Image cytometry accurately detects DNA ploidy abnormalities and predicts late relapse to high-grade dysplasia and adenocarcinoma in Barrett's oesophagus following photodynamic therapy

Abstract

BACKGROUND AND AIMS: DNA ploidy abnormalities (aneuploidy/tetraploidy) measured by flow cytometry (FC) are strong predictors of future cancer development in untreated Barrett's oesophagus, independent of histology grade. Image cytometric DNA analysis (ICDA) is an optical technique allowing visualisation of abnormal nuclei that may be undertaken on archival tissue. Our aim was to determine the accuracy of ICDA vs FC, and evaluate DNA ploidy as a prognostic biomarker after histologically successful treatment with photodynamic therapy (PDT). METHODS: Nuclei were extracted from 40 mm sections of paraffin-embedded biopsies and processed for ICDA at UCL and FC at UW using standardised protocols. Subsequently, DNA ploidy was evaluated by ICDA on a cohort of 30 patients clear of dysplasia 1 year after aminolaevulinic acid PDT for high-grade dysplasia (HGD). The results were correlated with long-term outcome. RESULTS: In the comparative study, 93% (41 out of 44) of cases were classified identically. Errors occurred in the near-diploid region by ICDA and the tetraploid region by FC. In the cohort study, there were 13 cases of late relapse (7 cancer, 6 HGD) and 17 patients who remained free of dysplasia after a mean follow-up of 44 months. Aneuploidy post-PDT was highly predictive for recurrent HGD or cancer with a hazard ratio of 8.2 (1.8 -37.8) (log-rank P ¼ 0.001). CONCLUSIONS: ICDA is accurate for the detection of DNA ploidy abnormalities when compared with FC. After histologically successful PDT, patients with residual aneuploidy are significantly more likely to develop HGD or cancer than those who become diploid. DNA ploidy by ICDA is a valuable prognostic biomarker after ablative therapy. British Journal of Cancer (2010) The incidence of oesophageal adenocarcinoma is rising rapidly in the developed world. Barrett's oesophagus (BE) is a precursor lesion that confers an increased risk of oesophageal adenocarcinoma, with incidence rates of 0.4 -2% per annum (Cameron et al, 1985;Robertson et al, 1988;Hameeteman et al, 1989;Williamson et al, 1991). Progression seems to occur through a metaplasiadysplasia -carcinoma sequence (Weston et al, 1999;Montgomery et al, 2001). High-grade dysplasia (HGD) confers a high probability of cancer, with rates varying between 31 and 59% over 5 years (Reid et al, 2000a;Buttar et al, 2001;Overholt et al, 2007). In recent years, there has been a paradigm shift in the treatment of HGD in BE from oesophagectomy to endoscopic therapy, with focal ablation of nodular disease (endoscopic mucosal resection (EMR)) and field ablation of residual flat dysplasia (photodynamic therapy (PDT), argon plasma coagulation, radiofrequency ablation and cryotherapy). The effectiveness of these approaches in eradicating HGD and reducing the risk of progression to cancer has been shown in randomised controlled trials (Overholt et al, 2007;Shaheen et al, 2009).Although complete ablation of a Barrett's segment is the ideal response to treatment, complete reversal of HGD at 1 year is currently used as a marker of ...

Diagnosis and risk stratification of Barrett’s dysplasia by flow cytometric DNA analysis of paraffin-embedded tissue

“…Also in BO, there is a limited number of studies that compared the results of image cytometry and traditional flow cytometry (the current gold standard). Although one study reported a concordance rate of 93%,47 another study concluded that flow cytometry missed the diagnosis of aneuploidy in 29%, whereas image cytometry detected all cases of aneuploidy 41. However, by virtue of identifying a small number of abnormal nuclei from the area of interest, image cytometry may identify much higher rates of rare aneuploid cells that are not detected by flow cytometry 41.…”

Influence of genetics on tumoral pathologies: The example of the adenocarcinoma arising in Barrett's esophagus

“…Aneuploidy (abnormal chromosome numbers) has been strongly associated in disease progression and predicts ADC development (12). Aneuploidy has been detected in ADC, dysplastic tissue and metaplastic Barrett's epithelium (13) but others authors suggested that aneuploidy characterizes more the dysplastic and the tumor development then the metaplastic step (14).…”

Automated Quantification of DNA Aneuploidy by Image Cytometry as an Adjunct for the Cytologic Diagnosis of Malignant Effusion

“…DNA aneuploidy has been reported as a prognostic and predictive biomarker of cancer. It was shown to be a predictive marker for progression of dysplasia in cervical cancer [9], transformation from dysplasia to malignancy in esophageal adenocarcinoma [10], and requirement of aggressive treatment in breast [11], ovarian [12] and endometrial cancers [13] as it is associated with adverse prognosis in those and other cancers [14]. Several recent studies have shown the value of automated quantitative analysis of DNA aneuploidy by image cytometry (ICM) in the cytologic diagnosis and screening of cervical, esophageal and oral cancer [5][6][7]15], among others.…”