Impact of neoadjuvant pembrolizumab adherence on pathologic complete response in triple-negative breast cancer: a real-world analysis

BACKGROUND

The addition of pembrolizumab (pembro) to neoadjuvant chemotherapy (NAC) is standard of care for the treatment of early triple-negative breast cancer (TNBC) after KEYNOTE-522 trial demonstrated improved pathologic complete response (pCR) rates with the combination. However, the optimal treatment strategy for TNBC remains uncertain as questions persist about which patients benefit from pembro and the best treatment schedule and regimen. We identified real-world clinical characteristics and treatment variables associated with response to NAC plus pembro.

METHODS

Patients with early TNBC treated with NAC plus pembro between February 2020 and September 2023 were identified. Univariate and multivariate analysis was performed using logistic regression to identify factors associated with pCR. Cox proportional hazard prediction models were used to identify predictors of invasive disease-free survival and overall survival in this cohort.

RESULTS

A pCR was achieved in 75 (63.6%) of 118 patients. Age at diagnosis (P = .04), Ki-67 (P = .004), duration from start of pembro to surgery (P = .006) and NAC to surgery (P = .01), number of cycles of pembro (P = .04) and NAC (P = .02), and completion of at least 8 cycles of pembro (P = .015) and NAC (P = .015) were each significantly associated with pCR in univariate analysis. In multivariate analysis, patients younger than 55 years at time of diagnosis (vs age > 55 years) and those completing at least 8 cycles of pembro remained predictive of pCR (OR's 2.50, 2.49, P = .035 and .037, respectively).

CONCLUSIONS

In this real-world analysis of patients with TNBC treated with NAC plus pembro, younger age and the completion of at least 8 cycles of pembrolizumab were associated with pCR.

Outcome prioritization and preferences among older adults with cancer starting chemotherapy in a randomized clinical trial

INTRODUCTION

Older adults with cancer facing competing treatments must prioritize between various outcomes. This study assessed health outcome prioritization among older adults with cancer starting chemotherapy.

METHODS

Secondary analysis of a randomized trial addressing vulnerabilities in older adults with cancer. Patients completed three validated outcome prioritization tools: 1) Health Outcomes Tool: prioritizes outcomes (survival, independence, symptoms) using a visual analog scale; 2) Now vs. Later Tool: rates the importance of quality of life at three times-today versus 1 or 5 years in the future; and 3) Attitude Scale: rates agreement with outcome-related statements. The authors measured the proportion of patients prioritizing various outcomes and evaluated their characteristics.

RESULTS

A total of 219 patients (median [range] age 71 [65-88], 68% with metastatic disease) were included. On the Health Outcomes Tool, 60.7% prioritized survival over other outcomes. Having localized disease was associated with choosing survival as top priority. On the Now vs. Later Tool, 50% gave equal importance to current versus future quality of life. On the Attitude Scale, 53.4% disagreed with the statement "the most important thing to me is living as long as I can, no matter what my quality of life is"; and 82.2% agreed with the statement "it is more important to me to maintain my thinking ability than to live as long as possible".

CONCLUSION

Although survival was the top priority for most participants, some older individuals with cancer prioritize other outcomes, such as cognition and function. Clinicians should elicit patient-defined priorities and include them in decision-making.

A phase I study of Mirvetuximab Soravtansine and gemcitabine in patients with FRα-positive recurrent ovarian, primary peritoneal, fallopian tube, or endometrial cancer, or triple negative breast cancer

OBJECTIVE

Platinum-resistant epithelial ovarian cancer (EOC), recurrent endometrial cancer (EC), and triple negative breast cancer (TNBC) are difficult to treat after failing standard therapies. This phase I study evaluated mirvetuximab soravtansine (MIRV) and gemcitabine in patients with recurrent FRα-positive EOC, EC, or TNBC to determine the maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D) (primary endpoint).

METHODS

FRα-positive patients with platinum-resistant EOC, EC, or TNBC with ≤4 prior chemotherapy regimens (2 for EC) were enrolled. FRα expression requirement varied among eligible tumors and changed during the study.

RESULTS

Twenty patients were enrolled; 17 were evaluable for DLT. Half the patients received ≥3 prior chemotherapy lines. Most EOC and EC patients (78%) were medium (50-74%) or high(75-100%) FRα expressors. TNBC patients were low (25-49%) FRα expressors. The MTD/RP2D was MIRV 6 mg/kg AIBW D1 and gemcitabine 800 mg/m2 IV, D1 and D8, every 21 days (Dose Level [DL] 3), where 5/7 patients demonstrated a partial response (PR) as their best response, including 2 confirmed ovarian responses whose time-to-progression and duration of response were 7.9/5.4 and 8.0/5.7 months respectively. Most common treatment-related adverse events at MTD were anemia and neutropenia (3/7 each, 43%), diarrhea, hypophosphatemia, thrombocytopenia, and leukopenia (2/7 each, 29%). DLTs were thrombocytopenia (DL1), oral mucositis (DL4) and diarrhea (DL4). Nine of 20 patients (45%; 95% CI: 21.1-68.9%) achieved PR as their best response, with 3/20 patients or 15% (95%CI, 0-32.1%) confirmed PR.

CONCLUSION

MIRV and gemcitabine demonstrate promising activity in platinum resistant EOC at RP2D, but frequent hematologic toxicities.

Bilateral Oophorectomy and Colorectal Cancer Incidence and Mortality in the Women's Health Initiative

BACKGROUND

The few cohort studies examining oophorectomy and colorectal cancer risk provide mixed results. Therefore, we examined this issue in Women's Health Initiative Observational Study participants.

METHODS

A total of 71,312 postmenopausal women were followed for 22.1 years (median). At enrollment, 55,643 (78%) had intact ovaries and 15,669 (22%) had undergone a bilateral oophorectomy. Colorectal cancers were verified by central medical record review with mortality findings enhanced by National Death Index queries.

RESULTS

With 1,421 incident colorectal cancers, 450 colorectal cancer-specific mortalities, after controlling for covariates, bilateral oophorectomy was not associated with colorectal cancer incidence or colorectal cancer mortality.

CONCLUSIONS

No significant associations between oophorectomy and colorectal cancer incidence and mortality were seen in a large cohort study with long follow-up.

IMPACT

As the oophorectomy and colorectal cancer question remains open, further studies of high quality, even with null findings, should be encouraged.

Inflammation-related proteins as biomarkers of treatment-related behavioral symptoms: A longitudinal study of breast cancer patients and age-matched controls

Background

Behavioral symptoms in breast cancer (BC) survivors have been attributed to cancer treatment and resulting inflammation. However, studies linking behavioral symptoms to BC treatment have observed patients only after some treatment. Our prospective study with pre-treatment baseline investigates post-treatment changes in inflammation-related biomarkers and whether those changes correlate with changes in symptoms.

Methods

Participants were postmenopausal women, newly-diagnosed with stage 0-3 BC before any treatment (n = 173 "patients"), and age-matched women without cancer (n = 77 "controls"), who were assessed on plasma markers [soluble tumor necrosis factor receptor type 2 (sTNF-RII), interleukin (IL)-6, IL-1 receptor antagonist (IL-1RA), C-reactive protein (CRP)]) and symptoms (Physical Functioning, Pain, Attention/concentration, Perceived Cognitive Problems, Fatigue, Sleep Insufficiency, Depression). Participants were assessed again 1 month, 1 year, and 2 years after completing primary treatment or similar interval in controls. Generalized linear mixed models tested 4 treatments (surgery alone or with chemotherapy, radiation, or both) for association with change per marker. Joint models tested change per marker for association with change per symptom. Models considered demographic, socioeconomic, and clinical covariates. False Discovery Rate method controlled risk of error from multiple hypotheses.

Results

At one month post-completion of treatment, sTNF-RII and IL-6 were elevated by all BC treatments, as were IL-1RA and CRP after surgery alone (all, p < 0.05). By 1 year, markers' average values returned to baseline. Throughout 2-year follow-up, increase-from-baseline in sTNF-RII, IL-1RA, and IL-6 coincided with worsened Physical Functioning, and increase-from-baseline in sTNF-RII coincided with increased Pain (all, p < 0.01). These biomarker-symptom associations (excepting IL-6) were exclusive to patients. No other symptoms worsened, and baseline Fatigue and Depression improved in all participants.

Conclusions

BC treatment, even surgery, is associated with transient elevation in inflammatory markers. In patients post-treatment, increase-from-baseline in sTNF-RII accompanies increased Pain and decreased Physical Functioning, suggesting that sTNF-RII merits development as a clinical biomarker in BC patients.

Predicting All-Cause Mortality in Women With and Without Breast Cancer Using the Schonberg Index: A Women's Health Initiative Study

BACKGROUND

When treating older women with breast cancer, life expectancy is an important consideration. ASCO recommends calculating 10-year mortality probabilities to inform treatment decisions. One useful tool is the Schonberg index, which predicts risk-based all-cause 10-year mortality. We investigated the use of this index in women aged ≥65 years with breast cancer in the Women's Health Initiative (WHI).

METHODS

We calculated 10-year mortality risk scores for 2,549 WHI participants with breast cancer ("cases") and 2,549 age-matched breast cancer-free participants ("controls") using Schonberg index risk scoring. Risk scores were grouped into quintiles for comparisons. Risk-stratified observed mortality rates and 95% confidence intervals were compared across cases and controls. Observed 10-year mortality rates in cases and controls were also compared with Schonberg index-based predicted 10-year mortality rates.

RESULTS

Compared with controls, cases were more often white (P=.005), had higher income and education levels (P<.001 for both), more often lived with their husband/partner (P<.001), scored higher on subjective health/happiness (P<.001), and needed less assistance in activities of daily living (P<.001). Participants with breast cancer had similar risk-stratified 10-year mortality rates compared with controls (34% vs 33%, respectively). Stratified results showed that cases had slightly higher mortality rates than controls in the lowest risk quintile and lower mortality rates in the 2 highest risk quintiles. Observed mortality rates in cases and controls were similar to Schonberg index-predicted mortality, with model c-indexes of 0.71 and 0.76, respectively.

CONCLUSIONS

Among women aged ≥65 years with incident breast cancer, the Schonberg index-based risk-stratified 10-year mortality rates were similar to those in women without breast cancer, demonstrating a similar performance of the index among both populations. Along with other health measures, prognostic indexes can help predict survival among older women with breast cancer and support geriatric oncology guidelines that promote using life expectancy calculation tools for shared decision-making.

NCCN Guidelines® Insights: Breast Cancer, Version 4.2023

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer address all aspects of management for breast cancer. The treatment landscape of metastatic breast cancer is evolving constantly. The therapeutic strategy takes into consideration tumor biology, biomarkers, and other clinical factors. Due to the growing number of treatment options, if one option fails, there is usually another line of therapy available, providing meaningful improvements in survival. This NCCN Guidelines Insights report focuses on recent updates specific to systemic therapy recommendations for patients with stage IV (M1) disease.

