Abstract
BACKGROUND: Patients with small (⩽ 2 cm) invasive lung adenocarcinoma are at high risk of poor prognosis and disease recurrence after complete surgical resection. Therefore, identification of high-risk individuals from these patients emerges as an urgent problem. Elevated MACC1 expression predicts a poor prognosis in multiple types of cancer that are independent of TNM staging. This study investigated the prognostic value of MACC1 expression in patients with small invasive lung adenocarcinoma. OBJECTIVE: The current study aimed to evaluate the relationship between MACC1 expression in patients' tumor tissue and prognosis in small invasive lung adenocarcinoma. METHODS: The records of 131 patients with small invasive lung adenocarcinoma who underwent complete surgical resection were reviewed. The MACC1 expression was detected by immunohistochemical staining in all specimens. Meanwhile, western blot and real-time quantitative PCR were used to examine the expression level of MACC1 in human lung adenocarcinoma cell lines. The effect of clinicopathological risk factors on patients' survival was analyzed using the Kaplan-Meier approach and multivariable Cox models. RESULTS: Elevated MACC1 expression was observed in 53 (40.5%) specimens, and in A549, H358, H460 and H322 lung adenocarcinoma cell lines. MACC1 overexpression was associated with differentiation (P= 0.005) and blood vessel invasion (P= 0.001). Compared with low MACC1 expression, elevated MACC1 expression was associated with significantly shorter overall survival (odds ratio = 6.515; 95% confidence interval: 1.382-30.721; P= 0.018) and disease-free survival (odds ratio = 3.270; 95% confidence interval: 1.117-9.569; P= 0.031). Multivariate analyses demonstrated high MACC1 expression is an independent risk factor of worse overall survival (odds ratio = 5.684; 95% confidence interval: 1.145-28.210; P= 0.034) and disease-free survival (odds ratio = 4.667; 95% confidence interval: 1.372-15.877; P= 0.014). CONCLUSION: MACC1 is an independent prognostic marker in patients with small invasive lung adenocarcinoma after complete surgical resection. Differential outcomes are associated with MACC1 expression level.