Adjuvant nivolumab, capecitabine or the combination in patients with residual triple-negative breast cancer: the OXEL randomized phase II study

Chemotherapy and immune checkpoint inhibitors have a role in the post-neoadjuvant setting in patients with triple-negative breast cancer (TNBC). However, the effects of nivolumab, a checkpoint inhibitor, capecitabine, or the combination in changing peripheral immunoscore (PIS) remains unclear. This open-label randomized phase II OXEL study (NCT03487666) aimed to assess the immunologic effects of nivolumab, capecitabine, or the combination in terms of the change in PIS (primary endpoint). Secondary endpoints included the presence of ctDNA, toxicity, clinical outcomes at 2-years and association of ctDNA and PIS with clinical outcomes. Forty-five women with TNBC and residual invasive disease after standard neoadjuvant chemotherapy were randomized to nivolumab, capecitabine, or the combination. Here we show that a combination of nivolumab plus capecitabine leads to a greater increase in PIS from baseline to week 6 (91%) compared with nivolumab (47%) or capecitabine (53%) alone (log-rank p = 0.08), meeting the pre-specified primary endpoint. In addition, the presence of circulating tumor DNA (ctDNA) is associated with disease recurrence, with no new safety signals in the combination arm. Our results provide efficacy and safety data on this combination in TNBC and support further development of PIS and ctDNA analyses to identify patients at high risk of recurrence.

Adjuvant nivolumab, capecitabine or the combination in patients with residual triple-negative breast cancer: the OXEL randomized phase II study

Chemotherapy and immune checkpoint inhibitors have a role in the post-neoadjuvant setting in patients with triple-negative breast cancer (TNBC). However, the effects of nivolumab, a checkpoint inhibitor, capecitabine, or the combination in changing peripheral immunoscore (PIS) remains unclear. This open-label randomized phase II OXEL study (NCT03487666) aimed to assess the immunologic effects of nivolumab, capecitabine, or the combination in terms of the change in PIS (primary endpoint). Secondary endpoints include the presence of ctDNA, toxicity, clinical outcomes at 2-years and association of ctDNA and PIS with clinical outcomes. Forty-five women with TNBC and residual invasive disease after standard neoadjuvant chemotherapy were randomized to nivolumab, capecitabine, or the combination. Here we show that a combination of nivolumab plus capecitabine leads to a greater increase in PIS from baseline to week 6 (91%) compared with nivolumab (47%) or capecitabine (53%) alone (log-rank p = 0.08), meeting the pre-specified primary endpoint. In addition, the presence of circulating tumor DNA (ctDNA) was associated with disease recurrence, with no new safety signals in the combination arm. Our results provide efficacy and safety data on this combination in TNBC and support further development of PIS and ctDNA analyses to identify patients at high risk of recurrence.

NCCN Guidelines® Insights: Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 2.2024

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic focus primarily on assessment of pathogenic/likely pathogenic (P/LP) variants associated with increased risk of breast, ovarian, pancreatic, and prostate cancer, including BRCA1, BRCA2, CDH1, PALB2, PTEN, and TP53, and recommended approaches to genetic counseling/testing and care strategies in individuals with these P/LP variants. These NCCN Guidelines Insights summarize important updates regarding: (1) a new section for transgender, nonbinary and gender diverse people who have a hereditary predisposition to cancer focused on risk reduction strategies for ovarian cancer, uterine cancer, prostate cancer, and breast cancer; and (2) testing criteria and management associated with TP53 P/LP variants and Li-Fraumeni syndrome.

Abstract PD9-02: Peripheral immune subsets and circulating tumor DNA (ctDNA) in patients (pts) with residual triple negative breast cancer (TNBC) treated with adjuvant immunotherapy and/or chemotherapy (chemo): The OXEL study

