Clinical significance of cancer-associated fibroblasts and their correlation with microvessel and lymphatic vessel density in lung adenocarcinoma

Background To determine whether cancer-associated fibroblasts (CAFs) are associated with microvessel density (MVD) and lymphatic vessel density (LVD) in lung adenocarcinoma (ADC) or are not prognostic. Methods Ninety-three lung adenocarcinoma patients without adjuvant therapy between January 2010 and June 2011 were enrolled. CAFs, MVD, and LVD were identified by alpha-smooth muscle actin (alpha-SMA), CD34 and D2-40 staining via immunohistochemistry. Staining intensities were assessed and quantified. For statistics, Pearson's chi-square test, logistic regression, Kaplan-Meier, and log-rank tests were applied. In addition, the Cox proportional hazards model was used for multifactor analysis to predict survival. Results CAFs abundance in lung adenocarcinoma is associated with higher MVD and LVD. In addition, a correlation was demonstrated between MVD and LVD (P < 0.05). CAFs, MVD, and LVD are significantly correlating with age, tumor size, differentiation grade, clinical stage, and lymph node metastasis (P < 0.05), but not influenced by gender, tumor location, and smoking history. Three-year overall survival in the CAFs-poor group is 64.5%, which is significant higher than that in the CAFs-rich cohort (41.9%). Further, we found that age, clinical stage, alpha-SMA, CD34, D2-40 positivity, tumor size, differentiation grade, and lymph node metastasis significantly correlate with overall survival of patients with lung adenocarcinoma. However, sex, smoking history, and tumor location have no association with 3-year survival. The clinical stage is an independent prognostic factor in overall survival (P < 0.05). Conclusions The density of CAFs identified by alpha-SMA staining is associated with progression and metastasis of lung adenocarcinoma and affects the patient's disease outcome.