The Challenges of Treating Patients with Breast Cancer and Obesity

Obesity is defined as a body mass index (BMI) of 30 kg/m² or more and is associated with worse outcomes in patients with breast cancer, resulting in an increased incidence of breast cancer, recurrence, and death. The incidence of obesity is increasing, with almost half of all individuals in the United States classified as obese. Patients with obesity present with unique pharmacokinetics and physiology and are at increased risk of developing diabetes mellitus and cardiovascular disease, which leads to specific challenges when treating these patients. The aim of this review is to summarize the impact of obesity on the efficacy and toxicity of systemic therapies used for breast cancer patients, describe the molecular mechanisms through which obesity can affect systemic therapies, outline the existing American Society of Clinical Oncology (ASCO) guidelines for treating patients with cancer and obesity, and highlight additional clinical considerations for treating patients with obesity and breast cancer. We conclude that further research on the biological mechanisms underlying the obesity-breast cancer link may offer new treatment strategies, and clinicals trials that focus on the treatment and outcomes of patients with obesity and all stages of breast cancer are needed to inform future treatment guidelines.

Predicting Hyperglycemia Among Patients Receiving Alpelisib Plus Fulvestrant for Metastatic Breast Cancer

BACKGROUND

Hyperglycemia is recognized as a common adverse event for patients receiving alpelisib but has been little studied outside of clinical trials. We report the frequency of alpelisib-associated hyperglycemia in a real-world setting and evaluate proposed risk factors.

PATIENTS AND METHODS

We retrospectively identified patients with PIK3CA-mutated, hormone receptor-positive, metastatic breast cancer who initiated treatment with alpelisib plus fulvestrant between August 2019 and December 2021. Ordinal logistic regression evaluated 5 characteristics (diabetes, prediabetes, body mass index [BMI], age, and Asian ancestry) as independent risk factors for ALP-associated hyperglycemia grades 2-4. Risk of error from multiple hypothesis testing was controlled using the false discovery rate method.

RESULTS

The study included n = 92 subjects, all but 1 female, mean age 59.9 (+11.9) years with 50% non-Hispanic White, 15% Hispanic/Latino, 13% Asian, 9% African/Black, and 13% other/unknown. In total 34% of patients had diabetes, 10% had pre-diabetes, and 56% had normoglycemia. Thirty-six percent were obese, 32% were overweight, 25% were normal weight, and 7% were lean. Frequency of grades 1-4 hyperglycemia in current subjects (64.1%) was similar to hyperglycemia reported in the SOLAR-1 trial (63.7%). Our subjects' risk of grades 2-4 hyperglycemia was independently increased by pre-existing diabetes (Odds ratio 3.75, 95% CI, 1.40-10.01), pre-diabetes (6.22, 1.12-34.47), Asian ancestry (7.10, 1.75-28.84), and each unit of BMI above 20 (1.17, 1.07-1.28).

CONCLUSION

While receiving alpelisib, patients of Asian ancestry, as well as patients with pre-existing hyperglycemia and/or BMI above 20, should be closely monitored for hyperglycemia. The mechanism underlying the current association of alpelisib-associated hyperglycemia with Asian ancestry is independent of BMI and merits further study. The high incidence of hyperglycemia resulted in a change in practice to include consultation with a diabetes nurse educator or endocrinologist at the start of alpelisib.

Abstract OT2-01-06: Phase II trial of palbociclib plus endocrine therapy followed by combination of pembrolizumab, palbociclib and endocrine therapy in patients with hormone receptor positive metastatic breast cancer

Background: The combination of CDK4/6 inhibitors (CDK4/6i) and endocrine therapy (ET) is standard-of-care for patients with hormone receptor positive (HR+) HER2- metastatic breast cancer (MBC). Immune modulatory effects of CDK4/6i are well documented preclinically but poorly understood in the clinical setting. Our previous study combining letrozole, palbociclib and pembrolizumab in patients with HR+ MBC (NCT02778685) showed a promising complete response rate of 31%. Dynamic changes in peripheral blood mononuclear cell (PBMC) subpopulations indicated that palbociclib may increase CD8+ TEMRA (terminally differentiated effector memory cells) and CD4+ TEM (effector memory cells) and enable immune activation. The current cohort 3 was designed to study the immune modulatory effect of palbociclib as an immune-priming agent with a biomarker enriched design. Methods: Women with ECOG 0-1, HR+ HER2- MBC, RECIST 1.1 measurable disease, no prior therapy for MBC were enrolled. Patients with endocrine therapy, including aromatase inhibitor +/- ovarian suppression or fulvestrant, were eligible. A palbociclib + ET lead-in design was used, starting on day -28 followed by combination therapy with pembrolizumab added on C1D1. Peripheral blood and tumor biopsy at baseline and on-treatment were collected to allow in-depth analysis of biomarkers predicting response to the combination. The primary endpoint was to evaluate if the palbociclib potentiated immune responses as a “priming” agent through PBMC analysis and on treatment tumor biopsy. Secondary endpoints included other immune cell subsets and changes that follow the combination with pembrolizumab. With 25 patients, assuming a standard deviation of 0.51 in the relative change in classic monocytes in PBMCs, there is 90% power to detect a relative change of log(C1D1/baseline) of 34.5% with a type I error (two-sided) of 0.05. Results: Between August 2020 and April 2022, 16 patients were enrolled in cohort 3. Currently 11 patients have adverse event (AEs) and 16 patients have response data. Median age was 57 years (39-72). 8/11 (73%) were non-Hispanic white, 1/11 (9%) Hispanic, 1/11 (9%) Asian, and 1/11 (9%) African American. 87% patients had grade 3 AEs, and 30% had grade 4 AEs. Grade 3 AEs were 9/11 (82%) neutropenia, 5/11 (45%) leukopenia, 1/11 (9%) elevated LFTs, and 1/11 (9%) each lymphopenia, hot flashes, febrile neutropenia, and pneumonitis. Grade 4 AEs were 1/11 (9%) lymphopenia. 8/16 (50%) patients achieved a partial response (PR), 5/16 (31%) had stable disease (SD), and 1/16 (6%) had progression of disease (PD) by RECIST 1.1. Additionally, 2/16 (13%) patients were too early to determine best overall response. Response rate (CR+PR) was 50%. PBMCs and tumor microenvironment profiling are ongoing. Conclusion: The combination of palbociclib, pembrolizumab and ET is well tolerated, and a response rate of 50% was identified in HR+ MBC patients who received this combination as front-line therapy. Dynamic changes in peripheral blood mononuclear cells and tumor microenvironment profiling are ongoing.

Citation Format: Yuan Yuan, Colt A. Egelston, Weihua Guo, Susan E. Yost, Paul H. Frankel, Christopher Ruel, Mireya Murga, Aileen Tang, Norma Martinez, Daniel Schmolze, Daphne Stewart, James Waisman, Kelly Yap, Joanne Mortimer, Niki Tank. Phase II trial of palbociclib plus endocrine therapy followed by combination of pembrolizumab, palbociclib and endocrine therapy in patients with hormone receptor positive metastatic breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT2-01-06.

Phase 2 prospective open label study of neoadjuvant nab-paclitaxel, trastuzumab, and pertuzumab in patients with HER2-positive primary breast cancer

BACKGROUND

The objective of this study was to evaluate the safety and efficacy of nab-paclitaxel, trastuzumab, and pertuzumab as neoadjuvant therapy (NAT) in patients with human epidermal growth factor receptor 2 HER2+ breast cancer (HER2+ BC) to determine pathologic complete response (pCR), invasive disease-free survival (iDFS), and overall survival.

METHODS

Forty-five patients with HER2+ BC Stages II-III were to be enrolled from 2013 to 2017. Patients were treated with weekly nab-paclitaxel (100 mg/m² intravenously), weekly trastuzumab (4 mg/kg loading dose, then 2 mg/kg), and six cycles of pertuzumab (840 mg loading dose, then 420 mg intravenously day 1 every 21 days).

RESULTS

Median follow-up was 60 months (95% CI, 32.3-55.6) and pCR was 29/45 (64%). The 5-year iDFS for patients who achieved pCR (N = 29) was 96.3% (95% CI, 76.5-99.5) and non-pCR patients (N = 16) was 74.3% (95% CI, 39.1-91.0). The 5-year overall survival (N = 45) was 94.1% (95% CI, 77.6-98.5). Based on hormonal status, the 5-year iDFS for HR+ pCR patients (N = 14) was 92.3% (95% CI, 56.6-98.9) and for HR- (N = 15) was 100% (p = .3).

CONCLUSIONS

This anthracycline/carboplatin-free regimen with nab-paclitaxel achieved a pCR rate of 64% in patients with HER2+ BC. The 5-year iDFS in patients with and without pCR was 96.3% and 74.3%, respectively. The pCR rate is comparable with docetaxel, carboplatin, trastuzumab, and pertuzumab therapy in the NAT setting, but with fewer treatment-associated toxicities. This finding suggests the possibility of safe avoidance of anthracyclines and carboplatin as components of NAT in patients with HER2+ BC.

Summary: Appropriate Use Criteria for Estrogen Receptor-Targeted PET Imaging with 16α-18F-Fluoro-17β-Fluoroestradiol

PET imaging with 16α-¹⁸F-fluoro-17β-fluoroestradiol (¹⁸F-FES), a radiolabeled form of estradiol, allows whole-body, noninvasive evaluation of estrogen receptor (ER). ¹⁸F-FES is approved by the U.S. Food and Drug Administration as a diagnostic agent "for the detection of ER-positive lesions as an adjunct to biopsy in patients with recurrent or metastatic breast cancer." The Society of Nuclear Medicine and Molecular Imaging (SNMMI) convened an expert work group to comprehensively review the published literature for ¹⁸F-FES PET in patients with ER-positive breast cancer and to establish appropriate use criteria (AUC). The findings and discussions of the SNMMI ¹⁸F-FES work group, including example clinical scenarios, were published in full in 2022 and are available at https://www.snmmi.org/auc Of the clinical scenarios evaluated, the work group concluded that the most appropriate uses of ¹⁸F-FES PET are to assess ER functionality when endocrine therapy is considered either at initial diagnosis of metastatic breast cancer or after progression of disease on endocrine therapy, the ER status of lesions that are difficult or dangerous to biopsy, and the ER status of lesions when other tests are inconclusive. These AUC are intended to enable appropriate clinical use of ¹⁸F-FES PET, more efficient approval of FES use by payers, and promotion of investigation into areas requiring further research. This summary includes the rationale, methodology, and main findings of the work group and refers the reader to the complete AUC document.

Abstract PD14-03: PD14-03 Reappraising the Fanconi Anemia DNA repair pathway in breast cancer risk and precision intervention: Insights and opportunities from the City of Hope INSPIRE study

Background: Fanconi Anemia (FA) proteins facilitate homologous recombination (HR)-mediated repair of DNA interstrand cross-links. Germline monoallelic, pathogenic/likely pathogenic (P/LP) variants in the highly-penetrant (HP) breast cancer (BC) FA genes, BRCA1 (FANCS), BRCA2 (FANCD1) and PALB2 (FANCN)), compromise HR and predispose to hereditary BC. The effects of monoallelic, pathogenic variants in other non-HP BC FA genes upon HR and BC predisposition remain less understood. In this investigation we report the germline mutational landscape of FA gene P/LP variants and somatic molecular consequences of patients with BC diagnoses from City of Hope’s (COH) INSPIRE (Implementing Next-generation Sequencing for Precision Intervention and Risk Evaluation) study.

