Objective:

To evaluate the relationship between International Association for the Study of Lung Cancer (IASLC) classification system and traditional computed tomography (CT) imaging features

and to construct a hierarchical prognosis model based on CT imaging features.

Methods:

The study retrospectively analyzed the medical records of 102 consecutive patients with primary pathological (p) stage I (T1N0M0 or T2aN0M0) LUAD in Nanjing Chest Hospital from January 2019 to May 2022. According to the 2020 IASLC grading system

patients were classified and the clinical pathological and imaging features were compared between different IASLC histological grades

as well as between recurrent and non recurrent groups. Logistic regression analysis was used to determine CT signs related to IASLC grading

and to determine influencing factors for disease-free survival (DFS) of patients through a multivariate Cox regression model.

Results:

A total of 102 patients with LUAD were divided into grade 1 (15 cases

14.7%)

grade 2 (63 cases

61.8%) and grade 3 (24 cases

23.5%). During the 30.4 months follow-up

16 patients (15.7%) relapsed. Higher CTR (OR=2.152

95% CI 1.530-3.264

P

=0.005) and higher CT value (OR=3.730

95% CI 2.841-6.353

P

=0.001) were independent risks of higher histological grade. The AUC value for conjoining the above two independentfactors to predict grade 3 was 0.912 (95% CI 0.877-0.937

P

＜0.001)

and it was not significantly different from the AUC for using the mean CT value or CTR alone. Multivariate Cox regression analysis showed age (HR=1.05

95% CI 1.02-1.09

P

=0.003)

CTR (HR=2.81

95% CI 1.16-6.77

P

=0.022)

CT value (HR=2.49

95% CI 2.30-15.43

P

0.001) and histological grade (HR=4.31

95% CI 2.28-8.14

P

＜0.001) were independent risk factors for DFS.

Conclusion:

Larger CTR and higher average CT value are independent predictors of higher IASLC histological grade. CTR (truncation values＜0.25 and ≥0.75) and average CT values (truncation values＜-410 HU and ≥-210 HU) can be used as preoperative substitutes for IASLC grading system.