Citations

Abstract B7-H3 (CD276) is a transmembrane glycoprotein of the B7 immune checkpoint superfamily that has emerged as a promising therapeutic target. To better understand the applicability of B7-H3–directed therapies, we analyzed 156,791 samples comprising 50 cancer types to interrogate the clinical, genomic, transcriptomic, and immunologic correlates of B7-H3 mRNA expression. DNA (592-gene/whole-exome) and RNA (whole-transcriptome) sequencing was performed from samples submitted to Caris Life Sciences. B7-H3 high versus low expression was based on top and bottom quartiles for each cancer type. Patients’ overall survival was determined from insurance claims data. Pathway analysis was performed using gene set enrichment analyses. Immune cell fractions were inferred using quanTIseq. B7-H3 is expressed across several human malignancies including prostate, pancreatic, ovarian, and lung cancers. High B7-H3 expression is associated with differences in overall survival, possibly indicating a prognostic role of B7-H3 for some cancers. When examining molecular features across all cancer types, we did not identify recurrent associations between B7-H3 expression and genetic alterations in TP53, RB1, and KRAS. However, we find consistent enrichment of epithelial-to-mesenchymal transition, Wnt, TGFβ, and Notch signaling pathways. In addition, tumors with high B7-H3 expression are associated with greater proportions of M1 macrophages, but lower fractions of CD8+ T cells. We have begun to define the genomic, transcriptomic, clinical, and immunologic features associated with B7-H3 expression in 50 cancer types. We report novel clinical and molecular features of B7-H3–high tumors which may inform how current B7-H3 therapeutics should be deployed and prioritized. Significance: B7-H3–targeting therapeutics have shown promising results in initial clinical trials. In this pan-cancer analysis of B7-H3 mRNA expression, we found that B7-H3 exhibits robust expression in many common cancer types. These results may inform further development of B7-H3–targeting therapeutics and may guide clinical decisions for patients with limited treatment options.

Abstract Introduction: Interstitial Lung Disease (ILD) is a known adverse event associated with Antibody Drug Conjugates (ADCs), causing fibrosis of the lung. In the DESTINY-Breast 04, TROPICS-02, and ASCENT trials the rate of ILD/Pneumonitis was 12.1%, 0.4%, and 0% respectively. In these studies, the time to first cross-sectional imaging after initiation of ADC was 6 weeks. However, prior treatment with a topoisomerase-1 inhibitor ADC was not permitted in these studies, so the influence of sequential ADC treatments remains unknown. Here, we aimed to characterize the frequency and management of ILD in sequential use of ADCs in a multi-institution retrospective analysis. Methods: We identified patients (pts) with HR+/HER2-low and HR-/HER2-low MBC who had received both Trastuzumab-deruxtecan (T-DXd) and Sacituzumab govitecan (SG) monotherapy (in either order, with or without intervening therapies) who were treated at five academic centers between 2020-2023. Patients had received treatment with the ADC in either routine clinical treatment or as a prior participant on a clinical trial with ADC monotherapy. Information regarding ILD diagnosis, imaging, timing of onset, peak and resolution along with management information was collected and analyzed. Retrospective assessment of ILD toxicity was graded using CTCAE v5.0, based on available clinical and radiographic reports. Results: 10/60 pts who received ADC therapy in this multi-institutional cohort were diagnosed with ILD (all grades). No differences in age or BMI were observed in those who developed ILD versus those who did not, and 9/10 pts were White, 1 was Asian, with a median age of 59 years (47-79 years). Pertinent history in these pts included 3/10 had a prior smoking history, 8/10 had a prior cardiac or pulmonary comorbidity (including sleep apnea, lung