Methods: COH-INSPIRE is a universal access study open to all patients at COH with a personal and/or family history of cancer. Patients undergo custom panel-based germline genetic testing to detect P/LP single nucleotide variants (SNVs), short insertions/deletions (indels) and exon-level deletions/duplications in 155 cancer-predisposition genes including the HP BC FA genes and 15 non-HP BC FA genes [FANCA, FANCB, FANCC, FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ (BRIP1), FANCL, FANCM, FANCO (RAD51C), FANCP (SLX4), FANCQ (ERCC4) and FANCU (XRCC2)]. Patients’ tumor specimens undergo somatic tumor (&gt;400X)-normal (&gt;180X) whole exome and transcriptome sequencing (&gt;50 million reads). Somatic sequencing identifies P/LP SNVs, indels, copy number events, and fusions. Secondary analyses assessed somatic homologous recombination deficiency (HRD) by examining tumor mutational signatures, as well as an ensemble HRD score derived by combining individual genomic loss of heterozygosity, telomeric allelic imbalance and large-scale molecular transition scores. Reference comparison of germline and somatic features to current FDA therapeutic guidelines and NIH clinical trials registrations determined eligibility for precision therapeutic intervention and clinical trial enrollment.

Results: Of 7,584 patients enrolled in COH-INSPIRE, 1,651 (21.8%) patients had a BC diagnosis. Germline panel testing of BC patients identified 204 (12.4%) with germline P/LP variant in a FA gene. Greater than one third of FA gene-altered BC patients (37.7%) carried a P/LP variant in a non-HP BC FA gene. We observed that BC patients with a non-HP BC FA gene variant may demonstrate HR compromise as evidenced by presence of a Signature 3 mutational profile or an elevated combined HRD score (&gt; 33 and/or &gt; 42). (Table 1) Further, we identified ostensible segregation of triple negative BC in a family harboring a germline pathogenic variant in FANCG. With regard to precision clinical actionability (i.e. qualification for targeted therapeutic intervention [PARP inhibitor (PARPi)] and/or clinical trial) for patients with advanced stage BC: All patients with germline P/LP HP BC FA gene variant and 20.7% (N=16) of patients with a P/LP FA non-HPBC FA gene variant met criteria for treatment with on/off-label PARPi. 100% of patients with advanced BC with germline P/LP HP BC or non-HPBC FA gene variant qualified for a clinical trial.

Conclusions: Patients with BC often carry a germline monoallelic, P/LP FA gene variant; in more than one third, the FA gene alteration occurs in a non-HP BC FA gene. BC patients harboring a monoallelic germline non-HP BC P/LP FA gene may exhibit somatic mutational signatures and HRD scoring consistent with compromise of HR. Somatic tumor evaluation of BC patients with germline P/LP non-HP BC FA gene variants expands opportunities for precision therapeutic intervention and clinical trial enrollment. Continued appraisal will clarify emerging questions of germline non-HP P/LP FA gene-associated autosomal dominant BC risk and management as well as facilitate optimization of precision BC care.

Table 1 Summary Molecular Features of BC patients with P/LP Variants in FA gene from COH-INSPIRE

Citation Format: Laura Kruper, Kevin McDonnell, Joseph Bonner, Kevin K. Tsang, Veronica Jones, Joanne Mortimer, Sidney S. Lindsey, Ilana Solomon, Heather Hampel, Wai Park, Gregory E. Idos, Stacy Gray, Stephen Gruber. PD14-03 Reappraising the Fanconi Anemia DNA repair pathway in breast cancer risk and precision intervention: Insights and opportunities from the City of Hope INSPIRE study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD14-03.

Abstract P1-05-03: Prevalence of BRCA1/2 mutations in an underrepresented population of women with breast cancer: Observations from the City of Hope INSPIRE study

Table 1. Incidence of BRCA 1 and 2 mutations by Race and Ethnicity BRCA1 BRCA2 BRCA1 or 2 VUS/Negative Native American 0 1 1 6 Asian 2 3 5 150 Black/African American 3 2 5 48 Native Hawaiian or Pacific Islander 0 0 0 5 Other 1 1 1* 26 White 25 17 42 688 Unknown 0 0 0 20 Declined 1 0 1 24 TOTAL 32 24 55 967 * Patient had both BRCA1 and BRCA2 mutations

Citation Format: Joanne Mortimer, Sidney S. Lindsey, Ilana Solomon, Wai Park, Duveen Sturgeon, Kathleen Blazer, Stacy Gray, Joseph Bonner, Xiaoyu Xia, Stephen Gruber. Prevalence of BRCA1/2 mutations in an underrepresented population of women with breast cancer: Observations from the City of Hope INSPIRE study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-05-03.

Molecular Assessment of HER2 to Identify Signatures Associated with Therapy Response in HER2-Positive Breast Cancer

Simple Summary

The HER2 status of breast cancers is accurately determined by measuring HER2 protein overexpression and gene amplification. However, these clinical diagnostic tests cannot predict the response to therapy. Single molecule imaging approaches can quantify molecular features of HER2, such as receptor nano-organization, with exquisite spatial resolution and sensitivity. The aim of our study was to assess how the molecular features of HER2 varied with the therapy response. According to our results in cultured cell lines and six patient specimens, the therapy response was associated with high detected HER2 densities and clustering. This advanced imaging approach can thus provide key data to complement the current diagnostic standards.

Abstract

Trastuzumab, the prototype HER2-directed therapy, has markedly improved survival for women with HER2-positive breast cancers. However, only 40–60% of women with HER2-positive breast cancers achieve a complete pathological response to chemotherapy combined with HER2-directed therapy. The current diagnostic assays have poor positive-predictive accuracy in identifying therapy-responsive breast cancers. Here, we deployed quantitative single molecule localization microscopy to assess the molecular features of HER2 in a therapy-responsive setting. Using fluorescently labeled trastuzumab as a probe, we first compared the molecular features of HER2 in trastuzumab-sensitive (BT-474 and SK-BR-3) and trastuzumab-resistant (BT-474^R and JIMT-1) cultured cell lines. Trastuzumab-sensitive cells had significantly higher detected HER2 densities and clustering. We then evaluated HER2 in pre-treatment core biopsies from women with breast cancer undergoing neoadjuvant therapy. A complete pathological response was associated with a high detected HER2 density and significant HER2 clustering. These results established the nano-organization of HER2 as a potential signature of therapy-responsive disease.

Breast Cancer, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

The therapeutic options for patients with noninvasive or invasive breast cancer are complex and varied. These NCCN Clinical Practice Guidelines for Breast Cancer include recommendations for clinical management of patients with carcinoma in situ, invasive breast cancer, Paget disease, phyllodes tumor, inflammatory breast cancer, and management of breast cancer during pregnancy. The content featured in this issue focuses on the recommendations for overall management of ductal carcinoma in situ and the workup and locoregional management of early stage invasive breast cancer. For the full version of the NCCN Guidelines for Breast Cancer, visit NCCN.org.

Cancer-cell-secreted extracellular vesicles suppress insulin secretion through miR-122 to impair systemic glucose homeostasis and contribute to tumour growth

Epidemiological studies demonstrate an association between breast cancer (BC) and systemic dysregulation of glucose metabolism. However, how BC influences glucose homeostasis remains unknown. We show that BC-derived extracellular vesicles (EVs) suppress pancreatic insulin secretion to impair glucose homeostasis. EV-encapsulated miR-122 targets PKM in β-cells to suppress glycolysis and ATP-dependent insulin exocytosis. Mice receiving high-miR-122 EVs or bearing BC tumours exhibit suppressed insulin secretion, enhanced endogenous glucose production, impaired glucose tolerance and fasting hyperglycaemia. These effects contribute to tumour growth and are abolished by inhibiting EV secretion or miR-122, restoring PKM in β-cells or supplementing insulin. Compared with non-cancer controls, patients with BC have higher levels of circulating EV-encapsulated miR-122 and fasting glucose concentrations but lower fasting insulin; miR-122 levels are positively associated with glucose and negatively associated with insulin. Therefore, EV-mediated impairment of whole-body glycaemic control may contribute to tumour progression and incidence of type 2 diabetes in some patients with BC.

Understanding drivers of the Black:White breast cancer mortality gap: A call for more robust definitions

Kim et al completed a pooled analysis of 8 National Surgical Adjuvant Breast and Bowel Project trials and highlight that, when compared with White patients, Black patients with estrogen receptor–positive (ER+) breast cancer have worse distant recurrence‐free survival, especially in the setting of neoadjuvant chemotherapy when pathologic complete response is not achieved. This editorial highlights that, to comprehend the drivers of this disparity, we must have more robust definitions of ER+ breast cancer and race.

The relationship between sleep and weight change among women diagnosed with breast cancer participating in the Women's Health Initiative

PURPOSE

Short and long sleep duration and poor sleep quality are risk factors for weight gain and cancer mortality. The purpose of this study is to investigate the relationship between sleep and weight change among postmenopausal breast cancer survivors.

METHODS

Women participating in the Women's Health Initiative who were diagnosed with incident breast cancer between year one and year three were included. Self-reported sleep duration was categorized as ≤ 5 h (short), 6 h, 7-8 h (optimal), and ≥ 9 h (long). Self-reported sleep quality was categorized as poor, average, and above average. Post-diagnosis weight change was the difference of weight closest to, but preceding diagnosis, and year 3 weight. We used linear regression to evaluate sleep duration and sleep quality associations with post-diagnosis weight change adjusted for potential confounders.

RESULTS

Among 1156 participants, 63% were weight stable after diagnosis; average weight gain post cancer diagnosis was 3.2 kg. Six percent of women reported sleeping ≤ 5 h, 26% reported 6 h, 64% reported 7-8 h, and 4% reported ≥ 9 h. There were no differences in adjusted estimates of weight change among participants with short duration (0.37 kg; 95% CI - 0.88, 1.63), or long duration (- 0.56 kg; 95% CI - 2.03, 0.90) compared to optimal duration, nor was there a difference among poor quality (- 0.51 kg; 95% CI - 1.42, 0.41) compared to above average quality.

CONCLUSION

Among postmenopausal breast cancer survivors, sleep duration and quality were not associated with weight change after breast cancer diagnosis. Future studies should consider capturing change in adiposity and to expand beyond self-reported sleep.