Background: Poor clinical outcomes are noted in pts with TNBC who do not achieve a pathologic complete response (pCR). We characterized peripheral immune subsets and the role of minimal residual disease (MRD) detection via ctDNA in pts who participated in the OXEL study. Methods: OXEL (Opdivo® -XELoda ®) is a recently completed phase II open-label 3-arm randomized study of nivolumab (nivo), capecitabine (cape) or the combination as adjuvant therapy (tx) for pts with residual TNBC after appropriate neoadjuvant chemo. Residual disease was defined as ≥ 1.0 cm of primary tumor and/or nodal involvement. Eligible pts had completed definitive local tx. Pts were randomly assigned to nivo 360 mg iv q3wks x 6 (arm A); cape 1250mg/m2 po bid D1-D14 q3 wks x 6 (arm B); nivo 360mg iv q3wks + cape 1250mg/m2 po bid D1-D14 q3 wks x 6 (arm C). Peripheral blood mononuclear cells (PBMCs) and ctDNA were assessed at baseline (D1 of cycle 1), 6, and 12 wks and at time of recurrence, if applicable. PBMCs were stained with 30 markers and analyzed by flow cytometry to identify changes in 158 immune cell subsets at 6 wks, as a percent of total PBMCs. RaDaRTM, a deep sequencing based, tumor-informed personalized assay was utilized to detect the presence of ctDNA in plasma. Distant disease-free survival (DDFS) and overall survival (OS) were analyzed by the Kaplan-Meier method and Log-Rank test was used to compare DDFS and OS according to baseline MRD results. All pts will be followed for distant recurrence and survival for 3 yrs. Here we report the translational endpoints of the OXEL study. Clinical endpoints according to treatment received will be reported in a future analysis. Results: 45 pts were enrolled between 8/2018 and 6/2021. 29 (64%) were Caucasian and 14 (31%) were African American. Mean age at enrollment was 51 [+/- 12]. 93% of pts received a taxane-anthracycline containing neoadjuvant tx. 15 pts were randomized to each arm. DDFS probability at 1-yr and 2-yrs was 0.71 (+/- 0.07) and 0.66 (+/- 0.08) respectively. At 12 mos of median follow up, 13/45 pts (29%) experienced distant recurrence, none had local recurrence. 43 pts were evaluated for PBMC subsets. Changes in PBMC subsets at 6 wks were different amongst the arms; in arm A, reductions in NK subsets, including a 33% reduction in CD56dimCD16- cells, were observed, while in arm B, increases in naïve CD4+ T cells (+45%) and CD73+CD8+ T cells (+12%) and reductions in ki67+CD8+ T cells (-48%) were noted. In arm C, increases were observed in conventional dendritic cells (+36%), effector memory ki67+CD4+ T cells (+46%), and CD56dimCD16- NK cells (+29%). 33 pts underwent successful MRD analysis. 12/33 (36%) pts were MRD+ at baseline. 2/12 pts MRD+ at baseline subsequently cleared MRD, with undetectable ctDNA on future time points; neither patient has had recurrence to date. The remaining 10/12 MRD+ pts (83%) have experienced distance recurrence. 21/33 (64%) pts were ctDNA negative at baseline; 20/33 remained negative for all follow up timepoints. 10/11 pts experiencing distant recurrence were MRD+ at baseline, compared to 1/11 pt who became MRD+ at wk 6 post initiation of tx. At 12 mos of median follow-up, baseline MRD+ testing was significantly associated with an inferior DDFS ( p<0.0001 Log-rank test, median DDFS 4.0 mos vs. not reached) and OS (p=0.02 Log-rank test, median OS not reached for both groups). Results will be updated at the time of abstract presentation. Conclusions: Changes in PBMC subsets were associated with receipt of chemo and/or immunotherapy. Our results suggest that baseline MRD+ in pts without pCR is a poor prognostic factor. Future trials aiming to optimize adjuvant treatment with chemo and/or immunotherapy in residual TNBC should consider incorporating ctDNA as a selection marker of pts at higher risk of recurrence.

Citation Format: Filipa Lynce, Candace Mainor, Xue Geng, Greg Jones, Ilana Schlam, Hongkun Wang, Ute Feger, Renee Donahue, Nicole Toney, Caroline Jochems, Jeffrey Schlom, Christopher Gallagher, Rita Nanda, Deena Graham, Erica M Stringer-Reasor, Neelima Denduluri, Julie Collins, Asma A Dilawari, Ami Chitalia, Shruti Tiwari, Raquel Nunes, Rebecca Kaltman, Katia Khoury, Margaret Gatti-Mays, Sandra M Swain, Heather A. Parsons, Paula Pohlmann, Claudine Isaacs. Peripheral immune subsets and circulating tumor DNA (ctDNA) in patients (pts) with residual triple negative breast cancer (TNBC) treated with adjuvant immunotherapy and/or chemotherapy (chemo): The OXEL study [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 PD9-02.

Disparities in Breast Cancer Associated With African American Identity

Persistent disparities in the burden of breast cancer between African Americans and White Americans have been documented over many decades. Features characterizing breast cancer in the African American community include a 40% higher mortality rate, younger age distribution, greater advanced-stage distribution, increased risk of biologically aggressive disease such as the triple-negative phenotype, and increased incidence of male breast cancer. Public health experts, genetics researchers, clinical trialists, multidisciplinary oncology teams, and advocates must collaborate to comprehensively address the multifactorial etiology of and remedies for breast cancer disparities. Efforts to achieve breast health equity through improved access to affordable, high-quality care are especially imperative in the context of the COVID-19 pandemic and its disproportionately high economic toll on African Americans.

Long-term follow-up assessment of cardiac safety in SAFE-HEaRt, a clinical trial evaluating the use of HER2-targeted therapies in patients with breast cancer and compromised heart function

PURPOSE

HER2-targeted therapies are associated with cardiotoxicity which is usually asymptomatic and reversible. We report the updated cardiac safety assessment of patients with compromised heart function receiving HER2-targeted therapy for breast cancer, enrolled in the SAFE-HEaRt trial, at a median follow-up of 3.5 years.

METHODS

Thirty patients with stage I-IV HER2-positive breast cancer receiving trastuzumab with or without pertuzumab, or ado-trastuzumab emtansine (T-DM1), with asymptomatic LVEF (left ventricular ejection fraction) 40-49%, were started on cardioprotective medications, with the primary endpoint being completion of HER2-targeted therapy without cardiac events (CE) or protocol-defined asymptomatic worsening of LVEF. IRB-approved follow-up assessment included 23 patients.

RESULTS

Median follow-up as of June 2020 is 42 months. The study met its primary endpoint with 27 patients (90%) completing their HER2-targeted therapies without cardiac issues. Of the 23 evaluable patients at long-term f/u, 14 had early stage breast cancer, and 9 had metastatic disease, 8 of whom remained on HER2-targeted therapies. One patient developed symptomatic heart failure with no change in LVEF. There were no cardiac deaths. The mean LVEF improved to 52.1% from 44.9% at study baseline, including patients who remained on HER2-targeted therapy, and those who received prior anthracyclines.

CONCLUSIONS

Long-term follow-up of the SAFE-HEaRt study continues to provide safety data of HER2-targeted therapy use in patients with compromised heart function. The late development of cardiac dysfunction is uncommon and continued multi-disciplinary oncologic and cardiac care of patients is vital for improved patient outcomes.

