Lugol Chromoendoscopy Combined with Image Cytometry and p53 LOH in Patients At Risk for Esophageal Squamous Cell Carcinoma

Abstract

Background and Aims: Patients with achalasia or with malignancies of the head and the neck are at increased risk of esophageal squamous cell cacinoma. We have previously found that squamous cell carcinoma and adjacent non-cancerous tissue of three patients with achalasia showed abnormal DNA pattern and p53 loss of heterozygosity (LOH) by image cytometry (ICM) and fluorescence in situ hybridisation (FISH). Therefore we conducted a prospective biomarker study combined with Lugol chromoendoscopy in these patients. Unstained and stained areas were compared for histology, ICM and p53 LOH by FISH to assess the risk of esophageal carcinogenesis in patients with achalasia and head and neck malignancies. Methods: 20 patients (17 m; 42 - 81 yr) with malignancies of the head and the neck region and 12 patients (8 m; 27 - 81 yr) with achalasia were included. Esophageal chromoendoscopy was performed in these patients with 1,2% Lugol solution. Biopsies and brush-cytologies for ICM were obtained from suspicious unstained and unsuspicous stained areas. Diploid, aneuploid and tetraploid (4 N) DNA patterns were differentiated by ICM. Two-color FISH was performed using a locus-specific probe for 17p13.1 (p53 gene) along with the chromosomal enumeration probe for chromosome 17. A pathological FISH probe was defined as p53 LOH in more than 2.9% of squamous cells (>mean + 3 SD of diploid controls). Results: Lugol staining revealed large (>3 cm2) unstained esophageal regions in three (15%) of 20 patients with head and neck malignancies. Two patients had high-grade dysplasia and one patient had a carcinoma in situ. All three had an aneuploid DNA pattern with p53 LOH. In two of these three patients the neoplastic areas were not visible and in one case under-estimated before staining. Two patients had a pathological tetraploid DNA-pattern with p53 LOH in one (1 cm2) unstained area without dysplasia. 27 of 32 patients (84%) had a normal chromoendoscopy without significant unstained areas and showed normal histology with a diploid DNA pattern without p53 LOH. Conclusion: Our interim analysis shows that esophageal chromoendoscopy with Lugol detects unstained areas with pathological DNA patterns and p53 LOH in patients with and without histological dysplasia. Patients with head and neck malignancies seem to be especially prone to develop biomarker abnormalities and neoplastic lesions originating from esophageal squamous epithelium. These findings justify further larger biomarker studies to improve screening in these patients.