A randomised controlled trial of ALA vs. Photofrin photodynamic therapy for high-grade dysplasia arising in Barrett's oesophagus

Lasers Med Sci. 2013 May;28(3):707-15. doi: 10.1007/s10103-012-1132-1. Epub 2012 Jun 15.

Abstract

Photofrin photodynamic therapy (PDT) is a licenced treatment for Barrett's oesophagus (BE) with high-grade dysplasia (HGD) but causes strictures and photosensitivity and complete reversal of dysplasia (CR-HGD) by 50 % at 5 years. 5-Aminolaevulinic acid (ALA) is an alternative treatment with non-randomised data suggesting 85 % CR-HGD and a low risk of side effects. We aimed to compare efficacy and side effect profile between the drugs. A single-centre randomised controlled trial was conducted. Presence of HGD was confirmed on three occasions by two specialist GI pathologists. Stratification was by length of BE and extent of dysplasia. Standard protocols for ALA and Photofrin-PDT were followed. Endoscopic follow-up with 2-cm four-quadrant biopsy was at 6 weeks, 4 months, and then annually. All adverse event data were collected. Sixty four patients were randomised, 34 ALA and 30 Photofrin-PDT. Median follow-up is 24 months. On intention-to-treat analysis, CR-HGD was 16/34 (47 %) with ALA-PDT and 12/30 (40 %) with Photofrin-PDT. The overall cancer incidence was 14 % (9/64). On sub-group log-rank analysis, for BE ≤ 6 cm, CR-HGD was significantly higher with ALA-PDT than Photofrin-PDT (χ(2) =5.39, p=0.02). Strictures and skin photosensitivity were significantly more common after treatment with Photofrin-PDT than ALA-PDT (33 vs. 9 % and 43 vs. 6 %, respectively, p<0.05). The rate of buried glands with either drug was significantly higher post-PDT (48 % of patients) than pre-PDT (20 %). ALA-PDT has a better risk profile than Photofrin-PDT. In patients with BE length ≤ 6 cm, preliminary results show ALA-PDT is associated with significantly higher CR-HGD. In longer segments of BE, neither PDT drug is sufficiently efficacious to warrant routine use.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / etiology
  • Adenocarcinoma / pathology
  • Adenocarcinoma / prevention & control
  • Aged
  • Aminolevulinic Acid / adverse effects
  • Aminolevulinic Acid / therapeutic use*
  • Barrett Esophagus / complications
  • Barrett Esophagus / drug therapy*
  • Barrett Esophagus / pathology
  • Dihematoporphyrin Ether / adverse effects
  • Dihematoporphyrin Ether / therapeutic use*
  • Disease Progression
  • Esophageal Neoplasms / etiology
  • Esophageal Neoplasms / pathology
  • Esophageal Neoplasms / prevention & control
  • Female
  • Humans
  • Male
  • Middle Aged
  • Photochemotherapy / adverse effects
  • Photochemotherapy / instrumentation
  • Photochemotherapy / methods*
  • Photosensitizing Agents / adverse effects
  • Photosensitizing Agents / therapeutic use
  • Treatment Outcome

Substances

  • Photosensitizing Agents
  • Aminolevulinic Acid
  • Dihematoporphyrin Ether