Use of 18F-FDG PET/CT as an Initial Staging Procedure for Stage II-III Breast Cancer: A Multicenter Value Analysis

BACKGROUND

Metastatic staging imaging is not recommended for asymptomatic patients with stage I-II breast cancer. Greater distant metastatic disease risk may warrant baseline imaging in patients with stage II-III with high-risk biologic subtypes. NCCN Guidelines recommend considering CT of the chest, abdomen, and pelvis (CT CAP) and bone scan in appropriate patients. CT CAP and bone scan are considered standard of care (SoC), although PET/CT is a patient-centered alternative.

METHODS

Data were available for 799 high-risk patients with clinical stage II-III disease who initiated screening for the I-SPY2 trial at 4 institutions. A total of 564 complete records were reviewed to compare PET/CT versus SoC. Costs were determined from the payer perspective using the national 2018 Medicare Physician Fee Schedule and representative reimbursements to the University of California, San Francisco (UCSF). Incremental cost-effectiveness ratio (ICER) measured cost of using PET/CT per percent of patients who avoided a false-positive (FP).

RESULTS

The de novo metastatic disease rate was 4.6%. Imaging varied across the 4 institutions (P<.0001). The FP rate was higher using SoC versus PET/CT (22.1% vs 11.1%; P=.0009). Mean time between incidental finding on baseline imaging to FP determination was 10.8 days. Mean time from diagnosis to chemotherapy initiation was 44.3 days with SoC versus 37.5 days with PET/CT (P=.0001). Mean cost per patient was $1,132 (SoC) versus $1,477 (PET/CT) using the Medicare Physician Fee Schedule, with an ICER of $31. Using representative reimbursements to UCSF, mean cost per patient was $1,236 (SoC) versus $1,073 (PET/CT) for Medicare, and $3,083 (SoC) versus $1,656 (PET/CT) for a private payer, with ICERs of -$15 and -$130, respectively.

CONCLUSIONS

Considerable variation exists in metastatic staging practices. PET/CT reduced FP risk by half and decreased workup of incidental findings, allowing for earlier treatment start. PET/CT may be cost-effective, and at one institution was shown to be cost-saving. Better alignment is needed between hospital pricing strategies and payer coverage policies to deliver high-value care.

Prevalence of Phosphatidylinositol-3-Kinase (PI3K) Pathway Alterations and Co-alteration of Other Molecular Markers in Breast Cancer

Background: PI3K/AKT signaling pathway is activated in breast cancer and associated with cell survival. We explored the prevalence of PI3K pathway alterations and co-expression with other markers in breast cancer subtypes. Methods: Samples of non-matched primary and metastatic breast cancer submitted to a CLIA-certified genomics laboratory were molecularly profiled to identify pathogenic or presumed pathogenic mutations in the PIK3CA-AKT1-PTEN pathway using next generation sequencing. Cases with loss of PTEN by IHC were also included. The frequency of co-alterations was examined, including DNA damage response pathways and markers of response to immuno-oncology agents. Results: Of 4,895 tumors profiled, 3,558 (72.7%) had at least one alteration in the PIK3CA-AKT1-PTEN pathway: 1,472 (30.1%) harbored a PIK3CA mutation, 174 (3.6%) an AKT1 mutation, 2,682 (54.8%) had PTEN alterations (PTEN mutation in 7.0% and/or PTEN loss by IHC in 51.4% of cases), 81 (1.7%) harbored a PIK3R1 mutation, and 4 (0.08%) a PIK3R2 mutation. Most of the cohort consisted of metastatic sites (n = 2974, 60.8%), with PIK3CA mutation frequency increased in metastatic (32.1%) compared to primary sites (26.9%), p < 0.001. Other PIK3CA mutations were identified in 388 (7.9%) specimens, classified as "off-label," as they were not included in the FDA-approved companion test for PIK3CA mutations. Notable co-alterations included increased PD-L1 expression and high tumor mutational burden in PIK3CA-AKT1-PTEN mutated cohorts. Novel concurrent mutations were identified including CDH1 mutations. Conclusions: Findings from this cohort support further exploration of the clinical benefit of PI3K inhibitors for "off-label" PIK3CA mutations and combination strategies with potential clinical benefit for patients with breast cancer.

Long-term follow-up assessment of cardiac safety in SAFE-HEaRt, a clinical trial evaluating the use of HER2-targeted therapies in patients with HER2-positive breast cancer and compromised heart function

12069

Background: HER2-targeted therapies are associated with cardiotoxicity, mostly asymptomatic and reversible. The impact of withholding these therapies on breast cancer outcomes is unknown. SAFE-HEaRt trial was the first study to evaluate the safety of HER2-targeted agents in patients with reduced left ventricular ejection fraction (LVEF) receiving concomitant cardioprotective medications and close cardiac monitoring. We report the 3-year follow-up (f/u) results. Methods: Thirty patients with stage I-IV HER2-positive breast cancer receiving trastuzumab, pertuzumab or ado-trastuzumab emtansine (TDM-1), with asymptomatic LVEF 40-49%, were started on beta blockers (ß-blockers) and/or ACE inhibitors/ARBs, with the primary endpoint being completion of HER2-targeted therapy without cardiac events (CE) or protocol-defined asymptomatic worsening of LVEF. Results: Patients were accrued from 10/2013 to 12/2017 and median f/u as of 2/7/20 is 37 months. The study met its primary endpoint with 27 patients (90%) completing their HER2-targeted therapies without cardiac issues. 24 patients were reconsented for long-term f/u. There were 23 evaluable patients (1 lost for f/u). Off study, 2 patients continued treatment with trastuzumab, 3 with trastuzumab and pertuzumab, and 3 with TDM-1 for metastatic disease. 1 of the 2 patients who had developed a CE with symptomatic heart failure (HF) died of progressive oncological disease, and the second had LVEF recovery on cardiac medications after completion of adjuvant HER2-targeted therapy. Almost 5 years later, she had an asymptomatic decline in her LVEF to 35% after deciding to stop her ß-blocker and ARB. Of the remaining 21 patients, 15 had recovery of their LVEF to ≥50%, 9 of whom remain on cardiac medications. 5 patients had stable LVEF 40-49% and remain asymptomatic on cardiac medications. Only 1 patient had symptoms suggestive of HF, with last documented LVEF stable at 45-50%, but she has not sought medical care for the last 15 months since relocating to another country. There were no new CE and no cardiac deaths. Mean LVEF was 45% at baseline, 46% at end of treatment, and 51.5% at long term f/u. Conclusions: Long-term f/u of the SAFE-HEaRt study continues to provide safety data of HER2-targeted therapy use in patients with compromised heart function. The late development of cardiac dysfunction is uncommon and continued multi-disciplinary oncologic and cardiac care of patients is essential for improved patient outcomes. Clinical trial information: NCT04143594 .

