Distinction between intraductal carcinoma of the prostate (IDC-P), high-grade dysplasia (PIN), and invasive prostatic adenocarcinoma, using molecular markers of cancer progression.
BACKGROUND
Prostate ducts and acini whose lumens are filled with malignant cells represent a well-recognized histological pattern recently termed intraductal carcinoma of the prostate (IDC-P). These tumors are often associated with rapid disease progression, and most recur after radical surgery. Controversy exists as to whether IDC-P should be recognized as a separate entity, an extension of high-grade dysplasia (PIN) or invasive carcinoma as described by the Gleason grading system. This study investigates the use of molecular markers in defining the position of IDC-P in the evolutionary hierarchy of prostate cancer progression.


METHODS
IDC-P, high-grade dysplasia, and invasive cancers from a cohort of 20 selected radical prostatectomy specimens were screened for loss of heterozygosity (LOH), using 12 polymorphic microsatellite markers frequently lost in prostate cancer.


RESULTS
LOH was absent in Gleason grade 3 cancer, infrequent in high-grade dysplasia (9%) and Gleason grade 4 cancer (29%), but common in IDC-P (60%). In IDC-P, and to a lesser extent Gleason grade 4 cancers, multiple sites of allelic loss in individual cases were usual.


CONCLUSIONS
Allelic instability provides further evidence that IDC-P is not a simple extension of dysplasia, nor does it represent invasion of Gleason grade 3 cancers into the ductal/acinar system. IDC-P and Gleason grade 4 cancer represent late but possibly separate events in prostate cancer evolution.
Dawkins
H J
HJ
Urological Research Centre, Department of Surgery, University of Western Australia, Nedlands, Australia.
Sellner
L N
LN
Turbett
G R
GR
Thompson
C A
CA
Redmond
S L
SL
McNeal
J E
JE
Cohen
R J
RJ
D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D000483:Alleles; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D018450:Disease Progression; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D009361:Neoplasm Invasiveness; D011468:Prostatectomy; D019048:Prostatic Intraepithelial Neoplasia / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery
D005819:Genetic Markers