Long-Term Results of Induction Chemotherapy Followed by 50 Gy Radiation Therapy Alone for Low-Risk HPV-Positive Oropharynx Cancer

PURPOSE/OBJECTIVE(S)

The standard of care for non-operative management of human papillomavirus-related oropharynx cancer (HPV-OPC) consists of concurrent cisplatin chemotherapy with radiotherapy (RT) to a total dose of 70 Gy. While the oncologic outcomes of this treatment approach have been excellent, there are considerable acute and late toxicities. Here, we report the 5-year survival and toxicity outcomes of 2 prospective HPV-OPC response-adapted de-escalation trials, in which low-risk (LR) patients were treated with dose-reduced RT to 50 Gy, without concurrent chemotherapy.

MATERIALS/METHODS

Patients with LR HPV-OPC and ≥50% response to induction by RECIST 1.1 treated per 2 prospective phase II trials as well as on a prospective cohort registry were included for analysis. Patients were considered LR if the following criteria were met: T1-T3, N0-N2b (AJCC 7th edition), and ≤20 pack-year smoking history. Patients were treated with induction chemo- or chemoimmunotherapy followed by RT alone to 50 Gy. In the early trial iteration, patients underwent a planned neck dissection following RT to confirm pathologic clearance of lymph nodes. Clinicodemographic characteristics were summarized using descriptive statistics. Overall survival (OS), progression-free survival (PFS), and local control (LC) were estimated using the Kaplan-Meier method.

RESULTS

From January 2015 through March 2020, 73 patients met LR criteria, of which, 54 (74%) had ≥50% response by RECIST and were de-escalated to RT alone. The median follow-up was 58 (range 10-92) months. The median age was 58 (range 38-84) years, and 92.6% were male. 57.4% of patients never smoked, and 42.6% smoked no more than 20 pack-years. The primary site was tonsil for 53.7% and base of tongue for 46.3%. 24.1% were T1, 53.7% were T2, and 22.2% were T3. 1.9% were N0, 5.6% were N1, 11.1% were N2a, and 81.5% were N2b. The 5-year OS, PFS, and LC were 96.3% (95% CI 91.3%-100%), 96.2% (95% CI 91.2%-100%), and 98.1% (95% CI 94.6%-100%), respectively. 2 (3.7%) patients required a G-tube during RT and none at 1 year following completion of RT. Of the 30 patients with a planned neck dissection, 2 (6.7%) had residual pathologic nodal disease.

CONCLUSION

With a median follow-up of 5 years, this analysis demonstrates excellent long-term local control, survival, and swallowing function among patients with low-risk HPV+ oropharynx cancer treated with induction systemic therapy followed by radiotherapy to 50 Gy without concurrent chemotherapy, including a large proportion of patients with N2b disease. Chemo-selection provides a means of identifying a favorable cohort of HPV+ oropharynx cancer patients who can safely receive RT dose de-escalation. Further work is needed to identify this population by other means, including radiographic and genomic factors.

Definitive Chemoradiotherapy for Salivary Gland Cancers

PURPOSE/OBJECTIVE(S)

Surgical resection is the standard of care for salivary gland tumors of the head and neck. The role of radiotherapy is typically reserved for the adjuvant setting in those patients with high risk factors on surgical pathology. Surgical resection in some cases may lead to significant impairment in speech or swallowing due to location of the primary tumor. In other cases, patients may not be medically able to receive an oncologic resection. Our institution has developed a protocol for organ preservation for well-selected salivary gland malignancies. Here we report disease outcomes of salivary gland cancer patients treated with definitive chemoradiotherapy.

MATERIALS/METHODS

We retrospectively reviewed all salivary gland cancer patients at our institution who received definitive chemoradiation from January 1990 to December 2019. Chemoradiation typically consisted of 4 to 6 alternating weekly cycles of paclitaxel (100 mg/m2 on d1), infusion 5-fluorouracil (600 mg/m2/d on d0-5), hydroxyurea (500 mg PO BID), and either 1.8 Gy or 2 Gy daily or 1.5 Gy twice-daily irradiation followed by a 9-day treatment break (TFHX). The Kaplan-Meier method was used to estimate rates of locoregional control (LRC), distant metastasis-free survival (DMFS), and overall survival (OS).

RESULTS

Nineteen patients met eligibility criteria and were included for analysis. 53% of patients had adenoid cystic histology. Salivary duct, mucoepidermoid, acinic cell, and myoepithelial histologies each were represented by 10.5% of patients. About 26% of tumors were located in the nasopharynx, 21% in the base of tongue and 26% in the parotid. 74% of the patients were node negative and 53% of patients had stage IVA disease. T3 disease occurred in 26.3% while T4a and T4b disease occurred in 31.6% each. Median follow-up was 45.8 (IQR: 29-66) months. 47% of patients were treated using a twice daily approach, while 53% were treated with daily fractionation with a median dose of 72 Gy (IQR: 70-75). Three-year locoregional control (LRC), distant-metastasis free survival (DMFS), and overall survival (OS) were 93%, 76%, and 81% respectively. Eight of nine distant failures had T4a/T4b disease. Accounting for competing risk of death, local failure was 5.6% at three years. The most common acute complications were grade 2-3 mucositis (74%) and skin toxicity (47%). One patient discontinued chemoradiation due to severe hand foot mouth syndrome. 42% of patients had late toxicity of xerostomia.

CONCLUSION

Promising organ preservation is seen with concurrent chemoradiation for salivary gland cancer patients. Further prospective study of organ preservation in salivary gland cancers is warranted.

Involved Site Radiotherapy in HPV Positive Oropharyngeal Cancer: Patterns of Failure Analysis Across Prospective De-Escalation Trials

PURPOSE/OBJECTIVE(S)

HPV-associated oropharyngeal cancers (HPV+OPC) have a favorable prognosis with ongoing efforts to reduce long term toxicity while maintaining oncologic outcomes. One method under investigation includes lowering the elective radiation dose or in some cases omitting radiation to elective lymphatic nodal stations. Furthermore, pre-clinical evidence demonstrates that elective nodal irradiation blunts the anti-tumor immune response in head and neck cancer. This is a pooled secondary analysis reporting patterns of failure in patients (pts) with HPV+OPC enrolled on consecutive induction chemo- or chemoimmunotherapy (IC) based response-adaptive de-escalation trials and treated with involved-site radiotherapy (ISRT).

MATERIALS/METHODS

Pts treated on two prospective phase II trials as well as on a prospective cohort registry were included for analysis. Pts with ≥ 50% response to IC based on RECIST 1.1 who received de-escalated definitive radiotherapy (RT) or concurrent chemoradiation (CRT) with ISRT were evaluable. Pts with locally advanced low risk or high-risk HPV+OPC (LR and HR, respectively) were eligible for enrollment. Pts were considered to have HR if at least one of the following criteria was met: T4 primary, N2c-N3 disease (AJCC 7th ed.), or > 10-20 pack years smoking. In the first trial, pts with ≥ 50% response to IC received RT to gross disease plus a 1.5 cm margin (PTV1) and to the next echelon of uninvolved nodes (PTV2). Pts with LR received 50 Gy in 2 Gy daily fractions without chemotherapy; pts with HR received 30 Gy in 1.5 Gy BID fractions to PTV2 with a 15 Gy sequential boost to PTV1 with CRT. In the subsequent trial, pts with ≥ 50% response received RT to PTV1 alone to 50 Gy in 2 Gy daily fractions; concurrent CRT was included if pts had HR. Survival was estimated using the Kaplan Meier method for progression free survival (PFS), locoregional PFS (LRPFS), and overall survival (OS). Patterns of failure analysis was performed by comparing RT plans to radiographic surveillance scans.

RESULTS

Of 172 evaluable pts, 119 (69.2%) achieved a ≥ 50% response to IC and received definitive ISRT. 45 (37.8%) pts evaluated received RT to gross disease only plus margin without the next nodal echelon included. With a median follow up of 46 (IQR 34-65) months, 3-year PFS, LRPFS, and OS with their 95% confidence intervals were 96.2% (90.1-98.5%), 97.1% (91.1-99.0%), and 96.2% (90.3-98.6%), respectively. All locoregional failures were in-field and in the high dose region. No failures were observed in the RT omitted neck.

CONCLUSION

This prospective experience demonstrates feasible volume de-escalation using IC response-based selection with progressively smaller elective volumes over time. Notably, despite a marked reduction in elective treatment volume, there were no regional out-of-field failures. IC may allow for selection of pts with favorable tumor biology and microscopic disease sterilization in the regional nodes. Further efforts at elective nodal de-escalation are needed.

Radiomics Based Assessment of Tumor Infiltrating CD8 T-Cells Predicts Induction Systemic Therapy Response in HPV+ Oropharyngeal Cancer: Exploratory Analysis of Prospective Trials

PURPOSE/OBJECTIVE(S)

The adaptive immune system is increasingly recognized to be important for tumor control in HPV+ oropharyngeal cancer (HPV+OPC), and pre-clinical models suggest tumor specific T-cell priming occurs in draining lymph nodes. De-escalation strategies incorporating T-cell infiltration present a novel prognostic biomarker. The purpose of this study was to examine the utility of a validated radiomics model of CD8 T-cell infiltration within the framework of 2 prospective HPV+OPC response-adaptive de-escalation trials. We hypothesized that nodal radiomics scores (RS) would be correlated with response to induction systemic therapy.

MATERIALS/METHODS

Patients enrolled on 2 prospective phase II response adapted de-escalation trials for low- and high-risk HPV+OPC were included in the analysis. Patients received induction chemotherapy and chemoimmunotherapy in trials 1 and 2, respectively. Primary tumors and nodes were retrospectively delineated on diagnostic CT scans before and after induction therapy to ascertain volumetric tumor burden & response. RS were generated on pre-induction scans for both primary tumors and nodes. RS and tumor response were dichotomized using a 50% threshold (high vs low, responder vs non-responder, respectively). Linear regression was used to evaluate the correlation between % volume change in tumor burden and RS. Fisher's exact test was used to evaluate concordance between RS and tumor response.

RESULTS

A total of 87 patients (N = 47 Trial 1, N = 40 Trial 2) were evaluable. The mean post-induction therapy reduction in primary and nodal volumetry was 80.7% and 67% respectively. Primary and nodal RS were not associated with primary (T1/T2 vs T3/T4) or nodal stage (N1-N2b vs N2c-N, p > 0.10 both). Both primary and nodal RS were correlated with % volume change, r = 0.24 (p = 0.034) and r = 0.37 (p = 0.002), respectively. The mean difference in % volume change in primary and node, using the RS, was 11.13% (p = 0.015) and 17. 69% (p = 0.004). There was no association between primary tumor RS and total lesion responder status (p = 0.312). However, there was an association between high vs low nodal RS and total lesion responder status (p = 0.005).

CONCLUSION

This is the first report of a validated radiomics score of CD8-T cell infiltration in HPV+OPC to predict response to systemic therapy. While radiomics scores in both the primary and nodes were associated with percent volume response, this association was stronger in nodes. Higher nodal radiomics scores were associated with improved volume reduction in total lesion burden. This effect however was not observed in the primary tumor. CD8-T cell infiltration in nodes, but not in the primary tumor, was associated with overall tumor response after systemic induction therapy in HPV+ oropharyngeal cancer.

Longitudinal Patient Outcomes in Chronic Dizziness: A Scoping Review

BACKGROUND

Chronic dizziness can cause significant functional impairment. Outcome measures used in this patient population have not been examined systematically. Consequently, providers lack consensus on the ideal outcome measures to assess the impact of their interventions.

OBJECTIVE AND METHODS

We conducted a scoping review to summarize existing literature on outcomes in chronic dizziness (with a minimum of 6 mo of patient follow-up). Among other details, we extracted and analyzed patient demographics, medical condition(s), and the specific outcome measures of each study.

RESULTS

Of 19,426 articles meeting the original search terms, 416 met final exclusion after title/abstract and full-text review. Most studies focused on Ménière's disease (75%) and recurrent benign paroxysmal positional vertigo (21%). The most common outcome measures were hearing (62%) and number of attacks by American Academy of Otolaryngology-Head & Neck Surgery criteria (60%). A minority (35%) looked formally at quality-of-life metrics (Dizziness Handicap Index or other).

CONCLUSIONS

Ménière's disease and benign paroxysmal positional vertigo are overrepresented in literature on outcome assessment in chronic dizziness. Objective clinical measures are used more frequently than quality-of-life metrics. Future work is needed to identify the optimal outcome measures that reflect new knowledge about the most common causes of chronic dizziness (including persistent postural-perceptual dizziness and vestibular migraine) and consider what is most important to patients.

Abstract 4407: Clinicopathologic characteristics and mutational analysis of MYC amplified head and neck squamous cell carcinoma (HNSCC)

Amplification of MYC proto-oncogene is commonly found in many types of cancer, and frequently associated with poor clinical outcomes. Analysis of the TCGA-HNSCC dataset indicates that MYC amplification is estimated to be present in ~12% of HNSCC cases, and has a significant impact on patients’ median survival (32.2 vs 56.9 months for patients with wild-type MYC). While the association between MYC amplification and HNSCC progression was previously reported, its role in regulating mechanisms of acquired resistance to therapy remain under investigated. In this study, we seek to further characterize the clinicopathological features associated with MYC amplified HNSCC, and highlight the molecular changes that may contribute to acquired resistance to treatment.

Seven HNSCC patients with MYC amplification were identified by searching the Oncoplus database at the University of Chicago. A retrospective chart review was conducted to collect demographic and clinical data for each patient, and mutational landscape was characterized. In a single patient, MYC amplification was acquired following treatment with chemoimmunotherapy (nivolumab, carboplatin, paclitaxel), chemoradiation, and maintenance nivolumab resulting in rapidly progressive disease despite an initial response to therapy. RNA sequencing and immunohistochemical staining was performed to compare specimens collected before and after progression.

Seven patients were diagnosed with HNSCC and were found to have MYC amplification on molecular testing of their cancer between 2018 and 2021. Four were male, median age 61 (range 46-71), stage T2-4 (n=6), N2-3 (n=6), p16+ (n=2). All patients (n=7) developed recurrent and/or metastatic disease following primary therapy with locoregional recurrence (n=3), metastatic recurrence (n=2), or both (n=2). Median survival for the cohort was 3.1 years. Previous therapy included surgery (n=4), radiotherapy (n=7), chemotherapy (n=7), targeted therapy (n=4), and immunotherapy (n=4). The most common mutations co-occurring with MYC amplification were CDKN2A loss (n=5), TP53 loss (n=5), CCND1 amplification (n=2) and KDM6A loss (n=2). Acquisition of MYC amplification and acquired resistance to chemoimmunotherapy was associated with upregulation of glycolysis pathway, WNT/beta-catenin signaling, and significant changes to tumor microenvironment (TME) such as tumor infiltrating lymphocytes repertoire and PD1/PD-L1 expression levels.

Alongside the data from TCGA, the cases described in this study highlight the poor prognosis associated with MYC amplified HNSCC. While loss of function mutations in CDKN2A and TP53, upregulation of glycolysis pathway, and TME reprogramming may contribute to treatment resistance and secondary immune evasion, further studies in larger cohorts are warranted to develop therapies that target MYC mediated mechanisms of resistance in HNSCC.

Citation Format: Thomas Cyberski, Alka Singh, Mark Lingen, Alexander Pearson, Nishant Agrawal, Evgeny Izumchenko, Ari Rosenberg. Clinicopathologic characteristics and mutational analysis of MYC amplified head and neck squamous cell carcinoma (HNSCC). [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4407.

