A case of different EGFR mutations in surgically resected synchronous triple lung cancer

Clinical Features and Surgical Treatment of Synchronous Multiple Primary Lung Adenocarcinomas With Different EGFR Mutations

Background

With the popularity of lung cancer screening and advances in imaging technology, more and more synchronous multiple primary lung adenocarcinomas (SMPLA) are being diagnosed clinically, however, the clinical characteristics and prognosis of SMPLA with different EGFR mutations remains unclear. We aimed to explore clinical features and surgical outcomes of these patients to aid in the diagnosis and treatment of SMPLA.

Methods

Medical records of patients with different EGFR mutations who have been diagnosed as SMPLA and underwent surgical resection from March 2015 to December 2019 were retrospectively analyzed. Clinical characteristics, surgical outcomes, recurrence-free survival (RFS) and overall survival (OS) were investigated.

Results

A total of 70 patients (68.6% female and 77.1% non-somkers) were included. Total of 161 lesions in all patients, 84.4% were ground-glass opacity (GGO) lesions. EGFR mutations were detected in 108 lesions, most of which were L858R (35.4%) and 19Del (20.5%). The mutation rate of mixed GGO is significantly higher than that of pure GGO and solid nodules (SN); the mutation rate of invasive adenocarcinoma is significantly higher than that of other histology subtypes; the mutation rate of lesions >20 mm was significantly higher than that of ≤20 mm. However, there is no significant difference in the mutation rate of specific driver gene between different radiological features, pathological characteristics and sizes. After a median follow-up time of 29 months, the 3-year OS and RFS were 94.4% and 86.0%, respectively.

Conclusions

A high discordance of EGFR mutations were identified between tumors in patients with SMPLA. Synchronous multiple lung adenocarcinomas with predominantly multiple GGO should be considered as SMPLA, and surgery may be aggressively performed for these patients due to a good prognosis.

Recent Advances in the Diagnosis and Management of Multiple Primary Lung Cancer

With the wide application of computed tomography in lung cancer screening, the incidence of multiple primary lung cancer (MPLC) has been increasingly reported. Despite the established criteria, the differentiation between MPLC and intrapulmonary metastasis remains challenging. Although histologic features are helpful in some circumstances, a molecular analysis is often needed. The application of next-generation sequencing could aid in distinguishing MPLCs from intrapulmonary metastasis, decreasing ambiguity. For MPLC management, surgery with lobectomy is the main operation method. Limited resection does not appear to negatively affect survival, and it is a reasonable alternative. Stereotactic ablative radiotherapy (SABR) has become a standard of care for patients refusing surgery or for those with medically inoperable early-stage lung cancer. However, the efficacy of SABR in MPLC management could only be found in retrospective series. Other local ablation techniques are an emerging alternative for the control of residual lesions. Furthermore, systemic therapies, such as targeted therapy for oncogene-addicted patients, and immunotherapy have shown promising results in MPLC management after resection. In this paper, the recent advances in the diagnosis and management of MPLC are reviewed.

Surgically Resected Second Primary Lung Adenocarcinoma After Pembrolizumab Administration

Non-small cell lung cancer (NSCLC) patients are sometimes referred for thoracic surgical consultation to address the possibility of resecting second primary lung cancer. We report a case of pulmonary resection for second primary lung adenocarcinoma after 3 cycles of pembrolizumab under circumstances in which the primary metastatic lung adenocarcinoma was controlled. The tumor statuses, including programmed death-ligand 1, epidermal growth factor receptor, and CD8+ tumor-infiltrating lymphocytes, were different between the surgically resected specimen and the previously biopsied sample. Surgery should be considered for second primary NSCLC in cases in which the primary NSCLC are well controlled with immune checkpoint inhibitors.