PowerPoint Presentation Integrating the 40-Gene Expression Profile (40-GEP) Test into Management of High-Risk Cutaneous Squamous Cell Carcinoma Aaron S. Farberg, MD1,2; Mary A. Hall, PhD, MBA3; Leah Douglas4; Kyle R. Covington, PhD3; Sarah J. Kurley, PhD3; Robert W. Cook, PhD3; Scott M. Dinehart, MD1 1Icahn School of Medicine at Mount Sinai, New York, NY; 2Arkansas Dermatology Skin Cancer Center, Little Rock, AR; 3Castle Biosciences, Inc., Friendswood, TX; 4Baylor College of Medicine, Houston, TX SYNOPSIS This study was sponsored by Castle Biosciences, Inc., which provided funding to contributing centers for tissue and clinical data retrieval. MAH, KRC, SJK, and RWC are employees and options holders of Castle Biosciences, Inc.. These data were previously presented, in part, at the 2019 American Society for Dermatologic Surgery Annual Meeting, Chicago, IL, October 24-27, 2019. METHODS RESULTS REFERENCES FUNDING & DISCLOSURES CONCLUSIONS 1. Rogers et al. 2015 JAMA Dermatol PMID: 25928283 2. Karia et al. 2013 J Am Acad Dermatol PMID: 23375456 3. Waldman et al. 2019 Hematol Oncol Clin N Am PMID: 30497667 4. American Cancer Society. https://www.cancer.org/cancer/ 5. Muzic et al. 2017 May Clin Proc PMID: 28522111 6. NCCN Guidelines. Squamous Cell Skin Cancer V1.2020 7. Skin Cancer Foundation. https://www.skincancer.org/ 8. US Census Bureau. https://www.census.gov/ 9. Wysong et al. 2019 American Society for Dermatologic Surgery Annual Meeting 10. Karia et al. 2018 JAMA Dermatol PMID:29261835 11. Ruiz et al. 2019 JAMA Dermatol PMID: 30969315 12. Jambusaria et al. 2013 JAMA Dermatol PMID: 23325457 13. Karia et al. 2014 JCO PMID: 24366933 Table 1. Cohort demographics of 300 NCCN high-risk cSCC cases Figure 1. Study design of the 40-GEP discovery, development, and validation • Cutaneous squamous cell carcinoma (cSCC) is the 2nd most common skin cancer, with ~1,000,000 cases diagnosed per year in the U.S.1-8 Incidence is growing rapidly (>5-fold increase in past 30 years) and it surpasses the incidence of invasive melanoma. • Regional metastasis rates of 13% have been reported, with most studies reporting <6% and most events occurring within 2-3 years of initial diagnosis and treatment.6 Disease-specific mortality is 1.5-2% and the number of deaths from cSCC per year is similar to that from melanoma.3,7 • National Comprehensive Cancer Network (NCCN) guidelines accommodate a broad range of treatment plan options for high-risk patients and recommend risk-directed implementation. These guidelines and the American Joint Committee on Cancer (AJCC) and Brigham and Women’s Hospital (BWH) staging systems have low positive predictive value (PPV) for identifying patients at high risk for metastasis (NCCN 15%9; AJCC 14-17%10-11; BWH 24-38%11-13). • Improved stratification for implementation of risk-appropriate treatment plans for patients with NCCN-defined high-risk cSCC is needed. • Integration of the recently validated 40-gene expression profile (40-GEP) test with AJCC or BWH T stage criteria into management of NCCN high-risk cSCC patients may be key to identifying those high-risk patients who would most benefit from aggressive treatment strategies, while concomitantly reducing unnecessary interventions for those who are low risk for poor outcomes. ACKNOWLEDGEMENTS Adult and Pediatric Dermatology: Dr. Toyohara Brook Army Medical Center: Drs. Xia and Dalton Brigham and Women’s Hospital: Dr. Schmults Cedars-Sinai: Dr. Gharavi Cleaver Dermatology: Dr. Cleaver Columbia University: Dr. Samie DermASAP: Dr. Reed