Analysis of formalin-fixed paraffin-embedded (FFPE) tissue by immunohistochemistry (IHC) is commonplace in clinical and research laboratories. However, reports suggest that IHC results can be compromised by biospecimen preanalytical factors. The National Cancer Institute’s Biospecimen Preanalytical Variables Program conducted a systematic study to examine the potential effects of delay to fixation (DTF) and time in fixative (TIF) on IHC using 24 cancer biomarkers. Differences in IHC staining, relative to controls with a DTF of 1 hr, were observed in FFPE kidney tumor specimens after a DTF of ≥2 hr. Reductions in H-score and/or staining intensity were observed for c-MET, p53, PAX2, PAX8, pAKT, and survivin, whereas increases were observed for RCC1, EGFR, and CD10. Prolonged TIF of 72 hr resulted in significantly reduced H-scores of CD44 and c-Met in kidney tumor specimens, compared with controls with 12-hr TIF. An elevated probability of altered staining intensity due to DTF was observed for nine antigens, whereas for prolonged TIF an elevated probability was observed for one antigen. Results reported here and elsewhere across tumor types and antigens support limiting DTF to ≤1 hr when possible and fixing tissues in formalin for 12–24 hr to avoid confounding effects of these preanalytical factors on IHC.

通过免疫组织化学 (IHC) 分析福尔马林固定石蜡包埋 (FFPE) 组织在临床和研究实验室中很常见。然而，报告表明 IHC 结果可能会受到生物样本分析前因素的影响。美国国家癌症研究所的生物样本分析前变量计划进行了一项系统研究，以使用 24 种癌症生物标志物检查固定延迟 (DTF) 和固定时间 (TIF) 对 IHC 的潜在影响。在 DTF ≥ 2 小时后，在 FFPE 肾肿瘤标本中观察到 IHC 染色的差异，相对于 DTF 为 1 小时的对照。观察到 c-MET、p53、PAX2、PAX8、pAKT 和 survivin 的 H 分数和/或染色强度降低，而 RCC1、EGFR 和 CD10 观察到增加。与使用 12 小时 TIF 的对照相比，延长 72 小时的 TIF 导致肾肿瘤标本中 CD44 和 c-Met 的 H 评分显着降低。对于九种抗原，观察到由于 DTF 改变染色强度的概率升高，而对于延长的 TIF，观察到一种抗原的概率升高。此处和其他地方报告的跨肿瘤类型和抗原的结果支持将 DTF 限制在 ≤1 小时，并在福尔马林中固定组织 12-24 小时，以避免这些分析前因素对 IHC 的混杂影响。