Abstract 4897: PRT543, a methyl transferase inhibitor, has potent anti-tumor activity against adenoid cystic carcinoma of salivary glands

Adenoid Cystic Carcinoma (ACC) is a rare but aggressive malignancy of salivary gland, associated with protracted clinical course and fatal outcome. Treatment modalities are restricted to surgery and/or adjuvant radiotherapy and patients develop recurrence and distant metastasis over time. The absence of effective systematic therapy makes it incurable in advanced stage. ACC display an overall low mutation frequency, therefore very few actionable genetic alterations critical to the ACC development have been recognized. MYB fusion/overexpression is the most frequently found genetic alteration in ACC and is present in ~70% patients. This is followed by activating NOTCH mutations, reported in ~20% patients. Despite the presence of few targetable genetic alterations, recent studies revealed substantial transcriptomic heterogeneity amongst ACC tumors suggesting the role of epigenetic alterations in ACC oncogenesis. Symmetric dimethylation is an important epigenetic mechanism that regulates mRNA splicing, transcription, translation, cell cycle and oncogenic signaling pathways. Protein Arginine Methyl Transferase 5 (PRMT5) is a predominant enzyme for symmetric dimethylation among a family of 9 methyl transferases. In was suggested that PRMT5 plays a role in regulating tumor progression via modulation of MYC signaling, cancer stemness, and a wide array of additional cellular and transcriptional pro-oncogenic processes. While inhibition of PRMTs showed anti-oncogenic response in several preclinical tumor models and a subset of patients with advanced solid malignancies (including ACC), preclinical studies investigating the effect of PRMT5 blockade in ACC remain inadequate. In part, due to the scarcity of ACC specimens and limited availability of the experimental models. PRT543 is a selective and potent small molecule PRMT5 inhibitor that specifically targets PRMT5 among 37 methyl transferases. In the present study, we have investigated the effect this novel agent using a unique collection of ACC cell lines, organoids, and patient derived xenograft mouse models. To our knowledge, this is the first study investigating the therapeutic effect of PRT543 in several preclinical models of ACC. Specifically, we found that PRT543 has potent antitumor activity in in-vitro and in-vivo models with MYB expression and activating NOTCH mutations. Further, based on these observations, we have sequenced a collection of 50 ACC tumor samples to identify the subset of patients who may potentially benefit from PRT543 treatment based on their underlying genetic signatures. This study provides evidence underscoring the role of PRMT5 signaling in ACC and supports the clinical development of PRMT5 inhibitors for this indication.

Citation Format: Vasudha Mishra, Alka Singh, Xiangying Chen, Michael Korzinkin, Claudia Wing, Viktoria Sarkisova, Alexandra Ozerova, Oksana Glushchenko, Venkat Thodima, Koichi Ito, Peggy Scherle, Mark Lingen, Rifat Hasina, Alexander Pearson, Ari Rosenberg, Alex Zhavoronkov, Bruce Ruggeri, Nishant Agrawal, Evgeny Izumchenko. PRT543, a methyl transferase inhibitor, has potent anti-tumor activity against adenoid cystic carcinoma of salivary glands. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4897.

Abstract 4845: Ultra-deep sequencing of mitochondrial genome to explore the dynamic mutational changes associated with oral cavity squamous cell carcinoma progression

Oral cavity squamous cell carcinoma (OCSCC) is a devastating disease, causing substantial morbidity and mortality. While many OCSCCs arise from an existing dysplastic lesion, not all oral premalignant lesions progress to OCSCC. Current methods for oral premalignancy and OCSCC diagnosis (visual and tactile exam followed by tissue biopsy and histologic evaluation) cannot discriminate between benign inflammatory changes and high-risk premalignant lesions that require interventions, underscoring the need for molecular-based biomarkers. The multi-step cancer progression from normal epithelium to premalignant lesion and invasive SCC is driven by the accumulation of genetic alterations, including changes in mitochondrial DNA (mtDNA). Due to the lack of protective histones and limited repair mechanisms, mtDNA is susceptible to damage by environmental carcinogens and reactive oxygen species, a byproduct of the oxidative phosphorylation system. As a result, mutation rate in mtDNA is ~10 times higher than in nuclear DNA, and may greatly facilitate the risk of mitochondrial dysfunction. Previous studies underscore that acquisition of somatic mtDNA mutations directly involved in tumorigenesis, and not merely epiphenomena. However, the impact of these studies is limited by an incomplete understanding of mitochondrial genomic alterations in the transition of preneoplastic lesions to invasive disease. In this study we used a unique cohort of 27 patients with matched longitudinally collected samples (histologically normal mucosa, dysplastic lesion, and SCC) coupled with novel ultra-deep mitochondrial sequencing (mtDNA-Seq) method to assess the mtDNA mutational landscape throughout the continuum of OCSCC progression. Using a custom bioinformatics workflow, somatic mutations were detected in a subset of the premalignant lesions, with overall higher mutational load observed in OCSCC specimens. While sequencing revealed a large degree of inter-patient heterogeneity, a panel of non-synonymous aberrations were present in both premalignant and invasive neoplasms. The majority of shared mutations showed an increase in fractional abundance in tumors, compared to the precursor lesions (suggesting a spatial expansion of these clones as they progressed histologically), and were enriched for coding mutations in complex-I subunits (critical region for ATP production), which is associated with an oncogenic phenotype. Additionally, mtDNA content increased in OCSCC tumor in a subset of patients, suggesting a cell compensation for defective oxidative phosphorylation and lower ATP production per mitochondria. Here we report the first comprehensive characterization of mitochondrial mutational landscape in dysplastic and invasive SCC lesions, and reveal key molecular events associated with the transition from non-invasive to invasive state.

Citation Format: Alka Singh, Ashwin Lakshman Koppayi, Ping Wu, Mark Lingen, Vasudha Mishra, Alexander Pearson, Ari Rosenberg, Nishant Agrawal, Karthik Suresh, Evgeny Izumchenko. Ultra-deep sequencing of mitochondrial genome to explore the dynamic mutational changes associated with oral cavity squamous cell carcinoma progression. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4845.

Machine learning for the prediction of toxicities from head and neck cancer treatment: A systematic review with meta-analysis

INTRODUCTION

The aim of the present systematic review (SR) is to summarize Machine Learning (ML) models currently used to predict head and neck cancer (HNC) treatment-related toxicities, and to understand the impact of image biomarkers (IBMs) in prediction models (PMs). The present SR was conducted following the guidelines of the PRISMA 2022 and registered in PROSPERO database (CRD42020219304).

METHODS

The acronym PICOS was used to develop the focused review question (Can PMs accurately predict HNC treatment toxicities?) and the eligibility criteria. The inclusion criteria enrolled Prediction Model Studies (PMSs) with patient cohorts that were treated for HNC and developed toxicities. Electronic database search encompassed PubMed, EMBASE, Scopus, Cochrane Library, Web of Science, LILACS, and Gray Literature (Google Scholar and ProQuest). Risk of Bias (RoB) was assessed through PROBAST and the results were synthesized based on the data format (with and without IBMs) to allow comparison.

RESULTS

A total of 28 studies and 4,713 patients were included. Xerostomia was the most frequently investigated toxicity (17; 60.71 %). Sixteen (57.14 %) studies reported using radiomics features in combination with clinical or dosimetrics/dosiomics for modelling. High RoB was identified in 23 studies. Meta-analysis (MA) showed an area under the receiver operating characteristics curve (AUROC) of 0.82 for models with IBMs and 0.81 for models without IBMs (p value < 0.001), demonstrating no difference among IBM- and non-IBM-based models.

DISCUSSION

The development of a PM based on sample-specific features represents patient selection bias and may affect a model's performance. Heterogeneity of the studies as well as non-standardized metrics prevent proper comparison of studies, and the absence of an independent/external test does not allow the evaluation of the model's generalization ability.

CONCLUSION

IBM-featured PMs are not superior to PMs based on non-IBM predictors. The evidence was appraised as of low certainty.

