Predicting Cancer Recurrence
One of the most frequent questions from patients is whether their cancer will come back after their surgical, radiation, or chemotherapy treatment is complete. Analyses of circulating tumor cells or the DNA associated with those cells (ctDNA) may be the answers. Can postoperative circulating tumor DNA (ctDNA) status predict recurrence-free survival (RFS) in patients with esophagogastric cancer with a pathologic complete response (pCR) or near-pCR?
A recent study evaluated this concept in a group of patients with esophagogastric cancer (EGC). Of the 60% of patients diagnosed with potentially curative locoregional disease in the United States, only 25%-30% survive five years from the time of diagnosis. After neoadjuvant therapy (NAT) and surgery, up to one third of patients with esophagogastric adenocarcinoma with a pathologic complete response (pCR; tumor regression grade 0 [TRG-0]) will recur.
The study aims to evaluate postoperative ctDNA as a predictor of recurrence in patients with pCR or near-pCR after curative-intent neoadjuvant chemotherapy or neoadjuvant chemoradiation and surgery. Within the subgroup of patients with EGC and favorable pathologic responses (TRG 0-1) after NAT, the presence of postoperative ctDNA identified patients with elevated recurrence risk. ctDNA is prognostic for recurrence even in patients who achieved a pCR or near-pCR.
With prospective validation in a larger cohort, ctDNA testing may become a useful surrogate modality along with other clinicopathologic factors to help identify patients who would benefit from adjuvant treatment. Capture of ctDNA results in our cancer registries will, no doubt, be important for patients with a variety of malignancies.
