Among patients with curatively resected early-stage biliary tract cancer (BTC), recent study findings from a real-world cohort trial revealed the value of circulating tumor DNA (ctDNA) as a prognostic biomarker for relapse, and the potential early detectability of recurrence by ctDNA compared with standard surveillance, according to study findings published in JCO Precision Oncology.
“To our knowledge, this report is the first to evaluate the prognostic value of a ctDNA assay in resected BTC in a real-world setting,” lead study author Dr. James Yu and his colleagues wrote in the study. “Our findings demonstrate that ctDNA detected by this personalized, tumor-informed … assay is highly prognostic of [relapse-free survival] and that ctDNA monitoring has the potential to detect molecular recurrence early ahead of standard radiographic surveillance in early-stage BTC.”
Yu is a practicing radiation oncologist at Smilow Cancer Hospital at Saint Francis Hospital, Department of Radiation Oncology, in Hartford, Connecticut.
After a median follow-up of 12.8 months from surgery, ctDNA positivity and negativity were assessed during the molecular residual disease window (median relapse-free survival: 6.6 months versus not reached, respectively) and the surveillance period (median relapse-free survival: 19.3 months versus not reached). In both periods, ctDNA positivity was associated with poorer relapse-free survival. Sixteen patients had confirmed recurrence. ctDNA identified recurrence in 93.8% (15 of 16) of recurred patients with an average lead time of 3.7 months. Carbohydrate antigen 19-9 levels did not show a significant correlation with relapse-free survival in contrast to ctDNA.
According to the study, the current standard of care for early-stage biliary tract cancer, a rare and aggressive cancer, is surgical resection followed by adjuvant capecitabine with or without chemoradiation.
“Analysis from our real-world cohort study revealed the promising value of ctDNA as a prognostic biomarker for relapse and potential early detection capacity for the recurrence of ctDNA compared with standard surveillance in curatively resected [biliary tract cancer],” study authors wrote. “Additionally, ctDNA exhibited a significant correlation with recurrence in contrast to [carbohydrate antigen 19-9].”
As noted in the study, 10.8% (4 of 37) of nonrecurrent patients with ctDNA-negative results initially had positive imaging findings that did not match the results obtained from confirmatory testing, highlighting ctDNA testing's potential to determine which indeterminate radiographic findings warrant further imaging or invasive biopsy.
In this retrospective, multicenter cohort study, a total of 195 plasma samples were collected from 56 patients with a median follow-up of 12.8 months. The cohort included 61% males (34 of 56) and 39% females (22 of 56). ctDNA results during the minimal residual disease window were available for 30 patients, 16.6% (5 of 30) of whom were ctDNA-positive. ctDNA measurements were available for 20 patients during adjuvant therapy, while 42 patients underwent ctDNA testing during the surveillance window.
“Further larger randomized controlled trials are warranted to confirm these findings,” study authors concluded. “Whether this early detection of recurrence by ctDNA can ultimately be translated into survival benefits by early intervention is the next question of investigation.
Reference:
“Detecting Early Recurrence With Circulating Tumor DNA in Stage I-III Biliary Tract Cancer After Curative Resection,” by Dr. James Yu, et al., American Society of Clinical Oncology.
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