Citations

Abstract Purpose: Programmed death ligand 1 [PD-(L)1]-targeted therapies have shown modest survival benefit in triple-negative breast cancer (TNBC). PD-L1+ microenvironments in TNBC are not well characterized and may inform combinatorial immune therapies. Herein, we characterized clinicopathologic features, RNA-based immune signatures, and spatially defined protein-based tumor–immune microenvironments (TIME) in early-stage PD-L1+ and PD-L1− TNBC. Experimental Design: From a large cohort of chemotherapy-naïve TNBC, clinicopathologic features, deconvoluted RNA immune signatures, and intraepithelial and stromal TIME (Nanostring GeoMX) were identified in subsets of PD-L1+ and PD-L1− TNBC, as defined by FDA-approved PD-L1 companion assays. Results: 228 of 499 (46%) TNBC were PD-L1+ (SP142: ≥1% immune cells-positive). Using PD-L1 22C3, 46% had combined positive score (CPS) ≥ 1 and 16% had CPS ≥10. PD-L1+ TNBC were higher grade with higher tumor-infiltrating lymphocytes (TIL; P < 0.05). PD-L1 was not associated with improved survival following adjustment for TILs and other variables. RNA profiles of PD-L1+ TNBC had increased dendritic cell, macrophage, and T/B cell subset features; and decreased myeloid-derived suppressor cells. PD-L1+ stromal and intraepithelial TIMEs were highly enriched in IDO-1, HLA-DR, CD40, and CD163 compared with PD-L1-TIME, with spatially specific alterations in CTLA-4, Stimulator of Interferon Genes (STING), and fibronectin. Macrophage- and antigen presentation–related proteins correlated most strongly with PD-L1 protein. Conclusions: In this early-stage TNBC cohort, nearly 50% were PD-L1+ (SP142 companion assay) while 16% were PD-L1+ with the 22C3 companion assay. PD-L1+ TNBC had specific myeloid-derived and lymphoid features. Spatially defined PD-L1+ TIME were enriched in several clinically actionable immune proteins. These data may inform future studies on combinatorial immunotherapies for patients with PD-L1+ TNBC. See related commentary by Symmans, p. 5446

548 Background: sTILs are a well-established prognostic and predictive biomarker in patients with operable TNBC receiving pre or postoperative systemic therapy. We1 and others2,3 have also shown that sTILs are prognostic in patients who did not receive adjuvant chemotherapy. Here, we detail the outcomes of systemically untreated patients with N0 TNBC according to sTIL score. We focused on the N0 subset as a group of patients who may be candidates for future prospective therapy de-escalation trials. Methods: From a clinically annotated cohort of 605 patients with centrally confirmed TNBC (ER/PR < 1% and HER2 negative) with long-term outcomes data, we identified 182 patients treated with locoregional therapy only (breast surgery +/- radiation therapy and no chemotherapy). The clinicopathological characteristics of this cohort have previously been published1. In this analysis, we report the 5- and 10-year invasive disease-free survival (iDFS) and overall survival (OS) rates of patients with N0 TNBC according to sTIL levels. IDFS and OS were defined as per the STEEP classification and estimated using the Kaplan–Meier method. Comparisons of the survival distributions between groups were assessed by the log-rank test. sTILs were assessed as a continuous parameter according to the International TIL Working Group guidelines. For comparisons of outcomes between groups, tumors were classified as lymphocyte-predominant TNBC (defined as containing ≥50% sTILs) vs non-lymphocyte-predominant ( < 50% sTILs). Results: Of 182 systemically untreated patients, 149 (82%) were N0 and most (78%) were post-menopausal. T