From the Departments of Pathology (Drs Guedes, Morais, Fedor, Hicks, Gurel, De Marzo, and Lotan), Oncology (Drs Trock, De Marzo, and Lotan), and Urology (Drs Trock and De Marzo), Johns Hopkins University School of Medicine, Baltimore, Maryland; the Department of Pathology, New York University School of Medicine, New York, New York (Drs Melamed and Lee); the Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York (Drs Gopalan and Fine); the Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, California (Dr Knudsen); the Department of Pathology, University of Washington, Seattle (Dr True); and Genitourinary Oncology Service, Department of Medicine, Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, New York (Dr Scher).
Arch Pathol Lab Med. 2019 Mar;143(3):338-348. doi: 10.5858/arpa.2018-0068-OA. Epub 2018 Oct 8.
CONTEXT.—: Phosphatase and tensin homolog (PTEN) is a promising prognostic and potentially predictive biomarker in prostate cancer.
OBJECTIVE.—: To assess the effects of preanalytic variables on an analytically validated and fully automated PTEN immunohistochemistry assay.
DESIGN.—: PTEN immunohistochemistry was performed on Ventana immunostaining systems. In benign prostate tissues, immunostaining intensity across variable conditions was assessed by digital image analysis. In prostate tumor tissues, immunostaining was scored visually.
RESULTS.—: Delay of fixation for 4 hours or longer at room temperature or 48 hours or longer at 4°C and duration of formalin fixation did not significantly alter immunostaining intensity. Intensity of staining was highest in 10% formalin compared with other fixatives. Tumor tissues with PTEN loss processed using protocols from 11 academic institutions were all evaluable and scored identically. PTEN immunostaining of needle biopsies where tissue blocks had been stored for less than 10 years was more frequently scored as nonevaluable compared with blocks that had been stored for 10 years or longer. This effect was less evident for radical prostatectomy specimens, where low rates of nonevaluable staining were seen for 23 years or more of storage. Storage of unstained slides for 5 years at room temperature prior to immunostaining resulted in equivalent scoring compared with freshly cut slides. Machine-to-machine variability assessed across 3 Ventana platforms and 2 institutions was negligible in 12 tumors, and platform-to-platform variability was also minor comparing Ventana and Leica instruments across 77 tumors (κ = 0.926).
CONCLUSIONS.—: Automated PTEN immunostaining is robust to most preanalytic variables in the prostate and may be performed on prostate tumor tissues subjected to a wide range of preanalytic conditions. These data may help guide assay development if PTEN becomes a key predictive biomarker.
磷酸酶与张力蛋白同源物（PTEN）是前列腺癌有前途的预后和潜在预测生物标志物。
评估分析前变量对经分析验证和全自动 PTEN 免疫组织化学检测的影响。
PTEN 免疫组织化学在 Ventana 免疫染色系统上进行。在良性前列腺组织中，通过数字图像分析评估各种条件下的免疫染色强度。在前列腺肿瘤组织中，免疫染色进行视觉评分。
室温下固定 4 小时或更长时间或 4°C 下固定 48 小时或更长时间，以及福尔马林固定时间的延迟均不会显著改变免疫染色强度。与其他固定剂相比，10%福尔马林固定的染色强度最高。使用来自 11 个学术机构的方案处理 PTEN 缺失的肿瘤组织均是可评估的且评分相同。与储存 10 年或更长时间的组织块相比，储存时间不到 10 年的针吸活检组织块的 PTEN 免疫染色更频繁地被评为无法评估。对于根治性前列腺切除术标本，这种影响不太明显，储存 23 年或更长时间后，无法评估的染色率仍然很低。在免疫染色前将未染色的载玻片在室温下储存 5 年，与新鲜切割的载玻片相比，评分结果相当。在 3 个 Ventana 平台和 2 个机构中评估的 12 个肿瘤的机器间变异性可以忽略不计，在 77 个肿瘤中比较 Ventana 和徕卡仪器的平台间变异性也很小（κ=0.926）。
全自动 PTEN 免疫染色对前列腺中的大多数分析前变量具有很强的稳健性，并且可以对广泛的分析前条件下的前列腺肿瘤组织进行检测。如果 PTEN 成为关键的预测生物标志物，这些数据可能有助于指导检测的发展。
