Photodynamic therapy has been shown to be effective in the treatment of high-grade dysplasia /mucosal carcinoma in Barrett's esophagus.
Substantial proportions of patients do not respond to photodynamic therapy or progress to carcinoma despite photodynamic therapy.
The role of biomarkers in predicting response to photodynamic therapy is unknown.
|40% were responders at 3 months after photodynamic therapy|
Dr Ganapathy Prasad and colleagues from Minnesota, USA determined if biomarkers known to be associated with neoplasia in Barrett's esophagus can predict loss of dysplasia in patients treated with ablative therapy for high-grade dysplasia /intramucosal cancer.
The team prospecitively studied patients with Barrett's esophagus and high-grade dysplasia/intramucosal cancer from 2002 to 2006.
Biomarkers were assessed using fluorescence in situ hybridization performed on cytology specimens, for region-specific and centromeric probes.
Patients were treated with photodynamic therapy using cylindric diffusing fibers.
The team performed univariate and multiple variable logistic regression to determine predictors of response to photodynamic therapy.
The researchers identified a total of 126 consecutive patients.
Of these, 71 underwent photodynamic therapy, and 55 patients who did not undergo photodynamic therapy and were under surveillance, to adjust for the natural history of high-grade dysplasia.
The research team noted that 40% of patients were responders at 3 months after photodynamic therapy.
On multiple variable analysis, P16 allelic loss predicted decreased response to photodynamic therapy.
Barrett's esophagus segment length, and performance of photodynamic therapy were other independent predictors of loss of dysplasia.
Dr Prasad's team concluded, "P16 loss detected by fluorescence in situ hybridization can help predict loss of dysplasia in patients with Barrett's esophagus and high-grade dysplasia/mucosal cancer."
"Biomarkers may help in the selection of appropriate therapy for patients and improve treatment outcomes."