cancer, hypertension, hyperlipidemia, thrombosis, or stroke). Prior to receiving their first ADC, 7/10 patients had metastatic disease to the lung. All 10 patients were diagnosed with ILD during treatment with T-DXd. 4 pts initially received T-DXd, then developed ILD and then upon recovery, subsequently received SG. The remaining 6 pts initially received SG (with no reports of ILD), and then received T-DXd and subsequently developed ILD. In the entire cohort, the median time from ADC initiation to first CT scan was 8 weeks (range 1-22 weeks). Within the cohort that developed ILD, the median time from initiation of T-DXd to first CT scan was also 8 weeks (range 6-13 weeks). The median time to diagnoses of ILD was 3 months after initiation of T-DXd (range 0.4-14.5 months). Dyspnea was the most common presenting symptom in 9/10 pts and at diagnosis of ILD, dyspnea was graded as III in 6/10 pts, II in 3/10 pts, and I in 1/10 pts. Diagnostic evaluation included CT chest (9/10), pulmonary consultation (8/10), pulmonary function testing (2/10), and bronchoscopy (1/10). 4/10 patients presented at their highest-grade toxicity at diagnosis. All patients stopped T-DXd treatment, 7 were hospitalized, 7 required supplemental oxygen, and 8 were prescribed steroids for treatment. Of those receiving steroids, the most common starting dose was prednisone 1 mg/kg and doses ranged from 0.5 mg/kg to 9mg/kg prednisone equivalents. No patient received a secondary immunosuppressive agent. The steroid treatment duration ranged from 1-4 months. None of the 10 pts underwent re-challenge with T-DXd and 3/10 developed grade V ILD (death). Conclusion: We observed a 16.6% incidence of all grade ILD (5% grade V ILD) with T-DXd and 0% with SG. In this small cohort study, we did not observe a clear increased risk for ILD with sequential treatment of ADCs. Practice patterns were consistent with recommended diagnostic evaluation and steroid management. Additional strategies are needed to characterize pts most at risk for developing ILD and to identify situations where re-challenge may be safe. Citation Format: Sarah Premji, Laura Huppert, Reshma Mahtani, Samantha Fisch, Naomi Dempsey, Angelina Raimonde-Taylor, Saya Jacob, Laura Quintal, Jo Chien, Michelle Melisko, Ana Sandoval-Leon, Lauren Carcas, Manmeet Ahluwalia, Natasha Harpalani, Jenna Hoppenworth, Dame Idossa, Ruta Rao, Hope Rugo, Karthik Giridhar. Interstitial Lung Disease (ILD) in Sequential Antibody Drug Conjugate (ADC) use in patients with Metastatic Breast Cancer (MBC): A Multi-Institutional experience [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 PO4-12-06.

Abstract Introduction. T-DXd is FDA-approved for patients (pts) with hormone receptor positive (HR+) or HR- HER2-low (IHC 1+ or 2+, ISH-) MBC and SG is FDA-approved for pts with HR+/HER2- and triple negative MBC. However, several outstanding questions impact the use of these drugs in clinic, including: 1) what is the efficacy and safety of these agents in real-world populations with diverse pt characteristics not well represented in the pivotal phase III trials, and 2) what is the impact of sequential treatment with ADCs on the efficacy and safety of these agents. Methods. In this multicenter retrospective cohort study, we identified pts with HR+/HER2-low and HR-/HER2-low MBC who had received both T-DXd and SG monotherapy (in either order, with or without intervening therapies) treated at 5 academic centers between 2020-2023. Pts received treatment per standard of care or on a clinical trial with ADC monotherapy. We describe pt demographic and clinical characteristics, treatment history, key safety parameters, and response and survival data by HR+ status and ADC sequence order. Results. Sixty pts with MBC treated sequentially with T-DXd and SG were included in this analysis, including 45 pts with HR+/HER2-low MBC (75.0%) and 15 pts with HR-/HER2-low MBC (25.0%). Most pts were female (n=59; 98.3%), non-Hispanic (n=49, 81.7%), and white (n=43, 