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Contains fulltext : 225429.pdf (Publisher’s version ) (Open Access) IMPORTANCE: Checkpoint inhibitors targeting programmed cell death 1 or its ligand (PD-L1) as monotherapies or in combination with anti-cytotoxic T-lymphocyte-associated antigen 4 have shown clinical activity in patients with metastatic non-small cell lung cancer. OBJECTIVE: To compare durvalumab, with or without tremelimumab, with chemotherapy as a first-line treatment for patients with metastatic non-small cell lung cancer. DESIGN, SETTING, AND PARTICIPANTS: This open-label, phase 3 randomized clinical trial (MYSTIC) was conducted at 203 cancer treatment centers in 17 countries. Patients with treatment-naive, metastatic non-small cell lung cancer who had no sensitizing EGFR or ALK genetic alterations were randomized to receive treatment with durvalumab, durvalumab plus tremelimumab, or chemotherapy. Data were collected from July 21, 2015, to October 30, 2018. INTERVENTIONS: Patients were randomized (1:1:1) to receive treatment with durvalumab (20 mg/kg every 4 weeks), durvalumab (20 mg/kg every 4 weeks) plus tremelimumab (1 mg/kg every 4 weeks, up to 4 doses), or platinum-based doublet chemotherapy. MAIN OUTCOMES AND MEASURES: The primary end points, assessed in patients with ≥25% of tumor cells expressing PD-L1, were overall survival (OS) for durvalumab vs chemotherapy, and OS and progression-free survival (PFS) for durvalumab plus tremelimumab vs chemotherapy. Analysis of blood tumor mutational burden (bTMB) was exploratory. RESULTS: Between July 21, 2015, and June 8, 2016, 1118 patients were randomized. Baseline demographic and disease characteristics were balanced between treatment groups. Among 488 patients with ≥25% of tumor cells expressing PD-L1, median OS was 16.3 months (95% CI, 12.2-20.8) with durvalumab vs 12.9 months (95% CI, 10.5-15.0) with chemotherapy (hazard ratio [HR], 0.76; 97.54% CI, 0.56-1.02; P = .04 [nonsignificant]). Median OS was 11.9 months (95% CI, 9.0-17.7) with durvalumab plus tremelimumab (HR vs chemotherapy, 0.85; 98.77% CI, 0.61-1.17; P = .20). Median PFS was 3.9 months (95% CI, 2.8-5.0) with durvalumab plus tremelimumab vs 5.4 months (95% CI, 4.6-5.8) with chemotherapy (HR, 1.05; 99.5% CI, 0.72-1.53; P = .71). Among 809 patients with evaluable bTMB, those with a bTMB ≥20 mutations per megabase showed improved OS for durvalumab plus tremelimumab vs chemotherapy (median OS, 21.9 months [95% CI, 11.4-32.8] vs 10.0 months [95% CI, 8.1-11.7]; HR, 0.49; 95% CI, 0.32-0.74). Treatment-related adverse events of grade 3 or higher occurred in 55 (14.9%) of 369 patients who received treatment with durvalumab, 85 (22.9%) of 371 patients who received treatment with durvalumab plus tremelimumab, and 119 (33.8%) of 352 patients who received treatment with chemotherapy. These adverse events led to death in 2 (0.5%), 6 (1.6%), and 3 (0.9%) patients, respectively. CONCLUSIONS AND RELEVANCE: The phase 3 MYSTIC study did not meet its primary end points of improved OS with durvalumab vs chemotherapy or improved OS or PFS with durvalumab plus tremelimumab vs chemotherapy in patients with ≥25% of tumor cells expressing PD-L1. Exploratory analyses identified a bTMB threshold of ≥20 mutations per megabase for optimal OS benefit with durvalumab plus tremelimumab. TRIAL REGISTRATION: ClinicalT rials.gov Identifier: NCT02453282.

