Stover, Daniel G.

Abstract Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype with low overall survival rates and high molecular heterogeneity; therefore, few targeted therapies are available. The luminal androgen receptor (LAR) is the most consistently identified TNBC subtype, but the clinical utility has yet to be established. Here, we constructed a novel genomic classifier, LAR-Sig, that distinguishes the LAR subtype from other TNBC subtypes and provide evidence that it is a clinically distinct disease. A meta-analysis of seven TNBC datasets (n = 1086 samples) from neoadjuvant clinical trials demonstrated that LAR patients have significantly reduced response (pCR) rates than non-LAR TNBC patients (odds ratio = 2.11, 95% CI: 1.33, 2.89). Moreover, deconvolution of the tumor microenvironment confirmed an enrichment of luminal epithelium corresponding with a decrease in basal and myoepithelium in LAR TNBC tumors. Increased immunosuppression in LAR patients may lead to a decreased presence of cycling T-cells and plasma cells. While, an increased presence of myofibroblast-like cancer-associated cells may impede drug delivery and treatment. In summary, the lower levels of tumor infiltrating lymphocytes (TILs), reduced immune activity in the micro-environment, and lower pCR rates after NAC, suggest that new therapeutic strategies for the LAR TNBC subtype need to be developed.

TPS613 Background: Approximately 50% of newly diagnosed breast cancers are stage 1, with the majority being ER/PR-positive, HER2-negative. Genomic assays such as the Oncotype DX® have identified patients (pts) with reduced risk of distant metastasis and without benefit from chemotherapy added to endocrine therapy, freeing them from excess toxicity. Genomic assays are also recognized as prognostic for in-breast recurrence (IBR) after BCS and could similarly allow de-escalation of adjuvant radiotherapy (RT). Reducing overtreatment is of interest to pts, providers, and payers. Methods: We hypothesize that BCS alone is non-inferior to BCS plus RT for in-breast recurrence and breast preservation in women intending endocrine therapy (ET) for stage 1 breast cancer (ER &/or PR positive, HER2-negative with an Oncotype DX Recurrence Score [RS] of ≤18). Stratification is by age (<60; ≥60), tumor size (≤1 cm; >1-2cm), & (RS <11, RS 11-18). Pts are randomized post-BCS to Arm 1 with breast RT using standard methods (hypo- or conventional-fractionated whole breast RT with/without boost, APBI) with ≥5 yrs of ET (tamoxifen or AI) or Arm 2 with ≥5 yrs of ET (tamoxifen or AI) alone. The specific regimen of ET in both arms is at the treating physician’s discretion. Eligible pts are stage 1: pT1 (2 cm), pN0, age ≥50 to <70 yrs, s/p BCS with negative margins (no ink on tumor), s/p axillary nodal staging (SNB or ALND), ER &/or PR positive (ASCO/CAP), HER2-negative (ASCO/CAP), and Oncotype DX RS of ≤18 (diagnostic core biopsy or resected specimen). Primary endpoint is in-breast recurrence. Secondary endpoints are breast conservation rate, invasive in-breast recurrence, relapse-free interval, distant disease-free survival, overall survival, patient-reported breast pain, patient-reported worry about recurrence, and adherence to ET. We assume a clinically acceptable difference in of 4% at 10 yrs to judge omission of RT as non-inferior (10-yr event-free survival for RT group is 95.6% vs 91.6% for the omission of RT group). The study is powered to detect a non-inferiority with 80% power and a one-sided α=0.025, assuming that there would be a ramp-up in accrual in the first two years (leveling off in Yrs 3-5); 1,670 (835 per arm) pts are required to be randomized. Conservative loss to follow-up is 1% per yr. Some of the T1a pts screened may have Oncotype DX scores >18, making them ineligible for the study. In the accrual process, pts will be required to register (1,714 pts) to ensure that our final randomized cohort is 1,670 pts. Current accrual (2-2-2022) is 52 screened and 45 randomized. Support: U10CA180868, -180822, NCT04852887. Clinical trial information: NCT04852887.

