Perez, Edith A.

Abstract Background: Trastuzumab (H), a monoclonal antibody against HER2, has revolutionized the treatment for HER2-positive breast cancer. Besides inhibiting downstream signaling of HER2, several studies showed that H also exerts its anti-tumor activity via immune-related mechanisms. While H is quite effective in preventing recurrence, significant numbers of patients still develop recurrence despite adjuvant H-based chemotherapy. In this study, we analyzed immune-related genes that were associated with poor outcome in N9831. Methods: NanoStringTM technology was used to quantify mRNA of immune-related genes in baseline samples from 1,280 patients in N9831. In N9831, patients in arm A were treated with chemotherapy alone (AC-T), arm B received chemotherapy followed by sequential H (AC-T-H), and arm C received H concurrently with chemotherapy (AC-TH). Cox proportional hazard ratio (HR) was used to determine the association of each immune-related gene with recurrence free survival (RFS). Different immune subset signatures, including CD45, CD8, cytotoxic-cells, and T-cells were analyzed using algorithms developed by NanoString. Results: With the median follow up of 10.6 years, we identified a total 77 genes that were associated with improved outcome in arm C. Among these 77 genes, there were 20 tumor necrosis factor (TNF)-related genes. Of those, only OX40 (TNFRSF4) and its ligand TNFSF4 have interaction p < 0.10. Interestingly, we found uneven distribution of OX40 expression in the N9831 specimens. Approximately, 9.5% of HER2-positive breast cancer expressed OX40 at distinctly low level. Low expression of OX40 was significantly associated with HR positivity (OX40 low 61% vs. OX40 high 51%, p 0.003) and larger tumor size but not patients’ age, tumor grade, and lymph node status. Low expression of OX40 was significantly associated with low mTIL-CD45, CD8, cytotoxic-cells, and T-cells immune signature scores. Tumors with low OX40 expression had significantly lower levels of CTLA4 (p 9.11e-71) and PD-L1 expressions (p 2.49e-92). Low expression of OX40 is associated with poorer outcome among patients treated with H in both sequential (HR 0.88, 95% CI 0.79-0.98, p 0.022) and concurrent arms (HR 0.86, 95%CI 0.76-0.98, p 0.027) but not in chemotherapy only arm (HR 0.9, 95%CI 0.90-1.09, p 0.8). Similar findings were observed with its ligand TNFSF4 in arm A (HR 1.02, 95%CI 0.92-1.15, p 0.68), arm B (HR 0.87, 95%CI 0.76-0.99, p 0.04), and arm C (HR 0.81, 95%CI 0.68-0.95, p 0.01). Conclusion: Our study suggests that pre-existing expression of OX40 and its ligand TNFSF4 are prognostic and may also be predictive of adjuvant H benefit. Patients with distinctly low level of OX40 had poor outcome despite adjuvant H-based adjuvant chemotherapy. Our study provides a rationale to further evaluate the strategy to increase immune activation to improve outcome in this group of patients. Citation Format: Saranya Chumsri, Daniel J. Serie, Afshin Mashadi-Hossein, Sarah Warren, Alvaro Moreno-Aspitia, Geraldo Colon-Otero, Keith L. Knutson, Edith A. Perez, E. Aubrey Thompson. Correlation of immune co-stimulatory molecule OX40 and outcome in trastuzumab treated HER2-positive breast cancer patients in the NCCTG-N9831 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1682. doi:10.1158/1538-7445.AM2017-1682

