Limburg, Paul J.

Abstract BACKGROUND: Effective approaches for prevention of hepatocellular carcinoma (HCC) will have a significant impact on HCC-related mortality. Data from preclinical models strongly support epidermal growth factor receptor (EGFR) as a target for chemoprevention of HCC. Erlotinib is a small-molecular EGFR tyrosine kinase inhibitor that is FDA-approved for cancer treatment. The side effects of erlotinib observed in patients receiving the oncology dose (150 mg/day) render it unacceptable as a chemoprevention agent at this dose. OBJECTIVE: The objective of this clinical trial was determination of a safe and minimum effective dose of erlortinib for which a ≥50% reduction phospho-EGFR immunohistochemical staining in the liver was observed. RESULTS: 46 participants were pre-registered and 25 participants were registered in this multicenter trial. In a dose de-escalation trial design, cohorts of participants received a 7 day course of erlotinib 75 mg/day, 50 mg/day or 25 mg/day with liver tissue acquisition prior to and after erlotinib. A ≥50% reduction phospho-EGFR immunohistochemical staining in the liver was observed in a minimum of 40% of participants at each of the dose levels. Erlotinib was very well tolerated with few side effects observed, particularly at the dose of 25 mg/day. A favorable modulation of the Prognostic Liver Signature was observed in participants that received the higher erlotinib doses (50 and 75 mg/day). CONCLUSION: These data support the selection a dose of 25 mg/day of erlotinib for a longer intervention to assess for evidence of efficacy as an HCC chemoprevention drug. Citation Format: Kenneth K. Tanabe, David Zahrieh, Carrie A. Strand, Yujin Hoshida, Thomas J. Flotte, Gary Della’Zanna, Asad Umar, Paul Limburg. Pilot study of EGFR inhibition with erlotinib in liver fibrosis for hepatocellular carcinoma prevention [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 3031.

Abstract Background: Multiple guideline-recommended colorectal cancer (CRC) screening options have been shown to reduce CRC incidence and mortality among average-risk patients. Yet, CRC screening continues to be underutilized in the US. Provider recommendation has consistently shown to improve screening completion. Our study aimed to delineate the pathways through which provider communication influences CRC screening completion. We tested how provider communication about the "Why” and “How” of mt-sDNA screening contributes to mt-sDNA screening intention through influencing patients’ screening outcome expectancies and perceived behavioral control. Methods: Data came from a behavioral theory-informed survey that we developed to identify psychosocial factors associated with mt-sDNA screening. The survey was administered between 3/22-6/22 by RTI International, with a sample of US adults ages 45-75 who received a valid order for mt-sDNA screening with a shipping date between 5/21-9/21. Participants completed an electronic or paper survey. We measured patients’ reports of providers’ “Why” communication with items on mt-sDNA screening performance, advantages/disadvantages, and cost. Providers’ “How” communication was measured with items on instructions and need for follow-up testing. We tested the proposed relationships using structural equation modeling and tested indirect effects using bootstrapping. Results: A total of 2973 participants completed the survey (response rate: 21.7%). “Why” communication was positively associated with perceived effectiveness of mt-sDNA screening (b = 0.349, p < .001) and negatively associated with CRC worry (b = -0.078, p = .002). “How” communication was positively associated with perceived ease of use (b = 0.392, p < .001) and perceived comfort of mt-sDNA screening (b = 0.138, p < .001). Perceived effectiveness and perceived ease of use were positively associated with intention to complete mt-sDNA screening (b = 0.404, p < .001; b = 0.339, p < .001). “Why” communication contributed to screening intention through influencing perceived effectiveness (b-indirect effect = 0.141, 95% CI: 0.115, 0.177). “How” communication contributed to screening intention through influencing perceived ease of use (b-indirect effect = 0.133, 95% CI: 0.104, 0.172). Conclusions: Improving patients’ beliefs about the effectiveness and ease of use of screening may be one pathway through which provider communication contributes to CRC screening completion. Efforts are needed to develop and implement provider-patient communication strategies and toolkits that are efficacious at fostering patient understanding of the rationale for CRC screening and the effectiveness of available screening options as well as addressing barriers and enhancing patients’ self-efficacy in completing their preferred screening option. Citation Format: Xuan Zhu, Paul Limburg, Linda Squiers, Leah Helmueller, Gabriel Madson, Brian Southwell, Carlye Gates, Shama Alam, Jennifer Laffin, Lila Finney Rutten. Provider communication contributes to colorectal cancer screening intention through improving screening outcome expectancies and perceived behavioral control [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 770.