Abstract P4-09-04: Prevalence of phosphatidylinositol-3-kinase (PI3K) pathway alterations and co-alteration of other markers in breast cancer

Background: PI3K/AKT signaling pathway is often activated in breast cancer (BC), through mutations in PIK3CA or AKT1, and alterations in PTEN, thus promoting cell survival. PI3K and AKT inhibitors have been shown to have significant activity against tumor progression and to overcome resistance in BC. We aim to explore the prevalence of PI3K pathway alterations and co-expression with other markers in different BC subtypes. This approach could allow identification of novel drug combinations that have the potential to elicit synergistic growth inhibition and be further explored in the clinical trial setting.

Methods: Molecular profiles of 4895 female and male BC cases submitted to Caris Life Sciences were reviewed to identify pathogenic or presumed pathogenic mutations in PIK3CA, AKT1, PTEN, PIK3R1 and PIK3R2 using 592-gene next generation sequencing (NGS; average read depth 500 ×). Cases with loss of PTEN by IHC were also included. Co-mutation frequency with PIK3CA-AKT1-PTEN alterations were examined, including homologous recombination deficiency (HRD) genes and DNA damage response (DDR) pathways, markers of response to immune-oncology (IO) agents and RAS signaling pathway. Cases were classified in BC subtypes according to the ASCO-CAP guidelines.

Results: The median age was 58 (range: 17-90). Gender frequency and primary/ metastatic site frequency were similar across BC subtypes. 3558 (72.7%) cases had at least one alteration in the PIK3CA-AKT1-PTEN pathway: 1472 (30.1%) cases harbored a PIK3CA mutation, 174 (3.6%) harbored an AKT1 mutation, and 2682 (54.8%) had PTEN alterations (PTEN mutation in 344, 7.0% and/or PTEN loss by IHC in 2516, 51.4% of cases). The most common hotspot mutations in PIK3CA were in the kinase domain (H1047R in 567 cases, 38.5% of all PIK3CA alterations) and in the helical domain (E545K in 304 cases, 20.7% of all PIK3CA alterations). Uncommon activating PIK3CA mutations were seen in 8.4% of breast tumors. The single hotspot mutation, E17K, was the most common AKT1 mutation (n=164, 94.3% of all AKT1 mutations). 81 (1.7%) tumors harbored a PIK3R1 mutation, with 66 unique alterations identified (4 pathogenic, 55 presumed pathogenic), and 4 (0.08%) cases harbored a PIK3R2 mutation (G373R mutation). With respect to the different BC subtypes, PIK3CA was the most frequent alteration in HER2 positive BC (present in 96.2% of mutated cases). Within HER2 negative subtypes, PTEN was most frequently altered and PTEN mutation or PTEN loss by IHC was present in 79.3% of mutated cases. Triple negative breast cancer (TNBC) was the subtype with the lowest frequency of PIK3CA mutations (18.0% in TNBC vs. 37% in other subtypes). The frequency of selected co-mutations with PIK3CA-AKT1-PTEN alterations is illustrated in table 1. Notable co-alterations in this cohort include increased PD-L1 expression and high tumor mutational burden (TMB). There were no significant increases in the frequency of mutations in DDR pathway mutations (not shown) in the PIK3CA-AKT1-PTEN altered cohort.

Conclusions: We observed a high prevalence of expected hotspot mutations in PIK3CA and AKT1 across BC subtypes. There was a significant increase in PD-L1 expression in tumor cells, and high TMB in PIK3CA-AKT1-PTEN mutated cohorts. A similar association was seen with RAS signaling pathways. Further development of drugs that affect the PIK3CA-AKT1-PTEN pathway in all BC subtypes and combination with drugs that target the immune system may be of interest.

Table 1. Selected co-alterations based on statistical significancePathwayGene/ ProteinAll subtypes (%)HR+ HER2+ (%)HR- HER2+ (%)HR+HER2- (%)TNBC (%)MTWTMTWTMTWTMTWTMTWTHomologous recombinationBRCA13.02.71.00.60.00.80.8*1.8*6.16.0BRCA24.15.41.02.53.62.34.1*7.9*4.43.0PALB20.7*1.3*0.00.00.00.00.5*2.5*0.90.3Possible predictors of IO benefitPD-149.850.038.552.266.766.737.541.766.058.1PD-L1 (SP142)6.9*4.2*3.30.78.14.93.33.011.68.1(Tumor Cells)PD-L1 (SP142)29.226.650.018.825.027.312.916.742.140.4(Immune Cells)MSI0.70.60.00.01.20.80.80.40.71.2TMB-High (≥ 10 mut/Mb)22.9*18.8*36.0*17.2*29.825.921.2*16.6*23.621.3Chromatin remodelingARID1A12.4*18.6*19.423.87.118.917.121.55.89.6ARID20.70.80.01.90.00.70.80.60.60.9RAS-RAF-MEK-ERK HRAS0.7*0.1*0.00.00.00.00.20.11.40.3KRAS2.0*1.1*1.00.00.00.01.91.22.22.0NRAS0.20.00.00.00.00.00.20.00.30.0BRAF0.50.11.00.01.20.00.60.30.40.0OthersTP5360.9*53.1*66.360.885.586.738.4*25.6*84.786.4CDH110.3*6.1*9.1*2.5*4.82.215.1*9.6*4.9*2.3*NF16.2*2.1*9.5*0.8*2.73.65.8*1.8*6.7*2.8*RB15.5*2.6*2.21.33.63.03.9*1.7*7.85.0ERBB22.3*3.4*3.03.13.56.73.23.51.0*2.3*Notes: MT = at least 1 pathogenic mutation in PIK3CA, AKT1, or PTEN or PTEN loss by IHC. WT = no pathogenic mutations in PIK3CA, AKT1, and PTEN.*statistically significant difference between MT and WT