Purpose Trastuzumab and pertuzumab are human epidermal growth factor receptor 2 (HER2) –targeted monoclonal antibodies, and trastuzumab emtansine (T-DM1) is an antibody–drug conjugate that combines the properties of trastuzumab with the cytotoxic activity of DM1. T-DM1 demonstrated encouraging efficacy and safety in a phase II study of patients with previously untreated HER2-positive metastatic breast cancer. Combination T-DM1 and pertuzumab showed synergistic activity in cell culture models and had an acceptable safety profile in a phase Ib and II study. Methods In the MARIANNE study, 1,095 patients with centrally assessed, HER2-positive, advanced breast cancer and no prior therapy for advanced disease were randomly assigned 1:1:1 to control (trastuzumab plus taxane), T-DM1 plus placebo, hereafter T-DM1, or T-DM1 plus pertuzumab at standard doses. Primary end point was progression-free survival (PFS), as assessed by independent review. Results T-DM1 and T-DM1 plus pertuzumab showed noninferior PFS compared with trastuzumab plus taxane (median PFS: 13.7 months with trastuzumab plus taxane, 14.1 months with T-DM1, and 15.2 months with T-DM1 plus pertuzumab). Neither experimental arm showed PFS superiority to trastuzumab plus taxane. Response rate was 67.9% in patients who were treated with trastuzumab plus taxane, 59.7% with T-DM1, and 64.2% with T-DM1 plus pertuzumab; median response duration was 12.5 months, 20.7 months, and 21.2 months, respectively. The incidence of grade ≥ 3 adverse events was numerically higher in the control arm (54.1%) versus the T-DM1 arm (45.4%) and T-DM1 plus pertuzumab arm (46.2%). Numerically fewer patients discontinued treatment because of adverse events in the T-DM1 arms, and health-related quality of life was maintained for longer in the T-DM1 arms. Conclusion T-DM1 showed noninferior, but not superior, efficacy and better tolerability than did taxane plus trastuzumab for first-line treatment of HER2-positive, advanced breast cancer.

Purpose In 1998, the US Food and Drug Administration (FDA) approved human epidermal growth factor receptor 2 (HER2) testing guidelines to determine eligibility for HER2-directed therapy (HDT) in breast cancer. ASCO and the College of American Pathologists published immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) HER2 testing guidelines in 2007 (AC2007) and updated these guidelines in 2013 (AC2013). We compared the HER2 FISH amplification frequency using these three guidelines. Methods Patient samples that were sent to the Mayo Clinic cytogenetics laboratory for FISH testing (n = 2,851; from November 2013 to October 2014) were analyzed. Frequency of HER2 FISH amplification was examined and impact of AC2013 assessed. Results IHC results were available for 1,922 patient samples (67.4%), 137 of which were from Mayo Clinic. Distribution was 2.4% IHC 0, 7.9% IHC 1+, 84.8% IHC 2+, and 2.5% IHC 3+. Among IHC 2+ patients, HER2 FISH positivity was 11.8% (FDA), 9.4% (AC2007), and 24.1% (AC2013). Overall, 11.8% (n = 339) were positive with a FISH ratio ≥ 2.0, 1.3% (n = 35) with a FISH ratio ≥ 2.0 despite a HER2 signal < 4.0, and 3.0% (n = 86) with HER2 signal ≥ 6.0 despite FISH ratio < 2.0. Among 405 patients (14.2%) who were initially considered FISH-equivocal (ratio < 2.0 with HER2 signal ≥ 4.0, but < 6.0; AC2013), use of an alternative chromosome 17 probe reassigned 212 (7.4% overall) patients to FISH-positive and 36 (1.3% overall) patients to FISH-negative, whereas 157 (5.5% overall) patients remained equivocal. Final HER2 positivity with AC2013 (23.6%) was increased (P < .001) compared with FDA (13.1%) and AC2007 (11%) guidelines. Conclusion In a reference laboratory cohort that was highly enriched for IHC 2+ patient samples, AC2013 guidelines led to a larger number of FISH-equivocal patients. Approximately one half of these FISH-equivocal patients (7.4% overall) became HER2-positive upon alternative FISH probe testing. However, these patients would not have participated in the pivotal HDT trials. Clinical utility data on HDT benefit in these patients and other special subsets are needed.