Abstract Purpose: To assess whether MUC1 peptide vaccine produces an immune response and prevents subsequent colon adenoma formation. Patients and Methods: Multicenter, double-blind, placebo-controlled randomized trial in individuals age 40 to 70 with diagnosis of an advanced adenoma ≤1 year from randomization. Vaccine was administered at 0, 2, and 10 weeks with a booster injection at week 53. Adenoma recurrence was assessed ≥1 year from randomization. The primary endpoint was vaccine immunogenicity at 12 weeks defined by anti-MUC1 ratio ≥2.0. Results: Fifty-three participants received the MUC1 vaccine and 50 placebo. Thirteen of 52 (25%) MUC1 vaccine recipients had a ≥2-fold increase in MUC1 IgG (range, 2.9–17.3) at week 12 versus 0/50 placebo recipients (one-sided Fisher exact P < 0.0001). Of 13 responders at week 12, 11 (84.6%) responded to a booster injection at week 52 with a ≥2-fold increase in MUC1 IgG measured at week 55. Recurrent adenoma was observed in 31 of 47 (66.0%) in the placebo group versus 27 of 48 (56.3%) in the MUC1 group [adjusted relative risk (aRR), 0.83; 95% confidence interval (CI), 0.60–1.14; P = 0.25]. Adenoma recurrence occurred in 3/11 (27.3%) immune responders at week 12 and week 55 (aRR, 0.41; 95% CI, 0.15–1.11; P = 0.08 compared with placebo). There was no difference in serious adverse events. Conclusions: An immune response was observed only in vaccine recipients. Adenoma recurrence was not different than placebo, but a 38% absolute reduction in adenoma recurrence compared with placebo was observed in participants who had an immune response at week 12 and with the booster injection.

61 Background: Although several guideline-recommended colorectal cancer (CRC) screening modalities have been shown to reduce CRC incidence and mortality, adherence remains below U.S. public health goals. Patient navigation services have been shown to improve CRC screening completion. Patient navigation services, including outbound phone, text, and e-mail reminders, and inbound phone support (>200 languages) are included with all mt-sDNA test (Cologuard) orders. A website and financial assistance (upon request and qualification) are also available for patients. We developed a survey, informed by behavioral theory, to identify psychosocial and communication factors associated with completion of mt-sDNA screening including questions to evaluate awareness and use of navigation services. Methods: Adults aged 45-75 years, with a US postal address, who received a valid order for mt-sDNA screening between 5/21-9/21 were eligible for sampling. RTI administered the survey between 3/22-6/22. Participants had the option to complete electronic- or paper-based surveys. We conducted crosstabulation with Chi Square to assess whether awareness and use of navigation services was significantly associated with (a) test completion within 6 months of the order date and (b) likelihood of future mt-sDNA use. Results: 2,973 participants completed the survey (RR= 21.7%; 65.15% by web and 34.85% by paper). Responders and non-responders did not differ significantly by age or sex. For each navigation service, awareness was significantly higher among those who completed the mt-sDNA test compared to those did not. Across all services, awareness was significantly higher among respondents reporting they were ‘very likely’ to complete mt-sDNA if recommended by a healthcare provider in the future than all other responses combined. A significantly higher proportion of completers (vs. non-completers) reported receiving the email reminder, using the Cologuard website, and using the English language inbound phone support. A significantly higher proportion of those “very likely” to complete mt-sDNA screening in the future reported receiving the email reminder, using the Cologuard website, and using the English language inbound phone support. Conclusions: Awareness and use of patient navigation services was associated with higher completion of the mt-sDNA test and with greater likelihood of future mt-sDNA test use. Patient navigation services comprised of evidence-based strategies, such as reminders, support patient adherence to CRC screening.

