Molecular Biology of Lung Carcinosarcoma: A Review of the Literature

Abstract

Lung Carcinosarcoma (LCS) is a rare, malignant aggressive biphasic tumor with an unfavorable prognosis, high mortality rate, and is composed of a mixture of epithelial and mesenchymal elements. The epithelial or carcinomatous element is most commonly squamous followed by adenocarcinoma, whereas the mesenchymal or sarcomatous element commonly contains the main component of the tumor and shows poorly differentiated spindle cell characteristics. Moreover, other foci of differentiated sarcomatous elements such as chondrosarcoma and osteosarcoma may be observed. LCS accounts for less than 0.1% of all lung cancers, has a poor prognosis due to late diagnosis and early metastases. It has been estimated that the median survival time is 9 (3-25) months, a prognosis poorer than other non-small cell lung carcinomas (NSCLC). According to the most recent 2015 World Health Organization (WHO) classification, pleomorphic carcinoma, giant cell carcinoma, lung blastoma, spindle cell carcinoma, and carcinosarcoma consist a heterogeneous category of primary lung cancer accounting from 0.3% to 3% of all primary lung malignancies, known as lung sarcomatoid carcinoma, depending on the observed morphology. Although genetic mutations of some common lung cancer subtypes have been extensively investigated, the molecular characteristics of LCS and the existence of abnormal target genes still remain unknown.