Radiotherapy in the management of lung oligometastases

In recent years, the development of both medical imaging and new systemic agents (targeted therapy and immunotherapy) have revolutionized the field of oncology, leading to a new entity: oligometastatic disease. Adding local treatment of oligometastases to systemic treatment could lead to prolonged survival with no significant impact on quality of life. Given the high prevalence of lung oligometastases and the new systemic agents coming with increased pulmonary toxicity, this article provides a comprehensive review of the current state-of-art for radiotherapy of lung oligometastases. After reviewing pretreatment workup, the authors define several radiotherapy regimen based on the localization and size of the oligometastases. A comment on the synergistic combination of medical treatment and radiotherapy is also made, projecting on future steps in this specific clinical setting.

Radiotherapy in the management of synchronous metastatic lung cancer

Metastatic lung cancer classically portends a poor prognosis. The management of metastatic lung cancer has dramatically changed with the emergence of immune checkpoint inhibitors, targeted therapy and due to a better understanding of the oligometastatic process. In metastatic lung cancers, radiation therapy which was only used with palliative intent for decades, represents today a promising way to treat primary and oligometastatic sites with a curative intent. Herein we present through a literature review the role of radiotherapy in the management of synchronous metastatic lung cancers.

Long duration of immunotherapy before radiosurgery might improve intracranial control of melanoma brain metastases

PURPOSE

Despite significant advances that have been made in management of metastatic melanoma with immune checkpoint therapy, optimal timing of combination immune checkpoint therapy and stereotactic radiosurgery is unknown. We have reported toxicity and efficiency outcomes of patients treated with concurrent immune checkpoint therapy and stereotactic radiosurgery.

PATIENTS AND METHODS

From January 2014 to December 2016, we analyzed 62 consecutive patients presenting 296 melanoma brain metastases, treated with gamma-knife and receiving concurrent immune checkpoint therapy with anti-CTLA4 or anti-PD1 within the 12 weeks of SRS procedure. Median follow-up time was 18 months (mo) (13-22). Minimal median dose delivered was 18 gray (Gy), with a median volume per lesion of 0.219 cm³.

RESULTS

The 1-year control rate per irradiated lesion was 89% (CI 95%: 80.41-98.97). Twenty-seven patients (43.5%) developed distant brain metastases after a median time of 7.6 months (CI 95% 1.8-13.3) after gamma-knife. In multivariate analysis, positive predictive factors for intracranial tumor control were: delay since the initiation of immunotherapy exceeding 2 months before gamma-knife procedure (P=0.003) and use of anti-PD1 (P=0.006). Median overall survival (OS) was 14 months (CI 95%: 11-NR). Total irradiated tumor volume<2.1 cm³ was a positive predictive factor for overall survival (P=0.003). Ten patients (16.13%) had adverse events following irradiation, with four grade≥3. Predictive factors of all grade toxicity were: female gender (P=0.001) and previous treatment with MAPK (P=0.05).

CONCLUSION

A long duration of immune checkpoint therapy before stereotactic radiosurgery might improve intracranial tumor control, but this relationship and its ideal timing need to be assessed in prospective trials.

Abstract P4-07-51: Impact of the Theralink CLIA protein/phosphoprotein assay on treatment selection in routine clinical practice: a prospective observational study in advanced breast cancer

Background: The Theralink Reverse Phase Protein Array-based (RPPA) CLIA assay is a novel molecular assay developed to assist physicians in therapy selection for patients diagnosed with advanced/recurrent breast cancer. The assay was specifically designed to quantitatively measure protein activation/phosphorylation of 32 FDA-approved and Phase III drug targets and pathway-linked downstream substrates, providing functional information on actionable oncogenic drivers in individual tumors. Given the recent commercialization of the Theralink assay (TLA), knowledge gaps exist regarding its use in routine clinical practice and the impact of the test on clinical decision-making in real world practice. The primary objective of this analysis was to assess how the TLA has been integrated in therapy selection for breast cancer patients with a focus on understanding its target population, the rationale for patient selection by the treating physician, and the utilization of the molecule information generated by the assay as part of the therapeutic decision-making process. Findings from this study will help optimize patient selection and maximize the clinical impact of the test as a tool for advancing precision oncology. Methods: We prospectively collected data from 124 women with advanced breast cancer whose tumors were profiled using the Breast Cancer TLA from February, 2021 to May, 2022. All patients were confirmed as actively managed for advanced/recurrent breast cancer. Eight μm FFPE sections (n=5) from a recently collected tissue biopsy were used to isolate tumor epithelia via Laser Capture Microdissection and to generate RPPA-based molecular profiles. Clinical management and therapy selection information for 68 patients was gathered via surveys completed by treating physicians. Results: Median age of the 124 participants was 53 years (range 26-82) and 111 (89.5%) patients had stage IV disease. The cohort included 66 hormone receptors positive (of which 5 were HER2+), 51 triple negative, and 7 HR-/HER2+ breast cancers. The TLA yielded molecular information for all specimens and profiles were generated on average in 11 days. One or more targets were highly activated (highly actionable) in 91 patients (73.4%) and moderately activated (partially actionable) in 29 patents; only 4 patients had no actionable target (3.2%). Previous treatment information was available for 118 (95.2%) patients. The TLA was requested to assist with the selection of first-line treatment in 36 patients (of which 24 had previously received neoadjuvant treatment), second-line treatment in 35 patients and third- or subsequential-lines of treatment in 47 patients. Clinicians provided feedback on the use of the assay for 68 patients included in the study. The survey revealed that the TLA impacted treatment selection in 50 (73.5%) cases and was used to either expand options beyond standard of care (30 cases), refine/re-prioritize available treatments (11 cases), narrow treatment from a plethora of options (2 cases) or a combination of the three (7 cases). When TLA data were used for treatment selection, physicians defined the assay highly and moderately beneficial for patient management in 15 and 27 cases, respectively. Conclusion: Our study suggests the TLA yields useful information for selecting treatment for breast cancer patients with advanced/recurrent disease. In this prospective analysis, the assay identified actionable targets in more than 90% of patients, which is significantly higher than what has previously been reported for genomic profiling alone. Overall, physicians found the information yielded by the assay useful for selecting treatment. The inclusion of the TLA in oncology may offer important insights for advancing precision medicine for breast cancer patients.

