What a Chest CT Study Reveals About Ground-Glass Opacities and Recurrence with Lung Adenocarcinoma

For patients undergoing lobectomy or pneumonectomy for the treatment of lung adenocarcinoma, the presence of ground-glass opacity (GGO) adenocarcinoma in pre-op computed tomography (CT) imaging is associated with reduced recurrence and risk of brain metastasis in patients with clinical stage I disease, and a nearly 15 percent higher overall survival rate overall in comparison to solid adenocarcinoma.

For the retrospective study, recently published in Radiology, researchers reviewed data from 1,019 patients (mean age of 62) who had chest CT exams prior to surgical treatment of lung adenocarcinoma. According to the study, 487 patients had GGO adenocarcinoma, and 532 patients had solid adenocarcinoma.

The researchers found that 36.1 percent of patients with solid adenocarcinoma on pre-op chest CT had recurrence in comparison to 16.2 percent of patients with GGO adenocarcinoma. Overall five-year survival rates were 14.5 percent higher for patients with GGO adenocarcinoma (92.3 percent) versus patients with solid adenocarcinoma (77.8 percent), according to the study authors. The study also revealed that patients with GGO adenocarcinoma had a median time to recurrence (50.2 months) that was eight months longer than those who had solid adenocarcinoma (42.2 months).

For patients with clinical stage I disease, the researchers noted that 69.1 percent of patients with solid adenocarcinoma had distant metastases (including 16.5 percent of patients who developed brain metastasis) in comparison to 54.9 percent of patients who had GGO adenocarcinoma (including brain metastasis in 7.8 percent of patients). In the GGO adenocarcinoma group, the study authors added that all regional recurrences were comprised of ipsilateral lung metastasis without metastasis in regional lymph nodes.

“Knowing the common sites of recurrence according to GGO presence and clinical stage may help radiologists read imaging examinations without missing lesions in patients under surveillance for recurrence and facilitate the establishment of personalized surveillance strategies or selection of candidates for adjuvant therapy based on the risk of specific recurrence patterns,” wrote Joon Beom Seo, M.D., Ph.D., a professor of radiology at the University of Ulsan College of Medicine and the Department of Radiology at the Asan Medical Center in Seoul, Korea, and colleagues.

(Editor’s note: For related content, see “Can Dual-Energy CT Have an Impact in Differentiating Primary Lung Cancer and Pulmonary Metastases?,” “Nine Takeaways from Recent Meta-Analysis on Lung Cancer Screening with Low-Dose CT” and “New Computed Tomography Study Shows High 20-Year Survival Rates for Early-Stage Lung Cancer.”)

For patients with clinical stage II disease or higher, the study authors found those with solid adenocarcinoma had a 17.1 percent higher incidence of recurrence, a 19.2 percent higher incidence of distant metastasis and a 15.3 higher incidence of contralateral lung metastasis than patients with GGO adenocarcinoma.

In regard to study limitations, the authors acknowledged a high frequency of variable epidermal growth factor receptor (EGFR) and favorable prognosis in data that was drawn from one ethnic group at one institution. They added that the association with recurrence patterns for EGFR and anaplastic lymphoma kinase (ALK) could not be evaluated due to missing variation status for both in many of the patients in the study cohort. Seo and colleagues also noted that two radiologists assessed GGO presence and only one observer performed tumor measurements and recurrence pattern analysis.