Abstract The addition of trastuzumab to chemotherapy extends survival among patients with HER2+ breast cancer. Prior work showed that trastuzumab and chemotherapy augments HER2 extracellular domain (ECD)-specific antibodies. The current study investigated whether combination therapy induced immune responses beyond HER2-ECD and, importantly, whether those immune responses were associated with survival. Pretreatment and posttreatment sera were obtained from 48 women with metastatic HER2+ breast cancer on NCCTG (now Alliance for Clinical Trials in Oncology) studies, N0337 and N983252. IgG to HER2 intracellular domain (ICD), HER2-ECD, p53, IGFBP2, CEA, and tetanus toxoid were examined. Sera from 25 age-matched controls and 26 surgically resected HER2+ patients were also examined. Prior to therapy, some patients with metastatic disease had elevated antibodies to IGFBP2, p53, HER2-ICD, HER2-ECD, and CEA, but not to tetanus toxin, relative to controls and surgically resected patients. Treatment augmented antibody responses to HER2-ICD in 69% of metastatic patients, which was highly associated with improved progression-free survival (PFS; HR = 0.5, P = 0.0042) and overall survival (OS; HR = 0.7, P = 0.038). Augmented antibody responses to HER2-ICD also correlated (P = 0.03) with increased antibody responses to CEA, IGFBP2, and p53, indicating that treatment induces epitope spreading. Paradoxically, patients who already had high preexisting immunity to HER2-ICD did not respond to therapy with increased antibodies to HER2-ICD and demonstrated poorer PFS (HR = 1.6, P &lt; 0.0001) and OS (HR = 1.4, P = 0.0006). Overall, the findings further demonstrate the importance of the adaptive immune system in the efficacy of trastuzumab-containing regimens. Cancer Res; 76(13); 3702–10. ©2016 AACR.

Purpose To provide formal expert consensus–based recommendations to practicing oncologists and others on the management of brain metastases for patients with human epidermal growth factor receptor 2 (HER2) –positive advanced breast cancer. Methods The American Society of Clinical Oncology (ASCO) convened a panel of medical oncology, radiation oncology, guideline implementation, and advocacy experts and conducted a systematic review of the literature. When that failed to yield sufficiently strong quality evidence, the Expert Panel undertook a formal expert consensus–based process to produce these recommendations. ASCO used a modified Delphi process. The panel members drafted recommendations, and a group of other experts joined them for two rounds of formal ratings of the recommendations. Results No studies or existing guidelines met the systematic review criteria; therefore, ASCO conducted a formal expert consensus–based process. Recommendations Patients with brain metastases should receive appropriate local therapy and systemic therapy, if indicated. Local therapies include surgery, whole-brain radiotherapy, and stereotactic radiosurgery. Treatments depend on factors such as patient prognosis, presence of symptoms, resectability, number and size of metastases, prior therapy, and whether metastases are diffuse. Other options include systemic therapy, best supportive care, enrollment onto a clinical trial, and/or palliative care. Clinicians should not perform routine magnetic resonance imaging (MRI) to screen for brain metastases, but rather should have a low threshold for MRI of the brain because of the high incidence of brain metastases among patients with HER2-positive advanced breast cancer.

Abstract Purpose: This study investigated the association between tumor MYC protein expression and disease-free survival (DFS) of patients randomized to receive chemotherapy alone (Arm A) or chemotherapy with sequential (Arm B) or concurrent trastuzumab (Arm C) in the N9831 (Alliance) adjuvant HER2+ trastuzumab breast cancer trial. Experimental Design: This analysis included 1,736 patients randomized to Arms A, B, and C on N9831. Nuclear MYC protein expression was determined in tissue microarray sections containing three biopsies per patient or whole tissue sections using standard immunohistochemistry (clone 9E10). A tumor was considered positive for MYC protein overexpression (MYC+) if the nuclear 3+ staining percentage was more than 30%. Results: Five hundred and seventy-four (33%) tumors were MYC+. MYC+ was associated with hormone receptor positivity (χ2, P = 0.006), tumors 2 cm or more (χ2, P = 0.02), and a higher rate of nodal positivity (χ2, P &lt; 0.001). HRs for DFS (median follow-up: 6.1 years) for Arm C versus A were 0.52 (P = 0.006) and 0.65 (P = 0.006) for patients with MYC+ and MYC− tumors, respectively (Pinteraction = 0.40). For Arm B versus A, HRs for patients with MYC+ and MYC− tumors were 0.79 (P = 0.21) and 0.74 (P = 0.04), respectively (Pinteraction = 0.71). For Arm C versus B, HRs for patients with MYC+ and MYC− tumors were 0.56 (P = 0.02) and 0.89 (P = 0.49), respectively (Pinteraction = 0.17). Conclusions: Our data do not support an impact of tumor MYC protein expression on differential benefit from adjuvant trastuzumab. Clin Cancer Res; 19(20); 5798–807. ©2013 AACR.

BACKGROUNDFluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) tests are commonly used to assess human epidermal growth factor 2 (HER2) status of tumors in patients with breast cancer. This analysis evaluates the likely cost‐effectiveness of expanded retesting to assess HER2 tumor status in women with early stage breast cancer.METHODSWe developed a decision‐analytic model to estimate the incremental cost‐effectiveness ratio (ICER) of expanded reflex testing from a US payer perspective. Expanded reflex testing is defined as retesting tumor specimens from patients whose tumors are IHC0, IHC1+, or FISH‐negative on their first test. In the base case, we assumed that 80% of patient tumors are initially IHC‐tested and 20% are FISH‐tested. Testing outcomes for IHC and FISH with and without retesting were based on published meta‐analyses. The cost of tests and treatment and the long‐term health outcomes were obtained from the literature.RESULTSIn the base case, we estimated that 2.27% of women who received expanded reflex testing would be HER2‐positive and receive trastuzumab treatment: the projected ICER was $36,721 per life year or $39,745 per quality‐adjusted life year (QALY). This varied between $47,100 per QALY and $35,500 per QALY if we assumed that 1%‐8% of patients retested were then HER2+, respectively. The results of deterministic and probabilistic sensitivity analysis were robust. This strategy would result in 4700 (2000‐17,000) patients being eligible to receive trastuzumab treatment annually.CONCLUSIONSRetesting patients who are IHC0, IHC1+, or FISH‐negative is projected to be a cost‐effective clinical strategy. Cancer 2013;119:3113–3122. © 2013 American Cancer Society.

BACKGROUNDIncreased soluble human epidermal growth factor receptor 2 (sHER2) is an indicator of a poor prognosis in HER2‐positive metastatic breast cancer. In this study, the authors evaluated levels of sHER2 during treatment and at the time of disease recurrence in the adjuvant North Central Cancer Treatment Group N9831 clinical trial.METHODSThe objectives were to describe sHER2 levels during treatment and at the time of recurrence in patients who were randomized to treatment arms A (standard chemotherapy), B (standard chemotherapy with sequential trastuzumab), and C (standard chemotherapy with concurrent trastuzumab). Baseline samples were available from 2318 patients, serial samples were available from 105 patients, and recurrence samples were available from 124 patients. The cutoff sHER2 value for the assay was 15 ng/mL. Statistical methods included repeated measures linear models, Wilcoxon rank‐sum tests, and Cox regression models.RESULTSThere were differences between groups in terms of age, menopausal status, and hormone receptor status. Within treatment arms A, B, and C, patients who had baseline sHER2 levels ≥15 ng/mL had worse disease‐free survival than patients who had baseline sHER2 levels <15 ng/mL (arm A: hazard ratio, 1.81; P = .0014; arm B: hazard ratio, 2.08; P = .0015; arm C: hazard ratio, 1.96; P = .01). Among the 124 patients who experienced disease recurrence, sHER2 levels increased from baseline to the time of recurrence in arms A and B but remained unchanged in arm C. Patients who had recurrence sHER2 levels ≥15 ng/mL had a shorter survival after recurrence with a 3‐year overall survival rate of 51% compared with 77% for those who had recurrence sHER2 levels <15 ng/mL (hazard ratio, 2.36; 95% confidence interval, 1.19‐4.70; P = .01).CONCLUSIONSIn patients with early stage, HER2‐positive breast cancer, a high baseline sHER2 level was identified as a prognostic marker associated with shorter disease‐free survival, and a high sHER2 level at recurrence was predictive of shorter survival. Cancer 2013;119:2675–2682. © 2013 American Cancer Society.