71.7%). Median age at start of ADC #1 was 56.6 years (range 23-82). Prior to treatment with ADC #1, most pts had visceral disease (n=45, 75.0%) and 16 (26.7%) had central nervous system metastases. Among pts with HR+/HER2-low MBC, median time from MBC diagnosis to treatment with ADC #1 was 49.0 months, with 4 median lines of prior therapy in the metastatic setting (2 endocrine, 2 chemo). Approximately half of the HR+ pts received T-DXd prior to SG (n=22, 48.9%; median 3.0 prior lines of therapy for MBC, range 1-9) while the other half received SG prior to T-DXd (n=23, 51.1%; median 4.5 prior lines of therapy for MBC, range 1-10). 44% (n=20) received an intervening therapy between ADCs. For HR+ pts who received T-DXd prior to SG, response and survival data is as follows for T-DXd and SG respectively: Overall response rate (ORR) [54.5% and 21.1%], time to next treatment (TTNT) [4.3 mo and 1.6 mo], and real-world overall survival (rwOS) [19.8 mo and 4.9 mo]. For HR+ pts who received SG prior to T-DXd, response and survival data is as follows for SG and T-DXd respectively: ORR [78.3% and 42.9%], TTNT [8.6 mo and 2.8 mo], and rwOS [22.3 mo and 7.3 mo]. Among pts with HR-/HER2-low MBC, median time from MBC diagnosis to treatment with ADC #1 was 8.2 months with 2 median lines of prior therapy in the metastatic setting (2 chemotherapy); 66.7% (n=10) received prior immunotherapy. Most HR- pts received SG prior to T-DXD (n=14, 93.3%) and 40.0% (n=6) received an intervening therapy between ADCs. For HR- pts who received SG prior to T-DXd, response and survival data is as follows for SG and T-DXd respectively: ORR [64.3% and 38.5%], TTNT [6.2 mo and 2.7 mo, and rwOS [15.7 mo and 6.5 mo]. In terms of key safety parameters during treatment with T-DXd, 13.3% of pts (8/60) required a dose reduction. 16.7% (10/60) were diagnosed with interstitial lung disease (ILD)/pneumonitis of any grade including 3 pts with grade 3-4 ILD (5.0%) and 3 pts with grade 5 ILD (5.0%). During treatment with SG, 40.0% of pts (24/60) required a dose reduction. 83.3% (50/60) received growth factor support (24 pts primary prophylaxis; 26 pts secondary prophylaxis); 9 pts (15%) required treatment delay due to neutropenia. Conclusion. This study represents the largest multicenter series to date of pts treated with sequential ADCs for HR+/HER2-low or HR-/HER2-low. ORR was higher and TTNT was longer for ADC #1 than ADC #2 in all subgroups, regardless of HR+ status and ADC sequence order. An additional ~30 pts will be reported at time of final analysis. Future prospective studies are planned to further clarify the efficacy and safety of sequential ADC use and to identify biomarkers of response and resistance. Key demographic, clinical and treatment characteristics in pts with HR+ and HR- HER2-low MBC treated sequentially with T-DXd and SG (in either order, with or without intervening therapies) Abbreviations: T-DXd (trastuzumab deruxtecan), SG (sacituzumab govitecan), MBC (metastatic breast cancer), ADC (antibody drug conjugate), HR (hormone receptor), HER2 (human epidermal growth factor receptor 2), CNS (central nervous system), ET (endocrine therapy), ORR (overall response rate), TTNT (time to next treatment), rwOS (real world overall survival), CI (confidence interval) * Several pts on ADC #2 with ongoing treatment and first scan pending, hence smaller denominator for response assessment Citation Format: Laura Huppert, Reshma Mahtani, Samantha Fisch, Naomi Dempsey, Sarah Premji, Angelina Raimonde-Taylor, Saya Jacob, Laura Quintal, Jo Chien, Michelle Melisko, Ana Sandoval-Leon, Lauren Carcas, Manmeet Ahluwalia, Natasha Harpalani, Jenna Hoppenworth, Dame Idossa, Ruta Rao, Karthik Giridhar, Hope Rugo. Multicenter retrospective cohort study of the sequential use of the antibody-drug conjugates (ADCs) trastuzumab deruxtecan (T-DXd) and sacituzumab govitecan (SG) in patients with HER2-low metastatic breast cancer (MBC) [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 PS08-04.

