Mamdani, Hirva Mansurali

e13730 Background: Financial toxicity, the burden of treatment cost, affects up to half of people with cancer and can affect survival. Financial toxicity is a health equity issue, disproportionately affecting Black patients. This cross-sectional study used baseline data from the Discussions of Cost (DISCO) Trial, an RCT to improve patient-provider treatment cost discussions and, in turn, mitigate financial toxicity, to examine whether Black and White patients differed in patient-provider communication perceptions and financial toxicity correlates. Methods: Data were collected from 2021-2025 at an NCI-designated comprehensive cancer center. Participants were Black or White patients diagnosed with solid tumor cancers. At baseline, patients completed demographic measures; communication measures of self-efficacy in patient-provider interactions (e.g., “I am confident I know what questions to ask a provider”); self-efficacy in managing cancer treatment costs (e.g., “I am confident I can understand treatment costs”); and whether they have a provider- or patient-centered approach (e.g., “the provider should decide what gets talked about”); and financial measures including economic burden (e.g., “it’s difficult to live on my income”); treatment cost distress (e.g., “worries about paying for my cancer treatment keep me up at night”); and anticipated material hardship (e.g., “I worry about the financial problems I will have in the future as a result of my treatment”). Comparisons were conducted by patient race. Results: A total of 202 patients participated (116 Black patients, 86 White patients). White patients were more likely to have advanced degrees, a higher annual income, and less likely to have Medicaid compared to Black patients. Black patients reported higher self-efficacy for managing treatment costs ( p = .002) and a higher provider-focused orientation to the patient-provider relationship ( p = .001), than White patients. Black patients reported greater levels of financial burden ( p < .001), cost distress ( p = .005), and anticipated material hardship ( p = .003). There was no difference in self-efficacy for interacting with providers. Conclusions: These results suggest that a communication intervention for patients may help mitigate the experience of financial toxicity, especially for Black patients. Clinical trial information: NCT04766190 . Patient characteristics. Black Patients White Patients p -value Race 116 86 Education < High School High School/GED Some College 2 or 4-year College Degree Graduate/Professional College Trade/Technical/Vocational School 10352626712 0141631187 < .001 Annual Household Income 0 - $19,999 $20,000 - 39,999 $40,000 - 59,999 $60,000 - 79,999 $80,000 - 99,999 $100,000 - 149,999 $150,000 + 53201611431 51215991716 <.001 Insurance Type* Medicaid Medicare Medicare supplement Private None 604911330 113726393 <.001>.99<.001.20.15 *Patients could select more than one

e13729 Background: Financial toxicity, the burden of treatment cost, affects up to half of people with cancer and can affect survival. Financial toxicity is a health equity issue, disproportionately affecting Black patients. Patient education about cost and patient-provider cost discussions are recommended to mitigate financial toxicity but occur infrequently. The Discussions of Cost (DISCO) App, designed to mitigate financial toxicity through a tailorable education and communication intervention, was assessed for efficacy in an RCT with Black and White patients. Here we describe the DISCO App's feasibility and acceptability. Methods: Data were collected from 2021 to 2025 at an NCI-designated comprehensive cancer center. Participants were Black or White patients diagnosed with solid tumor cancers. While waiting to see their provider, patients randomized to the intervention arm used the DISCO App on a tablet. The DISCO App includes a video about treatment costs, ways to manage costs, and the importance of discussing costs with providers. Once patients enter their socio-demographic information (e.g., employment) and financial concerns, they receive a tailored list of cost questions to ask their provider. Patients responded to measures immediately after using the DISCO App. Feasibility was assessed by patient reports of how much time they needed to use the DISCO App and if they were able to use the DISCO App before the provider entered the exam room. Acceptability was measured by items assessing patient perceptions of the DISCO App (1 = strongly disagree; 5 = strongly agree). Descriptive statistics summarized results and mean comparisons were used to assess perceptions by patient self-identified race. Results: Of the 202 patients recruited, 124 were randomized to the intervention arm (67 Black patients; 57 White patients). All patients completed using the DISCO App prior to their provider entering the exam room and 80% of patients needed 15 minutes or less to use the DISCO App, with no difference by patient race. Black patients ( M = 4.4) reported finding the DISCO App more helpful than White patients ( M = 3.9; p = .02) and it brought up cost issues they had not considered (Black patients = 3.5; White patients = 3.0; p = .05). Patients reported the questions were easy to understand ( M = 4.4), helped them feel it was okay to talk with their provider about cost ( M = 4.0), that it prompted cost questions ( M = 3.3), that they learned what costs to consider (55%), and learned ways to manage cost (62%) with no differences by patient race. Conclusions: The DISCO App was feasible and acceptable to Black and White patients with cancer, with Black patients reporting more favorable perceptions than White patients. Next steps include assessing effectiveness in improving outcomes including prompting patient-provider treatment cost discussions and related financial toxicity outcomes (e.g., treatment adherence). Clinical trial information: NCT04766190 .