stage distribution was T1: 68%, T2: 28%, T3/4: 4%. Among N0 patients, 31 (21%) had lymphocyte-predominant TNBC, and in this group the 5-year iDFS and OS were 89% (95% CI 76-100) and 96% (95% CI 89-100), while the 10-year iDFS and OS were 89% (95% CI 76-100) and 87% (95% CI 73-100), respectively. In contrast, outcomes for patients with non-lymphocyte predominant TNBC were significantly worse. For this group, 5-year iDFS and OS were 62% (95% CI 53-73) and 78% (95% CI 71-86) while the 10-year iDFS and OS were 45% (95% CI 36-58) and 66% (95% CI 68-76), respectively ( log-rank p = 0.02 for iDFS and log-rank p = 0.03 for OS). Conclusions: sTIL quantification identifies a subset of patients with early-stage N0 TNBC with an exceedingly good prognosis, even in the absence of adjuvant chemotherapy. These data provide support for the evaluation of sTILs as part of prospective investigation of systemic therapy de-escalation strategies in N0 TNBC. References:1Leon-Ferre et al, Breast Cancer Res Treat (2018) 167:89-99 2Park et al, Ann Oncol (2019) 12:1941-1949 3De Jong et al, ESMO 2020

Abstract Current therapies for breast cancer prevention only prevent estrogen receptor positive (ER+) disease and toxicity limits use of these agents. Vitamin D is a potential prevention therapy for both ER+ and ER− disease and is safe with few side effects. This study evaluates the effect of 1-year of vitamin D supplementation on mammographic density (MD), a biomarker of breast cancer risk in a multicenter randomized controlled trial. Premenopausal women with ≥25% MD and no history of cancer were randomly assigned to 2,000 international units (IU) of vitamin D or placebo orally daily for 1 year. Change in percent MD was evaluated using Cumulus software after all participants completed treatment. Three hundred women enrolled between January 2011 and December 2013 with a mean age of 43 and diverse ethnicity [14% Hispanic, 12% African American (AA)]. Supplementation significantly increased vitamin D levels compared with placebo (14.5 ng/mL vs. −1.6 ng/mL; P &lt; 0.0001) with all participants on the vitamin D arm achieving vitamin D sufficiency at 12 months. Vitamin D was safe and well tolerated. After adjustment for baseline MD, the mean between-arm difference (vitamin D vs. placebo) at 1 year was −0.75 (−0.26, 1.76; P = 0.56). A greater effect was seen for women with ≥50% MD and AA women, although neither reached significance. This randomized controlled trial demonstrated significant improvement in vitamin D levels with 2,000 IU for 1 year, with 100% of supplemented women achieving sufficiency. However, a null effect was seen regarding change in MD for premenopausal women (the primary outcome of the study). Prevention Relevance: Current therapies for breast cancer prevention only prevent estrogen receptor positive (ER+) disease and are underutilized due to toxicity and side effects. Vitamin D is a potential prevention therapy for both ER+ and ER− disease and is safe with few side effects.

Abstract Introduction: Stromal tumor-infiltrating lymphocytes (sTILs) have established prognostic and predictive significance in triple-negative breast cancer (TNBC). However, the roles of other immune cells in TNBC are less well-established. We performed high-plex quantitative spatial profiling in a cohort of early-stage TNBC to 1) apply spatial context to tumoral immune landscapes and 2) identify immune proteins associated with clinical outcomes, independently of TILs and other established prognostic clinicopathologic variables, in patients (pts) treated with or without adjuvant chemotherapy (CTX). Methods: The