The phase 3 MYSTIC study of durvalumab ± tremelimumab versus chemotherapy in metastatic non-small-cell lung cancer (NSCLC) patients with tumor cell (TC) programmed cell death ligand 1 (PD-L1) expression ≥ 25% did not meet its primary endpoints. We report patient-reported outcomes (PROs).Treatment-naïve patients were randomized (1:1:1) to durvalumab, durvalumab + tremelimumab, or chemotherapy. PROs were assessed in patients with PD-L1 TC ≥ 25% using EORTC Quality of Life Questionnaire (QLQ)-C30/LC13. Changes from baseline (12 months) for prespecified PRO endpoints of interest were analyzed by mixed model for repeated measures (MMRM) and time to deterioration (TTD) by stratified log-rank tests.There were no between-arm differences in baseline PROs (N = 488). Between-arm differences in MMRM-adjusted mean changes from baseline favored at least one of the durvalumab-containing arms versus chemotherapy (nominal P.01) for C30 fatigue: durvalumab (-9.5; 99% confidence interval [CI], -17.0 to -2.0), durvalumab + tremelimumab (-11.7; 99% CI, -19.4 to -4.1); and for C30 appetite loss: durvalumab (-11.9; 99% CI, -21.1 to -2.7). TTD was longer with at least one of the durvalumab-containing arms versus chemotherapy (nominal P.01) for global health status/quality of life: durvalumab (hazard ratio [HR] = 0.7; 95% CI, 0.5-1.0), durvalumab + tremelimumab (HR = 0.7; 95% CI, 0.5-1.0); and for physical functioning: durvalumab (HR = 0.6; 95% CI, 0.4-0.8), durvalumab + tremelimumab (HR = 0.6; 95% CI, 0.5-0.9) (both C30); as well as for the key symptoms of dyspnea: durvalumab (HR = 0.6; 95% CI, 0.5-0.9), durvalumab + tremelimumab (HR = 0.7; 95% CI, 0.5-1.0) (both LC13); fatigue: durvalumab + tremelimumab (HR = 0.6; 95% CI, 0.4-0.8); and appetite loss: durvalumab (HR = 0.5; 95% CI, 0.4-0.7), durvalumab + tremelimumab (HR = 0.7; 95% CI, 0.5-0.9) (both C30).Durvalumab ± tremelimumab versus chemotherapy reduced symptom burden and improved TTD of PROs, suggesting it had no detrimental effects on quality of life in metastatic NSCLC patients.

9560 Background: In Part 1 of the phase II CheckMate 568 study (NCT02659059), NIVO + IPI was active and tolerable in patients (pts) with advanced NSCLC. The addition of chemo to dual immune checkpoint inhibitor therapy may further improve initial disease control. We report results from Part 2 of CheckMate 568, which evaluates NIVO + IPI combined with 2 cycles of chemo in pts with advanced treatment-naive NSCLC. Methods: Adult pts with untreated stage IV NSCLC received NIVO 360 mg Q3W + IPI 1 mg/kg Q6W combined with 2 cycles of histology-based platinum-doublet chemo, followed by NIVO + IPI without chemo until disease progression/unacceptable toxicity for ≤ 2 years. The primary endpoints were dose-limiting toxicity (DLT) within the first 9 weeks and safety/tolerability. Treatment was considered safe if ≤ 25% of at least 22 evaluable pts had a DLT. DLTs included but were not limited to: uncontrolled grade 3 non-skin treatment-related adverse events (TRAEs), grade 4 TRAEs, grade 2 treatment-related pneumonitis not resolved within 14 days, and treatment-related hepatic function abnormalities. Results: In total, 36 pts received treatment; 97% of pts completed 2 cycles of chemo combined with NIVO + IPI. Three pts discontinued IPI while continuing NIVO. Minimum follow-up was 14.9 months. Only 1 (3%) pt experienced a DLT (transient, asymptomatic grade 3 AST and ALT elevation) within the first 9 weeks. The elevation occurred on cycle 1, day 21 and resolved 2 weeks later with discontinuation of IPI, delay of NIVO, and treatment with prednisone; chemo was continued throughout and NIVO was restarted thereafter without recurrent toxicity. Grade 3–4 TRAEs occurred in 21 (58%) pts. Eight (22%) pts experienced a TRAE leading to discontinuation, most commonly colitis, encephalopathy, pneumonitis, and arthralgia (each in 2 [6%] pts); these events occurred outside of the 9-week window for DLT assessment. The most common select TRAEs (defined as AEs of potential immunologic causes) were skin related (18 [50%] pts); the most common grade 3–4 select TRAEs were endocrine (3 [8%] pts), skin related, gastrointestinal, and pulmonary (each in 2 [6%] pts). No treatment-related deaths occurred. Updated safety in addition to efficacy data will be presented. Conclusions: In pts with untreated advanced NSCLC, the addition of 2 cycles of platinum-doublet chemo to NIVO + tumor-optimized IPI was tolerable. No unexpected safety signals were observed. Clinical trial information: NCT02659059 .