Citation Format: Kris Weinberg, Mariaelena Pierobon, Edik Blais, Justin Davis, Joyce O’Shaughnessy, Emanuel F. Petricoin. Impact of the Theralink CLIA protein/phosphoprotein assay on treatment selection in routine clinical practice: a prospective observational study in advanced breast cancer. [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 P4-07-51.

Abstract P5-03-12: DNA repair genes are more frequently mutated in non-white populations of metastatic breast cancer (MBC) patients

Background: Although improvements in detection, therapeutic development and molecular profiling have decreased MBC mortality over the last twenty years, clinical outcomes are not being equally realized among all patients. Representation and enrollment into clinical trials are often not reflective of the general MBC population in terms of race and ethnicity, with Black and Hispanic patients being largely and often underrepresented. Not only does this imbalance translate into overall access to novel agents, but the lack of understanding of therapeutic efficacy in minority populations and tumor-based molecular differences reduce the use of truly personalized treatments for these groups. There is an opportunity to improve clinical outcomes for all patients with MBC, starting with a better understanding of the degree of any potential differences in underlying tumor molecular biology between racial groups. Methods: We utilized data from two cohorts of patients whose tumors underwent molecular profiling to examine differences in the frequency of genetic mutations across racial groups with MBC. The first cohort included 856 MBCs whose genomic profiles were retrieved from the AACR Genomics Evidence Neoplasia Information Exchange (GENIE) publicly available database. The second cohort included a separate set of 91 patients with MBC from an ongoing precision medicine program sponsored by the Side-Out Foundation (SOF). While the GENIE data were collected at 19 large academic cancer centers, the SOF data are derived from patients treated in the community setting. We compared the relative distributions of age and reported ethnicity between datasets, and compared the 20 most frequently mutated genes in each racial group across datasets. The analysis across races included 73 genes that were examined for differences in mutation frequency using Fisher’s Exact test and Pearson Chi-Square test (p&lt; 0.05 uncorrected). Results: Although the GENIE set was significantly larger, race distribution was not statistically significant across the two populations. The combined populations included 831 white patients (88.4%), 43 Black patients (4.6%), 30 Asian patients (3.2%), and 35 Hispanic patients (3.7%). The age of initial (59.61) and metastatic (61.19) diagnosis was older in the SOF population compared to the GENIE population (48.81, 53.14; p &lt; 0.001). Hispanic patients (46.92) were diagnosed with MBC at a younger age compared to White patients (53.78; p &lt; 0.001). Of the 73 genes analyzed, 11 genes were found less frequently mutated in whites compared to non-whites including, NTRK1, SDHA, MSH6, TCF3, FANCC, GNAS, COP1, RECQL4, WRN, BCL6, and U2AF1. When the same 73 genes were examined for differences across racial groups, alterations of 22 genes reached statistical significance. The gene(s) with the largest difference compared to white patients were RECQL4 in black patients (13.95% vs 5.29%; p = 0.019), WRN in Asian patients (16.63% vs 2.53%; p &lt; 0.001), and RECQL4 and ERBB2 in Hispanic patients (16.13% vs 5.29%; p = 0.019, p = 0.020). Of the 22 genes that were more frequently altered in the non-white population, 6 have roles in DNA repair including RECQL4, WRN, ERCC2, BLM, MSH6, FANCC. 4/22 are receptor tyrosine kinases (RTKs), including NTRK2, RET, ERBB3, and ERBB2, and 3/22 have roles in immune function, including BCL6, CIITA, and TLR4. Conclusion: Analysis of genomic alterations derived from 2 independent real-world molecular profiling-based cohorts identified in non-whites MBC patients a set of candidate “actionable” genes involved in DNA damage repair, RTK expression, and immune function. Although these results require further validation, considering the relatively small samples sizes of the non-white populations, these findings may provide actionable targets for non-white patients with MBC that could be utilized in future trials.