Dermatology and Skin Health: Dr. Mendese Emory Dept. of Dermatology: Dr. Blalock Indiana University School of Medicine: Dr. Somani Mayo Clinic, Jacksonville: Dr. Fosko Medical College of Wisconsin: Dr. Kasprzak MetroDerm PC: Dr. Papadopoulos Miami Beach Skin Center: Dr. Rivlin Michael J. Fazio, MD: Dr. Fazio Moffitt Cancer Center: Drs. Messina and Zager Mount Sinai: Dr. Khorasani Northwestern University: Dr. Yoo Oakview Dermatology: Dr. Trotter OHSU: Dr. Bar Pariser Derm: Dr. Pariser Penn State: Dr. Neves Porter Adventist: Dr. Campana SFVAHCS: Dr. Arron Skin Cancer Specialists: Dr. Griego St. Louis University: Dr. Ramona The Indiana Skin Cancer Center: Dr. Michael Thomas Jefferson University: Dr. Curry University of Pennsylvania: Dr. Newman University of California, San Francisco: Dr. Arron University of Missouri: Drs. Smith, Edison and Braudis University of Rochester: Dr. Ibrahim University of Vermont Medical Center: Dr. Weinberger University of Pittsburg Medical Center: Dr. Bibee University of Southern California: Dr. Wysong University of Tennessee Health Science Center: Dr. Fleming University of Tennessee Medical Center: Dr. Lewis Zitelli and Brodland, P.C.: Drs. Zitelli and Brodland • Integration of the 40-GEP test into risk-directed management plans for NCCN high-risk cSCC patients identified a group of patients (Class 1, T1/T2) with risk approaching that of the general population, thereby warranting a low intensity management strategy and sparing these patients unnecessary procedures and potential adverse effects. • Conversely, those patients with rates of metastasis surpassing 50% (Class 2B) warrant a high intensity strategy that increases follow-up visits, utilizes imaging and/or biopsies for nodal assessment, and offers adjuvant treatments and clinical trials for probable metastatic events. • The data presented herein support integration of the 40-GEP into management of NCCN high-risk cSCC patients for implementation of risk-appropriate treatment plans for these patients. OBJECTIVE: To integrate a validated, prognostic 40-gene expression profile test into clinical decision making for risk-appropriate management of NCCN high-risk cSCC patients Figure 2. Kaplan-Meier analysis of metastasis-free survival (MFS) by 40-GEP Class (n=321)9 40-GEP Class n 3-year MFS Overall Event Rate Class 1 203 91.6% 8.9% Class 2A 93 80.6% 20.4% Class 2B 25 44.0% 60.0% M e ta s ta s is -F re e S u rv iv a l p<0.0001 Class 1 Class 2A Class 2B 100% 80% 60% 40% 20% 0% 0 1 2 3 4 5 Years Feature of Modeling Cohort (% of Cohort) Age: Median years (range) 70 (34-95) Sex: Male 219 (73%) Immune deficient 76 (25%) Located on H&N 201 (67%) Tumor diameter* : mean cm (≥2 cm) 1.85 (36%) Tumor thickness**: mean mm (>6 mm) 3.90 (16%) Poorly differentiated 36 (12%) Clark Level IV / V 62 (21%) PNI present 36 (12%) Subcutaneous fat invasion 43 (14%) 40-GEP Result Class 1 189 (63%) Class 2A 87 (29%) Class 2B 24 (8%) *275 cases had tumor diameter reported;**109 cases had thickness reported. NCCN, National Comprehensive Cancer Network; H&N, head and neck; PNI, perineural invasion; GEP, gene expression profile 40-GEP Risk Class and AJCC T stage (risk for metastasis**) Recommended Management Plan Low intensity management for 50% of patients: - Minimal clinical follow up (1-2x per year) - Reduced imaging (low frequency or none) - Reduced nodal assessment (palpation only) - Avoidance of adjuvant radiation or chemotherapy Moderate intensity plan: - Clinical follow up (2-4x per year for 3 years) - Baseline and annual nodal US/CT