Abstract P1-17-02: ZN-c5, an oral selective estrogen receptor degrader (SERD), in women with advanced estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer

Background: Hormone receptor+/HER2- breast cancer is the most common subtype of breast cancer. Resistance to endocrine therapy is a major clinical challenge. Although fulvestrant binds and degrades the ER and shows anti-tumor activity in patients with advanced breast cancer, intramuscular injection is inconvenient and precludes achievement of higher and potentially more efficacious exposure. ZN-c5 is a novel, orally bioavailable SERD with high potency and has demonstrated activity in estrogen-dependent tumor models. Methods: This Phase 1/2, open-label, multicenter study is evaluating the safety, pharmacokinetics and preliminary anti-tumor activity of ZN-c5 as monotherapy or in combination with palbociclib. In the Phase 1 portion evaluating ZN-c5 as monotherapy, participants were adult, post-menopausal (or receiving a gonadotropin-releasing hormone agonist) women with advanced adenocarcinoma of the breast, ER+/HER2- disease, and sensitive to endocrine therapy for metastatic disease (partial response [PR], complete response or stable disease [SD] lasting &gt; 6 months or disease recurrence after at least 24 months of adjuvant endocrine treatment). ZN-c5 was administered orally and continuously in 28-day cycles until disease progression or unacceptable toxicity. Dose escalation cohorts of subjects were enrolled at several dose levels of ZN-c5, based on a modified 3+3 design. Enrollment in the Phase 1 ZN-c5 monotherapy dose escalation and expansion has been completed and results are presented. Phase 1 testing of ZN-c5 in combination with palbociclib and Phase 2 testing in monotherapy are ongoing and will be presented at a future meeting. Results: In Phase 1 monotherapy, a total of 56 female subjects were enrolled to receive ZN-c5 at dose levels of 50 mg once daily (QD, n=16), 75 mg QD (n=3), 100 mg QD (n=3), 75 mg twice daily (BID, n=6), 150 mg QD (n=15), 150 mg BID (n=3), or 300 mg QD (n=10). Median age was 58.5 years (range, 38 - 89) and ECOG performance status was 0 (55%) or 1 (45%). Subjects had a median of 2 prior therapies for advanced/metastatic disease (range, 0 - 9), with a median of 2 prior hormonal-based therapies (range, 0 - 6) and a median of 0 prior chemotherapies (range, 0 - 3). Twenty-six subjects (46%) received prior fulvestrant and 38 (68%) received a prior CDK4/6 inhibitor. Twenty subjects (38%) had a baseline ESR1 mutation. The cut-off date for this analysis was 11 May 2021. There was no increase in severity of treatment-emergent adverse events (TEAEs) with increase in dose level. No dose-limiting toxicities were reported. The most common TEAEs were nausea (30%), fatigue (25%), and arthralgia (20%). Grade 3 TEAEs reported in &gt; 1 subject were gamma-glutamyltransferase (GGT) increased and hyponatremia (2 subjects each); no Grade 4 TEAEs were reported. Among treatment-related events, the most common were hot flushes and nausea (14% each); the only Grade 3 events were GGT increased and hypersensitivity in 1 subject each. ZN-c5 was rapidly absorbed, with a median Tmax of 2 to 4 hours. AUC and Cmax on Days 1 and 15 were less than dose proportional. No ZN-c5 accumulation after 15 days of dosing was observed. Confirmed PRs have been observed in 2 subjects (at 150 and 300 mg QD, respectively), and 14/45 (31%) evaluable subjects have experienced clinical benefit (PR or SD ≥ 24 weeks). Five of the 14 subjects with long SD received prior fulvestrant. Median progression-free survival (PFS) was 3.8 months (95% CI: 3.2, 5.3). Conclusions: In this first-in-human study, ZN-c5 monotherapy was well tolerated and showed clinical benefit, including confirmed PRs, in subjects with advanced ER+/HER2- breast cancer. These data warrant further evaluation of ZN-c5 as monotherapy and in combination with palbociclib.

Citation Format: Kevin Kalinksy, Vandana Abramson, Pavani Chalasani, Hannah M. Linden, Jasmina Alidzanovic, Rachel M. Layman, Živko Vranješ, Julie R. Nangia, Katherine D. Crew, Zoran Andric, Marijana Milovic-Kovacevic, Jasna Trifunovic, Jose Suarez, Matt Suster, Mieke Ptaszynski, Joanne Mortimer. ZN-c5, an oral selective estrogen receptor degrader (SERD), in women with advanced estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer [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 P1-17-02.

Abstract P3-03-22: Use of 64Cu-DOTA trastuzumab positron emission tomography to predict pathologic complete response in locally advanced HER2 positive breast cancer

Use of 64Cu-DOTA trastuzumab Positron Emission Tomography to predict pathologic complete response in locally advanced HER2 positive breast cancer. Background: We have demonstrated that 64Cu-DOTA trastuzumab is an effective PET imaging agent of HER2 positive breast cancer and correlated with HER2 status by IHC. Methods: Patients with locally advanced breast cancer were eligible if they had biopsy confirmed HER2 + disease, locally advanced disease and were to be treated with neoadjuvant therapy. Pretreatment staging included a breast MRI, 18F-FDG-PET/CT and 64Cu-trastuzumab-PET/CT (64CuT-PET). Prior to injection of 64Cu-trastuzumab, patients received 50 mg of cold trastuzumab per our previously established protocol. 64CuT-PET was obtained at 21-25 h over fields of view chosen in reference to MRI. Uptake in lesions was measured in terms of body wt-normalized SUV. Lesions with intensity &gt; adjacent tissue were considered positive on PET. Breast MRI was obtained after 4 cycles of chemotherapy and preoperatively. Response to therapy was determined on the surgical specimen. Results: Eighteen women have completed study and are evaluable for treatment response. The median age was 56 years (Range 32-62); 5 were ER- and PR-; 13 ER+/- PR+. One patient had increased 64CuT-PET uptake at T4 which was not appreciated on conventional imaging and subsequent biopsy confirmed metastatic disease. She is included in the analysis as she ultimately underwent surgical management of the breast. Complete pathologic response was seen in 14/18 patients - 11/14 ER+/- PR + and 3/4 ER-/PR-. Four patient had residual disease at surgery; 3 of 4 were HER2 negative and 1 was HER2+. Uptake on 64CuT-PET correlated with increased uptake on 18F-FDG-PET. The ratio of 64CuT-PET: 18F-FDG-PET ≥ 0.7 was associated with complete pathologic response at surgery.Conclusions: The ratio of 64CuT-PET to 18F-FDG-PET ≥ 0.7 was associated with complete pathologic response in women undergoing neoadjuvant chemotherapy for locally advanced HER2+ breast cancer. Residual disease after HER2-directed therapy was frequently HER2 negative.

Citation Format: Joanne Mortimer, Russell Rockne, Jessica Liu, Yuan Yuan, Daphne Stewart, James Waisman, Paul Frankel, Laura Kruper, Vikram Adhikarla. Use of 64Cu-DOTA trastuzumab positron emission tomography to predict pathologic complete response in locally advanced HER2 positive breast cancer [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 P3-03-22.

Abstract P4-11-12: Integrating the patient and partner distress and perceptions about prognosis in women with metastatic breast cancer guides the medical oncology consultation

Methods: Women with metastatic breast cancer and their partners completed couples’ tailored biopsychosocial screening and alignment in perception of prognosis immediately before consultation with a Medical Oncologist. In addition, couples were offered a standardized couples’ session before the medical consultation, individual couples’ counseling, and a strengths-based group intervention. As a component of biopsychosocial screening, each patient and her partner were asked individually their understanding of prognosis. They were asked their perception of likelihood of cure with supporting text and percentages provided: 76-100%; 51-75%; 26-50%, or 0-25%. Results: To date 254 women were considered eligible for this program. Complete data for both partners is available on 205. All the patients had metastatic breast cancer prior to their Medical Oncology appointment. The average age of the patient was 54 years (Range 25-84) and 55 years (Range 26-84) for the partner. In the perception of prognosis, 48.7% of patients and their partner were aligned and 51.3% were misaligned. The patient was more likely to have considered their prognosis worse in 59% and the partner 41%. The most commonly endorsed distress items for the patient were: Worry about the future 61%; Side effects of treatment 60%; Fatigue 59%; How my family will cope 58%; and Sleeping 49%. Distress for the partner included: Feeling anxious or fearful 49%; Wanting to best help my partner 37% and Sleeping 37%. Both the patient and partner sought assistance with Understanding treatment options 73.6%; Feeling anxious or fearful 62.5%, Worry about the future 57.3% Fatigue 56.3%, and Pain 56.3%- Partner practical distress was significantly higher for those couples who were not in alignment, p&lt;.05. Conclusions: It is possible to openly ask patients and their partners about prognosis. In women with metastatic breast cancer, lack of alignment with understanding prognosis was common with the patient being more likely to have realistic expectations than their partner. A better understanding of the patient/partner’s expectations about treatment outcome has the potential to guide the Medical Oncologist to individualize communications including discussion about goals of care.

Citation Format: Joanne Mortimer, James Waisman, Yuan, Sayeh Lavasani, Daphne Stewart, Mina Sedrak, Niki Patel, Courtney Bitz, Karen Clark, Marianne Razavi, Matthew J Loscalzo. Integrating the patient and partner distress and perceptions about prognosis in women with metastatic breast cancer guides the medical oncology consultation [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 P4-11-12.

Abstract P5-13-35: Mechanisms of CDK4/6 inhibitor resistance in hormone receptor positive metastatic breast cancer: Single institution retrospective analysis

Background: Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) are the standard of care for hormone receptor positive (HR+) metastatic breast cancer (MBC). Mechanisms of intrinsic and acquired resistances have been proposed but are poorly understood in the real-world setting. The current study aims to study the association of genomic biomarkers and CDK 4/6i resistance mechanisms utilizing genomic data acquired through routine clinical practice. Methods: Tumor genomic data from patients with HR+ MBC who received FDA-approved CDK4/6i (palbociclib, ribociclib, and abemaciclib) were obtained by chart review. Progression free survival (PFS) was determined from the first day of treatment until date of disease progression. Patients were divided by number of lines of treatment (first line vs. ≥ 2 lines of therapy) and subcategorized into early progressors (&lt; 6 months PFS), intermediate progressors (6-24 months PFS for first line and 6-9 months PFS for ≥ 2 lines of therapy), and late progressors (&gt;24 months PFS for first line and &gt; 9 months PFS for ≥ 2 lines of therapy). Genomic alterations from next-generation sequencing (NGS) were analyzed with PFS. PFS stratified by first vs. &gt;2 lines of treatment were performed using a Cox proportional hazards model with hazard ratios and 95% confidence intervals reported. Results: Among 795 patients with HR+ MBC treated with CDK 4/6i between 2015 and 2020 including 673 patients from a main campus and 122 patients from community sites, a total of 131 patients had genomic data available for the analysis. The obtaining rate of genomic data was 18% (122 out of 673 patients) from the main campus and 7% (9 out of 122 patients) from community sites. Seventy-one patients were treated with CDK4/6i as the first line of MBC, and 60 were treated as second or sequential lines. 35 patients had early progression, 40 patients had intermediate progression, 44 patients had late progression, and 12 patients were indeterminate. The distribution of genomic alterations was not significantly different between each group. The genomic alterations that were associated with impaired PFS were ZNF703(hazard ratio, HR 2.1, N=13), ERBB2 (HR 1.9, N=12), MDM2 (HR 3.3, N=6), PALB2 (HR 3.8, N=5), ARFRP1 (HR 3.1, N=4), FRS1 (HR 2.9, N=4), IRS2 (HR 6.9, N=2), and JAK2 (HR 6, N=2). RNA seq analysis is currently underway. Conclusion: Tumor genomic tests are not routinely performed for patients with HR+ MBC, particularly less performed from community practices. In this single institution retrospective analysis, we identified genomic alterations, such as ZNF703, ERBB2, PALB2, and MDM2, as potential resistance mechanisms of CDK4/6i. Tumor genomics through standard clinical practice are essential to understand resistance mechanisms to CDK4/6i.

Citation Format: Jin Sun Lee, Susan Yost, Yujie Cui, Paul Frankel, Sierra Min Li, Yate-Ching Yuan, Denise Morse, Judy Wong-Toh, Linda Bosserman, Joanne Mortimer, Yuan Yuan. Mechanisms of CDK4/6 inhibitor resistance in hormone receptor positive metastatic breast cancer: Single institution retrospective analysis [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 P5-13-35.

