Immunocytochemical characterization of lung tumors in fine-needle aspiration. The use of cytokeratin monoclonal antibodies for the differential diagnosis of squamous cell carcinoma and adenocarcinoma

Keratin expression in human tissues and neoplasms

Keratin expression in human tissues and neoplasms Keratin filaments constitute type I and type II intermediate filaments (IFs), with at least 20 subtypes named keratin 1-20. Since certain keratin subtypes are only expressed in some normal human tissues but not others, and vice versa, various tissues have been subclassified according to the pattern of keratin staining. Simple epithelia generally express the simple epithelial keratins 7, 18, 19, and 20, while complex epithelia express complex epithelial keratins 5/6, 10, 14, and 15. When an epithelium undergoes malignant transformation, its keratin profile usually remains constant. The constitution and expression patterns of keratin filaments in human epithelial neoplasms are complex and often distinctive. In this article, we first briefly review the molecular and cell biology of keratin filaments. We then focus on the expression patterns of keratin filaments in various human neoplasms.

The prognostic application of cytokeratin typing of nonsmall cell lung carcinoma. A retrospective study

BACKGROUND

In a previous study, the authors used a variety of anticytokeratin monoclonal antibodies to show that a large proportion of lung tumors cytologically diagnosed as squamous cell carcinoma contain cells expressing simple epithelial cytokeratins, suggesting that these tumors have their origin in adenocarcinoma. These findings raised the possibility that cytokeratin (CK) typing might have a diagnostic capacity not attainable by standard histopathology. The aim of the current study was to assess the value of CK typing for this purpose by determining the correlation between the diagnosis of lung tumors based on CK typing and the survival rate of the patients.

METHODS

Paraffin embedded tissue sections of 66 nonsmall cell lung carcinoma (NSCLC) specimens were examined. These included 18 adenocarcinomas, 32 squamous cell carcinomas, and 16 undifferentiated carcinomas, all diagnosed surgically and histopathologically, and further classified as either Stage I or II. CK typing was performed using the streptavidin-biotin-peroxidase method, employing the following anti-CK monoclonal antibodies: Ks.B.17 (which reacts with CK 18), A3-3 (which reacts with CK 13), and E5-9 (which reacts with CK 10).

RESULTS

Comparison between the 5-year survival rates (5 ysr) of patients with different NSCLC indicated that all types of Stage II tumors had a much poorer prognosis than Stage I tumors. Differences found in the 5 ysr among patients with different types of Stage I tumors were not statistically significant (adenocarcinomas, 33% 5 ysr; squamous cell carcinomas, 59% 5 ysr; undifferentiated carcinomas, 36% 5 ysr; all diagnosed by conventional histopathology). Similarly, no significant differences were noted in 5 ysr between patients with tumors stained positively or negatively with monoclonal antibodies A3-3 or E5-9 (anti-CK 13 and anti-CK 10, respectively). In contrast, highly significant differences (P = 0.002) were found in the 5 ysr between patients with Stage I tumors positively or negatively stained with monoclonal antibody Ks.B.17 (23% vs. 75% 5 ysr, respectively) regardless of the histologic types of tumors. Especially informative was a combination of immunohistochemical and histologic diagnoses, with best survival rates (87% 5 ysr) in Ks.B.17 negative tumors histologically diagnosed as Stage I squamous cell carcinomas and worst survival rates (14% 5 ysr) in Ks.B.17 positive tumors diagnosed as adenocarcinomas.

CONCLUSIONS

The current study showed that CK 18 typing of lung tumors can provide a more accurate diagnosis and therefore facilitate the planning of more suitable therapeutic approaches.

Flow cytometric analysis and cytokeratin typing of human lung tumors. A preliminary study

In the current study a comparative analysis of keratin typing and DNA content was carried out in human lung tumors from transthoracic fine needle aspiration biopsies (TFNAB) (18 patients) or from surgically resected tumor tissues (14 patients). According to the cytologic and histologic features, 2 of the 32 tumors were diagnosed as benign tumors, 11 as squamous cell carcinomas, 12 as adenocarcinomas, and 7 as undifferentiated large cell carcinomas. Two cases in the adenocarcinoma and one in the undifferentiated large cell carcinoma groups were pulmonary metastasis or second primary tumors. Malignant cells of tumors which reacted positively with KK8.60 anticytokeratin polypeptides No. 10 and 11 (and hence contain keratinizing cells) displayed diploid DNA content in a flow cytometric assay regardless of their cytologic or histologic appearance. In contrast, all tumors which lacked such positive cells (most of which were defined as adenocarcinomas and undifferentiated tumors) were hyperdiploid. The close correlation between high DNA content and both malignancy and the absence of advanced squamous differentiation (keratinization) suggests that such combined analysis may provide new tools for the cytologic diagnosis and prognosis of lung cancers.

Detection of tumor antigens with monoclonal antibodies: immunopathology and immunodiagnosis

The immunocytochemical demonstration, using monoclonal antibodies, of diverse cellular constituents has improved our understanding of many aspects of oncology. This review will focus on this approach to facilitate the detection of human tumors, improve their histological classification and provide functional parameters with potential aetiological, prognostic and/or therapeutic value.