Mayo TNBC cohort comprises pts with centrally-verified, CTX-naive tumors resected from 1985-2012. Using a cohort-based TMA, with Nanostring GeoMX DSP, we quantitated 58 proteins within spatially-distinct intra-epithelial, cytokeratin-positive tumor segments and adjacent cytokeratin-negative/nuclei-positive stromal segments. Differentially-expressed (DE) proteins were identified using a negative binomial generalized linear model (SNR&gt;2, p&lt; 0.05) and a target DE protein set was dichotomized (80th percentile). After adjusting for prognostic clinicopathologic variables, proteins associated with recurrence-free survival (RFS, defined as time from surgery to either local, regional, and distant recurrence, or death by any cause) were identified by performing variable selection using the Akaike Information Criterion (AIC) obtained from fitting all possible Cox proportional hazards regression models (performed separately for intra-epithelial/stromal segments, and in groups +/- adjuvant CTX. Results: From the TNBC TMA, DSP data (N=250 tumors) included 169 pts who received adjuvant CTX+ and 81 who did not (CTX-). Overall, 85/250 developed recurrent disease. In the CTX+ group, intra-epithelial tumor segments from pts without recurrent disease were enriched in 10 immune proteins, including CD8, markers involved in antigen presentation/dendritic cells (CD11c, CD40, HLA-DR) or NK cells (CD56) (FC: 1.4-2.1, p&lt;0.05); CD14 was increased in stroma (FC: 1.5, p&lt;0.05). In contrast, in the CTX- group, both the intra-epithelial tumor and stromal segments from pts without recurrences were enriched in immune proteins (N= 12 and 15 respectively; FC 1.6-5.5, p&lt; 0.05) most markedly CD40, IDO1 and HLA-DR (FC: 3.2-5.5, p&lt; 0.05). Overall, CD3, CD4, CD27, CD44, and ICOS among others were enriched only in the CTX- group; CD14 and CD56 were enriched only in the CTX+ group. Based on these spatial data, biologic function and DSP data from another set of TNBC (FinXX trial), CD11c, CD14, CD27, CD40, CD56, and IDO1 were selected for RFS analysis. After applying our model selection criterion and adjusting for pt age at surgery, tumor size, lymph node status, and sTILs, intra-epithelial CD56 was independently associated with improved RFS in the CTX+ group (HR: 0.31[0.12, 0.81]). In the CTX- group, intra-epithelial CD11c was independently associated with improved RFS (0.10 [0.01, 0.81]). Conclusion: In this early-stage TNBC cohort, spatially-distinct tumor immune landscapes were associated with RFS but differed according to receipt of CTX after surgical resection. In the patients who received CTX, the intra-epithelial compartment, rather than stromal compartment, was immune-enriched in pts without recurrences. Among a targeted protein set, intra-epithelial CD56 remained associated with improved outcomes, independent of sTILs and other clinicopathologic features. In the CTX- group, spatial landscapes were more balanced, and intra-epithelial CD11c was independently associated with improved outcomes. These data provide insight into the spatial context of intrinsic immune landscapes in TNBC, and identify candidate prognostic immune biomarkers which may inform therapeutic strategies. Citation Format: Jodi M Carter, Saranya Chumsri, David W Hillman, David M Zahrieh, Yaohua Ma, Xue Wang, Jennifer M Kachergus, Judy C Boughey, Minetta C Liu, Krishna R Kalari, JC Villasboas, Roberto A Leon Ferre, Fergus J Couch, Matthew P Goetz, E. Aubrey Thompson. Intra-epithelial tumor immune landscapes are associated with clinical outcomes in early-stage triple-negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS16-01.

