Prognostic factors for stage I lung adenocarcinoma and surgical management of subsolid nodules

Background: This study aims to identify the prognostic factors for stage I lung adenocarcinoma and to evaluate the surgical management of subsolid nodules. Methods: The study included 133 patients (90 males, 43 females; mean age 64.9 years; range, 29 to 82 years) who had undergone operation in our clinic for stage I lung adenocarcinoma between January 2007 and December 2015. Clinical, radiological and pathological data were retrospectively evaluated and their effects on recurrence and survival were examined by Kaplan-Meier and Cox regression analyses. Results: Comparing the histopathological tumor types according to the pathological tumors size, we determined that the prevalence of invasive adenocarcinoma significantly increased with increasing tumor size (p<0.001). For all nodules, a tumor disappearance rate lower than 25% negatively influenced disease-free survival and a maximum standardized uptake value higher than 5.6 negatively influenced overall survival (p=0.027 for both). The grouping, which was performed considering the maximum standardized uptake value 5.6 as the cut-off value, was an independent prognostic factor for overall survival (hazard ratio: 5.973, 95% confidence interval: 1.186-30.073, p=0.03). Five-year overall survival rate was statistically significantly higher in patients who underwent wedge resection or segmentectomy for subsolid nodules compared to those who underwent lobectomy (100% vs. 79.3%, p=0.044). Conclusion: Sublobar resections can be safely performed in subsolid nodules smaller than 2 cm in diameter with tumor disappearance rate >= 2.5% and maximum standardized uptake value <= 5.6.