Genomic Profiling in Patients with Endometrial Cancer by Deep Sequencing of Vaginal Swabs and Plasma

Endometrial cancer is a common gynecologic malignancy that lacks effective noninvasive screening tools as traditional approaches rely on invasive biopsies. In this large prospective study, we evaluated a novel approach combining vaginal swab DNA and plasma-based ctDNA for genomic profiling to provide a comprehensive framework for diagnosis, prognosis, and disease monitoring.

Adult patients with diverse stages of endometrial cancer, preneoplastic disease, and benign endometrial conditions were prospectively recruited over 2 years. Paired vaginal swab DNA and plasma-based ctDNA were collected preoperatively, and additional plasma samples were obtained at multiple time points postoperatively. Deep next-generation sequencing targeting 101 genes was performed, achieving an average depth exceeding 40,000×.

A total of 191 patients contributed 388 samples. Vaginal swab DNA demonstrated 77.7% sensitivity and 96.6% specificity. PTEN mutations were associated with favorable prognosis (HR: 0.27; 95% confidence interval, 0.092-0.77), and TP53 mutations were associated with poor prognosis (HR: 3.7; 95% confidence interval, 1.4-10). A novel classification system based on the mutational profile of PTEN/TP53 identified distinct prognostic groups. Plasma-based ctDNA was significantly associated with stage, lymphovascular invasion, and prognosis (P < 0.01 for all). Patients with preoperative positive plasma-based ctDNA results exhibited poorer outcomes (P < 0.01), whereas postoperative positive ctDNA results enabled early detection of recurrence.

These two noninvasive methods play distinct, complementary roles in the management of endometrial cancer. Vaginal swab DNA and novel PTEN/TP53-based classification have distinct prognostic advantages over existing frameworks. Plasma-based ctDNA provides dynamic insights into recurrence risk and disease progression.