Abstract Abstract Title: Real-world analysis comparing Black and White patients with triple-negative breast cancer receiving therapy per KEYNOTE-522 Background: KEYNOTE-522 was a randomized, double-blind, placebo-controlled phase 3 trial which resulted in the FDA approval of pembrolizumab with neoadjuvant chemotherapy for patients with newly diagnosed, high-risk, early-stage triple-negative breast cancer (TNBC). Despite the significant improvement in pathological complete response (pCR) and event-free survival rates across all patients, the landmark trial included only 4.5% Black patients. It is essential to assess outcomes in representative treatment populations. We assessed real-world toxicity and treatment outcomes across Black and White patients who received standard-of-care treatment per KEYNOTE-522. Methods: In this retrospective, multicenter study, we examined patients with early-stage TNBC who received planned treatment per KEYNOTE-522 as standard-of-care (SOC) therapy. 16 sites were included in the analysis. IRB approval was obtained from each participating site. Number and length of treatment delays, treatment-related toxicities (both chemotherapy and immune-related) of all grades, and pCR rate were collected from the electronic medical record of each participating site, and deidentified data were shared for central analysis. Results: Of the 577 patients who initiated treatment with chemotherapy and immunotherapy, 534 patients were included in this analysis with 105 patients who self-identified as Black (19.7%) and 429 who self-identified as White (80.3%). There were no statistically significant differences in clinical and pathological characteristics between the two groups. White women were more likely to have grade 3+ immune-related adverse events (irAEs) compared to Black women (33.8% vs 20.9%, P=0.011). There was no significant difference across Black and White patients with respect to grade 3+ chemotherapy-related adverse events. Out of the 444 patients who have completed surgery, no difference in pCR rate was observed between Black and White women (45/86 52.3% vs 200/358 55.9%) (p = 0.6). The authors also saw no difference in the rates of hospitalizations between Black and White women (39% vs 36% p = 0.5), and rates of acute care utilization (38% vs 38% p = 0.9). Conclusions: We report safety and efficacy across Black and White women in a real-world analysis of patients who received treatment per KEYNOTE-522. Notably, White patients had a significantly higher frequency of grade 3+ irAEs, although the reason for this finding is unclear based on this analysis. Black patients had similar pCR rates and rates of treatment-related hospitalizations compared to White patients. Assessment of outcomes and toxicity by race in clinical trials and real-world analyses are critical in drug development. Citation Format: Mara Hofherr, Andrew Davis, Spenser January, Emily Owen, Farah Raheem, Lida A. Mina, Suganya Arunachalam Karikalan, Lauren Lyons, Meredith Watson Rose, Katherine Madden, Jerline Hsin, Aimee Keegan, Wai Yu, Shawna Kraft, Allison Schepers, Emily Armgardt, Douglas Mazewski, Alison Svoboda, Kayla Harwood, Jodi Taraba, Yonatan Resnick, Shelly Hummert, Lisa Grate, Sidney Keisner, Jacob Hobbs, Todd Davis, Kristin Bastian, Dawn Minikel, Wiliam Adler, Traci White, Avneek Singh Sandu, Fouad Boulbol, Kelsey Finch, Katherine Clifton. Real-world analysis comparing Black and White patients with triple-negative breast cancer receiving therapy per KEYNOTE-522 [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 PS14-02.

