Abstract
Background Less invasive adenocarcinomas (LIAs) of the lung, including adenocarcinoma in situ
(AIS) and minimally invasive adenocarcinoma (MIA), are indications of sublobar resection
and has a 5-year disease-free survival rate of almost 100% after surgery. By distinguishing
invasive adenocarcinoma from LIA with computed tomography (CT) characteristics, it
is possible to determine the extent of resection and prognosis for patients with ground-glass
nodules (GGNs) before surgery.
Methods We reviewed CT and pathological findings of 728 GGNs in 645 consecutive patients
who received curative lung resection in a single center. Only AIS, MIA, and invasive
adenocarcinoma were included. Characteristics of CT, including maximum diameter of
the lesion (L
max) and maximum diameter of the consolidation (C
max), were assessed thoroughly.
Results Multivariate logistic regression showed that larger L
max (p < 0.001) and nonsmooth margin (p = 0.001) were independent factors for invasive adenocarcinoma in pure GGNs (pGGNs).
The optimal cut-off value of L
max was 12.0 mm. In mixed GGNs (mGGNs), multivariate analysis revealed that larger L
max (p < 0.001), larger C
max (p = 0.032), and vacuole sign (p = 0.007) were predictive factors for invasive adenocarcinoma, and the area under
curve of regression model was 0.866. The optimal cut-off values of L
max and C
max were 15.4 and 5.8 mm, respectively. No node metastasis was found in 295 patients
who had at least three stations of mediastinal lymph nodes dissected.
Conclusion In pGGNs, larger L
max (>12.0 mm) and nonsmooth margin were reliable predictors for invasive adenocarcinoma.
In mGGNs, lesions with larger L
max (>15.4 mm), larger C
max (>5.8 mm), and vacuole sign were more likely to be invasive adenocarcinoma.
Keywords
computed tomography - ground-glass nodules - lung adenocarcinoma