9563 Background: Pembrolizumab (P) is an immune checkpoint inhibitor (CPI) approved to treat 1L advanced NSCLC pts with high PD-L1 expression. PEG + CPI has demonstrated promising efficacy in NSCLC pts in a phase I trial (IVY; NCT02009449; Naing et al., 2019 Lancet Oncol), providing rationale for this randomized phase II trial (CYPRESS 1; NCT03382899). Methods: CYPRESS 1 was an open label phase II trial, for treatment-naïve, ECOG 0-1, PD-L1 high (22C3 clone TPS ≥ 50%), Stage IV NSCLC pts, without known EGFR/ALK mutations. Pts were randomized 1:1 to arm P (received 200mg IV on day 1 of a 21-day cycle) v. arm PEG+P (received P as above + PEG daily of 0.8 mg if weight ≤80kg and 1.6mg if weight> 80 kg up to 35 cycles in each arm). Pts were stratified by tumor histology and must have no prior history of cancer or prior CPI therapy. Primary endpoint was ORR (per RECIST v1.1 by investigator) Secondary endpoints included PFS, OS, and safety. Exploratory endpoints included ORR and PFS by blinded independent central review (BICR). Immune activation biomarkers (baseline and change from baseline) were assessed by serum immunoassay, IHC, and sequencing. Results: As of Dec 6, 2019, 101 pts were randomized to PEG+P (n=51) or P (n=50). Median follow-up time was 10.0 months (95% CI [8.4, 11.1]). Results for PEG+P versus P were: ORR per investigator was 47% v. 44% (p=0.76), ORR per BICR was 53% v. 46%(p=0.78), mPFS per investigator was 6.3 v. 6.1 months with HR = 0.94 (95% CI [0.54, 1.63];p=0.82), mPFS per BICR was 6.4 v. 7.2 months with HR = 1.10 (95%CI [0.62, 1.96]; p=0.74), and mOS was 16.3 months v. not reached with HR = 1.36 (95% CI [0.66, 2.77]; p-value=0.40). Gr ≥3 treatment related adverse events (TRAEs) were 62% for PEG+P versus 19% for P. Gr ≥3 TRAEs with ≥10% incidence included anemia (20% vs. 0%) and thrombocytopenia (12% vs. 2%). Biomarker data on immunostimulatory signals of the IL-10R pathway will be included. Conclusions: Adding PEG to P did not lead to improvement in ORR, PFS, or OS, in 1L advanced NSCLC with high PD-L1 expression. PEG+P arm demonstrated expected safety profile but overall higher toxicity compared to pembrolizumab alone. Clinical trial information: NCT03382899 .

