Telomere-specific reverse transcriptase (hTERT) and cell-free RNA in plasma as predictors of pathologic tumor response in rectal cancer patients receiving neoadjuvant chemoradiotherapy

Purpose: To investigate whether the plasma levels of cellfree RNA (cfRNA) and telomere-specific reverse transcriptase mRNA (hTERT) are associated with tumor response in rectal cancer patients who received preoperative chemoradiotherapy (pCRT). Methods: Patients who underwent pCRT for rectal cancer and for whom baseline and paired post-pCRT blood samples were available were studied. On the basis of tumor regression score, patients were classified as having response or having no response. Clinical variables and plasma levels of cfRNA and hTERT before and after the pCRT were evaluated. The association between each predictor and tumor response was assessed by univariate and multivariate analyses. Results: Of 98 eligible patients, 45 were determined to respond to therapy, and 53 did not respond to therapy. In univariate analysis, gender (P = 0.040), baseline levels of cfRNA (P = 0.026), post-pCRT levels of both hTERT and cfRNA (P