Citation Format: Sydney Hilley, Rick Dunetz, Edik Blais, Mariaelena Pierobon, Emanuel F. Petricoin, Elisa Baldelli. DNA repair genes are more frequently mutated in non-white populations of metastatic breast cancer (MBC) patients [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 P5-03-12.

Abstract C071: Keratin 17 excludes CD8-positive T cells and recruits CD163-positive macrophages in pancreatic ductal adenocarcinoma

Background: Keratin 17 (K17) is a negative prognostic biomarker, overexpressed in the biologically most aggressive forms of pancreatic ductal adenocarcinoma (PDAC). In other anatomic sites and disease processes, K17 expression also correlates with immune cell infiltrates and could block T-cell infiltration. Thus, we hypothesized that K17 expression correlates with the inflammatory microenvironment in PDAC. In this study, we aimed to determine the relationship between the stromal immune cell infiltrates and K17 expression, using multiplexed immunohistochemistry (mIHC) and our suite of deep learning tools to quantitatively evaluate the expression of four biomarkers of T-cells and macrophages in PDAC. Methods: mIHC was performed on representative sections of 201 primary PDACs from Stony Brook University Hospital, Thomas Jefferson University Hospital, Cedars Sinai Medical Center, and from a national cohort (KYT, Pancreatic Cancer Action Network, and Perthera). Antibodies for CD4 (helper T-cells), CD8 (cytotoxic T-cells), CD16 (pan-macrophage), CD163 (M2 macrophages), pancytokeratin, and K17 were provided by Roche Diagnostics Corporation through a sponsored research agreement. mIHC was performed on a Discovery Ultra Autostainer (Roche), using horseradish peroxidase (HRP) and alkaline phosphatase (AP)-based protocols with multiple chromogens (Red: CD4, Purple: CD8, Yellow: CD16, Green: CD163, Teal: pancytokeratin, and Brown: K17) to enable multispectral imaging of diverse immune cell populations within the cancer microenvironment. A deep learning analysis workflow was used to detect and classify stromal inflammatory cells, in whole slide images (WSIs), generated using an Olympus VS120 digital microscope (Olympus, Tokyo, Japan). Pixel-wise predictions from a color auto-encoder (ColorAE) union UNET anchor UNET model were combined to create multi-class masks that were further analyzed to perform detection and classification. Results: The analysis of the inflammatory microenvironment focused on defining immune cell infiltrates located within 25 microns of the closest K17-positive versus K17-negative tumor cell in each representative section. Across the sum of K17-positive and negative zones/section, CD4 cell counts ranged from 0-10,617 (mean 2,709), CD8 cell counts ranged from 63-28,596 (mean 6,745), CD16 cell counts ranged from 4-7,797 (mean 3,024), and CD163 cell counts ranged from 35-34,696 (mean 14,968). CD4 T-helper cells, CD8 cytotoxic T cells, and CD16 macrophages were more numerous (respectively, p=0.0012; p=&lt;0.0001; p=&lt;0.0001) in K17-negative tumor zones compared to K17-positive zones. By contrast, the number of CD163 (M2) tumor-promoting macrophages was greater in K17 positive zones (p=0.0019). Conclusion: K17 expression by tumor cells impacts the chronic inflammatory microenvironment, shielding tumor cells from immune cell mediated cytotoxic responses, while recruiting tumor-promoting M2 macrophages, indicating that K17 impacts the immune response as a fundamental hallmark of aggression in PDAC.

Citation Format: Lyanne Oblein, Michael Horowitz, Mahmudul Hasan, Sruthi Babu, Mariana Torrente-Goncalves, Lucia Roa, Jaymie Oentoro, Jason Harper, Xin Yao Zheng, Wei Jiang, Andrew Hendifar, Natalie Moshayedi, Brent Larson, Veronica Placencio-Hickok, Edik Blais, Emmanuel Petricoin, Joel Saltz, Natalia D. Marchenko, Luisa F. Escobar-Hoyos, Kenneth Shroyer. Keratin 17 excludes CD8-positive T cells and recruits CD163-positive macrophages in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C071.

[Efficacy and tolerance of salvage curative radiotherapy for patients with cervical relapse of differentiated thyroid carcinoma]

PURPOSE

Radiation therapy is often the last resource treatment for cervical relapse in iodine refractory differentiated thyroid cancer. We present locoregional control data in patients with cervical relapse treated with curative intent radiation therapy with or without concomitant carboplatin.

MATERIAL AND METHODS

This monocentric retrospective study gathered data on patients with differentiated thyroid carcinoma - vesicular or papillary - in relapse after thyroidectomy who received a curative intent cervical radiation therapy. Locoregional progression free survival (LRPFS), progression free survival (PFS), overall survival (OS) were gathered as well as acute and chronic adverse events assessed with the CTCAE v4.