e21744 Background: Nivolumab (N) is an immune checkpoint inhibitor (CPI) approved to treat post-platinum NSCLC as monotherapy. PEG in combination with N has demonstrated promising efficacy in NSCLC pts in a phase I trial (IVY; NCT02009449; Naing et al., 2019 Lancet Oncol), providing rationale for this randomized phase II trial (CYPRESS 2). Methods: CYPRESS 2 was an open label phase II trial, for ECOG 0-1, PD-L1 negative or low (TPS 0-49%), Stage IV NSCLC pts, without known EGFR/ALK mutations. Pts were randomized 1:1 to arm N (240 mg every 14-days or 480 mg every 28-days as decided by investigator) v. arm PEG+N (received N as above + PEG daily of 0.8 mg if weight ≤80kg and 1.6mg if weight > 80 kg). Pts were stratified by tumor histology and smoking history and must have no prior history of cancer or CPI therapy. Primary endpoint was ORR (per RECIST v 1.1 per investigator). Secondary endpoints included PFS, OS, and safety. Exploratory endpoints included immune activation biomarkers (baseline and change from baseline), assessed by immunoassay. Results: As of Aug 28, 2019, 52 pts were randomized to PEG+N (n=27) or N (n=25). Median follow-up time was 11.6 months. The following results were found for PEG+N versus N: ORR 14.8% v. 12.0%, mPFS 1.9 v. 1.9 months with HR = 1.01 (95% CI [0.52, 1.95]), mOS 6.7 v. 10.7 months with HR = 1.87 (95% CI [0.77, 4.53]). Gr ≥3 treatment related adverse events (TRAEs) for PEG+N versus N were 70.4% vs. 16.7%. Gr 3 TRAEs of ≥10% incidence included anemia (40.7% v. 0%), fatigue (18.5% v. 0%), and thrombocytopenia (14.8% v. 0%). In PEG+N arm, increased circulating IL-18, Granzyme B, FasL, and IFNg levels and decreased TGFb levels were observed on treatment. Conclusions: Exploratory pharmacodynamic results were consistent with immunostimulatory signals of the IL-10R pathway. Despite evidence of biological effect, adding PEG to N did not lead to improvement in ORR, PFS, or OS in post-platinum advanced NSCLC with no or low PD-L1 expression. PEG+N arm demonstrated expected safety profile but overall higher toxicity compared to nivolumab alone. Clinical trial information: NCT03382912.

Introduction For patients with recurrent SCLC, topotecan remains the only approved second-line treatment, and the outcomes are poor. CheckMate 032 is a phase 1/2, multicenter, open-label study of nivolumab or nivolumab plus ipilimumab in SCLC or other advanced/metastatic solid tumors previously treated with one or more platinum-based chemotherapies. We report results of third- or later-line nivolumab monotherapy treatment in SCLC. Methods In this analysis, patients with limited-stage or extensive-stage SCLC and disease progression after two or more chemotherapy regimens received nivolumab monotherapy, 3 mg/kg every 2 weeks, until disease progression or unacceptable toxicity. The primary end point was objective response rate. Secondary end points included duration of response, progression-free survival, overall survival, and safety. Results Between December 4, 2013, and November 30, 2016, 109 patients began receiving third- or later-line nivolumab monotherapy. At a median follow-up of 28.3 months (from first dose to database lock), the objective response rate was 11.9% (95% confidence interval: 6.5–19.5) with a median duration of response of 17.9 months (range 3.0–42.1). At 6 months, 17.2% of patients were progression-free. The 12-month and 18-month overall survival rates were 28.3% and 20.0%, respectively. Grade 3 to 4 treatment-related adverse events occurred in 11.9% of patients. Three patients (2.8%) discontinued because of treatment-related adverse events. Conclusions Nivolumab monotherapy provided durable responses and was well tolerated as a third- or later-line treatment for recurrent SCLC. These results suggest that nivolumab monotherapy is an effective third- or later-line treatment for this patient population.

