Thyroid transcription factor 1 (TTF-1) is an immunohistochemical marker in the identification of lung and thyroid tumors. However, positive labelling for TTF-1 can occur in tumors from other sites, and this can result in misdiagnosis if only a limited panel of antibodies is used. We assessed the frequency of expression of 3 TTF-1 antibody clones, namely, 8G7G3/1, SPT24, and SP141 on a tissue microarray of 104 colorectal cancer (CRC), and whole-tumor sections of 165 CRC with known microsatellite instability (MSI) status. We also analyzed the expression of TTF-1 in a tissue microarray of 112 prostatic adenocarcinomas. The association of TTF-1 expression with clinicopathologic parameters and patient survival was analyzed. Six of 104 (5.7%) primary colorectal carcinomas expressed TTF-1 with SPT24 and SP141 clones, whereas only 2 (2%) of these tumors labeled positive for TTF-1 with clone 8G7G3/1. A significant association of TTF-1 expression with younger age at diagnosis (P=0.001) was found, but not with stage, or survival. The SP141 clone also labelled 24/165 (14.5%) of 165 CRC with known MSI status. There was an association with younger age (P<0.001), but not with MSI status or survival. TTF-1 expression was found in 39/112 (34%) prostate adenocarcinomas with 6/112 (5.3%) labelling with clone 8G7G3/1, 26/112 (23%) with clone SP141, and 31/112 (28%) with clone SPT24. TTF-1 expression appeared to be associated with extracapsular extension (P=0.022) and with higher stage (P=0.039). Here too TTF-1 expression was not associated with survival. The mRNA expression of TTF-1 in these tumors was confirmed by RTPCR, indicating that this is not false-positive labelling. Depending on the clone used, TTF-1 expression can vary with the SP141 and SPT24 clones exhibiting higher incidence of labelling. Pathologists should be aware of the differences in performance profiles of the different TTF-1 clones in diagnostic practice.

中文翻译：

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用 TTF-1 抗体标记非肺腺癌的发生率和诊断意义

甲状腺转录因子 1 (TTF-1) 是鉴别肺和甲状腺肿瘤的免疫组织化学标志物。然而，其他部位的肿瘤中也可能出现 TTF-1 的阳性标记，如果只使用有限的一组抗体，这可能会导致误诊。我们评估了 3 个 TTF-1 抗体克隆的表达频率，即 8G7G3/1、SPT24 和 SP141 在 104 个结直肠癌 (CRC) 的组织微阵列和 165 个具有已知微卫星不稳定性 (MSI) 的 CRC 的全肿瘤切片上的表达频率。 ） 地位。我们还分析了 112 例前列腺癌组织微阵列中 TTF-1 的表达。分析了 TTF-1 表达与临床病理参数和患者生存的关联。104 例 (5.7%) 原发性结直肠癌中有 6 例表达 TTF-1 和 SPT24 和 SP141 克隆，而这些肿瘤中只有 2 个 (2%) 用克隆 8G7G3/1 标记为 TTF-1 阳性。发现 TTF-1 表达与诊断时的年轻年龄显着相关 (P=0.001)，但与分期或存活率无关。SP141 克隆还标记了具有已知 MSI 状态的 165 个 CRC 中的 24/165 (14.5%)。与年轻相关（P<0.001），但与 MSI 状态或生存无关。在 39/112 (34%) 前列腺腺癌中发现 TTF-1 表达，其中 6/112 (5.3%) 标记为克隆 8G7G3/1，26/112 (23%) 标记为克隆 SP141，31/112 (28%)与克隆 SPT24。TTF-1 表达似乎与囊外扩展（P=0.022）和更高的阶段（P=0.039）相关。在这里，TTF-1 表达也与生存无关。RTPCR证实了这些肿瘤中TTF-1的mRNA表达，表明这不是假阳性标签。根据所使用的克隆，TTF-1 的表达可能会随着 SP141 和 SPT24 克隆表现出更高的标记发生率而有所不同。病理学家应该意识到诊断实践中不同 TTF-1 克隆的性能特征的差异。