Abstract Title: Real-world analysis of adverse events in patients with triple-negative breast cancer receiving therapy per KEYNOTE-522 Background: KEYNOTE-522 was a randomized, double-blind, placebo-controlled phase 3 trial which resulted in the FDA approval of pembrolizumab with neoadjuvant chemotherapy for patients (pts) with newly diagnosed, high-risk, early-stage triple-negative breast cancer (TNBC). Given the improvement in pathological complete response (pCR) and event-free survival rates, this regimen has emerged as standard-of-care (SOC) therapy. To date, real world outcome analyses are limited. Methods: In this retrospective, multicenter study, we examined pts with early-stage TNBC who received planned treatment per KEYNOTE-522 as SOC. 16 sites were included in the analysis. IRB approval was obtained from each participating site. Number and length of treatment delays, treatment related toxicities (both chemotherapy and immune-related) of all grades, and pCR rate were collected from the electronic medical record of each participating site, and deidentified data were shared for central analysis. Results: 577 pts were included in this analysis. The median age of the cohort was 52 [range 27-77]. 457 pts had T1-2 disease and 139 had T3-4 disease. 316 pts had N0 disease and 261 had N1-3 disease. 506 pts had baseline ECOG 0, 62 had ECOG 1, and 9 had ECOG 2-3. Of the 482 patients who had surgery at the time of this analysis, 219 patients had pCR (54.5%) and 192 pts were still receiving treatment. 217 patients (37%) had an adverse drug event (ADE) causing dose reductions and 228 patients (39.5%) had to discontinue treatment early. There were 360 unplanned care visits, with 91 patients having 2+ visits. 66 patients had hospitalizations due to the regimen with 102 total hospitalizations. 179 (31%) of patients had grade 3+ immune related adverse events (irAEs), including many that are rare and potentially serious. 317 (54%) had an immune related adverse effect (see Table 1). There was no significant difference in the frequency of grade 3+ irAE based on age or body mass index. We observed no difference in residual disease between patients who discontinued treatment early and those who did not. However, if patients had an ADR causing a dose reduction, pts were significantly more likely to have residual disease (P=0.039) Conclusions: In a multicenter real-world analysis, the KEYNOTE-522 regimen was associated with a high frequency of dose reductions, early treatment discontinuations, ER visits, and hospitalizations. This may have accounted for a lower pCR rate than observed in the landmark clinical trial. Most grade 3+ irAEs occurred at greater frequency in our real-world analysis. Providers should carefully monitor for toxicity to ensure optimal patient outcomes. Table 1 Citation Format: Mara Hofherr, Katherine Clifton, Spenser January, Emily Owen, Farah Raheem, Lida A. Mina, Suganya Arunachalam Karikalan, Lauren Lyons, Meredith Watson Rose, Katherine Madden, Jerline Hsin, Aimee Keegan, Wai Yu, Shawna Kraft, Allison Schepers, Emily Armgardt, Douglas Mazewski, Alison Svoboda, Kayla Harwood, Jodi Taraba, Yonatan Resnick, Shelly Hummert, Lisa Grate, Sidney Keisner, Jacob Hobbs, Todd Davis, Kristin Bastian, Dawn Minikel, Traci White, William Adler, Avneek Singh Sandu, Fouad Boulbol, Kelsey Finch, Andrew Davis. Real-World Analysis of Adverse Events in Patients with Triple Negative Breast Cancer Receiving Therapy per KEYNOTE-522 [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 PS14-06.