Abstract P2-10-04: Breast cancer risk assessment tool (BCRAT) predicted breast cancer incidence and breast cancer mortality in the women's health initiative

Purpose Commonly used breast cancer risk models estimate breast cancer incidence. However, such model performance, re-purposed to predict breast cancer mortality, are largely unknown. Therefore, we examined whether the BCRAT model predicts long-term breast cancer mortality in postmenopausal women in the WHI. Participants and Methods Of 161,808 WHI participants aged 50-79 years, after exclusions,145,408 were in the analysis. BCRAT risk was calculated, with incident breast cancers verified by central medical record review. Breast cancer mortality was related to BCRAT 5-year risk groups (&lt; 1%, 1-2.99%, ≥ 3%) using unadjusted Cox proportional hazard models and in age-stratified, multi-variable models. An addition analysis compared proportion of participants with BCRAT risk ≥ 1.67% and ≥ 3% (former and current prevention thresholds). Results Of 145,408 participants, the ≥1.67% and the ≥3.0% risk groups included 40% and 9% of participants, respectively. Compared to women with BCRAT&lt;1% risk, women with BCRAT ≥ 3% risk had more common breast cancer family history and lower BMI. After 20 years median follow-up, with 8,849 breast cancers and 1,076 deaths from breast cancer, risk of death from breast cancer in BCRAT risk group ≥ 3% was not higher compared to BCRAT risk group &lt;1%. (Hazard Ratio [HR] 1.06 95% Confidence Interval [CI] 0.80-1.40, P = 0.76). Similarly, risk of death from breast cancer in BCRAT risk group 1-2.99% was not higher compared to BCRAT risk group &lt;1 (HR 1.15 95% CI 0.93-1.43). Conclusions Current guideline recommendation for threshold for endocrine-targeted interventions substantially reduces postmenopausal prevention candidates from 40% to &lt;10%. The BCRAT prediction model, even at the ≥ 3% 5-year risk threshold, does not identify women at significantly increased risk of death from breast cancer.

Citation Format: Rebecca Nelson, Kathy Pan, Rowan Chlebowski, Thomas E Rohan, Joanne Mortimer, Jean Wactawski-Wende, Dorothy Lane, Laura Kruper. Breast cancer risk assessment tool (BCRAT) predicted breast cancer incidence and breast cancer mortality in the women's health initiative [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 P2-10-04.

Abstract P4-11-13: Prevalence of treatment-related symptoms in patients with breast cancer undergoing (neo)adjuvant endocrine therapy with or without chemotherapy for early stage breast cancer

Prevalence of treatment-related symptoms in patients with breast cancer undergoing (neo)adjuvant endocrine therapy with or without chemotherapy for early stage breast cancer. Background: Survivorship care plans require identification of post-treatment problems.Methods: After completion of (neo) adjuvant therapy and immediately prior to a survivorship visit which included a treatment summary and care planning, patients completed an automated tablet-based series of 25 biopsychosocial questions (Survivorship-SupportScreen). Problems were identified and rated on a Likert scale of 1-5. This analysis addresses the differences in patient reported symptoms in women treated with endocrine therapy (ET) alone compared to those receiving chemotherapy and ET (CT+ET). Results: 204 women with a mean age of 57.5 years at screening time (Range 27-90) completed the Survivorship-SupportScreen within a median of 0.9 years of initial diagnosis. The 113 patients receiving CT+ET were younger than the 91 treated with ET alone (Mean 54.83 versus 60.89, with p&lt;0.001) with no significant difference in time from first diagnosis to screening.

Prevalence of problems was similar for both groups, except for neuropathy (p&lt;0.001). By Logistic regression models neuropathy was 2.5 times more likely in patients treated with chemotherapy. Patients ≥ 50 years treated with CT+ET reported more hot flashes and lack of regular exercise: OR=2.18, p=0.024, and OR=2.04, p=0.033. Conclusions: We have demonstrated the feasibility of screening patient as they transition from active treatment to survivorship. Except for neuropathy, all patients receiving CT+ET had similar problems compared with those on ET alone. Women ≥ 50 years who received CT+ET, were more likely to report hot flashes and lack of regular exercise. Despite the fact that most of these women are likely cured of their cancer, the negative lingering sequelae of problem-related distress were reported by all patients.

CT+ETET alonepFatigue81/110 (73.64%)65/88 (73.86%)0.971Worry about recurrence77/113 (68.14%)60/91 (65.93%)0.739Sleeping70/112 (62.5%)51/91 (56.04%)0.351Not being physically active67/110 (60.9%)50/89 (56.18%)0.500Neuropathy64/113 (56.64%)29/91 (31.87%)&lt;0.001Pain62/112 (55.36%)43/90 (47.78%)0.284Hot flashes61/113 (53.98%)52/91 (57.14%)0.652Thinking clearly53/111 (47.75%)38/89 (42.7%)0.476Vaginal dryness47/113 (41.59%)31/91 (34.07%)0.271Gained weight45/113 (39.82%)34/91 (37.36%)0.720

Citation Format: Joanne Mortimer, Sharla Moore, Niki Patel, Mina Sedrak, Daphne Stewart, Yuan Yuan, James Waisman, Brittany Bradford, Matthew Loscalzo, Karen Clark, Marianne Razavi. Prevalence of treatment-related symptoms in patients with breast cancer undergoing (neo)adjuvant endocrine therapy with or without chemotherapy for early stage breast cancer [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 P4-11-13.

Cardiometabolic risk factors, physical activity, and postmenopausal breast cancer mortality: results from the Women's Health Initiative

BACKGROUND

Higher physical activity levels are associated with lower breast cancer-specific mortality. In addition, the metabolic syndrome is associated with higher breast cancer-specific mortality. Whether the physical activity association with breast cancer mortality is modified by number of metabolic syndrome components (cardiometabolic risk factors) in postmenopausal women with early-stage breast cancer remains unknown.

METHODS

Cardiovascular risk factors included high waist circumference, hypertension, high cholesterol, and diabetes. Breast cancers were verified by medical record review. Mortality finding were enhanced by serial National Death Index queries. Cox proportional hazards regression models were used to estimate associations between baseline physical activity and subsequent breast cancer-specific and overall mortality following breast cancer diagnosis in Women's Health Initiative participants. These associations were examined after stratifying by cardiometabolic risk factor group.

RESULTS

Among 161,308 Women's Health Initiative (WHI) participants, 8543 breast cancers occurred after 9.5 years (median) follow-up in women, additionally with information on cardiometabolic risk factors and physical activity at entry. In multi-variable analyses, as measured from cancer diagnosis, higher physical activity levels were associated with lower all-cause mortality risk (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.78-0.95, trend P < 0.001) but not with breast cancer-specific mortality (HR 0.85, 95% CI 0.70 to 1.04, trend P = 0.09). The physical activity and all-cause mortality association was not significantly modified by cardiometabolic risk factor number.

CONCLUSIONS

Among women with early-stage breast cancer, although higher antecedent physical activity was associated with lower risk of all-cause mortality, the association did not differ by cardiometabolic risk factor number.

A Cross-Sectional Study of Distress Levels in Patients with Newly Diagnosed Breast Cancer: The Impact of Race, Ethnicity, and Language Preference

PURPOSE

Our objective was to assess distress levels in female breast cancer patients as a function of race, ethnicity, and preferred language. We hypothesized minority patients and non-English screen-takers would report higher distress levels compared to English screen-takers and non-Hispanic whites.

METHODS

We conducted a retrospective observational study of female breast cancer patients at an NCI designated cancer center from 2009 to 2016 who were administered a validated biopsychosocial distress screening questionnaire. Self-reported data on race and ethnicity was collected.

RESULTS

A total of 3,156 patients were included in the analysis; mean age of 56.3 (SD 12.25) years. The racial/ethnic cohort distribution included 54% non-Hispanic white (NHW), 19% Hispanic, 16% Asian, 7% Black/African American, and 4% other. On multivariable analysis only Hispanic patients were significantly more likely to report overall distress compared to NHW (OR [1.39; CI [1.03-1.87; p=0.03). Asians were significantly less likely to report distress in the functional domain (OR 0.71, CI [0.58-0.88]; p=0.002), while Black patients were significantly more likely to report highest distress levels in the physical (OR 1.53, CI [1.11-2.12]; p=0.01) domain. Hispanic Spanish screen-takers reported significantly more distress compared to Hispanic English screen-takers across all four domains of distress (p<0.05 for all).

CONCLUSIONS

Top sources of distress in female breast cancer patients vary as a function of race, ethnicity, and preferred language. Future studies should focus on identifying effective, culturally appropriate targeted interventions to mitigate emotional distress levels in ethnic and racial minorities as well as non-English speaking patients with breast cancer.

Phase I/II trial of palbociclib, pembrolizumab and letrozole in patients with hormone receptor-positive metastatic breast cancer

BACKGROUND

CDK4/6 inhibitors modulate immune response in breast cancer. This phase I/II trial was designed to test the safety and efficacy of palbociclib, pembrolizumab and letrozole in women with hormone receptor positive (HR⁺) human epidermal growth factor receptor 2 negative (HER2^-) metastatic breast cancer (MBC).

PATIENTS AND METHODS

Women with stage IV HR⁺ HER2^- MBC were enrolled and treated with palbociclib, pembrolizumab and letrozole. Primary end-points were safety, tolerability and efficacy.

RESULTS

Between November 2016 and July 2020, 23 patients were enrolled with 20 evaluable for response, including 4 patients in cohort 1 and 16 patients in cohort 2. Cohort 1 median age was 48 years (33-70) and cohort 2 median age was 55 (37-75). Cohort 1 closed early due to limited accrual. Grade III-IV adverse events were neutropenia (83%), leucopaenia (65%), thrombocytopenia (17%) and elevated liver enzymes (17%). In cohort 1, 50% achieved a partial response (PR) and 50% had stable disease (SD). In cohort 2, 31% achieved complete response (CR), 25% had PR and 31% had SD by Response Evaluation Criteria in Solid Tumours version 1.1. Median progression-free survival was 25.2 months (95% confidence interval [CI] 5.3, not reached) and median overall survival was 36.9 months (95% CI 36.9, not reached) in cohort 2 with a median follow-up of 24.8 months (95% CI 17.1, not reached). A correlative immune biomarker analysis was published separately.

CONCLUSION

The combination of palbociclib, pembrolizumab and letrozole is well tolerated, and a complete response rate of 31% was identified in HR⁺ MBC patients who received this combination as front-line therapy. Confirmatory trials are required to better understand the immune-priming effects of CDK4/6 inhibitors.

Recall of genomic testing results among cancer patients

BACKGROUND

Genomic testing of somatic and germline DNA has transformed cancer care. However, low genetic knowledge among patients may compromise care and health outcomes. Given the rise in genomic testing, we sought to understand patients' knowledge of their genetic test results.

MATERIALS AND METHODS

We conducted a survey-based study with 85 patients at a comprehensive cancer center. We compared self-reported recall of 1) having had somatic/germline testing and 2) their specific somatic/germline results to the genomic test results documented in the medical record.

RESULTS

Approximately 30% of patients did not recall having had testing. Of those who recalled having testing, 44% of patients with pathogenic/likely pathogenic germline mutations and 57% of patients with reported somatic alterations did not accurately recall their specific gene or variant-level results.

CONCLUSION

Given significant knowledge gaps in patients' recall of genomic testing, there is a critical need to improve patient-directed education and return-of-results strategies.