9048 Background: MYSTIC, an open-label, Phase 3 trial of first-line D (anti-PD-L1) ± T (anti-CTLA-4) vs platinum CT in mNSCLC, showed an improvement in overall survival (OS) with D vs CT in pts with tumor cell PD-L1 expression ≥25% (TC ≥25% [primary analysis population]; D vs CT, HR 0.76 [97.54% CI 0.56–1.02], p = 0.036; D+T vs CT, HR 0.85 [98.77% CI 0.61–1.17], p = 0.202). Here we summarize PROs from MYSTIC. Methods: Immunotherapy/CT-naïve mNSCLC pts were randomized (1:1:1) to D, D+T, or CT. Symptoms, function, and global health status/quality of life (QoL) were assessed using the EORTC QLQ-C30 v3 questionnaire and its lung cancer module, QLQ-LC13. A change in score from baseline ≥10 points was predefined as clinically meaningful (CM). Mean changes from baseline (over 12 mos) for prespecified symptoms were analyzed using a mixed model for repeated measures (MMRM). Time from randomization to the first CM deterioration (TTD) was analyzed. Results: Among pts with PD-L1 TC ≥25% (n = 488), there were no differences between arms in symptoms, function, or global health status/QoL at baseline. Compliance with completing the questionnaires was ≥60% to wk 120 in the D±T arms, and to wk 40 (C30) and wk 44 (LC13) in the CT arm. MMRM analysis showed significant between-arm differences in changes from baseline in favor of D for fatigue (difference vs CT −9.5) and appetite loss (−11.9; CM), and D+T for fatigue (−11.7; CM). Significantly longer TTD (median, mos) was seen with D and D+T vs CT for appetite loss (12.8 and 5.6 vs 4.5), constipation (14.6 and 9.0 vs 5.5), nausea/vomiting (16.7 and 9.7 vs 4.5), and dyspnea (10.6 and 7.4 vs 5.6); D vs CT for diarrhea (16.3 vs 9.0), insomnia (9.3 vs 6.2), and hemoptysis (not reached vs 10.3); and D+T vs CT for fatigue (5.6 vs 2.0). Significantly longer TTD (median, mos) was also seen with D and D+T vs CT for function (cognitive [9.1 and 6.6 vs 5.2], physical [9.0 and 7.4 vs 4.2], role [D vs CT only; 7.3 vs 3.7], social [12.9 and 5.4 vs 5.2]), and global health status/QoL (5.9 and 6.8 vs 5.5). Conclusions: Pts with PD-L1 TC ≥25% treated with D±T had a reduced symptom burden over time and longer TTD for symptoms, function, and global health status/QoL compared to pts receiving CT. Clinical trial information: NCT02453282.

9018Background: Responses in NSCLC to agents targeting the PD-1/PD-L1 axis are correlated with PD-L1 expression by immunohistochemistry (IHC), tumor mutational burden (TMB), interferon associated m...

The adrenal gland is a common site of cancer metastasis. Surgery remains a mainstay of treatment for solitary adrenal metastasis. For patients who cannot undergo surgery, radiation is an alternative option. Stereotactic body radiotherapy (SBRT) is an ablative treatment option allowing larger doses to be delivered over a shorter period of time. In this study, we report on our experience with the use of SBRT to treat adrenal metastases using CyberKnife technology. We retrospectively reviewed the Winthrop University radiation oncology data base to identify 14 patients for whom SBRT was administered to treat malignant adrenal disease. Of the factors examined, the biological equivalent dose (BED) of radiation delivered was found to be the most important predictor of local adrenal tumor control. We conclude that CyberKnife-based SBRT is a safe, non-invasive modality that has broadened the therapeutic options for the treatment of isolated adrenal metastases.