151 Background: Decision aids (DAs) for prostate cancer treatment can improve knowledge and reduce decisional conflict, but the relative effect of pre-visit and within-visit DAs is not known, and effect sizes for minority populations has not been estimated. Methods: We conducted a 3-arm, patient-level-RCT in specialty urology and radiation oncology practices in Ohio, South Dakota, and Alaska, test the effect of pre-consultation and with-in consultation decision aids on patient knowledge immediately after specialty consultation compared to usual care. We used linear regression to estimate effects of each intervention arm, including the respective standard error, two-sided 95% confidence interval, and two-sided P value for testing the study’s hypotheses. Results: 103 patients were recruited and randomized to receive either the pre-visit decision aid, within-visit decision aid, or neither decision aids (usual care). In 2017 and 20018, we accrued similar numbers of men to pre-consultation aid (n = 37), during-consultation aid (n = 33) and usual care arms, respectively (n = 33). The median (range) age in years was 64 [49, 81]; 67.6% were White, 15.7% were Black or African American, 16.7% were American Indian or Alaska Native, and 1% were not reported. 47.6%, 45.6%, and 6.8% had a baseline clinical stage of T1, T2, and T3, respectively. The median [range] prostate specific antigen (PSA) was 8.0 [2.4, 53.7]. There were no clinically notable imbalances. We obtained usable data on 102 of the 103 patient-participants. The pre-visit decision aid arm showed a mean knowledge effect of 0.694 (0.636, 0.753). The within-visit decision arm showed a very similar mean knowledge effect of 0.686 (0.625, 0.748). The usual care arm showed a mean knowledge effect of 0.644 (0.582,0.705). The linear regression model showed, that, compared with usual care, neither intervention effect achieved statistical significance in the primary analysis (p = 0.24, 0.330, for pre-visit and within-visit, respectively). Conclusions: Modest knowledge gains of pre-visit and during-visit decision aids for prostate cancer treatment were not statistically significant. Clinical trial information: NCT03182998 .

e24176 Background: Decision aids for prostate cancer treatment can improve knowledge, but the relative effect of pre-consultation and within-consultation DAs is not known. Methods: We conducted a parallel design, 2-by-2 factorial, 4-arm, cluster-RCT in urology practices affiliated with the NCI’s Alliance research base. We compared patient knowledge immediately after consultation (%12-item% correct) intervention arms compared to usual care. We used mixed effects regression modeling to assess effect of interventions on knowledge adjusting for site-clustering, race/ethnicity (non-Hispanic White; Other), age (years), clinical stage (T1-3), PSA, and Gleason score. Results: 15 of 21 randomized centers accrued 158 pts from Nov 2017 to June 2019. The arm delivering both DAs (n = 3 sites) recruited 25 pts. The pre-consultation DA arm (n = 4 sites) recruited 39 pts. The within-consultation DA arm (n = 4 sites) recruited 44 pts. The no DA arm (n = 4 sites) accrued 50 pts. Overall, mean age was 64; 54% were AA; 73% had T1 stage; median Gleason = 7; and median PSA = 7. The combined DAs group, followed by pre-consultation reported higher median knowledge (75% and 67%, respectively). The within-consultation and no DA arms both reported median knowledge scores (58%). Within arm, inter-site standard deviations in mean knowledge scores ranged from 0.164 in in the pre-consultation arm to 0.232 in the usual care arm. Neither pre-consultation nor within-consultation DAs had statistically significant effects (p = .15 and p = .99, respectively). Pre-specified adjusted difference [97.5% CIs], comparing the pre-consultation DA and the within-consultation DA with the control was 9.4% [-7.3%, 26.2%] and -0.4% [-16.9%, 16.1%], respectively. Intra-cluster correlation (ICC) coefficient was high (.24). No interaction effects were identified (p = .98). A post-hoc analysis comparing any DA vs usual care found a mean adjusted difference [95% CI] of 5.6% [-8.5%, 19.8%] (p = 0.40), 63.9% for any DA and 58.3% for usual care. Conclusions: Possible knowledge gains associated with some DAs for early prostate cancer were obscured by larger-than-expected intra-cluster correlation effects associated with the primary outcome. How interventions were used was not measured. Support:UG1CA189823; https://acknowledgments.alliancefound.org ; R01 MD008934-06. Clinical trial information: NCT03103321 .