Evaluation of Somatic Mutations in Solid Metastatic Pan-Cancer Patients

Metastasis continues to be the primary cause of all cancer-related deaths despite the recent advancements in cancer treatments. To evaluate the role of mutations in overall survival (OS) and treatment outcomes, we analyzed 957 metastatic patients with seven major cancer types who had available molecular testing results with a FoundationOne CDx® panel. The most prevalent genes with somatic mutations were TP53, KRAS, APC, and LRP1B. In this analysis, these genes had mutation frequencies higher than in publicly available datasets. We identified that the somatic mutations were seven mutually exclusive gene pairs and an additional fifty-two co-occurring gene pairs. Mutations in the mutually exclusive gene pair APC and CDKN2A showed an opposite effect on the overall survival. However, patients with CDKN2A mutations showed significantly shorter OS (HR: 1.72, 95% CI: 1.34-2.21, p < 0.001) after adjusting for cancer type, age at diagnosis, and sex. Five-year post metastatic diagnosis survival analysis showed a significant improvement in OS (median survival 28 and 43 months in pre-2015 and post-2015 metastatic diagnosis, respectively, p = 0.00021) based on the year of metastatic diagnosis. Although the use of targeted therapies after metastatic diagnosis prolonged OS, the benefit was not statistically significant. However, longer five-year progression-free survival (PFS) was significantly associated with targeted therapy use (median 10.9 months (CI: 9.7-11.9 months) compared to 9.1 months (CI: 8.1-10.1 months) for non-targeted therapy, respectively, p = 0.0029). Our results provide a clinically relevant overview of the complex molecular landscape and survival mechanisms in metastatic solid cancers.

Phase II study of neratinib in older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer

OBJECTIVE

The tolerability and efficacy of targeted therapy in older adults with cancer has not been adequately studied. Neratinib is a novel HER1, HER2, HER4 tyrosine kinase inhibitor that has recently been granted FDA approval for treatment of breast cancer. The major toxicity of neratinib is diarrhea, which affects up to 90% of patients. This phase II trial evaluates the safety and tolerability of neratinib in adults ≥60.

METHODS

Patients aged 60 or older with histologically proven metastatic breast cancer and HER2 amplification (defined by ASCO/CAP guideline) or HER2/HER3 activating mutation were enrolled to receive neratinib at 240 mg daily in 28-day cycles. The association between tolerability, defined as dose reduction and number of completed courses, and log2 Cancer and Aging Research Group (CARG) toxicity risk score was assessed using a Student's t-test and linear regression, respectively. Response rate, progression free survival, and overall survival were also evaluated.

RESULTS

25 patients were enrolled with median age of 66 (range 60-79). Seventy-six percent of patients were white, 16% Asian, and 8% African-American. Seventy-six percent were patients with hormone receptor (HR) positive metastatic breast cancer (MBC) and 24% were patients with HR negative MBC. Median number of prior lines of metastatic therapy were 3 (range 0-11). 20/25 (80%) had worst grade toxicities ≥2. A total of 9/25 (36%) had grade 3 toxicities including 5/20 (20%) diarrhea, 2/20 (8%) vomiting, and 2/20 (8%) abdominal pain. There were no grade 4 or 5 toxicities. A total of 9/25 (36%) had dose reduction, and 2/25 (8%) discontinued therapy due to toxicity. The association between dose reductions and CARG toxicity score reached borderline statistical significance suggesting a trend with participants with higher CARG toxicity risk scores being more likely to require a dose modification (p = 0.054). 1/25 (4%) had a partial response, 11/25 (44%) had stable disease, 12/25 (48%) had progression of disease, and 1/25 (4%) was not assessed. Median progression free survival (PFS) was 2.6 months (95% CI [2.56-5.26]), and median overall survival (OS) was 17.4 months (95% CI [10.3, NA]).

CONCLUSIONS

Neratinib was safe in this population of older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer (BC). Higher CARG toxicity risk score may be associated with greater need for dose adjustments. Future studies are needed to confirm this finding.

Metabolic syndrome risk components and mortality after triple-negative breast cancer diagnosis in postmenopausal women in the Women's Health Initiative

BACKGROUND

Triple-negative breast cancer (TNBC) has a high recurrence risk and poor clinical outcomes. Associations between metabolic syndrome (MetS) risk components and mortality in postmenopausal women with TNBC were examined in the Women's Health Initiative.

METHODS

Five hundred forty-four postmenopausal women were diagnosed with nonmetastatic TNBC. Baseline risk components included a high waist circumference (≥88 cm), high blood pressure, hypercholesterolemia, and diabetes. Groups were categorized by the number of MetS risk components: none, 1 or 2, or 3 or 4. Hazard ratios (HRs) and 95% confidence intervals (CIs) across groups were computed with multivariable adjusted Cox models. Outcomes included breast cancer-specific mortality and breast cancer overall mortality (breast cancer followed by death from any cause). Variables in the multivariable model included age at TNBC diagnosis; race/ethnicity; income; education; clinical/observational trial status; history of oral contraceptive, hormone, and/or statin use; cancer stage; and chemotherapy and/or radiation treatment status.

RESULTS

Of the 544 participants with TNBC, 33% had no MetS risk components (n = 178), 59% had 1 or 2 risk components (n = 323), and 8% had 3 or 4 risk components (n = 43). After a median follow-up from diagnosis of 8.3 years, multivariable results showed that women with 3 or 4 risk components had a nonsignificantly higher risk of breast cancer mortality (HR, 2.05; 95% CI, 0.94-4.47 trend P = .114) and a significantly higher risk of overall mortality (HR, 2.13; 95% CI, 1.22-3.71; trend P = .006) versus women with 0 risk components.

CONCLUSIONS

Postmenopausal women with TNBC and 3 or 4 MetS risk components have a nonsignificantly higher breast cancer mortality risk and a significantly higher overall mortality risk, likely because of negative influences of metabolic risk factors on several causes of death.

NCCN Guidelines® Insights: Breast Cancer, Version 4.2021

The NCCN Guidelines for Breast Cancer include up-to-date guidelines for clinical management of patients with carcinoma in situ, invasive breast cancer, Paget disease, phyllodes tumor, inflammatory breast cancer, male breast cancer, and breast cancer during pregnancy. These guidelines are developed by a multidisciplinary panel of representatives from NCCN Member Institutions with breast cancer-focused expertise in the fields of medical oncology, surgical oncology, radiation oncology, pathology, reconstructive surgery, and patient advocacy. These NCCN Guidelines Insights focus on the most recent updates to recommendations for adjuvant systemic therapy in patients with nonmetastatic, early-stage, hormone receptor-positive, HER2-negative breast cancer.

Analysis of Gut Microbiome Using Explainable Machine Learning Predicts Risk of Diarrhea Associated With Tyrosine Kinase Inhibitor Neratinib: A Pilot Study

Neratinib has great efficacy in treating HER2+ breast cancer but is associated with significant gastrointestinal toxicity. The objective of this pilot study was to understand the association of gut microbiome and neratinib-induced diarrhea. Twenty-five patients (age ≥ 60) were enrolled in a phase II trial evaluating safety and tolerability of neratinib in older adults with HER2+ breast cancer (NCT02673398). Fifty stool samples were collected from 11 patients at baseline and during treatment. 16S rRNA analysis was performed and relative abundance data were generated. Shannon's diversity was calculated to examine gut microbiome dysbiosis. An explainable tree-based approach was utilized to classify patients who might experience neratinib-related diarrhea (grade ≥ 1) based on pre-treatment baseline microbial relative abundance data. The hold-out Area Under Receiver Operating Characteristic and Area Under Precision-Recall Curves of the model were 0.88 and 0.95, respectively. Model explanations showed that patients with a larger relative abundance of Ruminiclostridium 9 and Bacteroides sp. HPS0048 may have reduced risk of neratinib-related diarrhea and was confirmed by Kruskal-Wallis test (p ≤ 0.05, uncorrected). Our machine learning model identified microbiota associated with reduced risk of neratinib-induced diarrhea and the result from this pilot study will be further verified in a larger study.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT02673398.

Phase II Trial of Neoadjuvant Carboplatin and Nab-Paclitaxel in Patients with Triple-Negative Breast Cancer

BACKGROUND

In this phase II clinical trial, we evaluated the efficacy of the nonanthracycline combination of carboplatin and nab-paclitaxel in early stage triple-negative breast cancer (TNBC).

PATIENTS AND METHODS

Patients with newly diagnosed stage II-III TNBC (n = 69) were treated with neoadjuvant carboplatin (area under the curve 6) every 28 days for four cycles plus nab-paclitaxel (100 mg/m2 ) weekly for 16 weeks. Pathological complete response (pCR) and residual cancer burden (RCB) were analyzed with germline mutation status, tumor-infiltrating lymphocytes (TILs), TNBC molecular subtype, and GeparSixto immune signature (GSIS).

RESULTS

Sixty-seven patients were evaluable for safety and response. Fifty-three (79%) patients experienced grade 3/4 adverse events, including grade 3 anemia (43%), neutropenia (39%), leukopenia (15%), thrombocytopenia (12%), fatigue (7%), peripheral neuropathy (7%), neutropenia (16%), and leukopenia (1%). Twenty-four patients (35%) had at least one dose delay, and 50 patients (72%) required dose reduction. Sixty-three (94%) patients completed scheduled treatment. The responses were as follows: 32 of 67 patients (48%) had pCR (RCB 0), 10 of 67 (15%) had RCB I, 19 of 67 (28%) had RCB II, 5 of 67 (7%) had RCB III, and 1 of 67 (2%) progressed and had no surgery. Univariate analysis showed that immune-hot GSIS and DNA repair defect (DRD) were associated with higher pCR with odds ratios of 4.62 (p = .005) and 4.76 (p = .03), respectively, and with RCB 0/I versus RCB II/III with odds ratio 4.80 (p = .01). Immune-hot GSIS was highly correlated with DRD status (p = .03), TIL level (p < .001), and TNBC molecular subtype (p < .001). After adjusting for age, race, stage, and grade, GSIS remained associated with higher pCR and RCB class 0/I versus II/III with odds ratios 7.19 (95% confidence interval [CI], 2.01-25.68; p = .002) and 8.95 (95% CI, 2.09-38.23; p = .003), respectively.

CONCLUSION

The combination of carboplatin and nab-paclitaxel for early stage high-risk TNBC showed manageable toxicity and encouraging antitumor activity. Immune-hot GSIS is associated with higher pCR rate and RCB class 0/1. This study provides an additional rationale for using nonanthracycline platinum-based therapy for future neoadjuvant trials in early stage TNBCs. Clinical trial identification number: NCT01525966 IMPLICATIONS FOR PRACTICE: Platinum is an important neoadjuvant chemotherapy agent for treatment of early stage triple-negative breast cancer (TNBC). In this study, carboplatin and nab-paclitaxel were well tolerated and highly effective in TNBC, resulting in pathological complete response of 48%. In univariate and multivariate analyses adjusting for age, race, tumor stage and grade, "immune-hot" GeparSixto immune signature (GSIS) and DNA repair defect (DRD) were associated with higher pathological complete response (pCR) and residual cancer burden class 0/1. The association of immune-hot GSIS with higher pCR holds promise for de-escalating neoadjuvant chemotherapy for patients with early stage TNBC. Although GSIS is not routinely used in clinic, further development of this immune signature into a clinically applicable assay is indicated.

