Cell-Free SHOX2 DNA Methylation in Blood as a Molecular Staging Parameter for Risk Stratification in Renal Cell Carcinoma Patients: A Prospective Observational Cohort Study

Abstract

BACKGROUND Novel targeted treatments and immunotherapies have substantially changed therapeutic options for advanced and metastatic renal cell carcinomas (RCCs). However, accurate diagnostic tests for the identification of high-risk patients are urgently needed. Here, we analyzed SHOX2 mRNA expression in RCC tissues and SHOX2 gene body methylation quantitatively in circulating cell-free DNA (ccfDNA) and RCC tissues with regard to risk stratification. METHODS The clinical performance of SHOX2 methylation was tested retrospectively and prospectively in a training and testing cohort of RCC tissue samples (n = 760 in total). SHOX2 mRNA expression analysis was included in the training cohort. In matched blood plasma samples from the testing cohort (n = 100), we prospectively examined the capability of pretherapeutic quantitative SHOX2 ccfDNA methylation to assess disease stage and identify patients at high risk of death. RESULTS SHOX2 gene body methylation was positively correlated with mRNA expression in RCC tissues (training cohort: Spearman ρ = 0.23, P < 0.001). SHOX2 methylation in tissue and plasma strongly correlated with an advanced disease stage (training cohort: ρ = 0.28, P < 0.001; testing cohort/tissue: ρ = 0.40, P < 0.001; testing cohort/plasma: ρ = 0.34, P = 0.001) and risk of death after initial partial or radical nephrectomy [training cohort: hazard ratio (HR) = 1.40 (95% CI, 1.24–1.57), P < 0.001; testing cohort/tissue: HR = 1.16 (95% CI, 1.07–1.27), P = 0.001; testing cohort/plasma: HR = 1.50 (95% CI, 1.29–1.74), P < 0.001]. CONCLUSIONS Pretherapeutic SHOX2 ccfDNA methylation testing allows for the identification of RCC patients at high risk of death after nephrectomy. These patients might benefit from an adjuvant treatment or early initiation of a palliative treatment.

DNA methylation-based classification and identification of renal cell carcinoma prognosis-subgroups

“…Therefore, it poses many challenges in the diagnosis and treatment of RCC, including the early diagnosis of malignant tumors, treatment selection, surgical benefits, side effects of chemotherapeutic drugs and prognosis assessment of patients. Since DNA methylation is one of the earliest molecular changes in cancer and is extensive and stable, its role in cancer biology has been extensively studied, including early diagnosis of renal cell carcinoma [37, 38]. Many studies have explored the role of DNA methylation in the etiology and progression of renal cell carcinoma.…”

Clinical Utility of Cell-free and Circulating Tumor DNA in Kidney and Bladder Cancer: A Critical Review of Current Literature

“…De Martino et al [52] failed to demonstrate a significant relationship between cfDNA methylation and survival. In a study ultimately encompassing 760 patients with RCC, Jung et al [64] showed that preoperative SHOX2 cfDNA methylation was associated with decreased OS after surgical intervention (HR 1.50, p < 0.001). Further studies are needed to delineate this possible relationship more clearly.…”

Potential clinical application of free-circulating DNA from blood in renal cancer

“…Эти пациенты имели более низкие показатели безрецидивной и 5-летней общей выживаемости [29]. Еще в одном исследовании со схожим дизайном была выявлена корреляция уровня метилирования в плазме крови фрагмента гена SHOX2 с общей выживаемостью [34].…”