Identifying High-Risk Patients With Cutaneous Squamous Cell Carcinoma for Clinical Trial
Posted: Monday, July 20, 2020
Chrysalyne Schmults, MD, of Brigham & Women’s Hospital, Boston, and colleagues have developed a prognostic 40-gene expression profile (40-GEP) test for identifying high-risk patients with cutaneous squamous cell carcinoma. According to their findings, the 40-GEP test may be a valuable tool for optimizing selection of patients with T2b or T3 tumors—those at the highest risk for metastasis—for adjuvant clinical trials. The study results were presented during the ASCO20 Virtual Scientific Program (Abstract e22091).
Previously, the researchers identified three groups with increasing metastasis risk profiles using the prognostic 40-GEP test: class 1 (low risk), class 2A (high risk), and class 2B (highest risk), with metastasis rates of 8.9%, 20.4%, and 60%, respectively. These results were validated by examining an independent cohort of patients with high-risk cutaneous squamous cell carcinoma and known clinical outcomes.
In this study, two-arm trial sample sizes were calculated by evaluating metastasis rates of Brigham and Women’s Hospital high-risk patients with T stage disease (T2b–T3) alone and in combination with 40-GEP results from the validation cohort. The rates of metastasis for cases with T2b or T3 tumors increased from 35.1% to 71.4% when selecting for T2b or T3 cases with a 40-GEP class 2B result.
To provide 80% power to detect a hazard ratio of 0.6 with 3 years of follow-up—in line with improvement rates by addition of radiation to surgery—a total of 434 patients with T2b or T3 tumors are required for randomization. However, “the sample size could be reduced by 51% to 214 patients by focusing enrollment on T2b–T3 patients with a 40-GEP class 2B result,” concluded Dr. Schmults and colleagues.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.