9091 Background: Although IL-10 has anti-inflammatory properties, it stimulates cytotoxicity and proliferation of intratumoral antigen activated CD8+ T cell at higher concentrations. AM0010 is anticipated to activate antigen stimulated, intratumoral CD8 T cells while PD-1 inhibits them, providing the rationale for combining AM0010 and anti-PD-1 antibody. Methods: We treated a cohort of 34 NSCLC pts with AM0010 (10-20mg/kg QD, SC) and a PD-1 inhibitor [pembrolizumab (2mg/kg, q3wk IV; n=5) or nivolumab (3mg/kg, q2wk IV; n=29)]. Tumor responses were assessed by irRC every 8 weeks. Immune responses were measured by analysis of serum cytokines (Luminex), activation of blood derived T cells (FACS) and peripheral T cell clonality (TCR sequencing). Tumor PD-L1 expression was confirmed by IHC (22C3). Results: Pts had a median of 2 prior therapies. Median follow-up is 9.6 mo (range 0.5-77.3) in this fully enrolled cohort. AM0010 plus anti-PD-1 was well-tolerated. TrAEs were reversible and transient, with most being low grade, most commonly fatigue and pyrexia. G3/4 TrAEs were thrombocytopenia (7), anemia (6), fatigue (4), rash (3), pyrexia (2), hypertriglyceridemia (1) and pneumonitis (1). As of Jan. 31 2017, 22 pts had at least 1 tumor assessment. Partial responses (PRs) were observed in 8 pts (36.4%). 17 of these 22 pts had tissue for analysis of percent of tumor cells with PD-L1 expression (22C3): 58.8% had 50%. Best response data stratified for PD-L1 are shown in the table. Median PFS and OS for the entire cohort have not been reached. Updated outcome data that includes all enrolled pts will be available at the meeting. AM0010 plus anti-PD1 increased serum Th1 cytokines (IL-18, IFNγ), the number and proliferation of PD1+ Lag3+ activated CD8+ T cells and a de-novo oligoclonal expansion of T cell clones in the blood while decreasing TGFβ. Conclusions: AM0010 in combination with anti-PD1 is well-tolerated in advanced NSCLC pts. The efficacy and the observed CD8+ T cell activation is promising. Clinical trial information: NCT02009449. [Table: see text]

Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) has been shown to have increased local control and overall survival relative to conventional external beam radiation therapy in patients with medically inoperable stage I non-small cell lung cancer (NSCLC). Excellent rates of local control have been demonstrated both in clinical trials as well as in single-center studies at large academic institutions. However, there is limited data on the experiences of small academic hospitals with SBRT for Stage I NSCLC. The purpose of this study is to report the local control and overall survival rates in patients treated with SBRT for Stage I NSCLC at Winthrop-University Hospital (WUH), a small academic hospital. Materials/Methods: This is a retrospective review of 78 Stage I central and peripheral NSCLC tumors treated between December 2006 and July 2012 with SBRT at WUH. Treatment was given utilizing fiducials and a respiratory tracking system. If the fiducials were not trackable, a spine tracking system was used for tumor localization. CT-based planning was performed using the ray trace algorithm. Treatment was delivered over 4 consecutive days for central tumors to a dose of 4800 cGy delivered in 4 fractions. Peripheral tumors were treated to a dose of 6000 cGy in 3 consecutive fractions. The Kaplan-Meier method was used to calculate local control and overall survival. Results: The median age was 78.5 years. 54% of the patient population was female. 67% of the tumors were Stage IA, and 33% of the tumors were Stage IB. 53% of the tumors were adenocarcinomas and 29% were squamous cell carcinomas, with the remainder being of unknown histology or NSCLC, not otherwise specified The 2-year local control rate was 87%, and the two-year overall survival was 68%. Conclusions: Our findings support that local control and overall survival at a small academic hospital are comparable to that of larger academic institutions' published experiences with SBRT for Stage I NSCLC.

