Risk stratification based on a prognostic factor index among patients with HR+, HER2- MBC

e12516

Background: Patient and tumor characteristics, such as tumor grade (TG), site of metastases, hormone receptor status, and endocrine resistance, affect the prognosis for patients (pts) with HR+, HER2- metastatic breast cancer (MBC). This study explored the impact of multiple clinical prognostic factors on pt overall survival (OS) and real-world progression-free survival (rwPFS). Methods: This retrospective study used electronic health record (EHR) data of US pts from a network of community oncology practices maintained in the Vector Oncology Data Warehouse from 1/1/2008 to 4/30/2017. Eligibility included HR+, HER2- MBC diagnosis in 2008 or later and prior systemic therapy for MBC. An index variable was created to assess the effect of multiple clinical prognostic factors collectively, including liver metastases (LM), primary endocrine resistance (PER) (Cardoso F et al. 2018), negative progesterone receptor (PR-) status, and high TG. Pts were grouped based on the number of prognostic factors present at MBC diagnosis: 0, 1, and 2+. Differences in rwPFS and OS from start of first line therapy were evaluated by Kaplan-Meier method and multivariable Cox proportional hazards regression. Results: Eligible pts (n=378) had a mean age of 60.3 years. Among these 57.1% were white, 36.5% were de novo metastatic, 22% had LM, 27.2% had high TG, and 27.1% were PR- at baseline. Among all pts, 170 (45%) had received endocrine therapy as first-line treatment, followed by chemotherapy (28%), CDK4 & 6 inhibitor (17%), or other anti-cancer treatment (9%). After adjustment, rwPFS and OS were significantly (p<.05) shorter in pts with 1 and 2+ clinical prognostic factors compared to pts with none (Table). Conclusions: Among pts with HR+, HER2- MBC, these data demonstrate the heterogeneity in pt survival outcomes depending on the presence and number of prognostic factors. Further research should explore the collective importance of these prognostic factors in treatment decisions. [Table: see text]

Genomic characterization of lung tumors and metastatic (Met) sites in advanced (Adv) NSCLC

2014

Background: Molecular alterations (MA) found in brain (Br) mets of NSCLC pts can differ from primary and/or other met sites, which may explain why therapies targeting primary tumors are less effective at preventing and treating intracranial disease. We analyzed the frequency of known driver genes in adv NSCLC pts and the association with overall survival (OS). Methods: This retrospective observational study identified pts from the Flatiron- Foundation Medicine NSCLC Clinico-Genomic Database who were diagnosed with adv NSCLC from 1 Jan 2011 to 31 Oct 2017 and had tumor tissue analyzed at any time following initial diagnosis via targeted DNA sequencing by FoundationOne. Descriptive statistics summarized MA from lung and met sites (Br and non-brain [NB]). OS was measured from adv diagnosis to death or last activity date (censored). Multivariable Cox proportional hazard regression model was used for time-to-event analysis. Results: Of 3257 pts, data were available from lung (n = 1621), Br (n = 180), and NB sites (n = 377): liver (n = 167), bone (n = 124), adrenal (n = 63), and spine (n = 23). Median age at adv diagnosis was 66.2 yrs. TP53(63.3%), KRAS(28.8%), EGFR(15.6%), STK11 (13.5%), and CDKN2A(8.5%) were frequently mutated genes in lung samples. Genes for Br vs NB sites included TP53(70.6%; 64.7%), KRAS(36.1%; 26.5%), EGFR (9.4%; 18.8%), STK11 (18.9%; 12.7%), and CDKN2A(6.1%; 10.1). KEAP1alterations were also present in 10% (Br), 7.4% (NB), and 6% of lung samples. In treated pts, lack of alterations in select genes ( STK11, TP53, KEAP1) was associated with longer OS, whereas lack of other alterations ( ARID1A, EGFR, ALK, ROS1) was associated with a shorter OS (p < 0.05). Patients with select mutations co-occurring with KRAS had higher risk of death compared to those with KRAS only (p < 0.05). Conclusions: Based on pts with NSCLC whose tumor tissue underwent DNA sequencing, the most frequently altered genes in lung and Br samples included TP53, KRAS, EGFR, STK11, and CDKN2A, with some being significantly associated with OS. Prognosis of NSCLC pts depends on clinical, demographic, and genomic factors and should be carefully considered to optimize clinical outcome.