Citation Format: Katia Khoury, Antoinette Tan, Andrew Elliott, Joanne Xiu, Zoran Gatalica, Arielle L Heeke, Claudine Isaacs, Paula R Pohlmann, Lee S Schwartzberg, Michael Simon, Michael W Korn, Sandra M Swain, Filipa Lynce. Prevalence of phosphatidylinositol-3-kinase (PI3K) pathway alterations and co-alteration of other markers in breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-09-04.

Molecular characterization of trophoblast cell surface antigen 2 (Trop-2) positive triple negative breast cancer (TNBC)

e14651

Background: Trop-2 is a glycoprotein found in various carcinomas, known to play a role in tumor development and progression. A humanized antibody drug conjugate (ADC) targeting Trop-2 for delivery of the topoisomerase-I (TOPO1) inhibitor SN-38 (payload) is currently in clinical development for TNBC. Clinical response in a previously reported phase I/II study was associated with Trop-2 immunohistochemistry (IHC) staining intensity (Bardia A et al. J Clin Oncol 2017). Herein we investigated the prevalence of Trop-2 expression in an unselected cohort of TNBC tumors, and the association with other markers of interest that could suggest novel drug combinations. Methods: A cohort of 68 TNBC specimens with available archival tumor submitted to Caris Life Sciences were tested via protein expression (IHC) for Trop-2 with dichotomous categorization for results. Positivity required at least 10% of tumor cells to be stained, with an intensity of 1+ (weak), 2+ (moderate) and 3+ (strong), with same cutoff used in ongoing clinical trials of Trop-2 ADC. Comprehensive molecular profiles were performed using 592-gene next generation sequencing (average read depth 500X). Chi-square tests were used for statistics. Results: The median age in this cohort was 54 (range: 28-90). 38 (56%) tumors were positive for Trop-2. There was no difference in age distribution between Trop-2 positive and negative tumors. Trop-2 expression was present in 48.6% (17/35) and 63.6% (21/33) of primary and metastatic sites, respectively. TOPO1 by IHC was negative in 11 (29%) of Trop-2 positive tumors. Trop-2 expression was inversely associated with PIK3CA and RB1 mutations (p = 0.012 and 0.011, respectively). There was no difference in PDL1 expression by IHC, tumor mutational burden (TMB), BRCA1/2 or other homologous recombination deficiency gene mutations between Trop-2 positive and negative tumors. Conclusions: In a cohort that used the same cutoffs in ongoing trials with Trop-2 ADC, we found a lower prevalence of Trop-2 positivity in TNBC than what has been previously reported. One third of Trop-2 positive tumors were TOPO1 negative which may have treatment implications given the pharmacology of ADC currently in development.

Abstract P5-15-01: The use of 18F-FDG PET/CT as an initial staging procedure for stage II-III breast cancer reduces false positives, costs, and time to treatment: A multicenter value analysis in the I-SPY2 trial

Introduction: Diagnostic metastatic staging imaging (SI) for asymptomatic stage I-II patients (pts) is not routinely recommended, but is warranted in stage II-III pts with high risk biological subtypes, where previous trials have shown up to a 15% rate of de novo metastatic disease. NCCN guidelines endorse CT CAP and bone scan (STD) for stage III pts, but not PET/CT, and PET/CT is not covered in most parts of the country. We present data on the performance and value of PET/CT.

Methods: Data were available for 799 high risk clinical stage II-III pts screened for I-SPY2 at UCSF, Uminn, UAB, and Georgetown. Of these, 564 pts ranging in age from 25-81 (median = 48) had complete records that were retrospectively reviewed for SI and potential false positives (FP), defined as incidental findings on SI proven benign by subsequent workup. Economic evaluation was conducted from the payer perspective using the mean national 2018 Medicare Physician Fee Schedule and representative costs from the UCSF billing department. The incremental cost effectiveness ratio (ICER) measured the cost of using PET/CT per percent patient (pt) who avoided a FP.

Results: The rate of de novo metastatic disease was 4.8% (38/799), range 3.6-6.4%. Of the 564 pts with complete records, diagnostic SI varied significantly among the four sites (p &lt; 0.0001). STD was used for most pts at UAB (92.8%, 141/152) and Georgetown (85.7%, 54/63), while PET/CT was used for most pts at UCSF (86.6%, 226/261) and Uminn (63.6%, 56/88). Chest X-ray was used for 29.5% (26/88) at Uminn. There were significantly more pts with FP in the group that received STD (22.1%, 51/231) vs. PET/CT (11.1%, 33/298) (p &lt; 0.05). Mean time between incidental finding on SI to determination of FP was 10.8 days. When controlling for institution, mean time from cancer diagnosis to initiation of neoadjuvant chemotherapy was significantly different between STD (44.3 days) and PET/CT (37.5 days) groups (p &lt; 0.05). When aggregating the four sites using mean costs from the 2018 Medicare Physician Fee Schedule, the mean cost/pt was $1132 for STD vs. $1477 for PET/CT. The mean increase in price from baseline SI costs due to FP workup was $216 (23.6%) for STD vs. $65 (4.6%) for PET/CT. The ICER was $31 per percent pt who avoided a FP. When analyzing UCSF pts alone using representative reimbursements from Medicare, the mean cost/pt was $1236 for STD vs. $1081 for PET/CT; using representative reimbursements from Anthem Blue Cross, the mean cost/pt was $3080 for STD vs. $1662 for PET/CT. The ICERs were -$10 and -$95 per percent pt who avoided a FP, respectively.

