ctDNA in Cutaneous Squamous Cell Carcinoma

The study aims to better understand whether circulating tumor DNA, or ctDNA, a type of personalized blood test informed by the tumor, can help monitor recurrence and treatment responses in patients with cutaneous squamous cell carcinoma (CSCC), especially during and after treatment. Blood samples will be collected during regular treatment visits or through mobile phlebotomy visits, and analyzed to study how ctDNA levels change over time. Participants will be in the study for 2 years. Circulating tumor DNA consists of small fragments of DNA shed into the bloodstream by cancer cells. It may serve as a non-invasive biomarker for detecting and monitoring CSCC, offering insights into tumor treatment response and/or progression. ctDNA can provide a "liquid biopsy," allowing real-time tracking of tumor dynamics. Specifically, the study is researching how ctDNA levels change in patients undergoing surgery, immunotherapy, or other standard treatments. The goal is to see if ctDNA can serve as a biomarker to better understand treatment response and detect potential progression/ recurrence of the cancer. This study does not involve any experimental drugs or devices. All drugs and treatments administered to participants, including surgery and immunotherapy, are part of standard of care. The ctDNA blood test is being used as a research tool and is not currently approved by the U.S. Food and Drug Administration (FDA) for monitoring CSCC. The study aims to evaluate its potential future use as a reliable biomarker.