RESUMO
<p><b>OBJECTIVE</b>To detect the cancer stem cells and to evaluate their prognostic implication in patients with lung adenocarcinoma.</p><p><b>METHODS</b>Three phenotypic markers of cancer stem cells (SP-C, CCSP and OCT4) in lung adenocarcinoma were detected by immunofluorecence staining. The correlation among the clinicopathological parameters and phenotypes of cancer stem cells as well as survival were analyzed by Cox proportional hazard method.</p><p><b>RESULTS</b>Of the 57 cases, cancer stem cells were detected in 52, including OCT4(+) bronchioloalveolar stem cell (BASC) phenotype (SP-C(+) CCSP(+) OCT4(+)) in 40 cases and OCT4(-) BASC phenotype (SP-C(+) CCSP(+) OCT4(-)) in 12 cases. Statistical analysis revealed that the phenotype of cancer stem cells was related with the cellular differentiation, i.e. the OCT4(+) BASC phenotype occurred more frequently in the well-differentiated tumors, while the OCT4(-) BASC phenotype usually presented in most of the poorly-differentiated ones. Cox analysis showed that the OCT4(+) BASC phenotype was one of prognostic factors.</p><p><b>CONCLUSION</b>The lung adenocarcinoma stem cells have phenotypic features of bronchioalveolar stem cells (SP-C(+) CCSP(+)). The expression of self-renewal regulatory gene OCT4 in these cells indicates an aggressive nature and unfavorable prognosis.</p>