Abstract PS12-20: A dose escalation study of the novel oral SERD-ZN-c5 in women with ER-positive, HER2-negative advanced/metastatic breast cancer

Background: ZN-c5 is an orally bioavailable selective estrogen receptor degrader (SERD) that binds potently to the estrogen receptors alpha and beta. It shows improved activity over fulvestrant in human tumor xenograft models and activity in tumor models that are resistant to tamoxifen. This is a Phase 1/2, open-label, multicenter, dose-escalation and expansion study to evaluate the safety, tolerability, pharmacokinetics (PK), and clinical activity of ZN-c5 in subjects with advanced/metastatic estrogen receptor (ER) positive/ human epidermal growth factor receptor (HER2) negative breast cancer, both as monotherapy and in combination with palbociclib. The results from the ongoing monotherapy dose escalation are reported. Methods: Single agent ZN-c5 is being evaluated at sequentially escalating doses starting at 50 mg/day, administered orally, once daily (QD). The endpoints are to determine a maximum tolerated dose (MTD) or recommended Phase 2 dose (RP2D), preliminary clinical activity and to characterize the PK profile. Subjects must be intolerant to or have breast cancer refractory to established therapies and to have received up to 2 prior lines of chemotherapy for the treatment of advanced breast cancer. Subjects must have a documented prior response to endocrine therapy for advanced/metastatic disease (SD, PR, or CR) lasting &gt; 6 months or disease recurrence after at least 24 months of adjuvant endocrine treatment. Results: A total of 15 female subjects (median age 57 years, range 51 - 89 years) were enrolled across 5 cohorts (3 subjects/dose level). The dose levels were 50, 75, 100, 150, and 300 mg/day. The subjects had a median of 4 prior therapies for advanced/metastatic disease, with a median of 3 prior hormonal-based therapies and a median of 1 prior chemotherapy. Eleven of 15 subjects (73%) received prior fulvestrant. The cut off-date for this analysis was 30 June 2020. There was no increase in incidence or severity of TEAEs with increase in dose level. The most frequent TEAEs reported in &gt; 1 subject were nausea (33%), arthralgia, cough, musculoskeletal pain and vomiting (20% each), alanine aminotransferase increased, anemia, back pain, blood alkaline phosphatase increased, breast pain, diarrhea, fatigue, gamma-glutamyl transferase increased, headache, hypophosphatemia, myalgia and skin mass (13% each). Grade 3 events were COVID-19, hypercalcemia, arthralgia, back pain musculoskeletal chest pain, pain in extremity and hypertension, none were deemed related to ZN-c5. Grade 4 events were not reported. No bradycardia was observed. A single subject reported a Grade 1 visual field defect, not deemed related to ZN-c5. No DLTs were reported. ZN-c5 demonstrated a best response of stable disease (SD) in 10/15 subjects (66.5%), while progression of disease (PD) was reported in 5/15 subjects (33.5%). The clinical benefit rate (CBR, SD ≥ 24 weeks) was 40%. In addition, the progression free survival (PFS) was a median of 3.8 months (95% [CI], 1.6 to 6.3). The preliminary PK was characterized by fast absorption with median Tmax values of 1 - 2 hrs. The exposures were approximately dose-proportional at the dose levels of 50 - 100 mg and less than dose-proportional between 100 - 300 mg. No ZN-c5 accumulation after 15 days of QD dosing was observed. The estimated mean elimination half-lives ranged between 11 - 18 hrs. Conclusion: This monotherapy dose escalation study demonstrates that ZN-c5 is very well-tolerated and has promising clinical activity in patients with ER+/HER2-negative advanced breast cancer who have disease that progressed on standard therapies. The trial with ZN-c5 in monotherapy and with palbociclib is ongoing and the RP2D has not been determined yet.

Citation Format: Pavani Chalasani, Vandana Abramson, Joanne Mortimer, Julie R Nangia, Jose Suarez, Matt Suster, Mieke Ptaszynski, Kevin Kalinsky. A dose escalation study of the novel oral SERD-ZN-c5 in women with ER-positive, HER2-negative advanced/metastatic 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 PS12-20.

Abstract PS5-41: Machine learning model of gut microbiota predicts neratinib induced diarrhea in patients with breast cancer

Background: Neratinib is a potent small molecule tyrosine kinase inhibitor (TKI) of human epidermal growth factor receptors (HER1,2,4). One of the major side effects of neratinib is diarrhea. The human gut contains a dense microbiome ecosystem that is essential in maintaining a healthy host physiology, and its disruption may lead to increased risk of toxicities from cancer therapy. In this study, we aimed to develop a machine learning model based on analysis of gut microbiota data to predict neratinib-induced diarrhea.

Methods: Patients were enrolled in a phase II trial evaluating safety and tolerability of neratinib in older adults with HER2+ breast cancer (NCT02673398). Neratinib was administered as single agent, 240 mg oral daily in a 28-day cycle. Stool samples were collected at baseline and during treatment for 16S rRNA gene sequencing. Using microbial relative abundance data, we developed gradient-boosted tree models with two nested loops of cross validations to classify whether diarrhea would occur or not after treatment onset. For the inner validation loop, we used ten-fold cross validation to determine the optimal model from hyper-parameters including regularization. For the outer validation loop, we utilized a leave-one-patient-out cross validation to test this model on the hold-out patient’s baseline data and the predictions were used for model assessment.

Results: A total of 11 patients and 50 longitudinal stool samples were collected. The median age was 66 years. 73% developed grade ≥ 1 diarrhea attributed to neratinib. Shannon diversity index of gut microbiome was not associated with diarrhea. For predictive modeling, the outer validation loop Area Under the Receiver Operating Characteristic Curve (AUROC) and Area Under the Precision Recall Curve (AUPRC) were 0.92 and 0.97, respectively. The two most important taxa predictive of protection from diarrhea were Ruminiclostridium 9, and Bacteroides sp. HPS0048. We found that patients with a larger relative abundance of Ruminiclostridium 9 and Bacteroides sp. HPS0048 have reduced risk of neratinib-related diarrhea.

Conclusions: The machine learning model can identify breast cancer patients at risk of diarrhea prior to neratinib use. Future studies are required to validate this finding.

Citation Format: Chi Wah Wong, Susan E. Yost, Jin Sun Lee, John D. Gillece, Megan Folkerts, Lauren Reining, Sarah K. Highlander, Zahra Eftekhari, Joanne Mortimer, Yuan Yuan. Machine learning model of gut microbiota predicts neratinib induced diarrhea in patients with 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 PS5-41.

Abstract OT-24-01: Phase I study combining ipatasertib with chemotherapy and atezolizumab in patients with metastatic triple negative breast cancer

Background: The PI3K-ATK pathway is one of the most common cancer drivers in breast cancer, and the AKT inhibitor ipatasertib (ipat) has shown great efficacy in patients (pts) with metastatic triple negative breast cancer (mTNBC). The current phase I trial is designed to test the safety and efficacy of the following ipat combinations: ipat + carboplatin (C) + paclitaxel (T); ipat + C; ipat + capecitabine (cape) + atezolizumab (atezo). Trial Design: This is a Phase I open-label study for pts with mTNBC. Eligible pts receive one of three regimens: A) weekly carbo AUC 2 plus taxol 80 mg/m2 days 1, 8, 15 and daily ipat 300 mg every 28 days; B) weekly carbo AUC 2, days 1, 8, 15 and daily ipat 400 mg every 28 days; C) cape 750 mg bid 1 week on 1 week off, ipat 300 mg daily and atezo 840 mg iv days 1, 15 every 28 days. Eligibility Criteria: Eligible patients must have histologically confirmed mTNBC (ER/PR ≤ 10%, HER2- per ASCO/CAP); RECIST 1.1 measurable disease; 0-2 lines of chemotherapy prior for mTNBC; AEs recovered to ≤ Gr 2 per CTCAE 5.0; adequate bone marrow, hepatic and renal function. Prior exposure to AKT targeted therapy is excluded.Specific Aims: Primary objectives are to evaluate the safety and tolerability of the combinations and determine the recommended Phase II dose (RP2D) of the combinations. Secondary objectives are to evaluate response rate, clinical benefit rate, progression free survival, and overall survival. Statistical Design: For the safety-lead in, a “3 at risk design” will be utilized to assess toxicity for the combination therapy. The DLT period is 1-cycle (28 days). Each participant will remain on the dosing level according to the escalation dose level they were enrolled in, and intra-dose level escalations will not be allowed, even if the MTD is defined at a higher dose level. Rules for escalation are as follows: if escalating from Level 1, two dose levels will be open, Level 2A, and Level 2B. Only if both 2A and 2B result in a decision to escalate will dose level 3 for this triplet be open. When both 2A and 2B are both open, slots will be given to the arm with the most open slots (starting with 2A if there are ties). When a maximum tolerable dose level has been defined by the dose escalation portion of the study, and the recommended phase 2 dose (RP2D not to exceed the MTD) has been selected, additional patients will be accrued to confirm the tolerability of the regimen. For Arm C, at least 12 patients will be treated at the RP2D to confirm tolerability. Additional patients can be accrued if the total number of patients accrued does not exceed 21 patients (e.g. if the RP2D is dose level 1, with 2A and 2B not well-tolerated based on 3 patients on each 2A and 2B, the total at RP2D could be 15). If one agent is discontinued due to toxicity, then the participant may continue to receive the remaining single agent or doublet agent therapy on protocol. With 12 patients, any specific severe toxicity with 20% incidence will be observed with 93% probability.

Citation Format: Yuan Yuan, Susan E. Yost, Jin Sun Lee, Paul H. Frankel, Christopher Ruel, Mireya Murga, Aileen Tang, Norma Martinez, James Waisman, Niki Patel, Mina Sedrak, Daphne Stewart, Sayeh Lavasani, Joanne Mortimer. Phase I study combining ipatasertib with chemotherapy and atezolizumab in patients with metastatic 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 OT-24-01.

Towards integration of 64Cu-DOTA-trastuzumab PET-CT and MRI with mathematical modeling to predict response to neoadjuvant therapy in HER2 + breast cancer

While targeted therapies exist for human epidermal growth factor receptor 2 positive (HER2 +) breast cancer, HER2 + patients do not always respond to therapy. We present the results of utilizing a biophysical mathematical model to predict tumor response for two HER2 + breast cancer patients treated with the same therapeutic regimen but who achieved different treatment outcomes. Quantitative data from magnetic resonance imaging (MRI) and 64Cu-DOTA-trastuzumab positron emission tomography (PET) are used to estimate tumor density, perfusion, and distribution of HER2-targeted antibodies for each individual patient. MRI and PET data are collected prior to therapy, and follow-up MRI scans are acquired at a midpoint in therapy. Given these data types, we align the data sets to a common image space to enable model calibration. Once the model is parameterized with these data, we forecast treatment response with and without HER2-targeted therapy. By incorporating targeted therapy into the model, the resulting predictions are able to distinguish between the two different patient responses, increasing the difference in tumor volume change between the two patients by > 40%. This work provides a proof-of-concept strategy for processing and integrating PET and MRI modalities into a predictive, clinical-mathematical framework to provide patient-specific predictions of HER2 + treatment response.

A Phase II Clinical Trial of Pembrolizumab and Enobosarm in Patients with Androgen Receptor-Positive Metastatic Triple-Negative Breast Cancer

LESSONS LEARNED

The combination of enobosarm and pembrolizumab was well tolerated and showed a modest clinical benefit rate of 25% at 16 weeks. Future trials investigating androgen receptor-targeted therapy in combination with immune checkpoint inhibitors are warranted.

