The strongest independent predictor of SCC metastasis
DecisionDx-SCC provides an independent risk of metastasis score as well as identifies patients likely to benefit from adjuvant radiation therapy (ART).
New publication in Future Oncology confirms DecisionDx-SCC identifies high-risk SCC patients who benefit most from adjuvant radiation therapy
DecisionDx-SCC has now been independently validated to predict ART treatment benefit in two studies comprising over 1,300 patients. Together, these two studies by Ruiz et al. in Future Oncology (2024) and Arron et al. in the Red Journal (2024) represent the largest published population of ART-treated high-risk SCC patients. Results from this study provide a validation of the performance of the previously reported (Arron et al. Red Journal 2024) benefit of ART for Class 2B tumors and a lack of benefit for Class 1 tumors and was conducted using 423 tumors from 399 patients from Brigham Women’s Health (BWH) and Cleveland Clinic. Given the consistency of the results from two independent cohorts, DecisionDx-SCC can aid in ART decision-making for patients with high-risk SCC tumors.
Key findings
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Select patients with completely resected high-risk squamous cell carcinoma are eligible for and undergo adjuvant radiation therapy (ART), but criteria for ART is heterogenous.
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Identifying patients with the highest risk of disease progression who would most benefit from ART is a clinical challenge.
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The 40-gene expression profile (40-GEP) test was recently reported to predict a benefit from ART for patients receiving a Class 2B result, and a low likelihood of benefit for a Class 1 result that together with low metastatic risk suggests these patients may consider deferring treatment.
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This validation study utilized an independent cohort of patients with high-risk cutaneous squamous cell carcinoma tumors matched on clinicopathological factors to compare disease progression rates and projected time to metastasis (using a “life expectancy” algorithm) for patients who received ART to those who did not.
New publication Red Journal shows DecisionDx-SCC identifies high-risk squamous cell carcinoma patients who are likely to benefit from adjuvant radiation therapy and those who can consider deferring treatment based on biological risk of metastasis
Association of a 40-Gene Expression Profile With Risk of Metastatic Disease Progression of Cutaneous Squamous Cell Carcinoma and Specification of Benefit of Adjuvant Radiation Therapy
In the study, patients with DecisionDx-SCC Class 2B test results, predicted to have the highest risk of metastasis by the test, who were treated with adjuvant radiation therapy (ART) had 50% higher metastasis-free survival (MFS) rates, on average, and slowed disease progression compared to Class 2B patients who did not receive ART.
Patients with Class 1 test results, predicted to have a lower risk of metastasis, did not see an improvement in survival after receiving ART, which together indicates these patients may be able to avoid the treatment.to non-ART treated patients. In addition, in patients with a Class 1 (lower risk) test result there was a non-significant benefit from ART treatment.
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key findings
Read full article- The DecisionDx-SCC test identified patients projected to receive the greatest benefit from ART to reduce metastatic disease progression. Patients with a Class 2B (highest metastatic risk) test result who were treated with ART had 50% higher MFS rates, on average, than Class 2B patients who did not receive ART at five years post-diagnosis
- A DecisionDx-SCC Class 2B result was the only independent risk factor that successfully identified patients who would most benefit from ART. Risk factors in the analysis included differentiation status, invasion into fat, perineural invasion and others, including National Comprehensive Cancer Network (NCCN) risk category and Brigham and Women's Hospital and American Joint Committee on Cancer Eighth Edition T-stages
- Class 2B patients who received ART showed a significant deceleration in disease progression compared to Class 2B patients who did not receive ART. For patients with a DecisionDx-SCC Class 2B test result who were not treated with ART, there was a peak rate of metastasis around two years; Class 2B, ART-treated patients had nearly five times longer projected time to metastasis
- DecisionDx-SCC identified patients who were less likely to show a significant benefit from ART in controlling disease progression. Patients with high-risk clinicopathologic features but who received a DecisionDx-SCC Class 1 (lower metastatic risk) test result did not show a significant benefit from ART. Given the low risk of metastasis for Class 1 patients, in addition to the lower likelihood of ART benefit, Class 1 patients may consider deferring treatment
