Mansfield, Aaron S.

Abstract Lung cancer is the leading cause of cancer-related death worldwide. In this study, we demonstrate that elevated expression of dopamine and cyclic adenosine monophosphate-regulated phosphoprotein, Mr 32000 (DARPP-32) and its truncated splice variant t-DARPP promotes lung tumor growth, while abrogation of DARPP-32 expression in human non-small cell lung cancer (NSCLC) cells reduces tumor growth in orthotopic mouse models. We observe a novel physical interaction between DARPP-32 and inhibitory kappa B kinase-α (IKKα) that promotes NSCLC cell migration through non-canonical nuclear factor kappa-light-chain-enhancer of activated B cells 2 (NF-κB2) signaling. Bioinformatics analysis of 513 lung adenocarcinoma patients reveals elevated t-DARPP isoform expression is associated with poor overall survival. Histopathological investigation of 62 human lung adenocarcinoma tissues also showed that t-DARPP expression is elevated with increasing tumor (T) stage. Our data suggest that DARPP-32 is a negative prognostic marker associated with increasing stages of NSCLC and may represent a novel therapeutic target. Citation Format: Sk. Kayum Alam, Matteo Astone, Ping Liu, Stephanie R. Hall, Abbygail M. Coyle, Erin N. Dankert, Dane K. Hoffman, Wei Zhang, Rui Kuang, Anja C. Roden, Aaron S. Mansfield, Luke H. Hoeppner. DARPP-32 and t-DARPP promote non-small cell lung cancer growth through regulation of IKKα-dependent cell migration and Akt/Erk-mediated cell survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5161.

Abstract Malignant pleural mesothelioma is a disease primarily associated with exposure to the carcinogen asbestos. Consistent with this carcinogenic exposure, cytogenetic analyses have identified multiple recurrent structural chromosomal abnormalities in this malignancy, but more recent high-throughput sequencing evaluations of point mutations suggest that there is a low mutational burden in mesothelioma. Since tumor mutational burden has been correlated with responses to treatment with immune checkpoint inhibitors such as nivolumab, it was not consistent that patients with mesothelioma and low mutation burdens would have similar response rates in clinical trials with immune checkpoint inhibitors as patients with non-small cell lung cancer which is associated with a high mutation burden. In order to reconcile these differences, and given the potential for an improved understanding of the molecular pathogenesis of mesothelioma to improve therapeutic options, we used mate-pair sequencing (MPseq) and RNA sequencing (RNAseq) to understand how structural variants affect the transcriptome. MPseq differs from standard next generation sequencing approaches by tiling the whole genome with larger fragments (2-5kb) to reliably detect structural variants such as insertions, deletions and rearrangements. Amongst 22 mesothelioma specimens there were 1535 chromosomal rearrangements (median 41, range 3-298 per specimen), that resulted in junctions or novel fusions of non-coding DNA or genes. Six-hundred thirty-seven of these rearrangements (median 22, range 5-103 range per specimen) resulted in novel fusions of genes. Many of these inter- or intra-chromosomal rearrangements were consistent with a pattern of chromoanagesis such as chromoplexy or chromothripsis. Chromosomal rearrangements detected by MPseq were used to guide analysis of RNAseq data and revealed that these chromosomal junctions resulted in the expression of 179 novel amino acid sequences (median 5, 0-51 range per specimen). To determine whether transcription of chromosomal rearrangement-related junctions have neoantigenic potential, we used in silico tools to determine whether any of the expressed junctions contained peptides that could be presented by patient-specific HLA molecules. The top candidate rearrangement-related peptides with neoantigenic potential bound patient-specific HLA molecules nearly as well or as well as a positive control in competitive binding assays. Our findings represent the discovery of potential neoantigen expression driven by structural chromosomal rearrangements. These results may have implications for the development of novel therapeutic strategies, the selection of patients to receive immunotherapy, and blood-based treatment monitoring strategies. Citation Format: Aaron S. Mansfield, Tobias Peikert, James B. Smadbeck, Julia B. Udell, Farhad Kosari, Stephen J. Murphy, Hongzheng Ren, Vishnu V. Serla, Janet L. Schaefer Klein, Giannoula Karagouga, Faye R. Harris, Carlos Sosa, Sarah H. Johnson, Wendy Nevala, Svetomir N. Markovic, Aaron O. Bungum, Eric S. Edell, Haidong Dong, John C. Cheville, Marie Christine Aubry, Jin Jen, George Vasmatzis. Rearrangement-related peptides with neoantigenic potential in malignant pleural mesothelioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5726.

Abstract Background: In stage IV non-small cell lung cancer (NSCLC), survival has significantly improved with the use of novel therapies and better supportive care. Despite such trends, it has been noted that patients (pts) frequently refuse cancer treatment. Therefore, we explored the factors associated with treatment refusal in pts with stage IV NSCLC. Methods: Utilizing the National Cancer Database (NCDB), we identified all incident cases with stage IV NSCLC from 2004 to 2014. Patients who received cancer treatment outside of the reporting facility or died before receiving treatment were excluded. Multivariable logistic regression models were used to determine associations with treatment refusal. Results: A total of 341,993 pts were identified. On average, 5.4% of pts refused radiation therapy and 10.3% refused chemotherapy despite provider recommendations. The proportion of pts refusing radiation and chemotherapy increased over the study period from 4.2% to 7.3% and 7.9% to 15%, respectively (p<0.001 for both). In multivariable analysis, men were less likely to refuse radiation or chemotherapy compared to women (OR: 0.82, 95%CI: 0.76-0.83, p<0.001; OR: 0.84, 95%CI: 0.81-0.86, p<0.001, respectively). Factors associated with radiation therapy refusal included: Medicaid or Medicare as primary insurance (OR: 1.95, 95%CI: 1.76-2.15, p<0.001; OR: 1.25, 95%CI: 1.17-1.34, p<0.001, respectively) or a >2 Charlson Comorbidity Index (OR: 1.97, 95%CI: 1.85-2.10, p<0.001). Moreover, receiving care at an academic center (OR: 0.57, 95%CI: 0.53-0.62, p<0.001) was associated with less likelihood of refusing radiation. Regarding chemotherapy, uninsured pts (OR: 2.45, 95%CI: 2.26-2.66, p<0.001), pts with Medicaid as primary insurance (OR: 2.17, 95%CI: 2.03-2.32, p<0.001) or with a high comorbidity index (OR: 1.76, 95%CI: 1.68-1.84, p<0.001) were more likely to refuse chemotherapy. Contrary to findings from previous studies, Non-Hispanic Blacks and Hispanics were less likely to refuse chemotherapy compared to non-Hispanic whites (OR: 0.86, 95%CI: 0.82-0.91, p<0.001; OR: 0.78, 95%CI: 0.72-0.89, p<0.001). Patients receiving care at an academic center and residing in high income neighborhoods were less likely to refuse chemotherapy (OR: 0.76, 95%CI: 0.72-0.80, p<0.001; OR: 0.76, 95%CI: 0.71-0.81, p<0.001, respectively). Distance from residence to treating facility and living in a rural county did not affect treatment refusal. Conclusions: Socioeconomic factors rather than race/ethnicity appear to influence refusal of cancer treatment in pts with stage IV NSCLC in the NCDB. Assessing socioeconomic challenges should be an essential part of patients' evaluation when discussing treatment options. Citation Format: Narjust Duma, Urshila Durani, Ryan Frank, Jonas Paludo, Gustavo Westin, Yanyan Lou, Leventakos Konstantinos, Julian Molina, Ronald Go, Aaron Mansfield, Sikander Ailawadhi, Alex Adjei. Influence of sociodemographic factors on treatment decisions in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4230.

Abstract Chromothripsis is a complex genomic event characterized by a high number of chromosomal rearrangements and copy number changes that typically localize to a specific region on a single chromosome. Next generation sequencing has led to the initial discovery and description of these events which have since been observed in multiple human cancers. Whereas most mutagenic processes occur gradually, the multiple structural variations of each chromothriptic event likely occur at once. The clinical significance of chromothripsis remains uncertain, so we sought to characterize the relationship between chromothripsis and survival across human malignancies. We analyzed 13,318 tumors of 36 types using publicly available data from The Cancer Genome Atlas with CTLPScanner, which uses a sliding window scan statistic to identify events consistent with a chromothripsis-like pattern (CTLP). Our cutoffs for CTLP of copy number variation ≥ 20 and a log10 likelihood ratio ≥ 8 were derived from a clinical training set previously described by CTLPScanner. We detected one or more events consistent with a CTLP in 8,276 tumors (62.1%) for a total 24,879 events. There were no events in 5,042 cases (37.86%), a significant decrease from established rates of CTLPs. CTLPs were more common in ovarian serous cystadenocarcinomas (89.8%), esophageal carcinomas (86.5%) and sarcomas (81.2%) than in thymomas (26.6%) and thyroid carcinomas (15.2%). Chromosomes 8, 1 and 6 were most frequently involved with CTLPs. CTLPs in chromosome 6 were associated with uveal melanoma, chromophobic renal cell carcinoma and cholangiocarcinomas whereas CTLPs involving chromosome 12 were associated with testicular germ cell tumors. Multiple CTLPs were found in 5,262 tumors (39.5%, range of events 2-18+) and were most common in ovarian serous cystadenocarcinomas and sarcomas. The presence of CTLPs was associated with diminished overall survival across all tumor types (HR 1.5, p<2e-16). Given the potential for multiple CTLPs to have a greater effect on outcomes, we compared the survival of patients whose tumors contained 3 or more CTLPs (n=3,255, 24.4%) to those with 0-1 or 2 CTLPs. The presence of 3 or more CTLPs was associated with the worst survival amongst these groups (HR 1.67, p<2e-16). We identified that CTLPs are common in human cancers despite their prior descriptions as rare events. This discrepancy is likely due to our detection parameters. In addition, we identified that having multiple co-occurring CTLPs is associated with a worse prognosis, suggesting this type of event is more clinically relevant than a single CTLP and can be used as a negative prognostic marker in human malignancies. Citation Format: Aaron S. Mansfield, Enrique Garcia-Rivera. Chromothripsis and survival in human malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2258.