TPS1659 Background: Financial toxicity, the material and psychological burden of treatment cost, affects up to half of people with cancer and can affect adherence and survival. Financial toxicity is a health equity issue, disproportionately affecting Black patients. Patient education about cost and patient-provider cost discussions are recommended to mitigate financial toxicity but occur infrequently. Our goal is to mitigate financial toxicity through a tailorable education and communication intervention, the DISCO App. The DISCO App was shown to be feasible, acceptable, and preliminarily effective at prompting cost discussions and improving related outcomes in a pilot trial. The aim of the ongoing trial is to test the effectiveness of the DISCO App on short- and longer-term outcomes for Black and White patients with cancer. Methods: This study is a longitudinal RCT. Oncologists are eligible if they treat patients with solid tumors at the trial site. Patients of participating oncologists are eligible if they are ≥ 18 years of age; identify as Black or White; can read and write in English; have an email address; and were diagnosed with a solid tumor for which systemic therapy is a likely recommended treatment. Strata were created to balance arms by patient race, income, age, and sex. Upon consent, patients are randomized to one usual care arm (1) or one of two intervention arms (2 and 3). All patients are asked to allow one treatment discussion with their oncologist to be video recorded for analysis. Prior to the recording, intervention patients utilize the DISCO App on an iPad. The DISCO App includes a video about treatment costs, ways to manage costs, and the importance of discussing costs with oncologists. Once patients enter their socio-demographic information (e.g., employment, insurance) and any financial concerns, they receive a tailored list of questions to ask their oncologist. Arm 3 patients receive an intervention booster via email two months after the recording. Patients complete measures at baseline, right after the recording, and at 1, 3, 6 and 12 months after the recording. Measures assess outcomes including cost discussions, communication quality, cost knowledge, self-efficacy for cost management, referrals for support, short- and longer-term financial toxicity, and treatment adherence. The patient-oncologist interaction is the unit of analysis and we will use multi-linear models to compare outcomes by arm. We anticipate recruiting up to 15 oncologists and 240 patients. Data collection began in March 2021 and will continue until July 2025. Participants to date include 13 oncologists and 192 patients (116 Black, 76 White). Most patients completed the baseline assessment (n=164), the post-interaction assessment (n=137), and at least 1 follow-up assessment (n=132); 125 treatment discussions have been recorded. The IRB reviewed the trial in December 2024 and approved continuation. Clinical trial information: NCT04766190 .