Abstract Roughly 50% of newly diagnosed breast cancer is stage 1, the majority being ER/PR positive, HER2- negative. Genomic assays such as Oncotype DX® have identified patients with reduced distant metastasis and lack of chemotherapy benefit, allowing patients to avoid excess toxicity. These genomic assays have been shown to be prognostic for local-regional recurrence (LRR). The de-escalation of therapy is of interest to patients, providers, and payers. Low risk, as identified by both the use of Oncotype and Mammaprint® is associated with low LRR after lumpectomy and breast radiotherapy. TRIAL DESIGN: In the DEBRA trial, we hypothesized that breast-conserving surgery (BCS) alone is non-inferior to BCS plus radiotherapy for in-breast cancer control and breast preservation in women intending appropriate endocrine therapy for stage 1 (ER and/or PR-positive, HER2-negative, and Oncotype DX Recurrence Score [RS] low) breast cancer. Stratification is by age (&lt;60; ≥60), tumor size (≤1 cm; &gt;1-2 cm), and RS &lt;11, RS 11-18. Patients are randomized to either breast radiotherapy (RT) plus endocrine therapy (arm 1) or to observation and endocrine therapy (arm 2). Arm 1 therapy is post-lumpectomy breast RT using standard methods (hypo- or conventional-fractionated whole breast irradiation with or without boost, accelerated partial breast irradiation) and at least 5 years of endocrine therapy (tamoxifen or aromatase inhibitor). In arm 2, at least 5 years of endocrine therapy (tamoxifen or aromatase inhibitor) will be given. The specific regimen of endocrine therapy in both arms is at the treating physician’s discretion. ELIGIBLITY: Patients who are stage 1: pT1 (2 cm), pN0, age ≥50 to &lt;70 years, status post (s/p) lumpectomy with negative margins (no ink on tumor ), s/p axillary nodal staging (SNB or AND), ER and/or PR positive by ASCO/CAP, HER2-negative by ASCO/CAP, and Oncotype DX RS of ≤18 on diagnostic core biopsy or resected specimen. ENDPOINTS: Primary: In-breast recurrence (IBR). Secondary: Breast conservation rate, invasive in-breast recurrence (IIBR), relapse free interval (RFI), distant disease-free survival (DDFS), overall survival (OS), patient-reported breast pain, patient-reported worry about recurrence, and adherence to endocrine therapy. STATISTICS: We assume a clinically acceptable difference in IBR of 4% at 10 years to judge omission of RT as non-inferior (10-year event-free survival for RT group is 95.6% versus 91.6% for the omission of RT group). To be able to detect non-inferiority with 80% power and a one sided α=0.025, and assuming that there would be a ramp-up in accrual in the first two years of the study (leveling off in Years 3-5), 1,670 (835 per arm) patients are required to be randomized. This conservatively assumes loss to follow-up will be 1% per year. Some of the T1a patients accrued to this study will have oncotype DX scores &gt;18, making them ineligible for the study. An extra step in the accrual process will require us to register 1,714 patients to ensure our final randomized cohort is 1,670 patients. Accrual: Screen 1,714 to randomize 1,670 into the study. Contact information: Protocol: CTSU member website: https://www.ctsu.org. NRG Oncology Pgh Clinical Coordinating Dpt: 1-800-477-7227 or ccd@nsabp.org. Support: U10CA180868, U10CA180822. NCT04852887. Citation Format: Julia White, Stewart J Anderson, Eleanor ER Harris, Eleftherios P Mamounas, Daniel G Stover, Patricia A Ganz, Reshma Jagsi, Reena S Cecchini, Carmen Bergom, Valerie Theberge, Mahmoud El-Tamer, Rich C Zellars, Dean A Shumway, Guang-Pei Chen, Thomas B Julian, Norman Wolmark. Evaluating de-escalation of breast radiation (DEBRA) following lumpectomy for breast conservative treatment of stage 1, hr+, HER2-, RS ≤18 breast cancer: NRG-BR007 a phase III trial [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-18-04.