Conclusion: As compared to STD metastatic staging workup, PET/CT added value by decreasing FP two-fold. This reduced direct costs of FP workup procedures that took a mean time of 10.8 days to resolve. PET/CT also accelerated treatment start. Reducing the chance of FP workup for metastatic disease is of enormous value to pts. Our data establish the value of PET/CT for staging in our high risk clinical stage II-III trial population and highlight the need for alignment between hospital pricing strategies and payer coverage policies in order to deliver high value care to pts.

Citation Format: Hyland CJ, Varghese F, Yau C, Beckwith H, Khoury K, Varnado W, Hirst G, Chien J, Yee D, Isaacs C, Forero-Torres A, Esserman L, Melisko M, I-SPY2 Consortium. The use of 18F-FDG PET/CT as an initial staging procedure for stage II-III breast cancer reduces false positives, costs, and time to treatment: A multicenter value analysis in the I-SPY2 trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-15-01.

Abstract OT3-04-01: Nivolumab or capecitabine or combination therapy as adjuvant therapy for triple negative breast cancer (TNBC) with residual disease following neoadjuvant chemotherapy: The OXEL study

Background: Long-term follow-up of neoadjuvant studies demonstrates poor clinical outcomes in patients with TNBC who do not achieve pathologic complete response, with only 35% remaining free of recurrence at 10 years. The addition of adjuvant capecitabine in the CREATE-X study prolonged disease free survival and overall survival (OS) in patients with HER2 negative breast cancer with residual invasive disease, with more striking benefit in patients with TNBC. Checkpoint inhibitors have not been approved in breast cancer yet, but recent studies suggest a benefit in combination with chemotherapy and low burden of disease. In the current study, we will evaluate the role of chemoimmunotherapy in the adjuvant setting for patients with TNBC with residual disease after neoadjuvant therapy. We will also investigate the role of the peripheral immunoscore (PIS) in predicting the benefit of immune checkpoint inhibition with or without chemotherapy.

Trial design: OXEL is a pilot open-label three arm randomized study of nivolumab, capecitabine or the combination as adjuvant therapy for 45 patients with residual TNBC after adequate neoadjuvant chemotherapy. Patients enrolled will be randomly assigned to 1 of 3 treatment arms: nivolumab 360 mg iv q3weeks for x 6 cycles; capecitabine 1250mg/m2 po bid D1-D14 q3 weeks x 6 cycles; nivolumab 360mg iv q3weeks + capecitabine 1250mg/m2 po bid D1-D14 q3 weeks x 6 cycles.

Main eligibility criteria: Patients ≥18 years of age with TNBC and ≥1cm of residual disease in the breast and/or node positive disease; receipt of neoadjuvant taxane +/- anthracycline, or platinum, and having completed definitive resection of primary tumor, with no prior use of capecitabine, fluorouracil or immunotherapy, and with no active autoimmune disease or chronic use of systemic steroids.

Specific aims: The primary endpoint is assessing the immunologic effects of capecitabine, nivolumab or the combination in the adjuvant setting by PIS. Additional endpoints include toxicity assessment, distant recurrence free survival (DRFS) and OS at 3-years, association between changes in PIS and circulating tumor DNA at different timepoints with clinical outcome variables and characterization of the immune contexture in residual tumors.

Statistical methods: The study is designed to assess the change in PIS at 6 weeks from baseline in each arm. The sample size of 15 per arm (45 total for 3 arms) will provide preliminary results. A sample size of 15 per arm will have 85% power to detect an effect size of 1 (the difference of the change in PIS from baseline to week 6 between two arms divided by the standard deviation) at 5% significance level.

Present accrual and target accrual: The Institutional Review Board at Georgetown University Medical Center has approved the study. Clinicaltrials.gov NCT03487666. Enrollment of the first patient is expected in July 2018 with a total of 45 patients planned to be recruited. Recruitment sites are MedStar Georgetown University Hospital, MedStar Washington Hospital Center, Hackensack University Medical Center. This trial is supported by Bristol-Meyers Squibb, P30CA051008-25 from NCI, Inivata and the Nina Hyde Center for Breast Cancer Research.

Citation Format: Khoury K, Isaacs C, Gatti-Mays ME, Donahue RN, Schlom J, Wang H, Gallagher C, Graham D, Warren R, Dilawari A, Swain SM, Pohlmann PR, Lynce F. Nivolumab or capecitabine or combination therapy as adjuvant therapy for triple negative breast cancer (TNBC) with residual disease following neoadjuvant chemotherapy: The OXEL study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT3-04-01.

Randomized trial of proactive rapid genetic counseling versus usual care for newly diagnosed breast cancer patients

PURPOSE

Breast cancer patients who carry BRCA1/BRCA2 gene mutations may consider bilateral mastectomy. Having bilateral mastectomy at the time of diagnosis not only reduces risk of a contralateral breast cancer, but can eliminate the need for radiation therapy and yield improved reconstruction options. However, most patients do not receive genetic counseling or testing at the time of their diagnosis. In this trial, we tested proactive rapid genetic counseling and testing (RGCT) in newly diagnosed breast cancer patients in order to facilitate pre-surgical genetic counseling and testing.