e20011 Background: The therapeutic landscape of lung cancer is rapidly evolving, presenting oncologists with the challenge of staying updated amidst an overwhelming influx of data. Clinical decision support (CDS) tools, including artificial intelligence (AI) and large language models (LLMs), may help bridge this gap. Evaluating the accuracy of LLMs in complex, real-world oncology scenarios is crucial to understanding their potential. Methods: Twenty-five de-identified lung cancer cases from the fellows’ clinic at Karmanos Cancer Institute, Detroit, MI, were analyzed. Two LLMs, GPT-4 (OpenAI) and Claude Opus (Anthropic), were assessed using advanced prompting techniques like persona-based and chain-of-thought prompting. Five board-certified lung cancer oncologists from NCI-designated centers evaluated LLM-generated responses based on accuracy, treatment recommendation comprehensiveness, and supportive care planning, using a 1–5 scale. Novel insights, the presence of fabricated information, and harmful recommendations were flagged as binary outcomes. Oncologists were blinded to the LLM source and actual treatment decisions. Results: Table 1 presents patient characteristics. GPT-4 achieved an average accuracy score of 4.2 (95% CI, 3.9–4.4), with 3.7 for comprehensiveness of medical/surgical treatment recommendations and 3.7 for supportive care planning. Six responses (32%) were flagged as potentially harmful, and two (8%) contained inaccuracies. Sixteen GPT-4 responses (64%) were rated trustworthy as a CDS tool. Claude Opus had an average accuracy score of 3.6 (95% CI, 3.1–4.1), scoring 3.6 for treatment recommendation comprehensiveness and 3.5 for supportive care planning. Nine responses (36%) were flagged for potential harm, and five (20%) included inaccuracies. Eleven Claude responses (44%) were deemed trustworthy. Significant differences were observed in accuracy (p=0.04) and trustworthiness (p=0.03) between models using McNemar's test. Other factors showed no statistical significance. Conclusions: GPT-4 outperformed Claude Opus in accuracy and trustworthiness, but both models demonstrated limitations, including harmful recommendations and inaccuracies. These findings highlight the need for improved LLM refinement before routine use as CDS tools in lung cancer treatment. Patient demographics and clinical characteristics. Category subcategory Number Median Age (range)- Yr 65 (26-78) Female 7 Male 18 Histology Adenocarcinoma 10 Squamous Cell Carcinoma (SCC) 7 Small Cell Carcinoma 6 Poorly Differentiated 2 Total 25 Stage NSCLC Stage 3 7 NSCLC Stage 4 13 Small Cell limited stage 3 Small Cell Extensive Stage 2

Abstract Background: While most EGFR-mutant NSCLC tumors are resistant to checkpoint inhibitors, a small subset has durable responses. Certain molecular subtypes of EGFR may be more responsive. There is a lack of clarity on the genomic and immune profiles of EGFR subtypes, and further elucidation of this may assist in optimally identifying those likely to respond to immune-based therapies. Methods: Profiles of 5,510 lung adenocarcinoma specimens were obtained utilizing next-generation sequencing of 592 genes (Caris Life Sciences) and categorized by EGFR subtype. PD-L1 expression (Ab: 22c3), tumor mutational burden (TMB), immune cell type fractions, and co-mutations in TP53 were assessed by EGFR subtype and compared to wild-type (WT) tumors. Results: Of the total cohort, 791 (14.4%) were EGFR-mutant (Table). Among EGFR-mutant tumors, exon 19 deletions were most common (49.7%), followed by L858R, (32.9%), exon 20 insertions (13.0%), L861Q (2.9%), and G719X (1.5%). PD-L1 positivity of each EGFR subtype as compared to WT did not vary, except for L858R tumors which had a significantly lower percentage of PD-L1 positive cases. Exon 19 deletion, L858R, and exon 20 insertion tumors were significantly less likely to have high