Abstract 5660: IGM-7354, an immunocytokine with IL-15 fused to an anti-PD-L1 IgM, induces NK and CD8+ T cell mediated cytotoxicity of PD-L1-positive tumor cells

Immunostimulatory cytokines are a promising immunotherapy for the treatment of advanced malignancies, but generally have been associated with severe toxicities when administered systemically. The recent development of antibody-cytokine fusion proteins, or immunocytokines, aims to localize cytokine activity to the tumor microenvironment and thus improve their therapeutic index. We have developed IGM-7354, a high affinity, high avidity anti-PD-L1 pentameric IgM antibody with an IL-15Rα chain and IL-15 fused to the joining (J) chain. The IGM-7354 immunocytokine was designed to deliver IL-15-mediated stimulation of NK and CD8+ T cells to PD-L1-expressing tumors and antigen-presenting cells, to enhance anti-tumor immune responses. The multivalent binding of IGM-7354 to PD-L1 provided a stronger binding avidity for human PD-L1 than the monovalent binding of IL-15 to IL-15Rb as confirmed in kinetic binding assays. In vitro IGM-7354 induced the proliferation of a cytotoxic T cell line responsive to IL-15 stimulation and enhanced the proliferation of NK and CD8+ T cells from healthy donor human PBMCs. In cytotoxicity assays with human PBMC and PD-L1+ cancer cell lines, IGM-7354 enhanced cancer cell killing through NK and CD8+ T cell expansion and cytotoxic activity, evidenced by Ki67 and Granzyme B upregulation in these cell populations. Next, in vivo pharmacodynamic studies were performed in two humanized mouse models: non-tumor-bearing BRGSF-HIS mice engrafted with human CD34+ cells, and PD-L1+ MDA-MB-231 tumor-bearing MHC-/- NSG mice engrafted with human PBMCs. In the BRGSF model, IGM-7354 increased NK cell activation and Granzyme B expression as well as NK and CD8+ T cell proliferation. In the tumor-bearing mouse model, IGM-7354 dose-dependently increased NK and CD8+ T cell proliferation in blood and infiltration of lymphocytes into the tumor. This pharmacodynamic activity correlated with IGM-7354 anti-tumor activity in the MDA-MB-231 model. Lastly, IGM-7354 increased the proliferation of NK and CD8+ T cells in cynomolgus monkeys and particularly induced the expansion of effector memory CD8+ T cells in the periphery. In summary, IGM-7354 induces NK and CD8+ T cell proliferation in both in vitro and in vivo preclinical models, resulting in the killing of PD-L1+ tumor cells. The strong avidity of IGM-7354 for PD-L1 may enhance IL-15 delivery to tumors and antigen-presenting cells and thus provide a more favorable safety profile. A Phase 1 clinical trial is planned.

Citation Format: Thierry D. Giffon, Melanie Desbois, Poonam Yakkundi, Susan Calhoun, Keerthana Sekar, Carolyn Denson, Tasnim Kothambawala, Alexander Pearson, Sivani Pandey, Deepal Pandya, Rodnie Rosete, Daniel Machado, Pat Raichlen, Dean Ng, Abhinav R. Jain, Roel Funke, Eric Humke, Paul R. Hinton, Beatrice Wang, Bruce A. Keyt, Maya F. Kotturi, Angus M. Sinclair. IGM-7354, an immunocytokine with IL-15 fused to an anti-PD-L1 IgM, induces NK and CD8+ T cell mediated cytotoxicity of PD-L1-positive tumor cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5660.

Abstract P2-11-08: Multimodal Prediction of Breast Cancer Recurrence Assays and Risk of Recurrence

Background: Hormone receptor positive breast cancer constitutes about 70% of newly diagnosed early-stage disease in the United States, and gene-expression based recurrence assays such as Oncotype DX (ODX) are strongly recommended by guidelines to aid in treatment decisions. However, recurrence assays are costly, time-consuming, underutilized in low resource settings, and unavailable in developing countries. Deep Learning (DL) using hematoxylin and eosin (H&E) stained digital pathology has been shown to approximate gene expression patterns for multiple cancer types, and may provide a cost-effective, fast, and scalable method to predict risk of recurrence in community settings. Methods: We first developed a model for ODX using only DL on pathology, comprised of two Xception-based modules, trained on 1,039 slides from The Cancer Genome Atlas (TCGA) tessellated into 10x magnification image tiles. The first module predicts tumor likelihood, and was trained using pathologist annotations for tumor regions versus normal stroma. The second module was trained to predict ODX score, estimated from gene expression data within TCGA. Patient-level predictions were calculated by weighting the predicted recurrence score by tumor likelihood for all tiles within a slide. Separately, ODX score was predicted from clinical variables using the University of Tennessee Nomogram, which incorporates grade, progesterone receptor, size, age, and histologic subtype. Finally, we developed a combined model by fitting a logistic regression to the DL pathologic model and the clinical nomogram predictions. Performance of the clinical nomogram, pathologic, and combined models were then compared in a single-institution external validation cohort of patients diagnosed with breast cancer between 2006 and 2020, all of whom had the commercial ODX assay run. Results: We identified 428 cases for our diverse validation cohort (69% White, 24% Black, 6% Asian, and 3% Hispanic) with mean ODX score of 18. Chemotherapy was administered for 104 (24.3%) of patients, the remaining 323 (75.4%) received endocrine therapy alone. Area under the receiver operating characteristic curve (AUROC) for prediction of high ODX score (≥ 26) of the combined model was 0.83 (95% confidence interval [CI] 0.78 – 0.89) in the validation cohort, which was higher than either the DL pathology model (AUROC 0.80, 95% CI 0.75 – 0.85, p = 0.026) or the Tennessee nomogram (AUROC 0.77, 85% CI 0.70 – 0.83, p = 0.003). Performance was similar in Black (AUROC 0.86, 95% CI 0.78 – 0.94) and White (AUROC of 0.81, 95% CI 0.74 – 0.88) subgroups. The combined model was more accurate in prediction of recurrence-free interval in patients receiving endocrine therapy (hazard ratio [HR] 2.02 per standard deviation [SD], 95% CI 1.16 – 3.52, p = 0.013, Concordance [C]-index 0.75) than the clinical nomogram (HR 1.75 per SD, 95% CI 1.09 – 2.81, p = 0.021, C-index 0.68). No model was prognostic in patients receiving chemotherapy. Pathologist review of heatmaps of DL model predictions identified lymphovascular invasion, necrosis, high grade, and infiltrative borders as features contributing to model prediction of high risk. Conclusions: DL can improve on existing clinical prediction of breast cancer with low recurrence risk. This approach could improve the speed at which treatment decisions are made due to the time-consuming nature of genomic testing and simultaneously reduce the cost of care. Given the equal performance in racial subgroups, this approach has promise for application in global health settings where genomic assays are not widely available or are prohibitively expensive.

Citation Format: Frederick M. Howard, James M. Dolezal, Sara Kochanny, Galina Khramtsova, Jasmine Vickery, Andrew Srisuwananukorn, Anna Woodard, Nan Chen, Rita Nanda, Charles Perou, Olufunmilayo I. Olopade, Dezheng Huo, Alexander Pearson. Multimodal Prediction of Breast Cancer Recurrence Assays and Risk of Recurrence [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-11-08.

The EU-funded I3LUNG Project: Integrative Science, Intelligent Data Platform for Individualized LUNG Cancer Care With Immunotherapy

Although immunotherapy (IO) has changed the paradigm for the treatment of patients with advanced non-small cell lung cancers (aNSCLC), only around 30% to 50% of treated patients experience a long-term benefit from IO. Furthermore, the identification of the 30 to 50% of patients who respond remains a major challenge, as programmed Death-Ligand 1 (PD-L1) is currently the only biomarker used to predict the outcome of IO in NSCLC patients despite its limited efficacy. Considering the dynamic complexity of the immune system-tumor microenvironment (TME) and its interaction with the host's and patient's behavior, it is unlikely that a single biomarker will accurately predict a patient's outcomes. In this scenario, Artificial Intelligence (AI) and Machine Learning (ML) are becoming essential to the development of powerful decision-making tools that are able to deal with this high-complexity and provide individualized predictions to better match treatments to individual patients and thus improve patient outcomes and reduce the economic burden of aNSCLC on healthcare systems. I³LUNG is an international, multicenter, retrospective and prospective, observational study of patients with aNSCLC treated with IO, entirely funded by European Union (EU) under the Horizon 2020 (H2020) program. Using AI-based tools, the aim of this study is to promote individualized treatment in aNSCLC, with the goals of improving survival and quality of life, minimizing or preventing undue toxicity and promoting efficient resource allocation. The final objective of the project is the construction of a novel, integrated, AI-assisted data storage and elaboration platform to guide IO administration in aNSCLC, ensuring easy access and cost-effective use by healthcare providers and patients.

