Image cytometry accurately detects DNA ploidy abnormalities and predicts late relapse to high-grade dysplasia and adenocarcinoma in Barrett's oesophagus following photodynamic therapy.
OBJECTIVE
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 mum 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=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.
Dunn
J M
JM
Department of Surgery, National Medical Laser Centre, University College London, 67-73 Riding House Street, London W1W 7EJ, UK.
Mackenzie
G D
GD
Oukrif
D
D
Mosse
C A
CA
Banks
M R
MR
Thorpe
S
S
Sasieni
P
P
Bown
S G
SG
Novelli
M R
MR
Rabinovitch
P S
PS
Lovat
L B
LB
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D000368:Aged; D001471:Barrett Esophagus / Q000175:diagnosis* / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D016022:Case-Control Studies; D002869:Chromosome Aberrations; D020732:Cytogenetic Analysis / Q000379:methods; D004273:DNA, Neoplasm / Q000235:genetics; D004947:Esophagus / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics; D019044:Image Cytometry / Q000379:methods / Q000592:standards; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010778:Photochemotherapy / Q000379:methods; D011003:Ploidies; D011379:Prognosis; D012008:Recurrence; D013997:Time Factors
D004273:DNA, Neoplasm
Br J Surg. 1988 Aug;75(8):760-3
3167523
Lasers Med Sci. 2008 Apr;23(2):203-10
17610005
Am J Gastroenterol. 1999 Dec;94(12):3413-9
10606296
Gut. 2008 Aug;57(8):1041-8
18305067
Methods Cell Biol. 1994;41:263-96
7861967
Cytometry. 1992;13(3):314-21
1576895
Gastrointest Endosc. 2007 Sep;66(3):460-8
17643436
Mod Pathol. 1991 Mar;4(2):178-82
2047381
N Engl J Med. 2009 May 28;360(22):2277-88
19474425
J Histochem Cytochem. 1983 Nov;31(11):1333-5
6619538
Am J Gastroenterol. 2001 Nov;96(11):3071-83
11721752
Cytometry. 1995 Sep 15;22(3):181-9
8556949
Am J Gastroenterol. 2000 Jul;95(7):1669-76
10925966
Cytometry. 1994 Dec 15;18(4):218-22
7895528
BMC Clin Pathol. 2008 May 30;8:5
18513411
Am J Gastroenterol. 2000 Nov;95(11):3089-96
11095322
Crit Rev Clin Lab Sci. 1994;31(1):1-34
8049032
Hum Pathol. 2001 Apr;32(4):379-88
11331954
Lasers Med Sci. 2009 Sep;24(5):729-34
19057983
Cancer. 1994 Mar 15;73(6):1595-607
8156486
Gastroenterology. 2001 Jun;120(7):1630-9
11375945
Cytometry. 1992;13(6):577-85
1451590
Gastroenterology. 1989 May;96(5 Pt 1):1249-56
2703113
Cancer. 2008 Aug 1;113(3):470-6
18553366
Br J Obstet Gynaecol. 1994 Jul;101(7):621-5
8043542
N Engl J Med. 1985 Oct 3;313(14):857-9
4033716
Arch Intern Med. 1991 Nov;151(11):2212-6
1953225
Anal Cell Pathol. 1995 Jan;8(1):67-74
7734413