60 Background: Colorectal cancer (CRC) screening has been shown to reduce CRC incidence and mortality. Several CRC screening modalities are guideline recommended for average-risk adults aged 45-75 years. CRC screening is underutilized in the US and access to facility-based options, such as colonoscopy, represents a potential barrier. Home-based stool tests are guideline-endorsed and offer a convenient, accessible, scalable option for CRC screening. Thus, understanding the factors that influence completion of stool-based CRC screening is important to guide interventions to improve adherence. We developed a survey, informed by behavioral theory, to identify psychosocial, behavioral and communication factors associated with completion of mt-sDNA screening. Methods: The survey instrument was finalized through expert review, quality testing, and cognitive testing. Adults aged 45-75 years, with a US postal address, who received a valid order for mt-sDNA and whose kit was shipped between 5/21-9/21 were eligible for sampling. RTI administered the survey between 3/22-6/22. Participants had the option to complete electronic or paper surveys. We fit a multivariable logistic regression to identify factors significantly associated with mt-sDNA test completion. Results: Of 17,370 individuals invited to participate, 2,973 completed the survey (AAPOR RR3 = 21.7%); 77.3% of the sample completed the mt-sDNA test. Responders and non-responders did not differ significantly by sex or age. Controlling for demographic characteristics and insurance status, the odds of mt-sDNA test completion were significantly higher among participants who reported greater perceived test effectiveness (OR = 1.20), greater ease (OR = 4.06), and greater comfort in test use (OR = 1.18). Odds of test completion were significantly higher among participants who reported their healthcare provider discussed the mt-sDNA test with them (OR = 2.01) and involved them a great deal in decision making about CRC screening (OR = 1.29). Participants who expressed greater worry about developing CRC were less likely to return their mt-sDNA kit (OR = 0.81). Conclusions: To improve population adherence to CRC screening recommendations, efforts are needed to ensure patients understand the attributes and effectiveness of available test options and feel adequately prepared to complete their preferred screening test. Additionally, healthcare providers must be appropriately prepared and resourced to educate and to engage patients in shared decision-making about CRC screening.

Abstract Background: Smoking is the most common etiology for lung cancer and smoking cessation does not eliminate the risk. An emerging area of interest for risk reduction is immunoprevention. MUC1 glycoprotein is aberrantly expressed in adenocarcinomas, including lung cancer and their premalignant lesions. MUC1 vaccine in the premalignant or high-risk setting may be effective in halting neoplastic development and progression. Trial design: Through the NCI-funded Cancer Prevention Network (CPN), we conducted a two-center pilot trial to evaluate immunogenicity of the MUC1 vaccine (assessed at 12 weeks), and safety (assessed at up to 24 weeks) in current and former heavy smokers. 87 participants were screened in order to have at least 40 evaluable for baseline and 12-week immunogenicity assessments. Smoking history of ≥30 pack-years and either current (still smoking or quit < 1 year prior to pre-registration) or former smoker (quit 1-15 years prior to pre-registration); ages 55-80 years; ECOG performance status ≤1; CT scan of the chest done ≤ 6 months prior to pre-registration showing either negative findings (no nodules) or solid or part-solid nodules < 6 mm in size (consistent with < 1% probability of malignancy, Lung-RADs Version 1.0). Exclusion criteria were standard for lung cancer screening. Methods: MUC1 peptide plus polyICLC adjuvant (Hiltonol) vaccine was given at week 0, 2 and 10. Blood was collected for safety tests and immune assays pre and 2 weeks post each vaccine, and at week 24. Anti-MUC1 IgG titer was evaluated by ELISA. Based on previous studies of this vaccine, 40 evaluable participants would provide 96% power to detect immune response rate of 15% versus 40%, using a 2-sided test of proportions with type I error rate of 0.05. PBMC were assayed for the presence of regulatory T cells (Treg) and myeloid derived suppressor cells (MDSC) (secondary endpoint). Circulating levels of inflammatory cytokines and hsCRP were evaluated using commercially available tests (exploratory endpoint). AEs and toxicities were monitored for up to 24 weeks from the first vaccine. Results: 87 individuals were screened and 50 registered. 45 completed the study, 26 current and 19 former smokers (time since last smoked: average 7.8 years; 11 months -13 years). The vaccine was well-tolerated with injection site reactions being the most common AE. Immune response to the vaccine was lower than expected, with 2 current and 2 former smokers developing anti-MUC1 IgG titers ≥2 fold higher at week 12 over baseline (10%). We found high circulating levels of MDSCs in PBMC of both current and former smokers and very low or no serum cytokines. Conclusions: A preventative vaccine trial was feasible in individuals at high risk for lung cancer. However, we discovered a high level of immune suppression, previously documented only in advanced lung cancer. Mitigating the development of lung cancer in heavy smokers through vaccine administration may be limited by related immunosuppression. Citation Format: Olivera J. Finn, Julie Ward, Tami Krpata, Samantha Fatis, John McKolanis, Jia Xue, Pamela Beatty, Camille Jacqueline, Sharon Kaufman, Colleen Akerley, April Felt, Karrie Fursa, Anne Holland, Liz S. Ambulay, Nathan Foster, Ryan McMurray, Carrie Strand, Andres M. Salazar, Lisa Bengtson, Eva Szabo, Paul Limburg, Malgorzata Wojtowicz, David E. Midthun, Arjun Pennathur. A pilot study of a MUC1 vaccine in current and former smokers at high risk for lung cancer. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr PR002.