The association between diabetes and mortality among adult patients hospitalized with COVID-19: Cohort Study of Hospitalized Adults in Ontario, Canada and Copenhagen, Denmark

Importance

Diabetes has been reported to be associated with an increased risk of death among patients with COVID-19. However, available studies lack detail on COVID illness severity and measurement of relevant comorbidities.

Design, Setting, and Participants

We conducted a multicenter, retrospective cohort study of patients over the age of 18 years who were hospitalized with COVID-19 between January 1, 2020 and November 30, 2020 in Ontario, Canada and Copenhagen, Denmark. Chart abstraction emphasizing co-morbidities and disease severity was performed by trained research personnel. The association between diabetes and death was measured using Poissson regression.

Main Outcomes and Measures

Within hospital 30-day risk of death.

Results

Our study included 1133 hospitalized patients with COVID-19 in Ontario and 305 in Denmark, of whom 405 and 75 patients respectively had pre-existing diabetes. In both Ontario and Denmark, patients with diabetes were more likely to be older, have chronic kidney disease, cardiovascular disease, higher troponin levels, and to receive antibiotics compared with adults who did not have diabetes. In Ontario, 24% (n=96) of adults with diabetes died compared with 15% (n=109) of adults without diabetes. In Denmark, 16% (n=12) of adults with diabetes died in hospital compared with 13% (n=29) among those without diabetes. In Ontario, the crude mortality rate ratio among patients with diabetes was 1.60 [1.24 – 2.07 95% CI] and in the adjusted regression model was 1.19 [0.86 – 1.66 95% CI]. In Denmark, the crude mortality rate ratio among patients with diabetes was 1.27 (0.68 – 2.36 95% CI) and in the adjusted model was 0.87 (0.49 – 1.54 95% CI)]. Meta-analysis of the two rate ratios from each region resulted in a crude mortality rate ratio of 1.55 (95% CI 1.22,1.96) and an adjusted mortality rate ratio of 1.11 (95% CI 0.84, 1.47).

Conclusions

Presence of diabetes was not strongly associated with in-hospital COVID mortality independent of illness severity and other comorbidities.

Precision of the GE Lunar Total Body-Less Head Scan for the Measurement of Three-Compartment Body Composition in Athletes

INTRODUCTION

Dual energy X-ray absorptiometry (DXA) is widely used for the assessment of lean mass (LM), fat mass (FM) and bone mineral content (BMC). When observing standardised protocols, DXA has a high level of precision for the assessment of total body composition, including the head region. However, including the head region may have limited relevance in athletes and can be problematic when positioning taller athletes who exceed scan boundaries. This study investigated the precision of a new total-body-less-head (TBLH) DXA scan for three-compartment body composition measurement in athletes, with outcomes compared to the standard total-body DXA scan.

METHODS

Precision errors were calculated from two consecutive scans with re-positioning (Lunar iDXA, GE Healthcare, Madison, WI), in male and female athletes from a range of sports. TBLH precision was determined from repeat scans in 95 athletes (male n = 55; female n = 40; age: 26.0 ± 8.5 y; body mass: 81.2 ± 20.5 kg; stature: 1.77 ± 0.11 m), and standard total-body scan precision was derived from a sub-sample of 58 athletes (male n = 19; female n = 39; age: 27.6 ± 9.9 y; body mass: 69.6 ± 14.8 kg; stature: 1.72 ± 0.94 m). Data from the sub-sample were also used to compare precision error and 3-compartment body composition outcomes between the standard total-body scan and the TBLH scan.

RESULTS

TBLH precision errors [root mean squared-standard deviation, RMS-SD (coefficient of variation, %CV)] were bone mineral content (BMC): 15.6 g (0.5%), lean mass (LM): 254.3 g (0.4%) and fat mass (FM): 199.4 g (1.3%). These outcomes compared favourably to the precision errors derived from the standard total-body scan [BMC: 12.4 g (0.4%), LM: 202.2 g (0.4%), and FM: 160.8 g (1.1%)]. The TBLH scan resulted in lower BMC (-19.5%), LM (-6.6%), and FM (-4.5%) compared to the total-body scan (BMC: 2,308 vs. 2,865 g; LM: 46,954 vs. 50,276 g; FM: 15,183 vs. 15,888 g, all p&lt;0.005). ConclusionThe TBLH scan demonstrates high in-vivo precision comparable to that of the standard total-body scan in a heterogeneous cohort of athletes. Given the impact of head exclusion on total body composition outcomes, TBLH scans should not be used interchangeably with the standard total-body scan.

Prospective study evaluating dynamic changes of cell-free HPV DNA in locoregional viral-associated oropharyngeal cancer treated with induction chemotherapy and response-adaptive treatment

BACKGROUND

Human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) has a favorable prognosis which has led to efforts to de-intensify treatment. Response-adaptive de-escalated treatment is promising, however improved biomarkers are needed. Quantitative cell-free HPV-DNA (cfHPV-DNA) in plasma represents an attractive non-invasive biomarker for grading treatment response and post-treatment surveillance. This prospective study evaluates dynamic changes in cfHPV-DNA during induction therapy, definitive (chemo)radiotherapy, and post-treatment surveillance in the context of risk and response-adaptive treatment for HPV + OPC.

METHODS

Patients with locoregional HPV + OPC are stratified into two cohorts: High risk (HR) (T4, N3, [Formula: see text] 20 pack-year smoking history (PYH), or non-HPV16 subtype); Low risk (LR) (all other patients). All patients receive induction chemotherapy with three cycles of carboplatin and paclitaxel. LR with ≥ 50% response receive treatment on the single-modality arm (minimally-invasive surgery or radiation alone to 50 Gy). HR with ≥ 50% response or LR with ≥ 30% and < 50% response receive treatment on the intermediate de-escalation arm (chemoradiation to 50 Gy with cisplatin). All other patients receive treatment on the regular dose arm with chemoradiation to 70 Gy with concurrent cisplatin. Plasma cfHPV-DNA is assessed during induction, (chemo)radiation, and post-treatment surveillance. The primary endpoint is correlation of quantitative cfHPV-DNA with radiographic response.

DISCUSSION

A de-escalation treatment paradigm that reduces toxicity without compromising survival outcomes is urgently needed for HPV + OPC. Response to induction chemotherapy is predictive and prognostic and can select candidates for de-escalated definitive therapy. Assessment of quantitative cfHPV-DNA in the context of response-adaptive treatment of represents a promising reliable and convenient biomarker-driven strategy to guide personalized treatment in HPV + OPC.

TRIAL REGISTRATION

This trial is registered with ClinicalTrials.gov on October 1st, 2020 with Identifier: NCT04572100 .

Monitoring Spontaneous Quiescence and Asynchronous Proliferation-Quiescence Decisions in Prostate Cancer Cells

The proliferation-quiescence decision is a dynamic process that remains incompletely understood. Live-cell imaging with fluorescent cell cycle sensors now allows us to visualize the dynamics of cell cycle transitions and has revealed that proliferation-quiescence decisions can be highly heterogeneous, even among clonal cell lines in culture. Under normal culture conditions, cells often spontaneously enter non-cycling G0 states of varying duration and depth. This also occurs in cancer cells and G0 entry in tumors may underlie tumor dormancy and issues with cancer recurrence. Here we show that a cell cycle indicator previously shown to indicate G0 upon serum starvation, mVenus-p27K-, can also be used to monitor spontaneous quiescence in untransformed and cancer cell lines. We find that the duration of spontaneous quiescence in untransformed and cancer cells is heterogeneous and that a portion of this heterogeneity results from asynchronous proliferation-quiescence decisions in pairs of daughters after mitosis, where one daughter cell enters or remains in temporary quiescence while the other does not. We find that cancer dormancy signals influence both entry into quiescence and asynchronous proliferation-quiescence decisions after mitosis. Finally, we show that spontaneously quiescent prostate cancer cells exhibit altered expression of components of the Hippo pathway and are enriched for the stem cell markers CD133 and CD44. This suggests a hypothesis that dormancy signals could promote cancer recurrence by increasing the proportion of quiescent tumor cells poised for cell cycle re-entry with stem cell characteristics in cancer.