RESULTS

Thirty-nine patients were consecutively included between 2005 and 2019. The median follow-up was 36.6months. Fifteen patients (38%) had a locoregional relapse, locoregional control at 2years was 66.7%. The median LRPFS was 48months [32.9-not reached] and the median overall survival 49months [38.8-not reached]. In multivariate analysis, initial incomplete resection was associated with poorer OS (HR: 24.39 [3.57-166.78], P=0.00113) and LRPFS (HR: 33.91 [4.46-257.61], P=0.00066), extra nodal spread was associated with poorer LRPFS (HR: 13.45 [1.81-99,76], P=0.011). ECOG performance status was associated with OS (HR: 5.11 [1.57-16.66], P=0.00688). Carboplatin association with radiation therapy was not associated with improved survivals (OS: P=0.34, LRPFS: P=0.84). The rate of acute grade 3 toxicities was 14%.

CONCLUSION

Salvage cervical radiation therapy was associated with a locoregional control of 66.7% at 2years with a reasonable toxicity rate. Carboplatin association with radiation therapy did not improve locoregional control nor overall survival in comparison with radiotherapy alone.

Histosurgical mapping of endoscopic endonasal surgery of sinonasal tumours to improve radiotherapy guidance

PURPOSE

Endoscopic endonasal surgery (EES) is becoming a standard for most malignant sinonasal tumours. Margin analysis after piecemeal resection is complex and optimally relies on accurate histosurgical mapping. Postoperative radiotherapy may be adapted based on margin assessment mapping to reduce the dose to some sinonasal subvolumes. We assessed the use of histosurgical mapping by radiation oncologists (RO).

MATERIAL AND METHODS

A French practice survey was performed across 29 ENT expert RO (2 did not answer) regarding integration of information on EES, as well as quality of operative and pathology reportsto refine radiotherapy planning after EES. This was assessed through an electronic questionnaire.

RESULTS

EES was ubiquitously performed in France. Operative and pathology reports yielded accurate description of EES samples according to 66.7% of interviewed RO. Accuracy of margin assessment was however insufficient according to more than 40.0% of RO. Additional margins/biopsies of the operative bed were available in 55.2% (16/29) of the centres. In the absence of additional margins, quality of resection after EES was considered as microscopically incomplete in 48.3% or dubious in 48.3% of RO. As performed, histosurgical mapping allowed radiotherapy dose and volumes adaptation according to 26.3% of RO only.

CONCLUSIONS

Standardized histosurgical mapping with margin and additional margin analysis could be more systematic. Advantages of accurate EES reporting could be dose painting radiotherapy to further decrease morbidity in sinonasal tumours.

Brachytherapy boost (BT-boost) or stereotactic body radiation therapy boost (SBRT-boost) for high-risk prostate cancer (HR-PCa)

Systematic review for the treatment of high-risk prostate cancer (HR-PCa, D'Amico classification risk system) with external body radiation therapy (EBRT)+brachytherapy-boost (BT-boost) or with EBRT+stereotactic body RT-boost (SBRT-boost). In March 2020, 391 English citations on PubMed matched with search terms "high risk prostate cancer boost". Respectively 9 and 48 prospective and retrospective studies were on BT-boost and 7 retrospective studies were on SBRT-boost. Two SBRT-boost trials were prospective. Only one study (ASCENDE-RT) directly compared the gold standard treatment [dose-escalation (DE)-EBRT+androgen deprivation treatment (ADT)] versus EBRT+ADT+BT-boost. Biochemical control rates at 9 years were 83% in the experimental arm versus 63% in the standard arm. Cumulative incidence of late grade 3 urinary toxicity in the experimental arm and in the standard arm was respectively 18% and 5%. Two recent studies with HR-PCa (National Cancer Database) demonstrated better overall survival with BT-boost (low dose rate LDR or high dose rate HDR) compared with DE-EBRT. These recent findings demonstrate the superiority of EBRT+BT-boost+ADT versus DE-EBRT+ADT for HR-PCa. It seems that EBRT+BT-boost+ADT could now be considered as a gold standard treatment for HR-PCa. HDR or LDR are options. SBRT-boost represents an attractive alternative, but the absence of randomised trials does not allow us to conclude for HR-PCa. Prospective randomised international phase III trials or meta-analyses could improve the level of evidence of SBRT-boost for HR-PCa.

A step towards personalizing next line therapy for resected pancreatic and related cancer patients: A single institution's experience

Background:

There is a lack of precision medicine in pancreatic ductal adenocarcinoma (PDA) and related cancers, and outcomes for patients with this diagnosis remain poor despite decades of research investigating this disease. Therefore, it is necessary to explore novel therapeutic options for these patients who may benefit from personalized therapies.

Objective:

Molecular profiling of hepatopancreaticobiliary malignancies at our institution, including but not limited to PDA, was initiated to assess the feasibility of incorporating molecular profiling results into patient oncological therapy planning.

Methods:

All eligible patients from Thomas Jefferson University (TJU) with hepatopancreaticobiliary tumors including PDA, who agreed to molecular testing profiling, were prospectively enrolled in a registry study from December 2014 to September 2017 and their tumor samples were tested to identify molecular markers that can be used to guide therapy options in the future. Next generation sequencing (NGS) and protein expression in tumor samples were tested at CLIA-certified laboratories. Prospective clinicopathologic data were extracted from medical records and compiled in a de-identified fashion.