Abstract Chronic hepatitis C can lead to cirrhosis and hepatocellular carcinoma. We studied the safety and immunogenicity of a novel therapeutic hepatitis C virus (HCV) genotype 1a/1b consensus DNA vaccine, INO-8000, encoding HCV NS3, NS4A, NS4B, and NS5A proteins alone or co-administered with DNA-encoding IL12 (INO-9012), a human cytokine that stimulates cellular immune function, in individuals with chronic hepatitis C. This was a phase I, multisite dose-escalation trial with an expansion cohort evaluating doses of 0, 0.3, 1.0, and 3.0 mg of INO-9012 (IL12 DNA) as an addition to 6.0 mg of (INO-8000; HCV DNA vaccine). Vaccines were administered by intramuscular injection followed by electroporation at study entry and at weeks 4, 12, and 24. HCV-specific CD4+ and CD8+ T-cell immune responses were measured by IFNγ ELISpot and flow cytometry–based assays. Transient, mild-to-moderate injection site reactions unrelated to IL12 DNA dose were common. Increases in HCV-specific IFNγ production occurred in 15/20 (75%) participants. Increases in the frequency of HCV-specific CD4+ and CD8+ T cells occurred at all dose levels, with the greatest increases seen at 1.0 mg of INO-9012. HCV-specific CD8+ and CD4+ T-cell activities increased in 16/18 (89%) and 14/17 (82%) participants with available data, respectively. The vaccine regimen was safe and induced HCV-specific CD4+ and CD8+ cellular immune responses of modest magnitude in most HCV-infected participants. The addition of 1.0 mg of IL12 DNA provided the best enhancement of immune responses. The vaccine regimen had little effect on controlling HCV viremia. Prevention Relevance: The administration of IL12 DNA along with a hepatitis C viral antigen DNA vaccine enhanced the HCV-specific immune responses induced by the vaccine in individuals with chronic hepatitis C, an important cause of hepatocellular carcinoma. IL12 could be an effective adjuvant in vaccines targeting HCV and other oncogenic viruses.

Abstract Background Obesity is an established risk factor for colorectal cancer (CRC), but the evidence for the association is inconsistent across molecular subtypes of the disease. Methods We pooled data on body mass index (BMI), tumor microsatellite instability status, CpG island methylator phenotype status, BRAF and KRAS mutations, and Jass classification types for 11 872 CRC cases and 11 013 controls from 11 observational studies. We used multinomial logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) adjusted for covariables. Results Higher BMI was associated with increased CRC risk (OR per 5 kg/m2 = 1.18, 95% CI = 1.15 to 1.22). The positive association was stronger for men than women but similar across tumor subtypes defined by individual molecular markers. In analyses by Jass type, higher BMI was associated with elevated CRC risk for types 1-4 cases but not for type 5 CRC cases (considered familial-like/Lynch syndrome microsatellite instability-H, CpG island methylator phenotype-low or negative, BRAF-wild type, KRAS-wild type, OR = 1.04, 95% CI = 0.90 to 1.20). This pattern of associations for BMI and Jass types was consistent by sex and design of contributing studies (cohort or case-control). Conclusions In contrast to previous reports with fewer study participants, we found limited evidence of heterogeneity for the association between BMI and CRC risk according to molecular subtype, suggesting that obesity influences nearly all major pathways involved in colorectal carcinogenesis. The null association observed for the Jass type 5 suggests that BMI is not a risk factor for the development of CRC for individuals with Lynch syndrome.

