Department of Pathology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Department of Thoracic and Cardiovascular Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Histopathology. 2017 Sep;71(3):437-445. doi: 10.1111/his.13237. Epub 2017 Jun 16.
Formalin fixation can cause tumour shrinkage. The aim of this study was to prospectively evaluate the effect of overnight formalin fixation on tumour size and the effect of clinicopathological parameters on changes in tumour size in small-sized non-small-cell lung cancer (NSCLC).
Our study included 126 surgically resected NSCLC specimens submitted in a fresh state. We measured the largest cross-sectional tumour diameters in the fresh and formalin-fixed specimens. Tumour size significantly differed (mean, 0.66 mm; P < 0.001) and was positively correlated (r = 0.982; P < 0.001) between fresh and formalin-fixed specimens. The percentage difference after fixation was 4.06%. Formalin fixation caused tumour shrinkage in 46.8%, tumour enlargement in 4.8%, and a tumour stage shift in 3.17%. The risk of a > 10% change in tumour size after formalin fixation was increased in tumours with a lepidic pattern [odds ratio (OR): 6.268; P = 0.001], in subsolid tumours (OR: 4.068; P = 0.011), and in the presence of adenocarcinoma in situ (AIS)/minimally invasive adenocarcinoma (MIA) histology (OR: 6.545; P = 0.003). Pleural dimpling lowered the risk of tumour size change after fixation (OR: 0.162; P = 0.019). On multivariate analysis, a lepidic pattern (OR: 4.601; P = 0.010) and AIS/MIA histology (OR: 4.381; P = 0.026) were still significant risk factors. Longer ischaemic time was the single risk factor for tumour shrinkage in the invasive adenocarcinoma subgroup (OR: 5.357; P = 0.021).
NSCLC tumours shrank or enlarged by 4.06% after overnight formalin fixation. A lepidic pattern and AIS/MIA histology were independent risk factors for both significant tumour shrinkage and growth after fixation. Longer ischaemic time was the single risk factor for significant tumour shrinkage in invasive adenocarcinoma.
福尔马林固定会导致肿瘤缩小。本研究旨在前瞻性评估过夜福尔马林固定对肿瘤大小的影响，以及临床病理参数对小细胞非小细胞肺癌（NSCLC）肿瘤大小变化的影响。
我们的研究纳入了 126 例新鲜切除的 NSCLC 标本。我们测量了新鲜和福尔马林固定标本中的最大肿瘤横截面积。肿瘤大小在新鲜和福尔马林固定标本之间存在显著差异（平均值为 0.66mm；P<0.001），且呈正相关（r=0.982；P<0.001）。固定后，肿瘤的百分比差异为 4.06%。福尔马林固定导致 46.8%的肿瘤缩小，4.8%的肿瘤增大，3.17%的肿瘤分期改变。福尔马林固定后肿瘤大小变化>10%的风险在具有鳞屑样模式的肿瘤中增加[优势比（OR）：6.268；P=0.001]，在亚实性肿瘤中增加（OR：4.068；P=0.011），在原位腺癌（AIS）/微浸润性腺癌（MIA）组织学中增加（OR：6.545；P=0.003）。脏层胸膜凹陷降低了固定后肿瘤大小变化的风险（OR：0.162；P=0.019）。多变量分析显示，鳞屑样模式（OR：4.601；P=0.010）和 AIS/MIA 组织学（OR：4.381；P=0.026）仍然是显著的危险因素。较长的缺血时间是浸润性腺癌亚组肿瘤缩小的唯一危险因素（OR：5.357；P=0.021）。
NSCLC 肿瘤在过夜福尔马林固定后缩小或增大 4.06%。鳞屑样模式和 AIS/MIA 组织学是固定后肿瘤显著缩小和生长的独立危险因素。较长的缺血时间是浸润性腺癌中肿瘤显著缩小的唯一危险因素。