BACKGROUND

Luminal androgen receptor is a distinct molecular subtype of triple-negative breast cancer (TNBC) defined by overexpression of androgen receptor (AR). AR-targeted therapy has shown modest activity in AR-positive (AR+) TNBC. Enobosarm (GTx-024) is a nonsteroidal selective androgen receptor modulator (SARM) that demonstrates preclinical and clinical activity in AR+ breast cancer. The current study was designed to explore the safety and efficacy of the combination of enobosarm and pembrolizumab in patients with AR+ metastatic TNBC (mTNBC).

METHODS

This study was an open-label phase II study for AR+ (≥10%, 1+ by immunohistochemistry [IHC]) mTNBC. Eligible patients received pembrolizumab 200 mg intravenous (IV) every 3 weeks and enobosarm 18 mg oral daily. The primary objective was to evaluate the safety of enobosarm plus pembrolizumab and determine the response rate. Peripheral blood, tumor biopsies, and stool samples were collected for correlative analysis.

RESULTS

The trial was stopped early because of the withdrawal of GTx-024 drug supply. Eighteen patients were enrolled, and 16 were evaluable for responses. Median age was 64 (range 36-81) years. The combination was well tolerated, with only a few grade 3 adverse events: one dry skin, one diarrhea, and one musculoskeletal ache. The responses were 1 of 16 (6%) complete response (CR), 1 of 16 (6%) partial response (PR), 2 of 16 (13%) stable disease (SD), and 12 of 16 (75%) progressive disease (PD). Response rate (RR) was 2 of 16 (13%). Clinical benefit rate (CBR) at 16 weeks was 4 of 16 (25%). Median follow-up was 24.9 months (95% confidence interval [CI], 17.5-30.9). Progression-free survival (PFS) was 2.6 months (95% CI, 1.9-3.1) and overall survival (OS) was 25.5 months (95% CI, 10.4-not reached [NR]).

CONCLUSION

The combination of enobosarm and pembrolizumab was well tolerated, with a modest clinical benefit rate of 25% at 16 weeks in heavily pretreated AR+ TNBC without preselected programmed death ligand-1 (PD-L1). Future clinical trials combining AR-targeted therapy with immune checkpoint inhibitor (ICI) for AR+ TNBC warrant investigation.

NCCN Guidelines Insights: Breast Cancer, Version 3.2018

These NCCN Guidelines Insights highlight the updated recommendations for use of multigene assays to guide decisions on adjuvant systemic chemotherapy therapy for women with hormone receptor-positive, HER2-negative early-stage invasive breast cancer. This report summarizes these updates and discusses the rationale behind them.

Hispanic ethnicity as a moderator of the effects of aerobic and resistance exercise on physical fitness and quality-of-life in breast cancer survivors

BACKGROUND

Exercise can profoundly affect physical fitness and quality of life in breast cancer survivors; however, few studies have focused on minorities. This secondary analysis examines Hispanic ethnicity as a moderator of the effects of a 16-week aerobic and resistance exercise intervention on physical fitness and quality of life in breast cancer survivors.

METHODS

Eligible breast cancer survivors (n = 100) were randomized to exercise (n = 50) or usual care (n = 50). The exercise intervention consisted of supervised moderate-vigorous aerobic and resistance exercise thrice weekly for 16 weeks. Physical fitness and quality of life were measured at baseline, post-intervention, and 28-week follow-up (exercise only). Linear mixed-models adjusted for baseline value of the outcome, age, disease stage, adjuvant treatment, and recent physical activity were used to evaluate effect modification by ethnicity.

RESULTS

The study sample included 57% Hispanic and 43% non-Hispanic breast cancer survivors. Hispanic breast cancer survivors were younger, less fit, and diagnosed with more advanced cancers compared with non-Hispanic breast cancer survivors (p < 0.001). Ethnicity was found to moderate the effects of exercise training on all physical fitness and quality-of-life measures including VO_2max (8.4 mL/kg/min; 95% confidence interval (95% CI) 3.2 to 13.4), physical well-being (12.3; 95% CI 4.2 to 18.4), and emotional well-being (11.4; 95% CI 5.9 to 15.5). In all cases, Hispanics experienced larger benefits than non-Hispanics.

CONCLUSIONS

Hispanic breast cancer survivors have poorer cardiorespiratory fitness, muscle strength, and quality-of-life and therefore may derive larger benefits from exercise than non-Hispanic breast cancer survivors. Clinical exercise interventions may attenuate existing health disparities among minority breast cancer survivors.

IMPLICATION OF CANCER SURVIVORS

Here we report psychosocial and fitness-related disparities among Hispanic breast cancer survivors when compared with their non-Hispanic counterparts. Our exercise intervention highlights the importance of exercise for minority cancer survivors and the need for distinct, culturally tailored exercise intervention approaches to reduce psychosocial and fitness-related disparities among this understudied population of cancer survivors.

Insurance Status Predicts Survival in Women with Breast Cancer: Results of Breast and Cervical Cancer Treatment Program in California

BACKGROUND AND PURPOSE

The Breast and Cervical Cancer Treatment Program (BCCTP) Act, passed by Congress in 2000, provides time-limited coverage to uninsured breast or cervical cancer patients. We examine survival differences between BCCTP cases and insured controls.

METHODS

Stage I-III breast cancer patients, covered under California's BCCTP from 2005 to 2009 (N = 6343), were 1:1 matched with California Cancer Registry controls on age, race/ethnicity, and cancer stage. Overall and disease-specific (OS and DSS) survival were compared using multivariate regression.

RESULTS

BCCTP cases were more often unmarried [odds ratio (OR) 2.47, 95% confidence interval (CI) 2.30-2.66], with poorly/undifferentiated tumors (OR 1.26, CI 1.13-1.40), classified as ER negative (OR 1.10, CI 1.02-1.20) and/or PR negative (OR 1.09, CI 1.01-1.17). Cases were more likely to undergo mastectomy (OR 1.13, CI 1.05-1.21) or no surgery (OR 1.64, CI 1.31-2.05) versus lumpectomy. Cases were also more likely to undergo radiation (OR 1.11, CI 1.03-1.19). Endocrine therapy rates were marginally lower in cases (OR 0.93, CI 0.86-1.00). OS and DSS were shorter in BCCTP cases on multivariate analysis (HR 1.29, CI 1.17-1.42 and HR 1.27, CI 1.14-1.42, respectively). When stratified by socioeconomic status (SES), cases had significantly shorter OS and DSS except in the lowest quintile. When stratified by stage, cases had significantly shorter OS and DSS, except for stage I.

CONCLUSIONS

The BCCTP provides uninsured breast cancer patients with comprehensive and timely care. Although our results suggest that BCCTP delivers quality care, BCCTP patients have shorter survival rates, even after accounting for SES and stage differences. Further assistance to vulnerable populations is warranted, including longer duration of treatment coverage, and surveillance adhering to NCCN compliant surveillance programs.

A first-in-human, phase 1, dose-escalation study of ABBV-176, an antibody-drug conjugate targeting the prolactin receptor, in patients with advanced solid tumors

ABBV-176 is an antibody-drug conjugate composed of the humanized antibody h16f (PR-1594804) conjugated to a highly potent, cytotoxic cross-linking pyrrolobenzodiazepine dimer (PBD; SGD-1882) targeting the prolactin receptor (PRLR), which is overexpressed in several solid tumor types. This phase 1, dose-escalation study (NCT03145909) evaluated the safety, pharmacokinetics, and preliminary activity of ABBV-176 in patients with advanced solid tumors likely to exhibit elevated levels of PRLR. Patients received ABBV-176 once every 3 weeks. Dose escalation was by an exposure-adjusted, continual reassessment method. Dose-limiting toxicities (DLTs) were assessed from the first day of dosing until the next dose of ABBV-176 to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Nineteen patients received ABBV-176 at doses from 2.7-109.35 μg/kg. Patients enrolled had colorectal cancer (n = 11), breast cancer (n = 6), or adrenocortical carcinoma (n = 2). DLTs occurred in 4 patients and included thrombocytopenia (n = 2; both at 99.9-μg/kg dose level), neutropenia (n = 2; 78.3-μg/kg and 99.9-μg/kg dose levels), and pancytopenia (n = 1; 109.35-μg/kg dose level). The most common treatment-emergent adverse events related to ABBV-176 were thrombocytopenia, neutropenia, increased aspartate aminotransferase, nausea, fatigue, and pleural effusions. Effusions and edema were common, and timing of onset suggested possible cumulative ABBV-176 toxicity. Tumor expression of PRLR varied among patients enrolled and analyzed. No patient had an objective response. MTD was not formally determined, as identification of a tolerable dose was confounded by late-onset toxicities. ABBV-176 was associated with significant toxicity in this phase 1, dose-escalation study. Although cytopenias were often dose limiting, effusions and edema were also common and had late onset that suggested cumulative toxicity. No responses were observed, although data were available from a small number of patients with variable tumor PRLR expression. This study was terminated after the dosing of 19 patients.

Strategies to Improve Participation of Older Adults in Cancer Research

Cancer is a disease associated with aging. As the US population ages, the number of older adults with cancer is projected to dramatically increase. Despite this, older adults remain vastly underrepresented in research that sets the standards for cancer treatments and, consequently, clinicians struggle with how to interpret data from clinical trials and apply them to older adults in practice. A combination of system, clinician, and patient barriers bar opportunities for trial participation for many older patients, and strategies are needed to address these barriers at multiple fronts, five of which are offered here. This review highlights the need to (1) broaden eligibility criteria, (2) measure relevant end points, (3) expand standard trial designs, (4) increase resources (e.g., institutional support, interdisciplinary care, and telehealth), and (5) develop targeted interventions (e.g., behavioral interventions to promote patient enrollment). Implementing these solutions requires a substantial investment in engaging and collaborating with community-based practices, where the majority of older patients with cancer receive their care. Multifaceted strategies are needed to ensure that older patients with cancer, across diverse healthcare settings, receive the highest-quality, evidence-based care.

Engaging Patients in Precision Oncology: Development and Usability of a Web-Based Patient-Facing Genomic Sequencing Report

PURPOSE

Evidence-based somatic and germline sequencing has transformed cancer care and improves patient outcomes. However, patients' low genetic literacy and misunderstanding of their own genomic results poses a threat to the realization of precision oncology. To optimize patient genomic comprehension, we developed a Web-based, patient-directed, genomic sequencing education and return-of-results tool, HOPE-Genomics.

METHODS

The HOPE-Genomics prototype included somatic and germline sequencing results, embedded multimedia genomic education, and interactive features (eg, request for genetic counseling). Between January and April 2018, we elicited feedback on tool usability and comprehensiveness through participant surveys, 4 focus groups of patients with cancer and their family members, and 3 provider focus groups (comprising 8 patients, 5 family members, and 19 providers).

RESULTS

We identified themes in patient/family tool-related responses, including the desire to view a patient-friendly report, a desire to receive multiple types of genomic information (eg, prognostic and uncertain), high acceptability of report content, and interest in tool-enabled access to genetic counseling. Major themes from the clinician focus groups included believing the tool could help patients formulate questions and facilitate patients' communication of results to family members. However, there were diverse responses from all participants in terms of tool implementation (ie, timing and nature of report release). Some participants preferred report release before meeting with the provider, and others preferred it during the appointment. Additionally, some clinicians were concerned about providing prognostic and treatment information through the tool.

CONCLUSION

There was high acceptability and interest from patients, family members, and providers in a patient-directed genomics report. Future work will determine whether direct-to-patient reporting of genomic results improves patient knowledge, care engagement, and compliance with genomically guided interventions.