for 2 years - Consider nodal biopsy or elective neck dissection - Consider adjuvant radiation or chemotherapy High intensity management for 8% of patients: - Increased clinical follow up (4-12x per year for 3 years) - Baseline and 4x per year nodal US/CT for 2 years - Offer nodal biopsy or elective neck dissection - Offer adjuvant radiation, chemotherapy, and/or clinical trials Class 1 T1-T2 (7.5%) Class 1 T3-T4 (16.7%) Class 2A T1-T2 (15.6%) Class 2A T3-T4 (34.8%) Class 2B T1-T2 (50.0%) Class 2B T3-T4 (87.5%) Patient with high-risk cSCC per NCCN* Perform 40-GEP Figure 4. Risk-aligned management recommendations based on 40-GEP and T stage prognosis A. Cohort stratification and metastasis rate by 40-GEP Class and T Stage 40-GEP Class AJCC T Stage* BWH T Stage* Overall Rate* T1-T2 T3-T4 T1-T2a T2b-T3 Class 1 9% (189) 7.5% (159) 16.7% (30) 8.1% (173) 18.8% (16) Class 2A 21% (87) 15.6% (64) 34.8% (23) 17.8% (73) 35.7% (14) Class 2B 63% (24) 50.0% (16) 87.5% (8) 58.8% (17) 71.4% (7) *Metastasis incidence and number (n) of patients in each Class and per T stage. B. Management intensity determined by risk for metastasis Figure 3. Integration of 40-GEP prognostication into patient management decisions for NCCN high-risk cSCC patients (n=300) • The 40-gene expression profile (40-GEP) test was developed and validated to stratify a patient’s risk for regional or distant metastasis at 3 years after diagnosis as low (Class 1), high (Class 2A), or highest (Class 2B) risk for metastasis (Figures 1 and 2).9 • As NCCN high-risk cSCC patients are the intended population for the 40-GEP test, cases categorized as such (n=300, Table 1) were used to analyze the effects of integration of 40-GEP risk stratification into patient management decision making. All cases were staged according to either AJCC or BWH staging system criteria for T stage. The numbers of patients in each Class/T stage combination along with metastasis rates were reported and used to align each patient group with risk-appropriate management recommendations. • Risk-aligned management recommendations based on 40-GEP results and T stage were developed for low, moderate, and high intensity management within the boundaries of acceptable NCCN patient management approaches for patients with high-risk localized disease. Metastasis rates of <10%, 10-50%, and >50% were aligned with low, moderate, and high intensity management recommendations, respectively. Ongoing validation: • Additional archival specimens • Prospective studies 1. Targeted approach qPCR analysis of 73 literature-identified genes 2. Global approach Microarray and deep learning→ qPCR validation of 67 genes Primary FFPE cSCC tissue w/ outcomes Discovery Expression from 140 genes for model development Development Deep learning model performance w/ 10X cross-validation Training cohort (archival, n=122) Final gene set and predictive algorithm Validation Independent validation (archival, n=321) Evaluate assay performance *Patients having a single NCCN high-risk feature (e.g., immunodeficiency, ≥2 cm tumor diameter, tumor of the mask area or genitals, or poor tumor differentiation) are deemed high risk by NCCN. **Risk for metastasis is reported for 40- GEP Class and AJCC 8th Edition T stage. n=149 n=127 n=24 n=168 n=108 n=24 n=16857.7% 34.3% 8.0% 53.0% 39.0% 8.0% 40-GEP + AJCC 40-GEP + BWH Low intensity (<10% risk) Moderate intensity (10-50% risk) High intensity (>50% risk) n=159 n=173 n=117 n=103 n=24n=24 https://www.cancer.org/cancer/ https://www.skincancer.org/ https://www.census.gov/