Combined immunohistochemistry of β-catenin, cytokeratin 7, and cytokeratin 20 is useful in discriminating primary lung adenocarcinomas from metastatic colorectal cancer

Abstract

Background: It is important to discriminate between primary and secondary lung cancer. However, often, the discriminating diagnosis of primary lung acinar adenocarcinoma and lung metastasis of colorectal cancer based on morphological and pathological findings is difficult. The purpose of this study was to evaluate the clinical usefulness of immunohistochemistry of β-catenin, cytokeratin (CK) 7, and CK20 for the discriminating diagnosis of lung cancer. Methods:We performed immunohistochemistry of β-catenin, CK7, and CK20 in 19 lung metastasis of colorectal cancer samples, 10 corresponding primary colorectal cancer samples and 11 primary lung acinar adenocarcinoma samples and compared the levels of accuracy of the discriminating diagnosis by using antibodies against these antigens.Results: Positive staining of β-catenin was observed in all the lung metastasis of colorectal cancer samples as well as in the primary colorectal cancer samples but in none of the primary lung acinar adenocarcinoma samples. Positive staining of CK7 was observed in 90.9% of the primary lung acinar adenocarcinoma samples and in 5.3% of the lung metastasis of colorectal cancer samples, but in none of the primary colorectal cancer samples. Positive staining of CK20 was observed in all the primary colorectal cancer samples and in 84.2% of the lung metastasis of colorectal cancer samples, but in none of the primary lung acinar adenocarcinoma samples. Conclusion:Combined immunohistochemistry of β-catenin, CK7, and CK20 is useful for making a discriminating diagnosis between lung metastasis of colorectal cancer and primary lung acinar adenocarcinoma. This method will enable accurate diagnosis of a lung tumor and will be useful for selecting appropriate therapeutic strategies, including chemotherapeutic agents and operation methods.

Shifting trends of lung tumours and its diagnosis by lung biopsy: a study of 78 cases

“…[29][30][31][32] In case of adenocarcinoma, in the present study, CK-7 was positive in 100% cases, TTF-1 was positive in 84% of cases and CK-20 was positive in 16% of cases, which is in concordance to other studies. 29,[33][34][35] In case of small cell carcinoma, the present study showed 100% positivity with CD-56 and TTF-1 and 75% with NSE, which is similar to other studies. [36][37][38][39][40] …”

Lung adenocarcinoma: Sustained subtyping with immunohistochemistry and EGFR, HER2 and KRAS mutational status

“…25---32 All morphological registered patterns comprising this series of lung adenocarcinomas expressed CK7 positivity, without differences (p > 0.05), and predominant negativity for CK20, like other series published in the literature. 8,27,33,34 CK20 was expressed in 3 cases of primary lung adenocarcinoma, with expression of CK7 and TTF1.…”

“…With the exception of papillary and solid patterns, all the other patterns had intense expression suggesting that some patterns showing decreased expression of TTF1 can explain a small number of cases developing in pure CK7 positive (bronchial) cells. 27,28 It is a classical concern of pathologists to report a parameter related with tumour proliferation index and Ki67-MIB1 as a nuclear proliferation associated antigen expressed in cell cycle (G1,S,G2 and M) but not in the resting phase, G0, which provides information about the portion of active cells in the cell cycle. 37,38 Ki-67 expression by immunohistochemistry can be a prognostic marker allowing the prediction of post-operative survival in different types of cancer.…”

Bronchial-pulmonary adenocarcinoma subtyping relates with different molecular pathways

“…CK7 is positive in 90---100% and CK20 is positive in only 7---10% of primary lung adenocarcinomas. 39 Chromogranin A is not expressed in an ordinary adenocarcinoma.…”