Next-generation sequencing (NGS) results among hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC) patients treated with a CDK4 & 6 inhibitor: A retrospective observational study based on real-world data

1042

Background: Few real-world studies have characterized the frequency of genomic alterations of MBC tumors. Data characterizing alterations before and after treatment containing a CDK4 & 6 inhibitor (CDK4 & 6i) are similarly limited. We explore the genomic landscape of HR+/HER2- MBC tumors from patients (pts) treated with a CDK4 & 6i in order to characterize potential mechanisms underlying sensitivity and resistance. Methods: NGS results of tumor and liquid biopsies obtained from 130 pts with estrogen receptor (ER+)/progesterone receptor (PR+)/HER2- MBC between Jan 2008 to Sept 2016 were analyzed. All pts received therapy containing a CDK4 & 6i for MBC at a community cancer network and had NGS results available before and/or after exposure to CDK4 & 6i. Samples were classified as sensitive (n = 69; duration of therapy ≥6 mo) or resistant (n = 61; duration of therapy < 6 mo). The frequency of genomic alterations with likely or known significance including short variants, indels, copy number variants, and fusions were characterized. Results: Alterations in 215 unique genes were identified from the NGS results; PIK3CA, TP53, ESR1, CCND1, and FGFR1 were the most frequently altered genes. Select alterations in ESR1 (n = 21 vs 9) and RAD21 (n = 5 vs 0) were more frequent after exposure to CDK4 & 6i. In NGS obtained before exposure to CDK4 & 6i, alterations in select genes including RB1, MDM2, AURKA, and MYC were more frequent in the resistant samples, whereas ARID1A alterations were more frequent in sensitive samples. Of the 6 pts with paired NGS samples pre- and post-CDK4 & 6i treatment, alterations in MYC, CDKN2A, PIK3CA, BRCA1, or RB1 were acquired in 3 pts. Conclusions: Based on real-world data, this study describes the genomic landscape of ER+/PR+/HER2- MBC tumors from pts treated with CDK4 & 6i and identifies potential mechanisms underlying sensitivity and resistance to this new class of drugs. Further evaluation in larger datasets is warranted. Data inclusive of other ER/PR subtypes will be presented.

Clinical characteristics, treatment (Tx) patterns, and overall survival (OS) in advanced (Adv) NSCLC patients (Pts) with and without brain metastases (BM)

2035

Background: BM in NSCLC pts are associated with significant morbidity and mortality. This analysis describes the frequency and timing of BM development, pt characteristics, systemic txs, and OS in NSCLC pts with and without BM. Methods: This retrospective observational study identified pts from the Flatiron-Foundation Medicine NSCLC Clinico-Genomic Database diagnosed from 1 Jan 2011 to 31 Oct 2017 with adv NSCLC and a tumor sample analyzed via FoundationOne. Tx pattern data were summarized by period (1 Jan 2011-1 Mar 2015; 2 Mar 2015-31 Dec 2017), therapy class (eg, anti-VEGF and EGFR, platinum-based), and BM occurrence. Descriptive statistics were used to summarize data; Chi-square and t-tests assessed statistically significant differences. OS was measured by site of met (BM only vs no-BM only vs BM and no-BM) via K-M methods from adv diagnosis until death or last activity date (censored). Results: Of 3257 pts, 1018/3257 (31.3%) had BM during follow-up; 726/1018 (71.3%) presented with BM within 30 days of adv diagnosis. The median age at adv diagnosis was 66.2 yrs. Relative to pts without BM, BM pts were younger, more likely to be female, of Asian descent, have stage IV disease, ≥2 met sites (including BM) at initial presentation, ≥3 met sites (including BM) during follow-up, and non-squamous histology (all p < 0.01). Approximately 78% (n = 2534) were treated with ≥1 systemic tx; platinum-based chemo-combinations were the most common 1st line tx, regardless of BM status. Increased use of PD-1/L1 tx was seen in 1st, 2nd, and 3rdline during the latter vs earlier period. No statistically significant difference in OS was observed in pts with BM only (17.1 mos; 95% CI 12.5-29.9), no-BM only (21 mos; 95% CI 19.4-22.8), or BM and no-BM (20.4 mos; 95% CI 18.9-23.3) (log rank p = 0.3027). Conclusions: In met NSCLC pts with a tumor sample that was molecularly profiled, OS was comparable, regardless of site(s) of disease; additional multivariate analyses including molecular profiles are needed. BM screening at initial diagnosis is important given the frequency in NSCLC. Future studies should assess whether the shift in systemic tx patterns impact the development and clinical outcomes.