Risk and response adapted de-intensified treatment for HPV-associated oropharyngeal cancer: Optima paradigm expanded experience

BACKGROUND

Favorable prognosis for Human papillomavirus-associated (HPV+) oropharyngeal cancer (OPC) led to investigation of response-adaptive de-escalation, yet long-term outcomes are unknown. We present expanded experience and follow-up of risk/response adaptive treatment de-intensification in HPV+ OPC.

METHODS

A phase 2 trial (OPTIMA) and subsequent cohort of sequential off-protocol patients treated from September 2014 to November 2018 at the University of Chicago were reviewed. Eligible patients had T3-T4 or N2-3 (AJCC 7th edition) HPV+ OPC. Patients were stratified by risk: High-risk (HR) (T4, ≥N2c, or >10PYH), all others low-risk (LR). Induction chemotherapy (IC) included 3 cycles of carboplatin and nab-paclitaxel (OPTIMA) or paclitaxel (off-protocol). LR with ≥50% response received low-dose radiotherapy (RT) alone to 50 Gy (RT50). LR with 30-50% response and HR with ≥50% response received intermediate-dose chemoradiotherapy (CRT) to 45 Gy (CRT45). All others received full-dose CRT to 75 Gy (CRT75).

RESULTS

91 patients consented and 90 patients were treated, of which 31% had >10PYH, 34% had T3/4 disease, and 94% had N2b/N2c/N3 disease. 49% were LR and 51% were HR. Overall response rate to induction was 88%. De-escalated treatment was administered to 83%. Median follow-up was 4.2 years. Five-year OS, PFS, LRC, and DC were 90% (95% CI 81,95), 90% (95% CI 80,95), 96% (95% CI 90,99), and 96% (88,99) respectively. G-tube placement rates in RT50, CRT45, and CRT75 were 3%, 33%, and 80% respectively (p < 0.05).

CONCLUSION

Risk/response adaptive de-escalated treatment for an inclusive cohort of HPV+ OPC demonstrates excellent survival with reduced toxicity with long-term follow-up.

Abstract PO021: Carcinoma-associated mesenchymal stem/stromal cells enhance ovarian cancer metastasis and increase cancer cell clonal heterogeneity through direct mitochondrial transfer

Ovarian cancer is the most deadly gynecologic cancer largely due to early, diffuse metastatic spread. The ovarian cancer tumor microenvironment (TME) significantly impacts the metastatic capacity of ovarian cancer. We recently demonstrated that a critical stromal progenitor cell within the TME, termed carcinoma-associated mesenchymal stem/stromal cells (CA-MSCs), dramatically enhance the metastasis of ovarian cancer cells. CA-MSCs directly bind to cancer cells forming heterocellular units which co-metastasize. The goal of this work is to understand the mechanism driving CA-MSC-mediated ovarian cancer metastasis. We hypothesize that CA-MSCs increase the metastatic potential of ovarian cancer cells during the process of co-metastasis. Ovarian cancer uses both hematogenous and transcoelomic routes of metastasis therefore we used two ovarian cancer murine models to evaluate both modes of metastasis. We used a genomic barcode system to assess the clonal patterns of metastasis. Ovarian cancer cells with one unique barcode per cell were grown with or without CA-MSCs. Sites of metastasis were quantified and cancer cells were harvested from each site. Barcodes were sequenced to determined clonal representation at each metastatic site. We found CA-MSCs increased the number of metastatic sites in both the hematogenous and transcoelomic mouse models. Interestingly, CA-MSCs also increased the clonal heterogeneity at all metastatic sites (2.5 - 5 fold increase in blood, lung and liver). To investigate the mechanism enabling CA-MSC-mediated enhancement of clonal heterogeneity, we studied primary patient derived CA-MSCs and ovarian cancer cells. The process of metastasis poses unique metabolic stresses on cancer cells and normal mesenchymal stem cells are known to donate mitochondria to damaged epithelial cells. We therefore assessed if CA-MSCs use a similar mechanism to enhance survival of metastatic cancer cells. We stably labeled CA-MSC mitochondria with COX8-GFP via lentiviral transduction to enable the visualization and quantification of potential mitochondrial transfer. We demonstrate that CA-MSCs actively transfer mitochondria to cancer cells. This transfer is dependent on the physical interaction of CA-MSCs with cancer cells and is increased 2-4 fold when CA-MSCs and cancer cells form metastatic heterocellular units under non-adherent conditions. We tested the functional consequences of CA-MSC to cancer cell mitochondrial transfer and demonstrate cancer cells which receive mitochondria have increased chemotherapy resistance, increased sphere forming capacity and stem-like properties. Collectively, our results indicate CA-MSCs are a significant driver of ovarian cancer metastasis by forming heterocellular metastatic units which enable CA-MSC to cancer cell mitochondrial transfer. This leads to increased cancer cell survival and tumor initiation properties and represents a novel method of maintaining cancer cell heterogeneity during metastasis.

Citation Format: Catherine A. Pressimone, Leonard G. Frisbie, Alexander Pearson, Lan G. Coffman. Carcinoma-associated mesenchymal stem/stromal cells enhance ovarian cancer metastasis and increase cancer cell clonal heterogeneity through direct mitochondrial transfer [abstract]. In: Proceedings of the AACR Virtual Special Conference on the Evolving Tumor Microenvironment in Cancer Progression: Mechanisms and Emerging Therapeutic Opportunities; in association with the Tumor Microenvironment (TME) Working Group; 2021 Jan 11-12. Philadelphia (PA): AACR; Cancer Res 2021;81(5 Suppl):Abstract nr PO021.

Phenotype Driven Analysis of Whole Genome Sequencing Identifies Deep Intronic Variants that Cause Retinal Dystrophies by Aberrant Exonization

Purpose

To demonstrate the effectiveness of combining retinal phenotyping and focused variant filtering from genome sequencing (GS) in identifying deep intronic disease causing variants in inherited retinal dystrophies.

Methods

Affected members from three pedigrees with classical enhanced S-cone syndrome (ESCS; Pedigree 1), congenital stationary night blindness (CSNB; Pedigree 2), and achromatopsia (ACHM; Pedigree 3), respectively, underwent detailed ophthalmologic evaluation, optical coherence tomography, and electroretinography. The probands underwent panel-based genetic testing followed by GS analysis. Minigene constructs (NR2E3, GPR179 and CNGB3) and patient-derived cDNA experiments (NR2E3 and GPR179) were performed to assess the functional effect of the deep intronic variants.

Results

The electrophysiological findings confirmed the clinical diagnosis of ESCS, CSNB, and ACHM in the respective pedigrees. Panel-based testing revealed heterozygous pathogenic variants in NR2E3 (NM_014249.3; c.119-2A>C; Pedigree 1) and CNGB3 (NM_019098.4; c.1148delC/p.Thr383Ilefs*13; Pedigree 3). The GS revealed heterozygous deep intronic variants in Pedigrees 1 (NR2E3; c.1100+1124G>A) and 3 (CNGB3; c.852+4751A>T), and a homozygous GPR179 variant in Pedigree 2 (NM_001004334.3; c.903+343G>A). The identified variants segregated with the phenotype in all pedigrees. All deep intronic variants were predicted to generate a splice acceptor gain causing aberrant exonization in NR2E3 [89 base pairs (bp)], GPR179 (197 bp), and CNGB3 (73 bp); splicing defects were validated through patient-derived cDNA experiments and/or minigene constructs and rescued by antisense oligonucleotide treatment.

Conclusions

Deep intronic mutations contribute to missing heritability in retinal dystrophies. Combining results from phenotype-directed gene panel testing, GS, and in silico splice prediction tools can help identify these difficult-to-detect pathogenic deep intronic variants.