Abstract Background: Triple-negative breast cancer (TNBC) is a heterogeneous disease and characterized by poor outcomes with a lack of targeted therapies. A comprehensive analysis of the molecular and immune landscape of invasive ductal TNBC can help improve our understanding of TNBC biology and identify novel targets and/or pathways for better management of this disease. Here, we characterized the molecular and immune signature of invasive ductal (ID) TNBC. Methods: 13,036 BC samples (ID TNBC, n=392; ID non-TNBC, n=927) were analyzed by NGS (592, NextSeq; WES, NovaSeq), WTS (NovaSeq) (Caris Life Sciences, Phoenix, AZ). A total of 10 pro-apoptotic (BAX, BAK1, BID, BAD, BIK, BCL2L11, BMF, HRK, PMAIP1, BBC3) and 6 anti-apoptotic (BCL2, BCL2L1, BCL2L2, MCL1, BCL2A1, BCL2L10) BCL2 family genes were analyzed. Immune cell fractions were calculated by deconvolution of WTS: Quantiseq. Real world overall survival (OS) and treatment-associated survival was extracted from insurance claims and calculated from tissue collection or treatment start to last contact using Kaplan-Meier estimates. Statistical significance was determined using chi-square and Mann-Whitney U test with p-values adjusted for multiple comparisons (q < 0.05). Results: ID TNBC had a higher frequency of TP53, RB1, NF1, PIK3R1, NOTCH1, CREBBP, BRCA1, FANCI, and HRAS mutations (Table 1), NOTCH2 (4.3% vs 0.47%), EGFR (3.4% vs 0%), NFIB (4% vs 0.6%), MYB (3.5% vs 0.5%), CCNE1 (4.4% vs 1.1%) and AKT2 (2.4% vs 0.3%) copy number alterations, and NOTCH2 (1.6% VS 0.2%) fusion (all p < 0.05) compared to invasive ductal non-TNBC. Analysis of inferred immune cell infiltrates showed that ID TNBC had increased infiltration of Tregs (2% vs 1.7%), DC (3.2% vs 2.4%), CD8 T cells (0.5% vs 0.1%), and M1 macrophages (M) (3.4% vs 2.9%), but decreased infiltration of B cells (4.5% vs 6%) and M2M (2.9% vs 4.5%) (all p < 0.05). ID TNBC had increased T cell inflamed score (23 vs -9, p < 0.05), IFNy score (-0.24 vs -0.34, p < 0.05), MHC class I genes (HLA-A, HLA-B, TAP1, TAP2, FC: 1.1-1.5, all p < 0.05), immune checkpoint genes (CD274, PDCD1, CTLA4, PD-L2, FOXP3, IDO, FC: 1.1-2, all p < 0.05) and PD-L1 protein expression (SP142: 49.8% vs. 28.4%; 22c3: 41.7% vs. 16.8%, all p < 0.05). ID TNBC had differential expression of BCL2 family genes (upregulation: BAK1, BID, MCL1, BCL2A1, BCL2L10, FC: 1.1-2.0; downregulation: BAD, BIK, BBC3, BCL2, BCL2L1, BCL2L2, FC: 1.2-2.8, all p < 0.05) compared to invasive ductal non-TNBC. ID TNBC was associated with worse OS compared to ID non-TNBC (mOS: 24.5 vs 54.6 months; HR: 0.5, 95% CI 0.47-0.57; p < 0.00001) but trend towards better survival with pembrolizumab (mOS: 29.4 vs 8.8 month; HR: 0.67, 95% CI 0.28-1.5; p=0.3) treatment. No significant OS difference was noted for by high vs. low pro and anti-apoptotic BCL2 genes except for anti-apoptotic BCL2A1 (higher expression associated with better OS (mOS: 5.7 months, HR: 0.78, 95% CI 0.6-0.99; p=0.047). Conclusion: These data indicate that ID TNBC is associated with distinct mutational profile compared to non-TNBC, has increased T cell inflamed score, IFNy score, MHC class I and immune checkpoint gene expression, and differential immune cell infiltration. Interestingly, TNBC was associated with increased M1 and decreased M2M. There is evidence to suggest that transcriptomically defined M1 high tumors are clinically aggressive and have worse OS in TNBC. BCL2 family genes are not prognostic for TNBC outcomes except BCL2A1, which needs further prospective validation. Table 1: Mutation frequency in invasive ductal TNBC and invasive ductal non-TNBC Citation Format: Pooja Advani, Sachin Deshmukh, Sharon Wu, Jacob Andring, Joanne Xiu, Alex Farrell, Jose Leone, Priya Jayachandran, Stephanie Graff, Matthew Oberley, George Sledge Jr, Asher Chanan-Khan. Comprehensive Molecular and Immunological Characterization of Invasive Ductal Triple-Negative Breast Cancer [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 PO4-24-01.

