Detection of clinically insignificant prostate cancer by allelic imbalance analysis

临床意义不大的前列腺癌的标准肿瘤体积(TV)已有报道，但不同的研究有所不同：有些报告了TV&lt；200 mm^3；另一些报告了TV&lt；500 mm^3。本研究的目的是用分子生物学方法区分临床意义不大的前列腺癌和显著的前列腺癌。总共选择了184例限定在3 mm范围内的微小癌(MC)和82个主要肿瘤结节(MT)。对位于6q22、8p23.2-23、13q14和13q33的13个微卫星座位进行杂合性缺失(LOH)检测。将MT分为TV&lt；500 mm^3或&gt；500 mm^3；TV&lt；200 mm^3或200 mm^3；TV&lt；200 mm^3或200 mm^3〓TV&lt；500 mm^3或〓500 mm^3；6q16-21、6q22、8p23.1、8p23.2、13q14的杂合性缺失频率(1.0%、2.7%、1.9%、1.1%和5.4%)显著低于MT(30.9%、40.4%、12%、8.7%和20.6%)。在这些电视设置中，没有发现LOH频率的显著差异。当微小肿瘤被定义为TV&lt；200 mm^3或&lt；500 mm^3时，它应该包括恶性潜能相当于较大肿瘤的肿瘤。有人建议，为了在严格的安全范围内识别微小肿瘤，TV应该设置得更低。

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 <500 mm^3 or > 500 mm^3 ; TV < 200 mm^3 or > 200 mm^3 ; and TV < 200 mm^3 or 200 mm^3 〓 TV < 500 mm^3 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%). No significant differences in LOH frequencies were found at any of these TV settings. 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.