Incorporating the 40-Gene Expression Profile (40-GEP) Test within Each Clinicopathologic Staging System Improves Metastatic Risk-Stratification in Patients Diagnosed with Cutaneous Squamous Cell Carcinoma (cSCC) and One or More High Risk Factors

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Ashley Wysong
Ally‐Khan Somani
Sherrif Ibrahim
Javier Cañueto
Alison Fitzgerald
Jennifer Siegel
Anesh Prasai
Matthew Goldberg
Aaron Farberg
Julia Kasprzak
David Brodland
Shlomo Koyfman
Sarah Arron


40-GEP, cSCC, stratification


Purpose: Three clinicopathologic-based risk assessment systems (Brigham and Women’s Hospital (BWH) staging, American Joint Committee on Cancer 8th Edition (AJCC8) staging or National Comprehensive Cancer Network (NCCN)) are used to guide treatment pathway decisions, including nodal assessment and adjuvant radiation therapy. Each of these systems suffers from accuracy limitations. The 40-GEP test was developed to use tumor biology to predict regional/distant metastasis and has previously been validated as an independent risk stratification test for cSCC patients who are diagnosed with one or more clinicopathologic risk factors. The purpose of this study was to evaluate the performance of the 40-GEP test in the prognostication of metastasis when results are used in the context of each of the clinicopathologic risk assessment system.

Study: Under an IRB-approved protocol, centralized pathology review, and sample analysis were performed in a CAP-accredited, CLIA-certified laboratory using formalin-fixed paraffin-embedded archival primary SCC tumor specimens with one or more risk factors (n=897).  Verified clinicopathologic information and outcomes data were collected from 58 contributing centers. Three-year risk stratification for regional and distant metastasis was assessed using Kaplan-Meier analysis for metastasis-free survival (MFS) for Class 1 (low risk), Class 2A (moderate risk), and Class 2B (high risk) groups. Nested Cox regression models and accuracy metrics were used to compare risk prediction of clinicopathologic risk assessment vs. clinicopathologic risk assessment in combination with 40-GEP.

Results: The overall cohort had a metastasis rate of 13.2%, substantiating the high-risk status of this population. For the overall cohort, the 40-GEP test showed clinically and statistically significant differences in MFS rates between Class 1 (94.1%), Class 2A (81.1%), and Class 2B (56.8%) (p<0.001, log-rank). Combining the results of the 40-GEP test with staging systems or NCCN risk categories led to increases in both NPV and PPV, indicating that a 40-GEP result improves the prediction of metastatic risk over the use of staging alone Table 1. Inclusion of 40-GEP with different clinicopathologic risk assessment methods (BWH and AJCC8, or NCCN risk subgroups) yielded significant improvements in prediction of metastatic events compared to each risk assessment method that did not include 40-GEP (ANOVA for deviance, p<0.0001 for each comparison).

Conclusions: Incorporating the 40-gene expression profile (40-GEP) test within each clinicopathologic risk assessment system improves risk-stratification, enabling more accurate treatment pathway decisions.


1. Karia PS, Han J, Schmults CD. Cutaneous squamous cell carcinoma: Estimated incidence of disease, nodal metastasis, and deaths from disease in the United States, 2012. J Am Acad Dermatol. 2013;68(6):957-966.

2. Ruiz ES, Kus KJB, Smile TD, et al. Adjuvant radiation following clear margin resection of high T-stage cutaneous squamous cell carcinoma halves the risk of local and locoregional recurrence: A dual-center retrospective study. Journal of the American Academy of Dermatology. 2022;87(1):87-94.

3. Wysong A, Newman JG, Covington KR, et al. Validation of a 40-gene expression profile test to predict metastatic risk in localized high-risk cutaneous squamous cell carcinoma. Journal of the American Academy of Dermatology. 2021;84(2):361-369.

4. Ibrahim SF, Kasprzak JM, Hall MA, et al. Enhanced metastatic risk assessment in cutaneous squamous cell carcinoma with the 40-gene expression profile test. Future Oncol. 2022;18(7):833-847.

5. National Comprehensive Cancer Network: Squamous Cell Skin Cancer, NCCN Guidelines Version 1.2023, in NCCN Clinical Practice Guidelines in Oncology [Internet]

6. Amin MB, Edge S, Greene F, et al., eds. AJCC Cancer Staging Manual, Eighth Edition. Springer International Publishing; 2017

7. Karia PS, Jambusaria-Pahlajani A, Harrington DP, Murphy GF, Qureshi AA, Schmults CD. Evaluation of American Joint Committee on Cancer, International Union Against Cancer, and Brigham and Women’s Hospital Tumor Staging for Cutaneous Squamous Cell Carcinoma. JCO. 2014;32(4):327-334.

8. Litchman GH, Fitzgerald AL, Kurley SJ, Cook RW, Rigel DS. Impact of a prognostic 40-gene expression profiling test on clinical management decisions for high-risk cutaneous squamous cell carcinoma. Curr Med Res Opin. Published online May 18, 2020:1-6

9. Hooper PB, Farberg AS, Fitzgerald AL, et al. Real-World Evidence Shows Clinicians Appropriately Use the Prognostic 40-Gene Expression Profile (40-GEP) Test for High-Risk Cutaneous Squamous Cell Carcinoma (cSCC) Patients. Cancer Invest. 2022;40(10):911-922

10. Saleeby E, Bielinski K, Fitzgerald A, Siegel J, Ibrahim S. A Prospective, Multi-Center Clinical Utility Study Demonstrates That the 40-Gene Expression Profile (40-GEP) Test Impacts Clinical Management for Medicare-Eligible Patients with High-Risk Cutaneous Squamous Cell Carcinoma (cSCC). J of Skin. 2022;6(6):482-496.

11. Singh G, Tolkachjov SN, Farberg AS. Incorporation of the 40-Gene Expression Profile (40-GEP) Test to Improve Treatment Decisions in High-Risk Cutaneous Squamous Cell Carcinoma (cSCC) Patients: Case Series and Algorithm. Clin Cosmet Investig Dermatol. 2023;16:925-935

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