Many targeted therapies—and, more recently, immunotherapies—have been approved by the U.S. Food and Drug Administration (FDA) with companion diagnostic tests. Next-generation sequencing (NGS) platforms are now approved to screen for many of these abnormalities, and they are increasingly being applied to guide therapeutic decision-making outside of these intended uses. The results provided by NGS testing can vary significantly based on the exact test performed and the analysis of the sequencing data. Given the complexities associated with interpreting NGS test results and acting on them, academic and community molecular tumor boards have been developed to provide multidisciplinary expertise for this endeavor. NGS test results may identify FDA-approved therapies, guide clinical trial recommendations, or prompt consideration of expanded access to investigational agents or off-label use of therapies approved for other indications. Many clinical trials now include NGS testing to assign treatments to patients based on the molecular profiles of their tumors. Although NGS testing may eventually help realize the development of individualized treatment regimens based on combinations of targeted therapies, the use of unproven and nonapproved combinations can be toxic and expensive. Given the increasing reliance on genetic biomarkers to guide therapeutic recommendations for FDA-approved therapies or enrollment into clinical trials, NGS will remain an integral part of the evolving medical oncology practice.

Although immune checkpoint inhibitors have resulted in durable clinical benefits in a subset of patients with advanced cancer, some patients who did not respond to initial anti–PD-1 therapy have been found to benefit from the addition of salvage chemotherapy. However, the mechanism responsible for the successful chemoimmunotherapy is not completely understood. Here we show that a subset of circulating CD8 + T cells expressing the chemokine receptor CX3CR1 are able to withstand the toxicity of chemotherapy and are increased in patients with metastatic melanoma who responded to chemoimmunotherapy (paclitaxel and carboplatin plus PD-1 blockade). These CX3CR1 + CD8 + T cells have effector memory phenotypes and the ability to efflux chemotherapy drugs via the ABCB1 transporter. In line with clinical observation, our preclinical models identified an optimal sequencing of chemoimmunotherapy that resulted in an increase of CX3CR1 + CD8 + T cells. Taken together, we found a subset of PD-1 therapy–responsive CD8 + T cells that were capable of withstanding chemotherapy and executing tumor rejection with their unique abilities of drug efflux (ABCB1), cytolytic activity (granzyme B and perforin), and migration to and retention (CX3CR1 and CD11a) at tumor sites. Future strategies to monitor and increase the frequency of CX3CR1 + CD8 + T cells may help to design effective chemoimmunotherapy to overcome cancer resistance to immune checkpoint blockade therapy.

SEEK and you may find cancer earlier Many cancers can be cured by surgery and/or systemic therapies when detected before they have metastasized. This clinical reality, coupled with the growing appreciation that cancer's rapid genetic evolution limits its response to drugs, have fueled interest in methodologies for earlier detection of the disease. Cohen et al. developed a noninvasive blood test, called CancerSEEK that can detect eight common human cancer types (see the Perspective by Kalinich and Haber). The test assesses eight circulating protein biomarkers and tumor-specific mutations in circulating DNA. In a study of 1000 patients previously diagnosed with cancer and 850 healthy control individuals, CancerSEEK detected cancer with a sensitivity of 69 to 98% (depending on cancer type) and 99% specificity. Science , this issue p. 926 ; see also p. 866