Progress in treating inherited retinal diseases: Early subretinal gene therapy clinical trials and candidates for future initiatives

Due to improved phenotyping and genetic characterization, the field of 'incurable' and 'blinding' inherited retinal diseases (IRDs) has moved substantially forward. Decades of ascertainment of IRD patient data from Philadelphia and Toronto centers illustrate the progress from Mendelian genetic types to molecular diagnoses. Molecular genetics have been used not only to clarify diagnoses and to direct counseling but also to enable the first clinical trials of gene-based treatment in these diseases. An overview of the recent reports of gene augmentation clinical trials by subretinal injections is used to reflect on the reasons why there has been limited success in this early venture into therapy. These first-in human experiences have taught that there is a need for advancing the techniques of delivery of the gene products - not only for refining further subretinal trials, but also for evaluating intravitreal delivery. Candidate IRDs for intravitreal gene delivery are then suggested to illustrate some of the disorders that may be amenable to improvement of remaining central vision with the least photoreceptor trauma. A more detailed understanding of the human IRDs to be considered for therapy and the calculated potential for efficacy should be among the routine prerequisites for initiating a clinical trial.

Psychological Factors in Acquired Visual Impairment: The Development of a Scale of Adjustment

A number of psychological variables bearing on the process of adjustment to acquired visual loss are examined conceptually and empirically in an attempt to clarify their relationships and to develop a testable model of adjustment which might enable rehabilitation specialists to identify clients with special problems, evaluate the effectiveness of rehabilitation programs, and determine the role of psychological factors in the context of skill acquisition. The model presented offers an alternative to existing psychodynamic models in that it is in principle a testable one. Preliminary analysis of data has resulted in the devising of a questionnaire tentatively called the Nottingham Adjustment Scale, which practitioners and researchers are encouraged to use.

Somatic mitochondrial mutation discovery using ultra-deep sequencing of the mitochondrial genome reveals spatial tumor heterogeneity in head and neck squamous cell carcinoma

Mutations in mitochondrial DNA (mtDNA) have been linked to risk, progression, and treatment response of head and neck squamous cell carcinoma (HNSCC). Due to their clonal nature and high copy number, mitochondrial mutations could serve as powerful molecular markers for detection of cancer cells in bodily fluids, surgical margins, biopsies and lymph node (LN) metastasis, especially at sites where tumor involvement is not histologically apparent. Despite a pressing need for high-throughput, cost-effective mtDNA mutation profiling system, current methods for library preparation are still imperfect for detection of low prevalence heteroplasmic mutations. To this end, we have designed an ultra-deep amplicon-based sequencing library preparation approach that covers the entire mitochondrial genome. We sequenced mtDNA in 28 HNSCCs, matched LNs, surgical margins and bodily fluids, and applied multiregional sequencing approach on 14 primary tumors. Our results demonstrate that this quick, sensitive and cost-efficient method allows obtaining a snapshot on the mitochondrial heterogeneity, and can be used for detection of low frequency tumor-associated mtDNA mutations in LNs, sputum and serum specimens. These findings provide the foundation for using mitochondrial sequencing for risk assessment, early detection, and tumor surveillance.

Organizational uptake of NICE guidance in promoting employees' psychological health

Background

Annual costs to organizations of poor mental health are estimated to be between £33 billion and £42 billion. The UK's National Institute for Clinical Excellence (NICE) has produced evidence-based guidance on improving employees' psychological health, designed to encourage organizations to take preventative steps in tackling this high toll. However, the extent of implementation is not known outside the National Health Service.

Aims

To assess the awareness and implementation of NICE guidance on workplace psychological health.

Methods

A total of 163 organizations participated in a survey of UK-based private, public and third sector organizations employing an accumulated minimum of 322 033 workers.

Results

Seventy-seven per cent of organizations were aware of the NICE guidance for improving mental well-being in the workplace, but only 37% were familiar with its recommendations. Less than half were aware of systems in place for monitoring employees' mental well-being and only 12% confirmed that this NICE guidance had been implemented in their workplace. Where employee health and well-being featured as a regular board agenda item, awareness and implementation of NICE guidance were more likely. Significant associations were found between organizational sector and size and uptake of many specific features of NICE guidance.

Conclusions

The majority of organizations are aware of NICE guidance in general, but there is a wide gap between this and possession of detailed knowledge and implementation. The role of sector and size of organization is relevant to uptake of some features of NICE guidance, although organizational leadership is important where raised awareness and implementation are concerned.

Children sustain high levels of skin DNA photodamage, with a modest increase of serum 25-hydroxyvitamin D3 , after a summer holiday in Northern Europe

BACKGROUND

Childhood solar ultraviolet radiation (UVR) exposure increases the risk of skin cancer in adulthood, which is associated with mutations caused by UVR-induced cyclobutane pyrimidine dimers (CPD). Solar UVR is also the main source of vitamin D, essential for healthy bone development in children.

OBJECTIVES

To assess the impact of a 12-day Baltic Sea (54° N) beach holiday on serum 25-hydroxyvitamin D₃ [25(OH)D₃ ] and CPD in 32 healthy Polish children (skin types I-IV).

METHODS

Blood and urine were collected before and after the holiday and assessed for 25(OH)D₃ and excreted CPD, respectively, and personal UVR exposure was measured. Diaries were used to record sunbathing, sunburn and sunscreen use. Before- and after-holiday skin redness and pigmentation were measured by reflectance spectroscopy.

RESULTS

The average ± SD daily exposure UVR dose was 2·4 ± 1·5 standard erythema doses (SEDs), which is borderline erythemal. The mean concentration of 25(OH)D₃ increased (× 1·24 ± 0·19) from 64·7 ± 13·3 to 79·3 ± 18·7 nmol L^-1 (P < 0·001). Mean CPD increased 12·6 ± 10·0-fold from 26·9 ± 17·9 to 248·9 ± 113·4 fmol μmol^-1 creatinine (P < 0·001). Increased 25(OH)D₃ was accompanied by a very much greater increase in DNA damage associated with carcinogenic potential. Overall, skin type had no significant effects on behavioural, clinical or analytical outcomes, but skin types I/II had more CPD (unadjusted P = 0·0496) than skin types III/IV at the end of the holiday.

CONCLUSIONS

Careful consideration must be given to the health outcomes of childhood solar exposure, and a much better understanding of the risk-benefit relationships of such exposure is required. Rigorous photoprotection is necessary for children, even in Northern Europe.

Geochemically distinct carbon isotope distributions in Allochromatium vinosum DSM 180T grown photoautotrophically and photoheterotrophically

Anoxygenic, photosynthetic bacteria are common at redox boundaries. They are of interest in microbial ecology and geosciences through their role in linking the carbon, sulfur, and iron cycles, yet much remains unknown about how their flexible carbon metabolism-permitting either autotrophic or heterotrophic growth-is recorded in the bulk sedimentary and lipid biomarker records. Here, we investigated patterns of carbon isotope fractionation in a model photosynthetic sulfur-oxidizing bacterium, Allochromatium vinosum DSM180^T . In one treatment, A. vinosum was grown with CO₂ as the sole carbon source, while in a second treatment, it was grown on acetate. Different intracellular isotope patterns were observed for fatty acids, phytol, individual amino acids, intact proteins, and total RNA between the two experiments. Photoautotrophic CO₂ fixation yielded typical isotopic ordering for the lipid biomarkers: δ¹³ C values of phytol > n-alkyl lipids. In contrast, growth on acetate greatly suppressed intracellular isotopic heterogeneity across all molecular classes, except for a marked ¹³ C-depletion in phytol. This caused isotopic "inversion" in the lipids (δ¹³ C values of phytol < n-alkyl lipids). The finding suggests that inverse δ¹³ C patterns of n-alkanes and pristane/phytane in the geologic record may be at least in part a signal for photoheterotrophy. In both experimental scenarios, the relative isotope distributions could be predicted from an isotope flux-balance model, demonstrating that microbial carbon metabolisms can be interrogated by combining compound-specific stable isotope analysis with metabolic modeling. Isotopic differences among molecular classes may be a means of fingerprinting microbial carbon metabolism, both in the modern environment and the geologic record.

Abstract P5-04-01: Cell cycle dynamics at single cell level dictates response to CDK4/6 inhibition

This abstract was withdrawn by the authors.