Results:

Seventy eight (78) patients were enrolled in the study, which included 65/78 patients with PDA (local and metastatic) and out of that subset, 52/65 patients had surgically resected PDA. Therapy recommendations were generated based on molecular and clinicopathologic data for all enrolled patients. NGS uncovered actionable alterations in 25/52 surgically resected PDAs (48%) which could be used to guide therapy options in the future. High expression of three proteins, TS (p ¼ 0.005), ERCC1 (p = 0.001), and PD-1 (p = 0.04), was associated with reduced recurrence-free survival (RFS), while TP53 mutations were correlated with longer RFS (p = 0.01).

Conclusions:

The goal of this study was to implement a stepwise strategy to identify and profile resected PDAs at our institution. Consistent with previous studies, approximately half of patients with resected PDA harbor actionable mutations with possible targeted therapeutic implications. Ongoing studies will determine the clinical value of identifying these mutations in patients with resected PDA.

Diagnostic performance of imaging techniques for detecting of local recurrence after prostate brachytherapy

PURPOSE

The purpose of this study was to evaluate MRI and fluorocholine PET/CT diagnostic performances for the detection of local recurrence following prostate brachytherapy for localised prostate cancer.

MATERIAL AND METHODS

In this single-centre study, we retrospectively reviewed data from 21 patients treated by brachytherapy for localised prostate cancer and diagnosed with biochemical recurrence according to Phoenix Criteria, who underwent MRI and fluorocholine PET/CT. We included patients with local relapse suspicion according to imaging exams, with biopsy for the final assessment of local recurrence. Patient analysis data were supplemented by segment analysis using an 8-segment model.

RESULTS

The fluorocholine PET/CT was positive for 81% and negative for 19% of patients. The sensitivity and specificity were 92% and 33% with diagnosis accuracy of 67%. The MRI was positive for 57% and negative for 43% of patients. The sensitivity and specificity were 67% and 56% with diagnosis accuracy of 62%. There was no statistically significant difference between fluorocholine PET/CT and MRI accuracy (P=0.63). On a segment-based analysis, the sensitivity and specificity were 44% and 82% for fluorocholine PET/CT with diagnosis accuracy of 78%. For MRI, specificity was 91% diagnosis accuracy was 82%.

CONCLUSION

Both MRI and fluorocholine PET/CT permit to highlight local recurrence sites after prostate brachytherapy. Confirmation biopsies are, however, necessary since this accuracy is insufficient.

Abstract C27: Association of mutant KRAS isoforms with weight loss in pancreatic cancer

Background: Patients with pancreatic cancer often develop progressive weight loss and sarcopenia, described as cancer cachexia syndrome. Despite evidence showing that pancreatic cancer cachexia is associated with a poor prognosis, reduced tolerance to therapy, and diminished quality of life, no predictive biomarkers have been identified to date. Certain mutant KRAS isoforms are associated with significant alterations to tumor metabolism and have been correlated with changes in weight and survival. However, the clinical implications resulting from specific KRAS mutations in pancreatic cancer have yet to be fully explored.

Methods: A retrospective analysis was performed to compare weight changes and survival in 150 pancreatic cancer patients with various KRAS alterations identified by next-generation sequencing (Foundation Medicine, Inc., Cambridge, MA). Survival data and weights documented between 6 months prior to diagnosis and the date of death or the last follow-up visit were abstracted from the medical record and evaluated using statistical analyses, including functional principal component analysis for sparse functional data, Ward cluster, logistic regression, analysis of variance, and Cox regression. Using derivative principal component scores, we separated patients into two groups demonstrating either constant or decreasing weight over time.

Results: 77% of evaluated patients had a KRAS mutation, and 21% had KRAS wild-type. Of patients with mutant KRAS, 84% had an alteration at G12, 10% at Q61, and 3% at G13. While there was no significant difference in weight changes between KRAS wild-type patients and patients with a Q61 mutation, patients with non-Q61 mutations were 2.5 times more likely (p = 0.05) than wild-type patients to demonstrate weight loss over time. Furthermore, KRAS mutants had worse survival when compared to KRAS wild-type patients. Irrespective of mutational status, patients whose weight did not decrease were 69% less likely to die (p = 0.039).

Conclusion: We demonstrated that mutant KRAS isoforms G12 and G13 mutations correlate with weight loss, whereas Q61 KRAS mutations and wild-type KRAS do not. Furthermore, weight loss in all patients increased their risk of death. These findings suggest that KRAS subtypes may have unique genotype-to-phenotype features, particularly with weight loss that could warrant tailored therapeutic strategies in at-risk subgroups. Future studies of larger scope, and ideally prospective in nature, are warranted in patients stratified by KRAS isoform.

Citation Format: Haesoo Kim, Camille Ng, Marcio A. Diniz, Michel H. Montoril, Michelle Guan, Victor Brodsky, Eric Vail, Richard Tuli, Edik Blais, Sungjin Kim, Emanuel Petricoin III, Jun Gong, Veronica R. Placencio-Hickok, Andrew E. Hendifar. Association of mutant KRAS isoforms with weight loss in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C27.