Abstract Background: Metaplastic Breast Cancer (MBC) is rare (0.2-5%), aggressive form of BC characterized by chemotherapy resistance and has worse outcomes in comparison to other BC subtypes. Resistance to chemotherapeutic agents is related to defects in intact intrinsic apoptosis pathway and the BCL2 family of proteins are the central regulators of this pathway. Majority of MBC have triple-negative receptor status and have no standard therapeutic approach and validated prognostic markers. Here, we examine the association of BCL2 family pro-apoptotic and anti-apoptotic genes expression with metaplastic TNBC (MTNBC) patient survival. Methods: 13,036 BC samples (MTNBC, n=102; metaplastic non-TNBC, n=20) were analyzed by next-generation sequencing (592, NextSeq; WES, NovaSeq), Whole Transcriptome Sequencing (WTS; NovaSeq) (Caris Life Sciences, Phoenix, AZ). A total of 10 pro-apoptotic (BAX, BAK1, BID, BAD, BIK, BCL2L11, BMF, HRK, PMAIP1, BBC3) and 6 anti-apoptotic (BCL2, BCL2L1, BCL2L2, MCL1, BCL2A1, BCL2L10) BCL2 family genes were analyzed. MTNBC with PMAIP1-high(H) and -low(L) expression was classified by top and bottom quartile, respectively. Pathway enrichment was determined by GSEA (Broad Inst). Real world overall survival (OS) was extracted from insurance claims and calculated from tissue collection to last contact using Kaplan-Meier estimates. Statistical significance was determined using chi-square and Mann-Whitney U test with p-values adjusted for multiple comparisons (q < 0.05). Results: MTNBC had enrichment of apoptosis (NES: 1.4, FDR: 0.05), glycolysis (NES: 1.48, FDR: 0.03), PI3K/AKT/mTOR signaling (NES: 1.43, FDR: 0.05), P53 (NES: 1.51, FDR: 0.06), NOTCH signaling (NES: 1.39, FDR: 0.05), TGFβ signaling (NES: 1.41, FDR: 0.05), WNTβ catenin signaling (NES: 1.41, FDR: 0.05) and IL2/STAT5 signaling (NES: 1.33, FDR: 0.09) pathways compared to metaplastic non-TNBC. MTNBC had higher expression of BCL2 pro-apoptotic genes BAX (Fold Change (FC): 1.6), BAK1 (FC: 1.3), BID (FC: 2), BAD (FC: 1.6), BCL2L11 (FC: 2.5) and BBC3 (FC: 1.5), and anti-apoptotic genes BCL2L1 (FC: 1.6) and BCL2L2 (FC: 1.3) (all p < 0.05) compared to metaplastic non-TNBC. Higher PMAIP1 gene expression was associated with worse MTNBC patient survival (mOS: 14.3 month; HR: 0.37; 95% CI 0.19-1.41; p=0.002) (Table 1), but not in metaplastic non-TNBC (mOS: Inf; HR: 1.96; 95% CI 0.64-6.02; p=0.23). PMAIP1-H MTNBC had higher expression of immune checkpoint genes CD274 (FC: 2.8), PDCD1 (FC: 2.2), TIM3 (FC: 1.8), LAG3 (FC: 2.1) and IDO1 (FC: 5.7) (all p < 0.05), compared to PMAIP1-L MTNBC. PMAIP1-H MTNBC had higher frequency of IHC-PD-L1 positivity (68.4% vs 14.3%, p < 0.05). PMAIP1-H MTNBC had higher expression of stem cell related genes CD44 (FC: 1.7), ALDH1A2 (FC: 2.2), ALDH1A3 (FC: 2.6), SOX2 (FC: 5.21) and NANOG (FC: 2.13) (all p < 0.05) compared to PMAIP1-L MTNBC. Conclusion: This is the first comprehensive analysis of expression and prognostic role of BCL2 family proteins in MBC. Our data suggest a strong association of higher expression of PMAIP1 with worse MTNBC patient survival, potentially attributed to higher immune checkpoint, stem cell-related genes expression, and higher frequency of PD-L1 positivity in PMAIP1-H tumors. These findings indicate PMAIP1 as a potential prognostic biomarker candidate in MTNBC but needs further validation in large prospective studies Table 1. Overall survival of metaplastic TNBC patient based on BCL2 family gene expression. Citation Format: Pooja Advani, Sachin Deshmukh, Sharon Wu, Jacob Andring, Joanne Xiu, Alex Farrell, Milan Radovich, George Sledge Jr, Dario Trapani, Evanthia Roussos Torres, Stephanie Graff, Asher Chanan-Khan. Comprehensive Characterization of BCL2 Family Genes in Metaplastic Triple Negative Breast Cancer [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 PO4-24-02.