Abstract Background: Stool-based screening with fecal immunochemical (FIT) or multitarget-stool DNA (mt-sDNA) tests is associated with increased colonoscopy polyp yield. mt-sDNA includes methylated markers, which improve detection of serrated polyps (SP) versus FIT. We compared SP detection in colonoscopies performed for positive FIT or mt-sDNA tests, as well as in colonoscopies without a preceding stool test, using the New Hampshire Colonoscopy Registry, a comprehensive statewide population-based registry. Methods: Across the three groups, we compared the frequency of clinically relevant SPs (CRSP: sessile SPs, hyperplastic polyps ≥10 mm, and traditional serrated adenomas). We also compared SP size, histology, number, and bulk (combined sizes). Results: Our sample included 560 mt-sDNA+ (age ± SD: 66.5 ± 7.9), 414 FIT+ (age ± SD: 66.3 ± 8.8), and 59,438 colonoscopy-only patients (age ± SD: 61.7 ± 8.0). mt-sDNA+ patients were more likely to have a higher yield of CRSPs and CRSP bulk than FIT+ (P < 0.0001) or colonoscopy-only patients (P < 0.0001). More mt-sDNA+ patients had CRSPs without large adenomas or colorectal cancers (17.9% vs. 9.9% of FIT+ and 8% of colonoscopy-only patients). After adjusting for synchronous large adenomas, colorectal cancers, and other risk factors, mt-sDNA+ patients were more likely (OR, 1.82; 95% CI, 1.18–2.85) than FIT+ patients to have CRSPs. Conclusions: mt-sDNA+ patients had a higher SP yield than FIT+ or colonoscopy-only patients, particularly in the absence of synchronous large adenomas or colorectal cancer. Impact: Our results suggest that screening with mt-sDNA tests could improve colorectal cancer screening by identifying more patients at increased risk from the serrated pathway.

Abstract Data supporting the clinical utility of multi-target stool DNA (mt-sDNA) at the guideline-recommended 3-year interval have not been reported. Between April 2015 and July 2016, candidates for colorectal cancer screening whose providers prescribed the mt-sDNA test were enrolled. Participants with a positive baseline test were recommended for colonoscopy and completed the study. Those with a negative baseline test were followed annually for 3 years. In year 3, the mt-sDNA test was repeated and colonoscopy was recommended independent of results. Data were analyzed using the Predictive Summary Index (PSI), a measure of the gain in certainty for dichotomous diagnostic tests (where a positive value indicates a net gain), and by comparing observed versus expected colorectal cancers and advanced precancerous lesions. Of 2,404 enrolled subjects, 2,044 (85%) had a valid baseline mt-sDNA result [284 (13.9%) positive and 1,760 (86.1%) negative]. Following participant attrition, the year 3 intention to screen cohort included 591 of 1,760 (33.6%) subjects with valid mt-sDNA and colonoscopy results, with no colorectal cancers and 63 advanced precancerous lesions [22 (34.9%) detected by mt-sDNA] and respective PSI values of 0% (P = 1) and 9.3% (P = 0.01). The observed 3-year colorectal cancer yield was lower than expected (one-sided P = 0.09), while that for advanced precancerous lesions was higher than expected (two-sided P = 0.009). Repeat mt-sDNA screening at a 3-year interval resulted in a statistically significant gain in detection of advanced precancerous lesions. Due to absence of year 3 colorectal cancers, the PSI estimate for colorectal cancer was underpowered and could not be reliably quantified. Larger studies are required to assess the colorectal cancer study findings. Prevention Relevance: Understanding the 3-year yield of mt-sDNA for colorectal cancer and advanced precancerous polyps is required to ensure the clinical appropriateness of the 3-year interval and to optimize mt-sDNA's screening effectiveness.