[Chemoradiation for oesophageal cancer: A critical review of the literature]

Locally advanced oesophageal cancer treatment requires a multidisciplinary approach with the combination of chemotherapy and radiotherapy for preoperative and definitive strategy. Preoperative chemoradiation improves the locoregional control and overall survival after surgery for locally advanced oesophageal cancer. Definitive chemoradiation can also be proposed for non-resectable tumours or medically inoperable patients. Besides, definitive chemoradiation is considered as an alternative option to surgery for locally advanced squamous cell carcinomas. Chemotherapy regimen associated to radiotherapy consists of a combination of platinum derived drugs (cisplatinum or oxaliplatin) and 5-fluorouracil or a weekly scheme combination of carboplatin and paclitaxel according to CROSS protocol in a neoadjuvant strategy. Radiation doses vary from 41.4Gy to 45Gy for a preoperative strategy or 50 to 50.4Gy for a definitive treatment. The high risk of lymphatic spread due to anatomical features could justify the use of an elective nodal irradiation when the estimated risk of microscopic involvement is higher than 15% to 20%. An appropriate delineation of the gross tumour volume requires an exhaustive and up-to-date evaluation of the disease. Intensity-modulated radiation therapy represents a promising approach to spare organs-at-risk. This critical review of the literature underlines the roles of radiotherapy for locally advanced oesophageal cancers and describes doses, volumes of treatment, technical aspects and dose constraints to organs-at-risk.

Abstract B26: Addressing gaps in molecular testing for patients with lung cancer

Background: For metastatic non-small cell lung cancer (NSCLC), guidelines include molecular testing for actionable biomarkers and recommend broad profile testing. Despite these recommendations, previous studies indicate that not all patients with NSCLC are receiving testing, even for actionable mutations in EGFR, ALK, and ROS. There are widespread gaps in the community setting, and Lung Cancer Alliance (LCA) data show that fewer than 50% of callers to the patient HelpLine have had molecular testing on their lung cancer.

Methods: To help address this problem, we developed an innovative program that combines direct patient services with increasing enrollment to clinical studies. Patients are recruited to the LungMATCH molecular testing program through conversations on the LCA HelpLine. They are then entered into the Perthera Program to receive a Perthera Report (PR) through consent into an IRB-approved registry protocol. The Program includes tissue acquisition, multi-omic molecular profiling, and collection of patient treatment history followed by integration into a computational pipeline with extensive drug and clinical trial databases to provide ranked therapeutic options matched to the patient. An every-patient, real-time medical review board then reviews and approves the PR. PRs are returned to both treating physicians and patients. Data are being collected longitudinally on treatment decisions, patient outcomes including progression-free and overall survival, and patient experience.

Results: In the first nine months, 72 patients were referred into the Program. The majority of the patients (76%) came from community centers across a wide geographic region in the United States. There were a number of barriers to signing informed consent and completing biopsy identified. Most common reasons included patients in poor health, cost concerns, unsupportive doctors, and patient loyalty to the physician (discomfort with advocating for the testing). Of the first 11 patients who received a PR, 9 had actionable alterations that indicated either a standard-of-care agent or a clinical trial. Actionable alterations were identified by next-generation sequencing, in situ hybridization, and immunohistochemistry. Two patients also had high tumor mutation burden.

Conclusions: We introduced a nonprofit-corporate partnership that navigates patients and their physicians through a comprehensive precision-therapy program. We have demonstrated that this type of program is feasible and there is broad patient interest, particularly from patients seen in nonacademic settings. A number of barriers were identified and are being addressed. Importantly, the majority of patients who received a completed PR (82%) had actionable molecular alterations, underscoring the potential impact of the program.

Citation Format: Jennifer C. King, Andrew Ciupek, Tara Perloff, Ashley Blanchard, Kimberly Mason, Edik Blais, David Halverson, Joseph Bender, Subha Madhavan, Emanuel Petricoin. Addressing gaps in molecular testing for patients with lung cancer [abstract]. In: Proceedings of the Fifth AACR-IASLC International Joint Conference: Lung Cancer Translational Science from the Bench to the Clinic; Jan 8-11, 2018; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(17_Suppl):Abstract nr B26.

[Advances in the management of cervical lymphadenopathies of unknown primary with intensity modulated radiotherapy: Doses and target volumes]

The definition of nodal and/or mucosal target volumes for radiation therapy for lymphadenopathies of unknown primary is controversial. Target volumes may include all nodal areas bilaterraly and be pan-mucosal or unilateral, selective, including the sole oropharyngeal mucosa. This review presents current recommendations in light of changes in the TNM classification, Human papillomavirus status and therapeutic advances. We conducted a systematic review of the literature with the following keywords: lymphadenopathy; head and neck; unknown primary and radiation therapy. There are no direct comparative studies between unilateral or bilateral nodal irradiation or pan-mucosal and selective mucosal irradiation. Contralateral lymph node failure rates range from 0 to 6% after unilateral nodal irradiation and 0 and 31% after bilateral irradiation. Occurrence of a mucosal primary varies between 0 and 19.2%. Initial clinical presentation and Human papillomavirus status are critical to define mucosal target volumes. Intensity-modulated radiotherapy is recommended (rather than three-dimensional irradiation) to avoid toxicities. Systemic treatments have similar indications as for identified primary head and neck cancers. Failures do not appear superior in case of unilateral nodal irradiation but comparative studies are warranted due to major biases hampering direct comparisons. Human papillomavirus status should be incorporated into the therapeutic strategy and practice-changing TNM staging changes will need to be evaluated.