PD-L1 or high TMB compared to WT. Among the EGFR subtypes, L861Q and G719X tumors had the greatest percentage with high TMB. TP53 co-mutations were frequent in EGFR tumors, especially among L861Q and G719X tumors. Exon 19 deletion and L858R tumors had significantly less CD8+ and greater CD4+ T cell fractions compared to WT. Neutrophil and M2 macrophage cell fractions were significantly higher in exon 19 deletion, L858R, and exon 20 insertion tumors compared to WT. Conclusions: Most subtypes of EGFR have profiles consistent with decreased immunogenicity; however L861Q and C719X tumors have a greater percentage with high TMB or TP53 co-mutations. Such features in uncommon EGFR subtypes may correlate with responsiveness to immune-based therapies and warrant further study. Tumor Characteristic EGFR WT(n=4719) Exon 19 del(n=393) L858R(n=260) Exon 20 ins(n=103) L861Q(n=23) G719X(n=12) PD-L1 positive (≥1%) 57.7% 51.0% 49.0% a 49.5% 47.8% 50.0% PD-L1 high (≥50%) 30.6% 19.7% a 18.8% a 14.4% a 21.7% 16.7% TMB high (≥10 mut/Mb) 35.3% 1.0% a 3.7% a 1.0% a 9.5% 18.2% TP53 co-mutation 53.9% 61.7% 63.6% a 59.2% a 69.6% a 83.3% a Median % cell fraction CD8+ 0.7 0.3 a 0.4 a 0.3 0.6 0.2 CD4+ 0.0 0.6 a 0.8 a 1.3 a 1.7 1.1 Neutrophils 5.5 8.0 a 7.3 a 7.8 a 7.4 6.4 M2 macrophages 5.5 6.4a 6.9a 6.7a 5.8 4.3 aq-value &lt; 0.05 when compared to EGFR WT (corrected for multiple comparisons) Citation Format: J. Nicholas Bodor, Joanne Xiu, Vinicius Ernani, Supreet Kaur, Hirva Mamdani, Pavel Brodskiy, Sai-Hong I. Ou, Patrick C. Ma, Margie L. Clapper, W. Michael Korn, Joseph Treat. Genomic and immune characteristics of EGFR subtypes in non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4119.

404 Background: Concurrent chemoradiation(CRT) followed by esophagectomy is a standard of care for locally advanced esophageal(LA-EAC) and GEJ adenocarcinoma. Approximately 50% of patients(pts) experience disease relapse within the 1st yr after treatment(tx) completion. No adjuvant tx has been shown to improve survival in these pts. Immune checkpoint inhibitors have activity in metastatic PD-L1 positive EAC. Preclinical studies have shown radiation +/- chemotherapy upregulate PD-1/PD-L1 pathway. Methods: We conducted a phase II trial evaluating safety and efficacy of durvalumab(durva) in pts with LA-EAC and GEJ adenocarcinoma who have residual disease in surgical specimen after neoadjuvant CRT and R0 resection. Pts received durva 1500mg IV every 4 weeks for up to 1yr. Results: 24 pts were enrolled from 4/2016-1/2018(median age: 60yrs (range, 43-70). 18 received carbo/paclitaxel and 6 received cis/5-FU concurrently with radiation. Staging at diagnosis: T2N0(n = 3, 12.5%), T2N2(n = 3, 12.5%),T3N0(n = 6, 25%), T3N1(n = 6, 25%), T3N2(n = 4, 17%), T3N3(n = 1, 4%), T3Nx(n = 1, 4%).19 pts(79%) had positive lymph nodes(LNs) at the time of surgery following CRT. 12 pts completed 1yr of tx, 12 came off tx because of relapse(6), AEs(5), and consent withdrawal(1). Most common AEs were fatigue(n = 8, 33.3%) and nausea(n = 6, 25%). 3pts (12.5%) developed grade 3 irAEs: pneumonitis(1), hepatitis(1), colitis(1). At median follow up of 21.9mo(range, 1.7-23.9mo), 11 pts have relapsed: 9 distant and 2 locoregional. Two of 3 pts with grade 3 irAEs are alive and disease free at 17 and 23 mo respectively. 1-yr RFS and OS were 79.2% and 95.5%, respectively. RFS at 26 mo was 20.6%. Overall mOS and mOS after relapse were 28.1mo(range, 22.9-28.1) and 11.1 mo(range, 0.1-11.3mo) respectively. The study was expanded to enroll 14 additional pts who are currently undergoing tx. Conclusions: Adjuvant durvalumab following trimodality therapy for LA-EAC and GEJ adenocarcinoma is safe with improvement in 1-yr RFS to 79.2% compared to historical rate of 50%. RFS was 20.6% at 26 months. Evaluation of predictive biomarkers of RFS with durva is underway. Clinical trial information: NCT02639065.