Learning objectives
To describe CT features of the primary tumor and patterns of pulmonary metastases in positive Epidermal Growth Factor Receptor (EGFR) mutation status lung adenocarcinoma.
Identify common EGFR mutations in patients with disseminated intrapulmonary carcinomatosis.
Background
Lung adenocarcinomas are characterized by distinct genomic changes that allow further classification into clinically relevant molecular subsets, qualifying them as important molecular target in cancer therapy. Specifically, the discovery of epidermal growth factor receptor (EGFR) mutations is associated with a dramatic clinical response to the EGFR tyrosine kinase inhibitors (EGFR TKIs) - erlotinib, gefitinib, afatinib and osimertinib.
Clinically this type of mutation is associated with non-smoking status, female gender and East Asian ethnicity3.
Computed tomography (CT) imaging features in EGFR mutated adenocarcinomas may help identify...
Findings and procedure details
Population study:
We analyze pre-treatment CT scan of histologically proven stage IV lung adenocarcinoma patients who tested positive for EGFR mutations (exons 18-21), by polymerase chain reaction and direct DNA sequencing methods.
A total of 68 cases (39 women and 29 men), diagnosed at our institution between 2010 and 2019, were retrospectively reviewed.
[Table 1] resumes CT features analyzed:
Primary tumor:
-Main tumors were evaluated for location (central or peripheral), margins (spiculated/non spiculated) and morphology, being divided into three types, specifically nodular lesions (≤30mm), masses...
Conclusion
Current guidelines advocate routine molecular testing for all patients with advanced adenocarcinoma or those with disease recurrence or progression3.
When there is only limited tissue samples, or even in cases when patient frailty rules out the possibility of biopsy, a non-invasive procedure to increase the pre-test probability for EGFR mutation analysis would be advantageous. The presence of a dominant primary lung mass associated with diffuse lung metastases should raise suspicion for the presence of EGFR mutation. Therefore, the radiologist must determine which patients may potentially...
Personal information and conflict of interest
V. Carvalho; Lisbon/PT - nothing to disclose J. M. Veiga; Lisbon/PT - nothing to disclose S. Alfarroba; Lisbon/PT - nothing to disclose C. A. S. Ruano; Lisbon/PT - nothing to disclose A. Araujo; Lisbon/PT - nothing to disclose
References
1.Subba R. Digumarthy et al., Diffuse Lung Metastases in EGFR-Mutant Non-Small Cell Lung Cancer; Cancers 2019, 11, 1360.
2.Hsu F., Adenocarcinoma of the Lung with Miliary Metastases and Primary Resistance Exon 20 Mutations. Cureus 10(10): e3533, October 2018
3.Planchard D. et al., Metastatic non-small cell lung cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up, Volume 29, Supplement 4, October 2018.
4.Su Jin Hong et al., Radiogenomic correlation in lung adenocarcinoma with epidermal growth factor receptor mutations: Imaging features and histological subtypes; Eur Radiol,...