Multiomic molecular comparison of primary versus metastatic pancreatic tumors

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Background: Pancreatic cancer metastasizes very early, as evidenced by the fact that > 70% of patients with operable disease ultimately develop metastases. Thus, it is likely that the molecular characteristics of primary pancreatic tumors are similar to metastatic lesions. We compared the frequency of genetic alterations and protein expression from primary vs. metastatic pancreatic tumors, and from metastases from different sites. By focusing on actionable genetic and proteomic information, we sought to explore whether targeted therapies could be tailored to patients at metastatic progression based on primary surgical material. Methods: Next generation DNA sequencing (NGS) data of 208 genes and a limited set of protein markers were analyzed from pancreatic tumors of 431 patients enrolled in the Know Your Tumor initiative. Of the 208 genes tested, mutations in 70 were considered potentially actionable based on preclinical and clinical evidence. We compared 146 primary pancreatic tumors against 285 metastatic lesions, and examined subgroups for liver vs. lung vs. other metastatic lesions. Molecular alterations were compared between independent groups for each gene/protein using Fisher’s exact test. Significance was assessed using a false discovery rate adjusted q-value threshold of 0.05. Results: No differences in the specific mutation or expression pattern were observed between primary vs. metastatic lesions, nor across the site of metastasis after correcting for multiple hypotheses. Even the proportion of actionable alterations (including mutations in the homologous recombination DNA repair pathway) was similar across subgroups. Conclusions: Comparison of the muli-omic profile of primary vs. metastatic pancreatic adenocarcinoma reveals that the molecular architecture is very similar, and that actionable alterations are identified at the same frequency. This is unlike the data observed from other solid tumors, (e.g. colon and breast cancer), in which substantial molecular discordance and heterogeneity exists between primary tumors and metastatic sites, but is consistent with the belief that primary pancreatic cancers metastasize early and thus are molecularly indistinguishable from metastatic lesions.

Abstract 5553: A computational model for integrating genomic data with public datasets for molecular tumor board recommendations

Recent genomic profiling studies in pancreatic adenocarcinoma (PDA) have revealed actionable mutations affecting multiple signaling pathways, but in spite of these mutations, targeted inhibitors of these pathways have low success rates. A possible reason for these failures is that single-gene biomarkers (e.g. a KRAS mutation as an indicator of MEK inhibitor sensitivity) fail to account for crosstalk within and between dysregulated pathways. We have previously curated a knowledgebase of published studies as evidence to support molecular tumor board recommendations to cancer patients after multi-omic profiling. Here we present a computational framework for integrating this knowledgebase with drug response data from cancer cell lines to propose “actionable” biomarkers based on a panel of pathways instead of targeting a single gene mutation. We constructed a computational model encompassing a broad range of cancer-related pathways, including RAS/RAF/MEK/ERK, PI3K/AKT, cell cycle regulation, and DNA repair. The model consisted of a set of ordinary differential equations (ODE) with protein interactions following Hill-type kinetics and the rate of cell division and apoptosis modeled dependent on key signaling nodes, including the level of phosphorylated ERK and AKT. We integrated two sources of publicly available data: 1) published studies correlating phosphoprotein measurements and resistance pathways to targeted inhibitors in clinical development; and 2) mutation data correlated with drug-specific response metrics (e.g. IC50 values), such as CCLE and NCI-60. We systematically screened frequently observed overlapping disrupted signaling pathways (i.e., combinations of mutations) by simulating predicted IC50 values for targeted inhibitors. Based on these simulations, we then simulated the effect of pairs of drugs to explore which drug combinations may be best suited for inhibiting tumor growth when tumors harbor multiple mutations. We present two applications of this computational approach: a comparison of CDK4/6 inhibition in CDKN2A-mutated PDA vs. hormone receptor-positive breast cancer and a comparison of PARP inhibition in BRCA1/2-mutated PDA and ovarian cancer. The predictions generated by our simulations were consistent with clinical observations in that fewer combinations of mutations in PDA were sensitive to these inhibitors than in breast and ovarian cancer, suggesting ways to refine biomarkers for sensitivity to these drugs in PDA. The computational approach presented here takes into account multiple datasets from a knowledgebase to provide a prioritized list of treatments that match a patient’s molecular profile while also providing the rationale for the recommendation. This represents a step toward incorporation of systems biology in precision oncology.

