Epidermal growth factor receptor mutation‐specific immunohistochemical antibodies in lung adenocarcinoma

Abstract

Immunohistochemistry using EGFR mutant-specific antibodies may be useful in shortening the diagnostic time of lung adenocarcinoma with most common EGFR mutations, especially in samples with low tumour cellularity.

Novel use for an EGFR mutation‐specific antibody in discriminating lung adenocarcinoma from reactive pneumocyte hyperplasia

“…By contrast, EGFR mutations were present in 43% of morphologically normal bronchial and bronchiolar epithelial tissue samples from lung ADCs with EGFR mutations, but none of them from ADCs without mutations . A recent analysis also revealed that some morphologically normal bronchial epithelial samples from lung ADCs carrying EGFR mutations were positive for a novel L858R‐specific antibody, which was not tested in the present study; however, 13 of the 16 cases (81%) were negative for this mutation according to sequencing . In addition, although the antibodies against L858R and E746_A750 have been shown to be highly specific, as we have mentioned in previous reports, they have some limitations; thus, they should be used meticulously, and a careful interpretation of the results is essential.…”

Cell block samples from malignant pleural effusion might be valid alternative samples for anaplastic lymphoma kinase detection in patients with advanced non‐small‐cell lung cancer

“…Because a tissue sample is difficult to obtain from such patients, thoracentesis provides a higher yield of malignant cells and is more available and less invasive than other diagnostic modalities. Cytological smear samples and cell‐free pleural fluid are also suitable for ALK rearrangement assays; however, cell blocks are preferred to smear preparations, because of the ability to correlate the findings with malignant cell content and the non‐overlapping tumour cells suitable for fluorescence in‐situ hybridization (FISH)/immunohistochemistry (IHC) analysis . Cell blocks are increasingly being used in diagnostic pathology as a complementary tool to fine needle aspiration biopsy or serous effusions …”

Current and future molecular diagnostics in non-small-cell lung cancer

“…Two antibodies targeting the most common EGFR mutations, L858R substitution (SP125) and E746-A750 deletion (SP111) have sensitivities of 76 and 83%, respectively and positive predictive values of 73 and 94%, respectively [126]. The suboptimal sensitivity prevents them to use for screening [126].…”

“…The suboptimal sensitivity prevents them to use for screening [126]. Nevertheless, the main advantage of these mutation-specific antibodies is to overcome some of the difficulties from polymerase chain reaction methods such as minimal sample materials in core biopsies and fine needle aspirates, low tumor cellularity due to contamination with non-neoplastic tissue because IHC staining can be performed on tiny tissue from biopsies and cytological specimens [126,127].…”