(1) Background: The objective of this study was to determine the long-term efficacy of fractional CO2 laser therapy in breast cancer survivors. (2) Methods: This was a single-arm study of breast cancer survivors. Participants received three treatments of fractional CO2 laser therapy and returned for a 4 week follow-up. Participants were contacted for follow-up at annual intervals. The Vaginal Assessment Scale (VAS), the Female Sexual Function Index (FSFI), the Female Sexual Distress Scare Revised (FSDS-R), the Urinary Distress Inventory (UDI), and adverse events were collected and reported for the two-year follow-up. The changes in scores were compared between the four-week and two-year and the one-year and two-year follow-ups using paired t-tests. (3) Results: In total, 67 BC survivors were enrolled, 59 completed treatments and the four week follow-up, 39 participated in the one-year follow-up, and 33 participated in the two-year follow-up. After initial improvement in the VAS from baseline to the four week follow-up, there was no statistically significant difference in the VAS score (mean Δ 0.23; 95% CI [−0.05, 0.51], p = 0.150) between the four week follow-up and the two-year follow-up. At the two-year follow-up, the FSFI and FSDS-R scores remained improved from baseline and there was no statistically significant change in the FSFI score (mean Δ −0.83; 95% CI [−3.07, 2.38] p = 0.794) or the FSDS-R score (mean Δ −2.85; 95% CI [−1.88, 7.59] p = 0.227) from the one to two-year follow-up. The UDI scores approached baseline at the two-year follow-up; however, the change between the one- and two-year follow-ups was not statistically significant (mean Δ 4.76; 95% CI [−1.89, 11.41], p = 0.15). (4) Conclusions: Breast cancer survivors treated with fractional CO2 laser therapy have sustained improvement in sexual function two years after treatment completion, suggesting potential long-term benefit.

Breast cancer is the most prominent type of cancer among women. Understanding the microenvironment of breast cancer and the interactions between cells and cytokines will lead to better treatment approaches for patients. In this study, we developed a data-driven mathematical model to investigate the dynamics of key cells and cytokines involved in breast cancer development. We used gene expression profiles of tumors to estimate the relative abundance of each immune cell and group patients based on their immune patterns. Dynamical results show the complex interplay between cells and molecules, and sensitivity analysis emphasizes the direct effects of macrophages and adipocytes on cancer cell growth. In addition, we observed the dual effect of IFN-γ on cancer proliferation, either through direct inhibition of cancer cells or by increasing the cytotoxicity of CD8+ T-cells.

Breast cancer is a heterogenous disease with variability in tumor cells and in the surrounding tumor microenvironment (TME). Understanding the molecular diversity in breast cancer is critical for improving prediction of therapeutic response and prognostication. High-plex spatial profiling of tumors enables characterization of heterogeneity in the breast TME, which can holistically illuminate the biology of tumor growth, dissemination and, ultimately, response to therapy. The GeoMx Digital Spatial Profiler (DSP) enables researchers to spatially resolve and quantify proteins and RNA transcripts from tissue sections. The platform is compatible with both formalin-fixed paraffin-embedded and frozen tissues. RNA profiling was developed at the whole transcriptome level for human and mouse samples and protein profiling of 100-plex for human samples. Tissue can be optically segmented for analysis of regions of interest or cell populations to study biology-directed tissue characterization. The GeoMx Breast Cancer Consortium (GBCC) is composed of breast cancer researchers who are developing innovative approaches for spatial profiling to accelerate biomarker discovery. Here, the GBCC presents best practices for GeoMx profiling to promote the collection of high-quality data, optimization of data analysis and integration of datasets to advance collaboration and meta-analyses. Although the capabilities of the platform are presented in the context of breast cancer research, they can be generalized to a variety of other tumor types that are characterized by high heterogeneity.