AbstractThe adiposity influence on colorectal cancer prognosis remains poorly characterised. We performed a systematic review and meta‐analysis on post‐diagnosis adiposity measures (body mass index [BMI], waist circumference, waist‐to‐hip ratio, weight) or their changes and colorectal cancer outcomes. PubMed and Embase were searched through 28 February 2022. Random‐effects meta‐analyses were conducted when at least three studies had sufficient information. The quality of evidence was interpreted and graded by the Global Cancer Update Programme (CUP Global) independent Expert Committee on Cancer Survivorship and Expert Panel. We reviewed 124 observational studies (85 publications). Meta‐analyses were possible for BMI and all‐cause mortality, colorectal cancer‐specific mortality, and cancer recurrence/disease‐free survival. Non‐linear meta‐analysis indicated a reverse J‐shaped association between BMI and colorectal cancer outcomes (nadir at BMI 28 kg/m2). The highest risk, relative to the nadir, was observed at both ends of the BMI distribution (18 and 38 kg/m2), namely 60% and 23% higher risk for all‐cause mortality; 95% and 26% for colorectal cancer‐specific mortality; and 37% and 24% for cancer recurrence/disease‐free survival, respectively. The higher risk with low BMI was attenuated in secondary analyses of RCTs (compared to cohort studies), among studies with longer follow‐up, and in women suggesting potential methodological limitations and/or altered physiological state. Descriptively synthesised studies on other adiposity‐outcome associations of interest were limited in number and methodological quality. All the associations were graded as limited (likelihood of causality: no conclusion) due to potential methodological limitations (reverse causation, confounding, selection bias). Additional well‐designed observational studies and interventional trials are needed to provide further clarification.

AbstractLow physical activity and high sedentary behaviour have been clearly linked with colorectal cancer development, yet data on their potential role in colorectal cancer survival is limited. Better characterisation of these relationships is needed for the development of post‐diagnosis physical activity and sedentary behaviour guidance for colorectal cancer survivors. We searched PubMed and Embase through 28 February 2022 for studies assessing post‐diagnosis physical activity, and/or sedentary behaviour in relation to all‐cause and cause‐specific mortality and recurrence after colorectal cancer diagnosis. Total and recreational physical activity were assessed overall and by frequency, duration, intensity, and volume using categorical, linear, and non‐linear dose–response random‐effects meta‐analyses. The Global Cancer Update Programme (CUP Global) independent Expert Committee on Cancer Survivorship and Expert Panel interpreted and graded the likelihood of causality. We identified 16 observational studies on 82,220 non‐overlapping patients from six countries. Physical activity was consistently inversely associated with colorectal cancer morbidity and mortality outcomes, with 13%–60% estimated reductions in risk. Sedentary behaviour was positively associated with all‐cause mortality. The evidence had methodological limitations including potential confounding, selection bias and reverse causation, coupled with a limited number of studies for most associations. The CUP Global Expert panel concluded limited‐suggestive evidence for recreational physical activity with all‐cause mortality and cancer recurrence. Total physical activity and its specific domains and dimensions, and sedentary behaviour were all graded as limited‐no conclusion for all outcomes. Future research should focus on randomised trials, while observational studies should obtain objective and repeated physical activity measures and better adjustment for confounders.