e24086 Background: Nasal vestibulitis has been infrequently described as a side effect of cancer-directed therapy; however, a preliminary study reported that 71% of patients undergoing taxane chemotherapy experienced nasal vestibulitis symptoms. This natural history trial describes the incidence, characteristics, and severity of nasal vestibulitis symptoms among patients undergoing paclitaxel, docetaxel, and non-taxane chemotherapy. Methods: Eligible participants who reported baseline (prior to starting chemotherapy) nasal symptoms ≤ 2 on a 10-point scale were enrolled in this trial upon initiation of a new treatment regimen, involving paclitaxel or docetaxel, or non-taxane chemotherapy. Participants completed nasal symptom logs each time they received a dose of therapy until either the regimen was stopped or four months had passed. The proportion of patients reporting new nasal symptoms was estimated within each cohort with the 95% exact confidence interval (CI). A cumulative incidence model was utilized to quantify the incidence of treatment-emergent nasal symptoms within each cohort, while controlling for age, sex, smoking history, and history of asthma or allergies. Results: Thirty-five participants received paclitaxel, 21 received docetaxel, and 25 received other types of chemotherapy. 86.4% of participants were female, mean age was 60.2 ± 11.2 years; 93.8% of participants completed 2 or more surveys. A higher percentage of participants in the paclitaxel cohort experienced new nasal vestibulitis symptoms than participants in the other two cohorts. The percentage (95% CI) of participants with nasal symptoms, for patients receiving paclitaxel, docetaxel, and non-taxane chemotherapy were 74.3% (56.7%, 87.5%), 47.6% (25.7%, 70.2%), and 44.0% (24.4%, 65.1%), respectively. Epistaxis was reported by 60% of participants in the paclitaxel cohort. Paclitaxel-receiving participants also reported nasal dryness (48.6%), scabbing (40.0%), and pain (20.0%). Nearly half of participants reported moderate symptoms (4-7 out of a 10-point scale), with 8.6% reporting symptoms as severe (8-10 on a 10-point scale). Conclusions: Nasal vestibulitis is a common side effect of chemotherapy, especially paclitaxel chemotherapy.

e13617 Background: Breast cancer (BC) is the most prevalent cancer of women in the United States (US). The incidence rates for BC among American Indian and Alaska Native (AI/AN) women vary across the US. A novel application of Bayesian disease mapping was applied to quantify potential inequities in 10-year BC incidence in New Mexico (NM) in order to better inform health equity initiatives within the AI/AN at-risk population. Methods: Surveillance, Epidemiology, and End Results Program (SEER) data from 2005 to 2014 were used to identify new cases of BC within the 33 counties in NM. Initially, a Poisson-gamma model was applied to quantify the reduction in risk of BC within the at-risk AI/AN population compared with the general at-risk population. To account for spatial variation and to address the small area estimation problem inherent in these data by borrowing strength globally and locally in NM, we applied Bayesian disease mapping to the counts of county-level BC cases. We quantified the disparity effect, as measured by the rate ratio (95% credible interval [CI]), comparing the incidence of BC between at-risk AI/AN and non-AI/AN women, and assessed if the rate ratio differed between counties. Markov chain Monte Carlo sampling was used to estimate posterior quantities and the deviance information criterion was used for model selection. Results: In 2010, 1,041,758 women were at-risk for BC of which 107,656 (10.3%) were AI/AN women. During the 10-year study period, 12,974 new BC cases were recorded in the general at-risk population. In the at-risk AI/AN population, the expected number of new cases during the 10-year study period, therefore, was 1,340.74; however, 597 incidence cases of BC were diagnosed in the at-risk AI/AN population resulting in a posterior mean for the true relative risk of 0.445 (95% CI: 0.410, 0.482). Based on the selected model that accounted for over dispersion and spatial correlation among the 33 counties, the posterior mean of the overall adjusted rate ratio was 0.405 (95% CI: 0.336, 0.478). The adjusted rate of BC in AI/AN women was 0.40 times the corresponding adjusted rate for women who were non-AI/AN. Further, the adjusted rate ratios were similar for each county. Conclusions: The novel application of Bayesian disease mapping to these data provided substantial evidence of a significant overall disparity effect in BC incidence within NM between at-risk AI/AN and non-AI/AN women, which was more marked than previous reports. Targeted state-wide health equity initiatives may lead to reducing disparities in BC incidence in AI/AN at-risk women.