Abstract

BACKGROUND
Making the distinction between large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC) is difficult in some samples of biopsy tissues, but we have to separate LCNEC from SCLC because the two types of cancer may need different therapy and they have different prognostic implications. Thus far, there are no specific immunohistochemical markers that allow distinguishing these two kinds of tumors.
METHODS
We performed an immunohistochemical analysis to study the expressions of p63, Bcl-2, and 34betaE12 and to investigate whether these 3 molecules have correlations in LCNEC and SCLC. We also evaluated the expression of the neuroendocrine markers chromogranin, synaptophysin and CD56.
RESULTS
A statistical analysis was performed for p63, Bcl-2, and 34betaE12 in separate and combined panels. According to the combinations of p63, Bcl-2, and 34betaE12, there were frequent expressions of p63-/Bcl-2+ or Bcl-2+/34betaE12- in the SCLC, and there was a superior proportion of them in the SCLC rather than that in the LCNEC. The p63-/Bcl-2+ and Bcl-2+/34betaE12- antibody combinations showed higher specificities compared to any single antibody for diagnosing SCLC.
CONCLUSIONS
Bcl-2 and selective p63 or 34betaE12 made up a most useful panel of markers for making the differential diagnosis of LCNEC and SCLC.

• Keywords: Large cell neuroendocrine carcinoma;Small cell lung carcinoma;p63;Bcl-2;34betaE12