Detecting plasma SHOX2, HOXA9, SEPTIN9, and RASSF1A methylation and circulating cancer cells for cholangiocarcinoma clinical diagnosis and monitoring

Abstract

Background: Cholangiocarcinoma (CCA), also known as bile duct cancer, is a devastating malignancy primarily affecting the biliary tract.

Aim: To assess their performance in clinical diagnosis and monitoring of CCA, plasma methylation and circulating tumor cells were detected.

Methods: Plasma samples were collected from Hubei Cancer Hospital (n = 156). Plasma DNA was tested to detect SHOX2, HOXA9, SEPTIN9, and RASSF1A methylation using TaqMan PCR. Circulating tumor cells (CTCs) were detected in the peripheral blood of patients using the United States Food and Drug Administration-approved cell search system before and after clinical therapy. The CCA diagnostic value was estimated using the area under the curve. The independent prognosis risk factors for patients with CCA were estimated using Cox and logistic regression analyses.

Results: The sensitivity and specificity of the four DNA plasma methylations exhibited 64.74% sensitivity and 93.88% specificity for detecting CCA. The receiver operating characteristic curve of the combined value for CCA diagnosis in plasma was 0.828 ± 0.032. RASSF1A plasma methylation was related to the prognosis of patients with CCA. We determined the prognostic hazard ratio for CCA using CTC count, tumor stage, methylation, and carbohydrate antigen 19-9 levels as key factors. Our overall survival nomogram achieved a C-index of 0.705 (0.605-0.805).

Conclusion: SHOX2, HOXA9, SEPTIN9, and RASSF1A plasma methylation demonstrated increased sensitivity for diagnosing CCA. RASSF1A plasma methylation and CTCs were valuable predictors to assess CCA prognosis and recurrence.

Keywords: Cholangiocarcinoma; Circulating cancer cells; Diagnosis; Methylation; Prognosis.