METHODS

We recruited newly diagnosed breast cancer patients at increased risk for carrying a BRCA1/2 mutation. Of 379 eligible patients who completed a baseline survey, 330 agreed to randomization in a 2:1 ratio to RGCT (n = 220) versus UC (n = 108). Primary outcomes were genetic counseling and testing uptake and breast cancer surgical decisions.

RESULTS

RGCT led to higher overall (83.8% vs. 54.6%; p < 0.0001) and pre-surgical (57.8% vs. 38.7%; p = 0.001) genetic counseling uptake compared to UC. Despite higher rates of genetic counseling, RGCT did not differ from UC in overall (54.1% vs. 49.1%, p > 0.10) or pre-surgical (30.6% vs. 27.4%, p > 0.10) receipt of genetic test results nor did they differ in uptake of bilateral mastectomy (26.6% vs. 21.8%, p > 0.10).

CONCLUSIONS

Although RGCT yielded increased genetic counseling participation, this did not result in increased rates of pre-surgical genetic testing or impact surgical decisions. These data suggest that those patients most likely to opt for genetic testing at the time of diagnosis are being effectively identified by their surgeons.

Abstract P1-03-06: BRCA1 and BRCA2 mutations in ethnic Lebanese Arab high risk women for hereditary breast cancer

Background: Breast cancer is the most common malignancy in women in Lebanon and Arab countries with 50% of cases below age 50. The incidence of hereditary breast cancer in Lebanese and Arab women is unknown.

Methods: 250 Lebanese women with breast cancer, of young age with or without family history, were recruited at the American University of Beirut Medical Center (AUBMC) between 2009 and 2012. Study was approved by IRB. All signed an informed consent. Risk assessment questionnaire, medical chart review, and whole blood were collected. Coding exons and intron-exon boundaries of BRCA1 and BRCA2 were sequenced. Full BRCA gene sequencing was performed at Institut Jean Perrin, France. Study was funded in part by an Ethnic Research Initiative (ERI) grant awarded by GSK.

Results:

14 out of the 250 patients (5.6%) had a deleterious BRCA mutation (7 BRCA1, 7 BRCA2) and 31 (12.4%) had a variant of uncertain significance (VUS). Table 1 shows deleterious BRCA mutations based on age group and FH.

Deleterious BRCA mutations based on age group and family history TotalAge ≤ 40 (with no FH)Age ≤ 40 (with positive FH)Age 41-50 (with positive FH)Age ≥ 51 (with positive FH)Number of patients25074747527Patients with deleterious mutations (%)14 (5.6%)1 (1.4%)8 (10.8%)4 (5.3%)1 (3.7%)BRCA 170610BRCA 271231

All 7 BRCA1 mutation carriers had a positive family history, were between 32 and 48 years of age, and had Grade 3 IDC with negative ER, PR, HER2 receptors (TNBC). Six BRCA2 mutation carriers had IDC with positive hormone receptors (HR) and 2 had HER2-positive disease. We found 31 VUS. One VUS (BRCA2) was seen in two sisters with breast cancer. One VUS (BRCA2) was seen in 4 patients and another in 2 patients, while 2 VUS (BRCA1) mutations were seen in 2 sets of 2 patients. The significance of these VUS cannot be ascertained at this time. Haplotype analysis is ongoing.

Conclusions:

This is the first large study of ethnic Lebanese Arab women with breast cancer. The prevalence of BRCA deleterious mutations in women with breast cancer who are considered high risk of carrying a BRCA mutation is 5.6% in our total cohort, while in patients ≤40 with positive FH it is 10.6%. Those numbers are lower than expected from US and European populations. Tumor grade and pathology characteristics in this patient population correlated with that previously documented for BRCA1 (TNBC) and BRCA2 (positive HR) associated breast cancers. Our data supports use of young age together with positive FH should be used to select patients for counseling and BRCA testing in Lebanon and Arab countries with resource-sensitive guidelines. Several VUS were found in patients and sisters with breast cancer. The finding that 94.4% of high risk patients had no deleterious BRCA mutations suggests the need to look for alternate gene mutations and other factors that may contribute to the development of breast cancer in these high risk patients. Conclusions regarding haplotypes and diversity will be reported at the meeting.

Citation Format: Nagi El Saghir, Nancy Uhrhammer, Hussein Assi, Katia Khoury, Stephanie Decousous, Yannick Bidet, Sara Jaber, Raghid Charara, Rania Farhat, Ziad Salem, Ali Shamseddine, Arafat Tfayli, Jaber Abbas, Faek Jamali, Muhieddine Seoud, Deborah Armstrong, Yves-Jean Bignon, Nathalie Zgheib. BRCA1 and BRCA2 mutations in ethnic Lebanese Arab high risk women for hereditary breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-03-06.

[Acutely ruptured intracranial aneurysms treated with GDC coils. Results from a single center over a period of 5 years]

PURPOSE

We prospectively reviewed the clinical results of acutely ruptured cerebral aneurysms treated with GDC over a 5 year period, in order to characterize death and dependency factors.

METHODS

Between 1997 and 2002, 229 patients (254 aneurysms treated, 140 females, 89 males; mean age: 51 years) with aneurysmal subarachnoid hemorrhage were treated with GDC (Boston Scientific Neurovascular, Fremont, CA) once the anatomical conditions of feasibility had been achieved. Over 90% of the aneurysms treated (mean size: 5,8 mm) were located in the anterior circulation. The anterior communicating artery complex (87 cases), the posterior aspect of the internal carotid artery (65 cases), and the middle cerebral artery (49 cases) were most commonly treated.

