Can image analysis on high-resolution computed tomography predict non-invasive growth in adenocarcinoma of the lung?

Prognostic impact of highly solid component in early-stage solid lung adenocarcinoma

Background

Based on computed tomography (CT) findings of lung cancer, solid nodules have a much worse prognosis than subsolid nodules, even if the nodules are subcentimeter in size. There is, however, no systematic method for determining the prognosis of solid tumors on CT. This study aimed to discover the prognostic factor of early-stage solid lung adenocarcinoma using three-dimensional CT volumetry.

Methods

Patients with pathological stage I solid lung adenocarcinoma who underwent complete resection between 2007 and 2012 were selected in this retrospective study. Clinicopathological data and preoperative multidetector CT findings, such as tumor size on the two-dimensional axial image, three-dimensional tumor volume between -600 and 199 HU, and three-dimensional solid volume between 0 and 199 HU, which corresponded to highly solid components, were compared between recurrence and non-recurrence. Furthermore, these radiological values were compared to pathological invasive volume (PIV).

Results

During this time, 709 patients had their lung cancer completely removed. From this cohort, 90 patients with pathological stage I solid lung adenocarcinoma were selected. In addition, recurrence was found in 26 patients (28.9%). Although two-dimensional axial image, serum carcinoembryonic antigen (CEA) level, and SUVmax on 18F fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) did not differ statistically between recurrent and non-recurrent patients, three-dimensional tumor and solid tumor volume did. Multivariate analysis indicated that three-dimensional solid tumor volume [hazard ratio: 2.440; 95% confidence interval (CI): 1.110-5.361, P=0.026] and epidermal growth factor receptor (EGFR) mutation (hazard ratio: 4.307; 95% CI: 1.328-13.977, P=0.015) were significantly associated with disease-free survival (DFS). When three-dimensional tumor and solid tumor volume were compared to PIV, three-dimensional solid tumor volume (3,091 mm3 on average) showed a highly similar value with PIV (2,930 mm3 on average), whereas three-dimensional tumor volume (6,175 mm3 on average) was significantly larger than PIV (P<0.001).

Conclusions

In patients with early-stage solid lung adenocarcinoma, the measurement of three-dimensional solid tumor volume, which is correlated with PIV, accurately predicted the postoperative outcome.

Impact of ground glass opacity in a three-dimensional analysis for pathological findings and prognosis in stage IA pure solid lung cancer

BACKGROUND

We investigated whether a three-dimensional (3D) analysis could correct the discrepancy between conventional computed tomography findings and pathological findings and contribute to prognostic stratification in early pure solid lung cancer.

METHODS

A total of 370 patients with two-dimensional (2D) pure solid, clinical stage IA non-small cell lung cancer (NSCLC) who underwent complete resection at our hospital between January 2010 and March 2021 were included in the present study. We classified the patients into the 3D solid group and the 3D ground glass opacity (GGO) group according to the consolidation volume/tumor volume ratio (C/T volume ratio) measured using a Synapse Vincent 3D analysis workstation, and compared the pathological findings and prognosis between the two groups.

RESULTS

There were 142 (38.4%) patients in the 3D GGO group. Lepidic lesions were significantly more frequent in the 3D GGO group (27.6% vs. 59.2%, P<0.001). Lymphatic invasion, vascular invasion and lymph node metastasis were significantly more frequent in the 3D solid group (52.2% vs. 27.5%, P<0.001; 67.5% vs. 43.0%, P<0.001; 22.3% vs. 11.2%, P=0.04). A Cox proportional hazards multivariate analysis for overall survival (OS) and recurrence-free survival (RFS) showed that 3D solid was an independent poor prognostic factor [hazard ratio (HR): 1.981, P=0.02; HR: 1.815, P=0.02]. Kaplan-Meier curves for 5-year OS (74.1% vs. 87.8%, P<0.001) and 5-year RFS (65.6% vs. 84.9%, P<0.001) showed significant differences between the two groups.

CONCLUSIONS

The C/T volume ratio determined by a 3D analysis detects GGO and reflects the pathological findings, and further prognostic stratification is possible in early 2D pure solid lung cancer.

Correlation and significance of COX-2, Ki67, VEGF and other immune indexes with the growth of malignant pulmonary nodules

Objective

This study intends to explore the factors affecting the growth of pulmonary nodules in the natural process by immunohistochemical method.

Methods

40 cases of pulmonary nodules followed up for more than 3 years were divided into growth group (n = 20) and stable group (n = 20). The expressions of cyclooxygenase-2 (COX-2), Ki67, vascular endothelial growth factor (VEGF), CD44V6, epidermal growth factor receptor (EGFR), double microsome 2 (MDM2) and transforming growth factor (TGF)-β1 in pulmonary nodules were detected by immunohistochemical method so as to explore the relationship between it and the growth of pulmonary nodules.

Results

Compared with stable pulmonary nodules, the positive rates of COX-2, Ki67 and VEGF in the growth group were 85%, 80% and 55%, respectively. There was significant difference between the stable group and the growth group (P < 0.05). The correlation between other indexes and the growth of pulmonary nodules was not statistically significant (Pcd44v6 = 0.104;PEGFR = 0.337; PMDM2 = 0.49; PTGF-β1 = 0.141). In the subgroup of patients with non-invasive lung cancer, there was a correlation between VEGF and the growth of pulmonary nodules (P < 0.05).

Conclusion

The high expression of COX-2, Ki67 and VEGF proteins may be significantly related to the growth of pulmonary nodules, and VEGF may be an important factor affecting the growth of malignant pulmonary nodules. This study intends to provide a research direction for further searching for the essential causes of the growth of pulmonary nodules.

The "solid" component within subsolid nodules: imaging definition, display, and correlation with invasiveness of lung adenocarcinoma, a comparison of CT histograms and subjective evaluation

OBJECTIVE

To validate three proposed definitions of the "solid" component of subsolid nodules, as compared to CT histograms and the use of different window settings, for discriminating the invasiveness of adenocarcinomas in a manner that facilitates routine clinical assessment.

METHODS

We retrospectively analyzed 328 pathologically confirmed lung adenocarcinomas, manifesting as subsolid nodules. Three-dimensional CT histograms were generated by setting 11 CT attenuation intervals from - 400 to 50 HU, at 50 HU intervals, and the voxel percentage within each CT attenuation interval was generated automatically. Three definitions of the "solid" component were proposed, and 10 medium window settings were set to evaluate the "solid" component. The diagnostic performance of the three definitions for identifying invasive adenocarcinoma was compared with that of CT histogram analysis and subjective evaluation with medium window settings.

RESULTS

A parallel diagnosis using five intervals with the largest AUC (AUC ≥ 0.797) demonstrated good differential diagnostic performance, with 78% sensitivity and 73.7% specificity. Definition 2 (visibility in the mediastinum window) yielded higher accuracy (75.6%) than the other two definitions (p < 0.01). A medium window setting of - 50 WL/2 WW gave a larger AUC than the other nine medium window settings as well as definition 2, with 82.5% specificity and 88.5% PPV, which was higher than those of parallel diagnosis with CT histogram and definition 2.

CONCLUSION

Using - 50 WL/2 WW is the optimum approach for evaluating the "solid" component and discriminating invasiveness, superior to using 3D CT histograms and definition 2, and convenient in routine clinical assessment.

KEY POINTS

• - 50 WL/2 WW gave a larger AUC than definition 2. • The specificity of - 50 WL/2 WW was higher than CT histograms. • - 50 WL/2 WW offers the best evaluation of the solid component.