Genetically-damaged cell lines persist after photodynamic therapy for Barrett's esophagus, even when there has been histological downgrading.
179 patients underwent photodynamic therapy for Barrett's esophagus. Each had 3-monthly endoscopic biopsies, for a mean of 32 ± 2 months (range, 8-85 months).
"Decreasing or even elimination of dysplasia is not an adequate endpoint of photodynamic therapy."
3 of these patients had initial dysplasia within the Barrett's esophagus. This was downgraded histologically by the therapy, but relapsed into high-grade dysplasia on long-term follow-up.
Although histological examination of biopsies immediately after photodynamic therapy indicated an improvement, there was evidence that genetically-damaged cell clones persisted.
These cells can progress to high-grade dysplasia, and eventually to adenocarcinoma.
Kenneth Lang and his colleagues conclude, "Decreasing or even elimination of dysplasia is not an adequate endpoint of photodynamic therapy".