What long-term results can be expected from laser ablation in adenocarcinomas?

P. Sharma (Kansas City)

Esophageal adenocarcinoma develops through the metaplasia-carcinoma sequence from Barrett's esophagus without dysplasia ? low-grade dysplasia (LGD) ? high-grade dysplasia (HGD) ? adenocarcinoma. The diagnosis of early adenocarcinoma in patients with Barrett's esophagus needs a curative resection. However, given the high morbidity and mortality rates reported with esophagectomy, and the comorbidities frequently present in these older patients - local endoscopic ablative techniques have been utilized for the eradication of early cancer. Moreover, certain patients may not be deemed fit to undergo surgery after a surgical evaluation or may decline esophagectomy.

ND:YAG laser

Barrett's mucosa, including HGD and early adenocarcinoma, can be destroyed by laser photocoagulation. Thermal energy is delivered to the tissue by means of a fiber inserted through the channel of an endoscope and given the greater depth of injury with laser, one of its potential uses is in patients with early Barrett's adenocarcinoma. Patients with documented Barrett's esophagus and early adenocarcinoma who had either refused surgery or were poor candidates for surgery were offered endoscopic therapy of their tumor with Nd:YAG plus electrocoagulation [1]. The patients were treated with 20 mg of omeprazole twice a day and underwent therapy with Nd:YAG laser and multipolar electrocoagulation

Table I. Laser ablation of Barrett's with and without adenocarcinoma.

(MPEC). All 6 patients had a complete initial response to therapy. One patient on chronic immunosuppressive therapy had recurrence of the tumor after a 36 month follow-up. The cancer was eliminated in the remaining 5 patients, with 2 having complete reversal of their Barrett's esophagus as well. The patients were followed up for a mean of 3.4 years (range 9-86 months).

Potassium titanyl phosphate laser

Two published reports have utilized potassium titanyl phosphate (KTP) laser for reversal of Barrett's esophagus. Sixteen patients with long segment Barrett's esophagus were treated with KTP laser and 40 mg of omeprazole [2]. Eleven of 16 patients had intestinal metaplasia (IM) underlying squamous mucosa following treatment, whereas 9 demonstrated squamous mucosa regeneration within previous Barrett's glands.

In the second study on KTP, Gossner et al. treated 10 patients with Barrett's esophagus including 4 with LGD, 4 with HGD, and 2 with early adenocarcinoma using KTP laser while the patients were maintained on omeprazole 80 mg/day [3]. Dysplasia was eliminated in all 10 patients who were followed for a mean of 10.6 months. Two of the 10 patients showed IM underlying the normal squamous mucosa and no complications were reported in this pilot study.

References

1. Sharma P, Jaffe PE, Bhattacharyya A, Sampliner RE. Laser and multipolar electrocoagulation ablation of early Barrett's aenocarcinoma: long-term follow-up. Gastrointest Endosc 1999;49:442-446.

2. Barham CP, Jones RL, Biddlestone LR, Hardwick RH, Shepherd NA, Barr H. Photothermal laser ablation of Barrett's esophagus: endoscopic and histological evidence of squamous re-epithelialization. Gut 1997;41:281-284.

3. Gossner L, May A, Stolte M, Seitz G, Hahn E, Ell C. KTP laser destruction of dysplasia and early cancer in columnarlined Barrett's esophagus. Gastrointest Endosc 1999;49:8-12.

4. Meyer B, Boyer S, Nawau G, et al. Nd:YAG laser combined with omeprazole as a treatment of Barrett's esophagus. Preliminary results of a prospective multicenter study. Endoscopy 1996;38:P03.

5. Salo J, Salminen J, Kiviluoto T, Namoander A, Ramo O, Farkkila M, et al. Treatment of Barrett's esophagus by endoscopic laser ablation and antireflux surgery. Ann Surg 1998;227:40-44.

6. Berenson MM, Johnson TD, Markowitz NR, Buchi KN, Samowitz WS. Restoration of squamous mucosa after ablation of Barrett's esophagus epithelium. Gastroenterology 1993;104:1686-1691.