The Oncotype DX recurrence score (RS) reduces breast cancer adjuvant treatment utilization, but the reasons for this effect are not straightforward. We performed a retrospective chart review of 89 consecutive node-negative breast cancer patients for whom RS was ordered to facilitate adjuvant treatment decisions. By subtracting the relapse rate predicted by RS from that calculated using the Adjuvant! Online (AOL) web-based instrument, a “prognostic delta” (P∆) was determined, reflecting the difference between prognoses predicted by these two indices. Clinician interviews were conducted to evaluate the actual effect of RS on treatment decisions and its relation to P∆. Adjuvant chemotherapy use decreased from 61 to 26 % as a consequence of RS results (p

e17512 Background: On December 31 2013, USPSTF recommended that all persons age 55 - 80 with 30 pack-year smoking within past 15 years should undergo low-dose computed tomography (LDCT) screening, ...

84 Background: OT (Oncotype DX), MS (Mammostrat) and MP (Mammaprint) are three prognostic measures of breast cancer recurrence risk. All three were retrospectively validated in large patient cohorts and are now used when deciding on risk-reducing adjuvant chemotherapy. Our objective was to directly compare these three assays and their potential for differential effects on adjuvant chemotherapy decision making. Methods: We have previously reported that OT reduces adjuvant chemotherapy utilization, whereas MS did not exhibit this same net tendency in identical patients. In this study, we performed MP assays in 31 ER+ N0 breast cancer patients for which we already had OT and MS results. Decision analysis was applied to determine changes in management that would be most likely depending on which assay was used to guide decision making. Results: Our decision analysis demonstrated that in a substantial proportion of breast cancer patients, each of the three assays led to changes in adjuvant treatment decisions compared with what would have been chosen based upon conventional criteria alone. OT changed the decision in 55% of patients, and MS and MP would have changed those decisions in 45% and 65% of patients, respectively. In two-by-two paired analyses, treatment decisions would have differed in 61% of cases for OT versus MS; 29% for OT versus MP and 38% for MS versus MP. OT had the greatest tendency to eliminate adjuvant chemotherapy use (in 55% of patients versus MS and in 22% of patients versus MP), whereas MS had the greatest tendency to increase chemotherapy use (in 55% of patients versus OT and 35% versus MP). Conclusions: In this study of 31ER+ N0 breast cancer patients, three commercially available prognostic assays (OT, MS and MP) often yielded discordant risk category results. Our decision analysis suggests that these discordant results may frequently lead to different chemotherapy choices based upon which assay had been selected to guide decision making.

599 Background: Oncotype DX (Genomic Health, Redwood City CA) and Mammostrat (Clarient, Aliso Viejo CA) are two distinct prognostic measures currently marketed to facilitate adjuvant chemotherapy decision making for ER+ breast cancer patients and their physicians. Both assays define three prognostic strata—favorable, intermediate, and unfavorable. Both assays were also validated in the same retrospective cohorts, but there is significant discordance between these assays, suggesting that assay selection may affect clinical decisions. Methods: We have previously reported that Oncotype DX significantly reduces adjuvant chemotherapy use in 89 consecutive ER+, N0 patients for whom this assay was ordered at our institution. Mammostrat assays were performed on 46 of these cases for which tumor blocks were available. Decision analysis was applied to determine changes in management that would have been most likely if Mammostrat had been substituted for Oncotype DX. Results: Oncotype DX and Mammostrat were concordant for prognostic strata in just 11 (24%) cases. Oncotype DX predicted a more favorable prognosis than Mammostrat in 27 (59%) cases, while Mammostrat predicted a more favorable prognosis in the remaining 8 (17%) cases. As shown in the Table, Oncotype DX reduced chemotherapy utilization whereas Mammostrat would have increased it. Conclusions: Despite being validated in identical patient cohorts, Oncotype DX and Mammostrat are frequently discordant and may often affect adjuvant treatment decisions in opposite directions. [Table: see text]

e21176 Background: Excision repair cross-complementation group 1 (ERCC-1) over-expression by non-small cell lung cancer (NSCLC) has been reported to predict for resistance to platinum-based therapi...