RESULTS

At the end of the initial hospitalization period, 14 patients (6.1%) died. Major procedural complications were associated with perforation of the aneurysmal sac in 9 patients (3.9%), thromboembolic events in 10 patients (4.3%) which resulted in 2 deaths (0.8%) and permanent neurologic morbidity in 7 patients (3%). The univariate analysis demonstrated no correlation between death and time-to-treatment, the topography of the aneurysm, or the occurrence of treatment related complications. The results of the logistical regression model demonstrated that the clinical score upon entry, and the occurrence of delayed ischemia were the only independent factors correlated with patient death. The prognostic factors affecting the degree of sequellae identified by the logistical regression model were the clinical score upon admission, age, treatment related complications, and pulmonary complications.

CONCLUSIONS

Endovascular treatment of ruptured anterior circulation aneurysms with GDC, including MCA aneurysms, is associated with low morbidity and allows good overall outcomes in patients with subarachnoid hemorrhage. A better understanding of dependency factors associated with endovascular coiling will foster further technical advances in order to improve the treatment of small and medium sized ruptured aneurysms.

[Muscular manifestations in periodic disease]

Between 1976 and 1983, the authors studied 50 new patients affected with periodic disease. 16 of them-mean age: 29-presented muscular manifestations. They may be grouped into two clinical aspects: muscular pain and contractures. The authors consider that these symptoms, first described in 1945, are an inherent part of the clinical picture of the disease. They discuss their relationship with periarteritis nodosa and remind the fact that their pathogenesis remains unknown.

Cerebral hypoxia from bicarbonate infusion in diabetic acidosis

To study the delivery of oxygen to the cerebral tissue during metabolic acidosis and its therapy with bicarbonate (NaHCO3), oxygen partial pressure of the cisternal fluid was measured in 12 experiments of HCl-induced acidemia and eight experiments of diabetic ketoacidosis in 16 unanesthetized dogs. Full correction of acidosis with bicarbonate caused a significant (P less than 0.05) decrease in Pcsf 2: in the HCl acidotic dogs, Pcsfo2 decreased from 53.9 +/- 2.2 torr to 45.9 +/- 2.3 torr within one hour; in the ketoacidotic dogs, Pcsfo2 decreased for 48.5 +/- 5.4 torr to 26.7 +/- 6.6 torr within six hours. In the ketoacidotic dogs not treated with bicarbonate, there was no significant change in Pcsfo2. An inverse relationship (P less than 0.01) between the cisternal lactic acid level and the cisternal PO2 was also observed. It is concluded that NaHCO3 therapy in diabetic ketoacidosis decreases the cerebral O2 availability and that cerebral hypoxia contributes to the brain dysfunction encountered after the initiation of such therapy in acidemia.

The measurement of volatile chromium in biological materials

Chromium is an essential trace element in mammals since dietary chromium deficiency results in glucose intolerance due to decreased sensitivity to insulin. In humans, both adults and children with glucose intolerance have been improved by treatment with chromium. Furthermore, chromium deficiency has been implicated as a causative factor in hypercholesterolemia and atherosclerosis. However, little is known of the metabolism of chromium in humans, primarily because of analytical difficulties. The biologically active form of chromium is the "glucose tolerance factor" (GTF) which is a co-ordination complex of trivalent chromium with nicotinic acid and certain amino acids. At physiological pH, ionic chromium as a simple inorganic salt is insoluble in water, but trivalent chromium forms stable complexes with ascorbic acid, amino acids and other substances present in blood and tissue. Chromium is present in serum, bound to protein and also as dialysable or ultrafiltrable chromium (free chromium). The free chromium includes G.T.F. and other coordination complexes and represents the metabolically active form of the element; the ratio free/protein bound chromium in serum varies within the individual according to the diet and the metabolic state.

Glucose and insulin metabolism in Friedreich's ataxia

Our prospective survey of 50 ataxic patients confirms the previous finding of frequent clinical or chemical diabetes in Friedreich's ataxia. Eighteen percent of our typical cases have clinical diabetes and 40% at least an abnormal glucose tolerance curve. However, this finding does not appear to be specific to that form of ataxia. Furthermore, we have shown that most patients with ataxia have normal or low fasting insulin levels, but a hyperinsulinic response to a glucose load.

[Periodic disease (familial paroxysmal polyseritis). 52 cases]

On the basis of well defined diagnostic criteria, the authors conclude that periodic disease affects males in particular. It commences before the age of 20 years in 80 percent of cases. In particular it occurs in Armenian and Shiite communities. Its evolution is normally benign ; amyloidosis is found in only 8 percent of cases. Joint manifestations are found in 48 percent of cases and may take on different aspects and occur in several different sites : myaglia or arthralgia, monoarthitis, oligoarthritis, polyarthritis, neck or sacroiliac pain. The authors have not noted prolonged peripheral joint episodes. No cases of amyloidosis were diagnosed before the appearance of the clinical signs of the disease. An autosomal, dominant heredity with incomplete penetration seems to be the most likely hypothesis.

Preliminary report on a mass screening program for neonatal hypothyroidism

We have recently developed an immunoassay that can measure thyroxine rapidly and accurately in the eluate of 40 mul of dried blood spotted on filter paper at the fifth day of life. The method is completely automated and by using the samples received by the Central Laboratory of the Quebec Network for Genetic Medicine and their follow-up facilities, we are now screening every newborn in the province of Quebec for neonatal hypothyroidism. To date, from 47,000 measurements, three newborn infants with abnormally low TBG and seven hypothyroid infants have been detected. From these data we conclude that the frequency of congenital hypothyroidism is about one in 7,000 births and that our method is effective in detecting thyroid hormone abnormalities with an acceptable percentage of false positive measurements; no false negative results have occurred to our knowledge.