Citation Format: R Joseph Bender, Edik Blais, Apoorva Kulkarni, Michael J. Pishvaian, David Halverson, Jonathan R. Brody, Emanuel Petricoin, Subha Madhavan. A computational model for integrating genomic data with public datasets for molecular tumor board recommendations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5553. doi:10.1158/1538-7445.AM2017-5553

LungMATCH: Rates of molecular testing in the lung cancer community

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Background: For metastatic non-small cell lung cancer (NSCLC), guidelines include molecular testing for actionable biomarkers and recommend broad profile testing. Yet previous studies indicate that not all patients with NSCLC receive testing, even for actionable mutations in EGFR, ALK, and ROS. We hypothesized low testing rates for patients calling a community HelpLine and that we could increase rates with one-on-one caller education and free precision medicine services. Methods: Caller statistics were collected on the toll-free Lung Cancer Alliance (LCA) HelpLine from Sept 1, 2016 – Jan 31, 2017. Recruitment to the LungMATCH molecular testing program began Nov 10, 2017. Patients are recruited through conversations on the LCA HelpLine, then consented into Perthera Cancer Analysis (PCA) through an IRB-approved registry protocol. PCA includes tissue acquisition, multi-omic molecular profiling, and medical review of testing results and clinical and treatment history. PCA reports are returned to both treating physicians and patients. Data is being collected longitudinally on treatment decisions, patient outcomes including progression-free and overall survival, and patient experience. Results: Data from the LCA Helpline identified a gap in molecular testing. 50% (57/115) of patients asked if they received any kind of molecular testing replied "No". Of 32 patients who were tested and knew the results, patients indicated potentially actionable changes in EGFR(15), ALK(8), PD-L1(3), RET, MET, BRAF, and HER2, along with KRAS (4). Since LungMATCH launch, 23 interested patients were referred for PCA. Six patients consented and are undergoing PCA with seven more in the consent process. Reasons for non-consent include: doctor refusal, initiation of testing at the treating institution, concern about financial implications, and one death. Updated results will be presented. Conclusions: Our data indicate that patients with lung cancer are not receiving molecular testing in accordance to guidelines. To address this, we created a program through nonprofit-corporate partnership that navigates patients and their physicians through comprehensive precision therapy. This type of program is feasible and there is patient interest.

An efficient sample preparation method for high-throughput analysis of 15(S)-8-iso-PGF2α in plasma and urine by enzyme immunoassay

Although several methods have been reported on the analysis of the oxidative stress marker 15(S)-8-iso-prostaglandin-F2alpha (8-iso-PGF2α) in biological fluids, they either involve extensive sample preparation and costly technology or require high sample volume. This study presents a sample preparation method that utilizes low sample volume for 8-iso-PGF2α analysis in plasma and urine by an enzyme immunoassay (EIA). In brief, 8-iso-PGF2α in deproteinized plasma or native urine sample is complexed with an antibody and then captured by molecular weight cut-off filtration. This method was compared with two other sample preparation methods that are typically used in the analysis of 8-iso-PGF2α by EIA: Cayman's affinity column purification method and solid-phase extraction on C-18. The immunoaffinity purification method described here was superior to the other two sample preparation methods and yielded recovery values of 99.8 and 54.1% for 8-iso-PGF2α in plasma and urine, respectively. Analytical precision (relative standard deviation) was ±5% for plasma and ±15% for urine. The analysis of healthy human plasma and urine resulted in basal 8-iso-PGF2α levels of 31.8 ± 5.5 pg/mL and 2.9 ± 2.0 ng/mg creatinine, respectively. The robustness and analytical performance of this method makes it a promising tool for high-throughput screening of biological samples for 8-iso-PGF2α.

90-day repeated inhalation exposure of surfactant Protein-C/tumor necrosis factor-alpha, (SP-C/TNF-alpha) transgenic mice to air pollutants

Tumor necrosis factor (TNF)-alpha, a cytokine present in inflammed lungs, is known to mediate some of the adverse effects of ozone and inhaled particles. The authors evaluated transgenic mice with constitutive pulmonary expression of TNF-alpha under transcriptional regulation of the surfactant protein-C promoter as an animal model of biological susceptibility to air pollutants. To simulate a repeated, episodic exposure to air pollutants, wild-type and TNF mice inhaled air or a mixture of ozone (0.4 ppm) and urban particles (EHC-93, 4.8 mg/m3) for 4 h, once per week, for 12 consecutive weeks and were sacrificed 20 h after last exposure. TNF mice exhibited chronic lung inflammation with septal thickening, alveolar enlargement, and elevated protein and cellularity in bronchoalveolar lavage fluid (genotype main effect, p < .001). Repeated exposure to pollutants did not result in measurable inflammatory changes in wild-type mice and did not exacerbate the inflammation in TNF mice. The pollutants decreased recovery of alveolar macrophages in tavage fluid of both wild-type and TNF mice (exposure main effect, p < .001). Exacerbation of the rate of protein nitration reactions specifically in the lungs of TNF mice was revealed by the high ratio of 3-nitrotyrosine to L-DOPA after exposure to the air pollutants (Genotype x Exposure factor interaction, p = .014). Serum creatine kinase-MM isoform increased in TNF mice exposed to pollutants (Genotype X Exposure factor interaction, p = .043). The marked pollutant-related nitration in the lungs of the TNF mice reveals basic differences in free radical generation and scavenging in the inflamed lungs in response to pollutants. Furthermore, elevation of circulating creatine kinase-MM isoform specifically in TNF mice exposed to pollutants suggests systemic adverse impacts from lung inflammatory mediators, possibly on muscles and the cardiovascular system.