Abstract
Abstract
Objectives
The prognosis of invasive mucinous adenocarcinoma has not been well investigated because of its rarity, especially with regard to early-stage disease. This study aimed to compare the prognosis of early-stage invasive mucinous adenocarcinoma with that of non-mucinous adenocarcinoma and to clarify oncologic characteristics of early-stage invasive mucinous adenocarcinoma.
Methods
Patients with pathological stage IA lung adenocarcinoma, excluding pT1mi tumors, who underwent surgery at three institutions were retrospectively examined. Overall survival and recurrence-free survival were compared between patients with invasive mucinous adenocarcinoma and non-mucinous adenocarcinoma. Propensity score matching was applied to reduce baseline imbalances.
Results
Among the 1228 patients, 1128 had non-mucinous adenocarcinoma and 100 had invasive mucinous adenocarcinoma. Before matching, invasive mucinous adenocarcinoma was significantly associated with smaller pathological whole tumor size, larger pathological invasive tumor size and a lower frequency of lymphovascular invasion. The 5-year overall survival rates were 92.5% and 92.7%, and the 5-year recurrence-free survival rates were 87.5% and 92.3% in patients with invasive mucinous and non-mucinous adenocarcinoma, respectively. Baseline covariates including pathological tumor size and stage were generally balanced after matching. The 5-year overall survival rates were 90.4% and 92.7%, and the 5-year recurrence-free survival rates were 83.7% and 93.3%, respectively, with no significant differences in survival curves between groups.
Conclusions
The postoperative prognosis of patients with pathological stage IA invasive mucinous adenocarcinoma was comparable to that of patients with non-mucinous adenocarcinoma. These findings suggest that mucinous histology alone should not be considered an adverse prognostic factor in early-stage disease.