e24108 Background: Clonal hematopoiesis of Indeterminate Potential (CHIP) is associated with adverse clinical outcomes including increased risk of hematologic malignancies and heart disease. Limited data suggest an increased prevalence of CHIP in patients treated for solid tumors, particularly after exposure to radiation and chemotherapy. CHIP testing may inform risk-reduction strategies for cancer survivors. Little is known about patient knowledge, attitudes, and preferences regarding CHIP testing. Methods: We surveyed survivors without history of recurrence participating in an ongoing prospective cohort study of young women with breast cancer (BC). The survey was sent by email and included an introduction to CHIP including risk factors and clinical associations. Respondents then reviewed a vignette and were asked about CHIP testing preferences (definitely/probably test vs. definitely/probably not test) considering sequentially: 1) population-based 10-year risk of BC recurrence, hematological malignancy and heart disease; 2) estimated increase in these risks with CHIP; 3) current CHIP management; 4) a dedicated CHIP clinic; and 5) a theoretical CHIP treatment. Changes in preferences from the prior scenario were evaluated with the McNemar's test using a type I error rate of 5%. Results: 528/642 (82.2%) eligible women responded to the survey, at a median age of 46 (range: 31-54) years (median time from diagnosis: 108 months (range: 60-168)), and 88% were white. Most had stage 1/2 BC (78.8%) and had received chemotherapy (73.1%) and/or radiation (61.9%). 93.6% had never heard of CHIP prior to survey. After initial patient vignette presentation, most women (87.1%,) recommended CHIP testing if offered. Preferences for testing decreased (p<0.05) when considering population-based risks, with 11.1% shifting their preference from CHIP testing to not testing. After considering increased risks associated with CHIP, interest in testing increased (p<0.05), with 10.1% shifting their preference to testing. Interest significantly (p<0.05) increased with the possibility of managing CHIP through a clinic or a hypothetical CHIP treatment, with 7.2% and 14.1% switching their preferences towards testing, respectively. Finally, 75.8% responded that they themselves, after learning about CHIP and reviewing the vignette, would want to have CHIP testing; 28.2% reported that learning about CHIP and the associated risks caused them at least moderate anxiety. Conclusion: Few young BC survivors were aware of CHIP yet most indicated an interest in testing after learning about it. Testing preferences were influenced by risks presented and potential management strategies. Findings highlight the importance of effective risk communication and the need for adequate psychosocial support when considering testing for CHIP and other potential clinical biomarkers predictive of cancer and other medical risks in cancer survivors.

e18739 Background: Hair loss is a well-known side effect of chemotherapy. The Paxman Hair Loss Prevention System, a scalp cooling device, has been shown to be effective in reducing chemotherapy induced alopecia in patients receiving chemotherapy (Nangia, JAMA, 2017). The National Comprehensive Cancer Network and the European Society for Medical Oncology guidelines have recommended scalp cooling as category 2A and 2B options, respectively. Methods: The real world use of scalp cooling using the Paxman device, as documented by orders through the Paxman Hub during the years of 2017-2020 was summarized. Descriptive statistics were used to summarize demographics and utilization. Results: Data from 6649 patients who used scalp cooling were reviewed. Patients with breast cancer were the most common users of scalp cooling (78%, n=5197) followed by gynecology (12%, n=775), gastrointestinal (3%, n=201), lung (1%, n=81) and genitourinary (1%, n=52). The majority of patients were between the ages of 45-65 (55%), followed by 65-74 (18%), older than 75 (5%), and 25-44 (2%). Average number (#) of cycles of cooling completed was 6.53 (range of average # of cycles 4.50-12). Scalp cooling with this device was commonly used in 39 out of 50 states. Conclusions: This is the largest report of scalp cooling usage in the real world setting in the USA, including scalp cooling usage in older adults. Uptake of scalp cooling across various cancers has not been uniform and this deserves further study.