Informs risk appropriate management

The integrated DecisionDx-SCC test result combines the 40-gene expression profile with clinicopathologic risk factors and optimized nested predictive models to deliver refined risk-assessment across 4 result classes.

Test ordered

Biopsy from a patient with high-risk cutaneous SCC
Optimized nested predictive models

The i40-GEP

Gene expression algorithm

The molecular signature is based on 40 genes

Clinicopathologic factors

Immunosuppression, tumor diameter, differentiation, PNI, and anatomic site

Integrated into a single, validated risk classification.
Four risk classes

Class 1A
Low risk

Class 1B
Moderate risk

Class 2A
High risk

Class 2B
Highest risk

Test ordered

Biopsy from a patient with high-risk cutaneous SCC
Optimized nested predictive models

The i40-GEP

Gene expression algorithm

The molecular signature is based on 40 genes

Clinicopathologic factors

Immunosuppression, tumor diameter, differentiation, PNI, and anatomic site

Integrated into a single, validated risk classification.
Four risk classes

Class 1A
Low risk

Class 1B
Moderate risk

Class 2A
High risk

Class 2B
Highest risk

DecisionDx-SCC testing process

DecisionDx-SCC is performed in Castle Biosciences’ CLIA certified, CAP-accredited and NY state approved laboratory using formalin-fixed, paraffin embedded (FFPE) primary tumor tissue from either a biopsy or excision.

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‍Tissue biopsy submitted

Tissue blocks or slides from the primary tumor tissue biopsies are sent to our laboratory for testing.

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RNA/DNA preparation

Once tissue is received in our laboratory, RNA is isolated from the tissue and converted to cDNA. The cDNA for each of the 40 genes is amplified and the gene signature recorded.

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Signature interpretation

By combining the 40-gene expression profile with clinicopathologic risk factors and optimized nested predictive models a class result is provided.

Green abstract geometric shapes forming a stylized letter S on a white background.

DecisionDx-SCC reporting

The integrated DecisionDx-SCC report provides a class result based on a patient’s risk for metastasis and local recurrence:

Class 1: Low risk
Class 1B: Moderate risk
Class 2A: High risk
Class 2B: Highest risk

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Provides precise, personalized risk to inform patient management & treatment guidance

40-GEP

PNI, poor differentiation, immunosuppression, tumor diameter and tumor location

i40-GEP result
(MFS on validation cohort)

Clinical utility
Based on metastatic risk

Class 1A

Low risk

MFS 97.3% | LRFS 96.8%

ART benefit
Low likelihood
0–5% metastatic risk
- Safe to defer imaging
- Safe to defer ART
Class 1B

Moderate risk

MFS 94.6% | LRFS 90.0%

ART benefit
Low likelihood
5–10% metastatic risk
- Consider increased surveillance
- Consider imaging
- Safe to defer ART
Class 2A

High risk

MFS 77.9% | LRFS 83.1%

ART benefit
Low likelihood
>20% metastatic risk
- Recommend increased surveillance
- Recommend imaging
- Recommend multidisciplinary consult
- Unlikely benefit from ART
Class 2B

Highest risk

MFS 66.2% | LRFS 82.1%

ART benefit
High likelihood
>20% metastatic risk
- Recommend increased surveillance
- Recommend imaging
- Recommend multidisciplinary consult
- Likely benefit from ART

40-GEP

PNI, poor differentiation, immunosuppression, tumor diameter and tumor location

i40-GEP result
(MFS on validation cohort)

Clinical utility
Based on metastatic risk

Class 1A

Low risk

MFS 97.3% | LRFS 96.8%

ART benefit
Low likelihood
0–5% metastatic risk
- Safe to defer imaging
- Safe to defer ART
Class 1B

Moderate risk

MFS 94.6% | LRFS 90.0%

ART benefit
Low likelihood
5–10% metastatic risk
- Consider increased surveillance
- Consider imaging
- Safe to defer ART
Class 2A

High risk

MFS 77.9% | LRFS 83.1%

ART benefit
Low likelihood
>20% metastatic risk
- Recommend increased surveillance
- Recommend imaging
- Recommend multidisciplinary consult
- Unlikely benefit from ART
Class 2B

Highest risk

MFS 66.2% | LRFS 82.1%

ART benefit
High likelihood
>20% metastatic risk
- Recommend increased surveillance
- Recommend imaging
- Recommend multidisciplinary consult
- Likely benefit from ART

40-GEP

PNI, poor differentiation, immunosuppression, tumor diameter and tumor location

i40-GEP result
(MFS on validation cohort)

Clinical utility
Based on metastatic risk

Class 1A

Low risk

MFS 97.3% | LRFS 96.8%

ART benefit
Low likelihood
0–5% metastatic risk
- Safe to defer imaging
- Safe to defer ART
Class 1B

Moderate risk

MFS 94.6% | LRFS 90.0%

ART benefit
Low likelihood
5–10% metastatic risk
- Consider increased surveillance
- Consider imaging
- Safe to defer ART
Class 2A

High risk

MFS 77.9% | LRFS 83.1%

ART benefit
Low likelihood
>20% metastatic risk
- Recommend increased surveillance
- Recommend imaging
- Recommend multidisciplinary consult
- Unlikely benefit from ART
Class 2B

Highest risk

MFS 66.2% | LRFS 82.1%

ART benefit
High likelihood
>20% metastatic risk
- Recommend increased surveillance
- Recommend imaging
- Recommend multidisciplinary consult
- Likely benefit from ART

References: Ratner et al, AAD Innovation Academy 2026, Shah M, et al. J of Skin. 2025, Patel VA, et al. Cancer Med. 2022, Rentroia-Pacheco B, et al.eClinicalMedicine. 2023, Gupta N, et al. J Am Acad Dermatol. 2022, Wang DM, et al. JAMA Dermatol. 2025. *Report distribution experienced in validation.

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Informs risk appropriate management

Test ordered

The i40-GEP

Gene expression algorithm

Clinicopathologic factors

Four risk classes

Test ordered

The i40-GEP

Gene expression algorithm

Clinicopathologic factors

Four risk classes

DecisionDx-SCC testing process

‍Tissue biopsy submitted

RNA/DNA preparation

Signature interpretation

DecisionDx-SCC reporting

Provides precise, personalized risk to inform patient management & treatment guidance ​

40-GEP

i40-GEP result(MFS on validation cohort)

Clinical utilityBased on metastatic risk

Class 1A

Class 1B

Class 2A

Class 2B

40-GEP

i40-GEP result(MFS on validation cohort)

Clinical utilityBased on metastatic risk

Class 1A

Class 1B

Class 2A

Class 2B

40-GEP

i40-GEP result(MFS on validation cohort)

Clinical utilityBased on metastatic risk

Class 1A

Class 1B

Class 2A

Class 2B

Get started with DecisionDx-SCC

Scientific Evidence

Provides precise, personalized risk to inform patient management & treatment guidance

i40-GEP result
(MFS on validation cohort)

Clinical utility
Based on metastatic risk

i40-GEP result
(MFS on validation cohort)

Clinical utility
Based on metastatic risk

i40-GEP result
(MFS on validation cohort)

Clinical utility
Based on metastatic risk