Abstract 2380: Head and neck patient derived xenografts acquire histopathological and growth rate changes over increasing passages

The purpose of this work was to model the growth rate and histopathological features of patient derived xenograft (PDX) tumors across multiple in-vivo passages. PDX models are frequently deployed in translational cancer research, but the growth rate consistency over time is unclear. While growth rates are generally assumed to be stable, changes in PDX growth over time in the absence of treatment could significantly change the interpretation of translational studies. Here, we examined PDX tumors over time to determine if they have stable growth rates and histopathological features from initial implantation across multiple passages. We implanted and developed three distinct PDX models derived from primary human head and neck squamous cell carcinoma (HNSCC) and adenoid cystic carcinoma (ACC) through at least four passages. To compare growth rates over multiple mouse life spans, we developed a mathematical approach to merge growth data from different passages into a single measure of log relative tumor volume (log-RTV) normalized to study initiation size. We analyzed log-RTV over time with linear mixed effect models and found that tumor growth rate changed over time. In each of the three PDX models tested, the log-RTV was significantly better described by a positive quadratic function compared to a linear function (P &lt; 0.0001 in all three models). This finding implies that the growth rate is not stable over long periods of time, and changes across multiple xenograft passages. To further investigate the etiologies of these changes, two oral pathologists were blinded and analyzed PDX tissues for SCC and ACC models to determine if histopathological features changed over in-vivo passages. We found a significant correlation between passage number and HNSCC nuclear pleomorphism (p = 0.01), ACC histopathological pattern (p &lt; 0.0001), and other features indicative of higher tumor grade in both the squamous cell carcinoma and adenoid cystic models. Our log-RTV transformation of PDX data allows statistical analysis of tumor growth data over long periods of time, including over multiple xenograft passages. In conclusion, this new analysis method allows for the design of longer translational xenograft experiments that span across multiple in-vivo passages. Non-linear tumor growth in our regression models revealed the exponential growth rate of PDX models increased over time. The tumor growth rate changes corresponded with quantifiable histopathological features closely related to passage number in multiple types of head and neck cancer.

Citation Format: Alexander Pearson, Kelsey A. Finkel, Kristy A. Warner, Felipe Nor, David A. Tice, Manoela D. Martins, Trachette L. Jackson, Jacques E. Nor. Head and neck patient derived xenografts acquire histopathological and growth rate changes over increasing passages. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2380.

Changes in soil organic carbon fractions after remediation of a coastal floodplain soil

Coastal floodplain soils and wetland sediments can store large amounts of soil organic carbon (SOC). These environments are also commonly underlain by sulfidic sediments which can oxidise to form coastal acid sulfate soils (CASS) and contain high concentrations of acidity and trace metals. CASS are found on every continent globally except Antarctica. When sulfidic sediments are oxidised, scalds can form, which are large bare patches without vegetation. However, SOC stocks and fractions have not been quantified in these coastal floodplain environments. We studied the changes in soil geochemistry and SOC stocks and fractions three years after remediation of a CASS scald. Remediation treatments included raising water levels, and addition of either lime (LO) or lime and mulch (LM) relative to a control (C) site. We found SOC concentrations in the remediated sites (LO and LM) were more than double than that found at site C, reflected in the higher SOC stocks to a depth of 1.6 m (426 Mg C/ha, 478 Mg C/ha and 473 Mg C/ha at sites C, LO and LM, respectively). The particulate organic C (POC) fraction was higher at sites LO and LM due to increased vegetation and biomass inputs, compared to site C. Reformation of acid volatile sulfide (AVS) occurred throughout the profile at site LM, whereas only limited AVS reformation occurred at sites LO and C. Higher AVS at site LM may be linked to the additional source of organic matter provided by the mulch. POC can also potentially contribute to decreasing acidity as a labile SOC source for Fe(3+) and SO4(2-) reduction. Therefore, coastal floodplains and wetlands are a large store of SOC and can potentially increase SOC following remediation due to i) reduced decomposition rates with higher water levels and waterlogging, and ii) high C inputs due to rapid revegetation of scalded areas and high rates of biomass production. These results highlight the importance of maintaining vegetation cover in coastal floodplains and wetlands for sequestering SOC.

Recording occupation in general practice--a second cycle audit

BACKGROUND

An audit of working age patients' records in two Cornish general practices in 2012 found infrequent and inconsistent recording of patients' occupations. A concurrent survey of general practitioners (GPs) in Cornwall found that a majority of them believed it was important to do so.

AIMS

To review occupation recording in the same practices a year later and to audit a third practice, following the introduction of the electronic fit note. To repeat the survey of attitudes to recording occupation in GPs in Cornwall.

METHODS

We manually checked 300 randomly selected patient records in Practice A and electronically searched all records of working age patients (aged 16-65 years) in Practices B and C for recorded occupation. We sent an electronic survey of attitudes to recording occupation to 202 GPs in Cornwall.

RESULTS

Recording of occupation increased from 17 to 30% of records (χ(2) = 15, P < 0.001) in Practice A and from 12 to 14% (χ(2) = 16.5, P < 0.001) in Practice B. In Practice C, 1% of records had occupation recorded and coded. The proportion of GPs in Cornwall who said that it is important to records patients' occupation increased from 70 to 90% (Fisher's exact statistic 0.01, P < 0.05).

CONCLUSIONS

Recording of patients' occupation increased in both practices from 2012 to 2013, but remains infrequent and inconsistent and the very low levels in a third practice not previously audited is of concern.

Strong influence of the littoral zone on sedimentary lipid biomarkers in a meromictic lake

Planktonic sulfur bacteria growing in zones of photic zone euxinia (PZE) are important primary producers in stratified, sulfur-rich environments. The potential for export and burial of microbial biomass from anoxic photic zones remains relatively understudied, despite being of fundamental importance to interpreting the geologic record of bulk total organic carbon (TOC) and individual lipid biomarkers. Here we report the relative concentrations and carbon isotope ratios of lipid biomarkers from the water column and sediments of meromictic Mahoney Lake. The data show that organic matter in the central basin sediments is indistinguishable from material at the lake shoreline in both its lipid and carbon isotopic compositions. However, this material is not consistent with either the lipid profile or carbon isotope composition of biomass obtained directly from the region of PZE. Due to the strong density stratification and the intensive carbon and sulfur recycling pathways in the water column, there appears to be minimal direct export of the sulfur-oxidizing planktonic community to depth. The results instead suggest that basinal sediments are sourced via the littoral environment, a system that integrates an indigenous shoreline microbial community, the degraded remains of laterally rafted biomass from the PZE community, and detrital remains of terrigenous higher plants. Material from the lake margins appears to travel downslope, traverse the strong density gradient, and become deposited in the deep basin; its final composition may be largely heterotrophic in origin. This suggests an important role for clastic and/or authigenic minerals in aiding the burial of terrigenous and mat-derived organic matter in euxinic systems. Downslope or mineral-aided transport of anoxygenic, photoautotrophic microbial mats may have been a significant sedimentation process in early Earth history.

Coupled reductive and oxidative sulfur cycling in the phototrophic plate of a meromictic lake

Mahoney Lake represents an extreme meromictic model system and is a valuable site for examining the organisms and processes that sustain photic zone euxinia (PZE). A single population of purple sulfur bacteria (PSB) living in a dense phototrophic plate in the chemocline is responsible for most of the primary production in Mahoney Lake. Here, we present metagenomic data from this phototrophic plate--including the genome of the major PSB, as obtained from both a highly enriched culture and from the metagenomic data--as well as evidence for multiple other taxa that contribute to the oxidative sulfur cycle and to sulfate reduction. The planktonic PSB is a member of the Chromatiaceae, here renamed Thiohalocapsa sp. strain ML1. It produces the carotenoid okenone, yet its closest relatives are benthic PSB isolates, a finding that may complicate the use of okenone (okenane) as a biomarker for ancient PZE. Favorable thermodynamics for non-phototrophic sulfide oxidation and sulfate reduction reactions also occur in the plate, and a suite of organisms capable of oxidizing and reducing sulfur is apparent in the metagenome. Fluctuating supplies of both reduced carbon and reduced sulfur to the chemocline may partly account for the diversity of both autotrophic and heterotrophic species. Collectively, the data demonstrate the physiological potential for maintaining complex sulfur and carbon cycles in an anoxic water column, driven by the input of exogenous organic matter. This is consistent with suggestions that high levels of oxygenic primary production maintain episodes of PZE in Earth's history and that such communities should support a diversity of sulfur cycle reactions.