title: Prediction of clinically insignificant prostate cancer by detection of allelic imbalance at 6q, 8p and 13q.
abstract: The criterion tumor volume (TV) for clinically insignificant prostate cancer has been reported, but it differs from study to study: some have reported TV < 200 mm(3); others, < 500 mm(3). The aim of the present study was to distinguish clinically insignificant cancers from significant ones using molecular biological methods. A total of 184 microscopic cancers (MC) defined as limited within a 3 mm circle and 82 main tumor (MT) nodules were selected. Thirteen microsatellite loci at 6q22, 8p23.2-23, 13q14 and 13q33 were evaluated for loss of heterozygosity (LOH). MT were subgrouped as TV > or = 500 mm(3) or < 500 mm(3); TV > or = 200 mm(3) or < 200 mm(3); and TV < 200 mm(3), 200 mm(3) < or = TV < 500 mm(3) or TV > or = 500 mm(3); and frequencies of LOH were compared between these three groups. Frequencies of LOH at 6q16-21, 6q22, 8p23.1, 8p23.2, 13q14 were significantly lower in MC (1.0%, 2.7%, 1.9%, 1.1% and 5.4%) than in MT (30.9%, 40.4%, 12%, 8.7% and 20.6%), but no significant differences in LOH frequency were found within each of the three TV groups, between each cut-off. When insignificant tumor is defined as TV < 200 mm(3) or < 500 mm(3), it should include tumors with malignant potential equivalent to larger tumors. It is suggested that in order to identify insignificant tumor within a strict safety range, TV should be set lower.
authors.affiliation: Department of Pathology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Nakano
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Taizo
authors.initials: T
authors.lastname: Shiraishi
authors.forename: Tomoe
authors.initials: T
authors.lastname: Lu
authors.forename: Masakuni
authors.initials: M
authors.lastname: Furusato
authors.forename: Shin
authors.initials: S
authors.lastname: Wakui
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hano
mesh_terms: D000368:Aged; D022981:Allelic Imbalance; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology*