conducted at 8 tertiary eye centers in China. A total of 88 Chinese patients (88 eyes) with advanced PACG without cataract were enrolled from January 2022 to July 2023. Data were analyzed from August 2024 to September 2024. Mean (SD) patient age was 60.3 (7.3) years, and 52 patients (59.1%) were female. Forty-three patients were randomized to SPI + GSL + GT and 45 were randomized to trabeculectomy; 86 patients (97.7%) completed the 12-month follow-up.InterventionsParticipants were randomized 1:1 to receive SPI + GSL + GT or trabeculectomy.Main Outcomes and MeasuresThe primary outcome was IOP at 12 months (noninferior margin: 4 mm Hg). Secondary outcomes included surgical success (IOP: 5-18 mm Hg, ≥20% reduction from baseline, with or without antiglaucoma medications); postoperative complications and interventions, including bleb massage, suture lysis, or releasable sutures; and number of antiglaucomatous medications prescribed.ResultsAt 12 months, the SPI + GSL + GT group had a mean (SD) IOP of 15.6 (4.0) mm Hg vs 14.9 (4.2) mm Hg in the trabeculectomy group (difference, 0.5 mm Hg; 95% CI, −1.2 to 2.2; P = .55), which was within the 4-mm Hg noninferiority margin. Qualified success rates were 38 of 43 participants (88.4%) for SPI + GSL + GT and 42 of 45 participants (93.3%) for trabeculectomy (difference, −5.0%; 95% CI, −19.6% to 8.5%; P = .48). However, complete success rates were lower in the SPI + GSL + GT group (26 participants [60.5%]) vs the trabeculectomy group (37 participants [82.2%]; difference, −21.8%; 95% CI, −40.2% to −2.4%; P = .03). Postoperative complications were present for 8 participants (18.6%) in the SPI + GSL + GT group vs 9 participants (20.0%) in the trabeculectomy group (difference, −1.4%; 95% CI, −17.9% to 15.1%; P = .71). Postoperative interventions were lower in the SPI + GSL + GT group (3 participants [7.0%] vs 25 participants [55.6%]; difference, 48.6%; 95% CI, 32.2%-65.0%; P &amp;lt; .001). Median (IQR) numbers of medications used decreased from 2 (0-3) to 0 (0-1) in the SPI + GSL + GT group and from 2 (2-3) to 0 (0-0) in the trabeculectomy group (difference, −0.81; 95% CI, −1.36 to −0.26; P = .004).Conclusions and RelevanceIn this randomized clinical trial among patients with advanced PACG without cataract, SPI + GSL + GT demonstrated noninferiority (4-mm Hg margin) to trabeculectomy for IOP at 12 months, with fewer interventions (including bleb massage, suture lysis, or releasable sutures) but no difference in postoperative medication use. This suggests SPI + GSL + GT as a potential alternative to trabeculectomy for similar cases, pending validation in larger sample sizes with smaller noninferiority margins.Trial RegistrationClinicalTrials.gov Identifier: NCT05163951

ImportanceIntraocular pressure (IOP) reduction with phacogoniotomy (phacoemulsification plus goniosynechialysis plus goniotomy) was not less than that of phacotrabeculectomy for advanced primary angle-closure glaucoma (PACG) with cataract at 1-year follow-up, but longer-term outcomes are needed.ObjectiveTo investigate if phacogoniotomy is noninferior to phacotrabeculectomy for advanced PACG with cataract at 2 years.Design, Setting, and ParticipantsThis multicenter, noninferiority, randomized clinical trial took place in 7 ophthalmology centers in China. The trial started May 31, 2021, and 2-year follow-up ended May 31, 2024. Included in this analysis were patients with advanced PACG and cataract. Study data were analyzed from September 2024 to January 2025.InterventionsRandom assignment (1:1) to phacogoniotomy or phacotrabeculectomy.Main Outcomes and MeasuresThe primary outcome measure was reduction in IOP from baseline to the 2-year visit with a noninferiority margin of 4 mm Hg.ResultsA total of 124 participants (124 eyes) were randomized (mean [SD] age, 66.4 [8.6] years; 67 female [54.0%]), 65 (52.4%) to the phacogoniotomy group and 59 (47.6%) to the phacotrabeculectomy group. A total of 59 patients (90.7%) in the phacogoniotomy group and 52 patients (88.1%) in the phacotrabeculectomy group completed 2-year visits. All participants were Chinese. Mean (SD) IOP reduction was −25.6 (10.2) mm Hg and −24.7 (9.4) mm Hg in the phacogoniotomy and phacotrabeculectomy groups, respectively, and the upper boundary of the CI for difference in change between groups was lower than the 4-mm Hg noninferiority margin (mean difference, −0.5 mm Hg; 97.5% CI, −1.7 mm Hg to 0.8 mm Hg; P = .42). The mean difference for complete success for phacogoniotomy vs phacotrabeculectomy was −6.7% (95% CI, −21.4% to 8.8%; P = .47) and for qualified success was 1.4% (95% CI, −11.0% to 14.3%, P = .30). Median (IQR) number of antiglaucomatous medication was 0 (0) vs 0 (0; Hodges-Lehmann estimate of location shift, 0; 95% CI, 0; P =.12) with phacogoniotomy vs phacotrabeculectomy, respectively (mean difference, 0.13; 95% CI, −0.36 to 0.63; P = .60).Conclusions and RelevanceMean IOP reduction with phacogoniotomy was noninferior to phacotrabeculectomy for advanced PACG and cataract at 2-year follow-up with no differences detected in complete or qualified success or mean number of antiglaucomatous medications. These findings support phacogoniotomy as an alternative to phacotrabeculectomy for patients with advanced PACG and cataract.Trial registrationClinicalTrials.gov Identifier: NCT04878458

Abstract Background: Prior research on the associations of p16, COX-2, and Ki67 immunopositivity in ductal carcinoma in situ (DCIS) tissue with the risk of subsequent ipsilateral invasive breast cancer (IBC) is limited. Methods: In a case–control study nested in a cohort of women diagnosed with DCIS, immunostaining for p16, COX-2, and Ki67 was performed on DCIS tissue from those who developed subsequent ipsilateral IBC (cases; n = 146) and on matched subjects who did not develop IBC (controls; n = 273). Conditional logistic regression was used to estimate ORs and 95% confidence intervals for the associations between immunopositivity for p16, COX-2, and Ki67 and the risk of subsequent ipsilateral IBC. Results: There was no association between p16, COX-2, and Ki67 immunopositivity, examined either individually or in combination, and a risk of ipsilateral IBC. Compared with all other groups, the multivariable OR (95% confidence interval) for women who were triple positive for the three markers was 1.16 (0.38–3.54). Conclusions: p16, COX-2, and Ki67 immunopositivity was not associated with altered risk of ipsilateral IBC in women with DCIS. Impact: p16, COX-2, and Ki67 may not be prognostic for ipsilateral IBC in women with DCIS.