Department of Pathology & Neurosurgery, Sri Venkateswara Institute of Medical Sciences, Tirupati, India.
Indian J Med Res. 2017 Dec;146(6):738-745. doi: 10.4103/ijmr.IJMR_1179_15.
BACKGROUND & OBJECTIVES: Glioblastoma (GB) is the most frequent brain tumour, manifesting at any age, with a peak incidence between 45 and 75 years. Primary and secondary GBs constitute relatively distinct disease entities in evolution, in expression profiles and in therapeutic response. Histopathologically, primary and secondary GBs are indistinguishable. The aim of this investigation was to study the immunohistochemical (IHC) expression of p53 and epidermal growth factor receptor (EGFR) in GB with the objective of categorizing the morphological variants of GB into primary and secondary based on the presence of low-grade areas and knowing the variable expression of p53 and EGFR in primary and secondary GB.
A total of 28 patients with GB were studied and categorized into primary and secondary based on the presence of low-grade areas, i.e. discernible astrocytic morphology, gemistocyte and oligodendroglia. Tumours with the presence of combination of the above features or any one of the above features were taken as secondary GB, whereas tumours with highly pleomorphic areas were considered as primary GB. IHC was done on the representative tissue blocks for p53 and EGFR.
Majority of the patients were in the fifth and sixth decades of life with a mean age of 46.96±13 yr with male preponderance (male:female 2.5:1). Mean age of presentation was 48.93±12 yr in primary and 44.69±15 yr in secondary GB. All cases of GB were classified into primary (53.57%) and secondary (46.43%) based on morphology. EGFR was more frequently expressed than p53. Based on IHC, 50 per cent of cases were classified into primary, three per cent into secondary and 47 per cent as unclassified.
INTERPRETATION & CONCLUSIONS: Histopathological features, i.e. presence of low-grade areas, may play a role in classifying GB into primary and secondary. EGFR has a pivotal role in gliomagenesis. Combination of p53 and EGFR alone may not be sufficient to clarify GB into primary and secondary.
胶质母细胞瘤（GB）是最常见的脑肿瘤，可发生于任何年龄，但在 45 至 75 岁之间发病率最高。原发性和继发性 GB 在演化、表达谱和治疗反应方面是相对不同的疾病实体。组织病理学上，原发性和继发性 GB 无法区分。本研究旨在研究胶质母细胞瘤中 p53 和表皮生长因子受体（EGFR）的免疫组织化学（IHC）表达，目的是根据低级别区域的存在将 GB 的形态变异体分为原发性和继发性，并了解原发性和继发性 GB 中 p53 和 EGFR 的可变表达。
共研究了 28 例胶质母细胞瘤患者，并根据低级别区域（即可识别的星形胶质细胞形态、巨星形细胞瘤和少突胶质细胞瘤）的存在将其分为原发性和继发性。存在上述特征组合或任何一种特征的肿瘤被认为是继发性胶质母细胞瘤，而高度多形性区域的肿瘤被认为是原发性胶质母细胞瘤。对 p53 和 EGFR 的代表性组织块进行了免疫组化检测。
大多数患者年龄在 50 至 60 岁之间，平均年龄为 46.96±13 岁，男性居多（男：女为 2.5:1）。原发性和继发性胶质母细胞瘤的平均发病年龄分别为 48.93±12 岁和 44.69±15 岁。所有胶质母细胞瘤病例均根据形态学分为原发性（53.57%）和继发性（46.43%）。EGFR 的表达频率高于 p53。根据免疫组化，50%的病例被归类为原发性，3%的病例被归类为继发性，47%的病例为未分类。
组织病理学特征，即低级别区域的存在，可能在将胶质母细胞瘤分为原发性和继发性方面发挥作用。EGFR 在神经胶质瘤发生中起关键作用。单独使用 p53 和 EGFR 的组合可能不足以将胶质母细胞瘤分为原发性和继发性。
