Actionable Risk Thresholds for Adjuvant Radiation Therapy and Surveillance Imaging in High-Risk Cutaneous Squamous Cell Carcinoma

Abstract

Aim: Assess the actionable clinical risk thresholds for patients with high-risk cutaneous squamous cell carcinoma (cSCC) that clinicians use to guide adjuvant radiation therapy (ART) and surveillance imaging decisions and how the 40-gene expression profile (40-GEP) test impacts management decisions.

Methods: Physician, Physician’s Assistant, and Nurse Practitioner clinicians with at least ten recent or 12 total 40-GEP requisitions were invited to complete an online survey.

Results: In total, 244 out of 752 (32.4%) invited clinicians completed the survey. Preferred formalized staging or risk assessment strategies (AJCC, BWH, NCCN, or individual risk factors) were highly variable. Clinicians most commonly reported recommending ART at 20% risk of local recurrence or regional/distant metastasis and surveillance imaging for patients who had at least a 10% risk. ART was considered at a minimum risk threshold of 10% for local recurrence or regional/distant metastasis. A 40-GEP Class 2B result was ranked among the top two most important high-risk factors for ART and surveillance image decision-making, along with extensive perineural invasion.

Conclusion: Clinicians considered 10% and 20% risk of local recurrence or regional/distant metastasis as clinically relevant thresholds for recommending use of surveillance imaging or ART, respectively. Clinicians reported the 40-GEP test results to be one of the most important factors in assessing risk of disease progression used to guide management decisions regarding ART and surveillance imaging, and the 40-GEP can be used to guide risk-aligned management in patients with high risk cSCC.