Pan-Driver-Negatives <i>versus</i> Epidermal Growth Factor Receptor Mutants for C-Stage IA Lung Adenocarcinoma with Ground-Glass Opacity

Prevalence, clinical and molecular characteristics of early stage EGFR-mutated lung cancer in a real-life West-European cohort: Implications for adjuvant therapy

OBJECTIVES

The landmark ADAURA study recently demonstrated a significant disease-free survival benefit of adjuvant osimertinib in patients with resected EGFR-mutated lung adenocarcinoma. However, data on prevalence rates and stage distribution of EGFR mutations in non-small cell lung cancer in Western populations are limited since upfront EGFR testing in early stage lung adenocarcinoma is not common practice. Here, we present a unique, real-world, unselected cohort of lung adenocarcinoma to aid in providing a rationale for routine testing of early stage lung cancers for EGFR mutations in the West-European population.

MATERIAL AND METHODS

We performed routine unbiased testing of all cases, regardless of TNM stage, with targeted next-generation sequencing on 486 lung adenocarcinoma cases between 01- January 2014 and 01 February 2020. Clinical and pathological data, including co-mutations and morphology, were collected. EGFR-mutated cases were compared to KRAS-mutated cases to investigate EGFR-specific characteristics.

RESULTS

In total, 53 of 486 lung adenocarcinomas (11%) harboured an EGFR mutation. In early stages (stage 0-IIIA), the prevalence was 13%, versus 9% in stage IIIB-IV. Nine out of 130 (7%) stage IB-IIIA patients fit the ADAURA criteria. Early stage cases harboured more L858R mutations (p = 0.02), fewer exon 20 insertions (p = 0.048), fewer TP53 co-mutations (p = 0.007), and were more frequently never smokers (p = 0.04) compared to late stage cases with EGFR mutations. The KRAS-mutated cases were distributed more evenly across TNM stages compared to the EGFR-mutated cases.

CONCLUSION

As (neo-)adjuvant targeted therapy regimes enter the field of lung cancer treatment, molecular analysis of early stage non-small cell lung cancer becomes relevant. Testing for EGFR mutations in early stage lung adenocarcinoma holds a substantial yield in our population, as our number needed to test ratio for adjuvant osimertinib was 14.4. The observed differences between early and late stage disease warrant further analysis to work towards better prognostic stratification and more personalised treatment.

The comparison of Lobe-Specific or Systematic Mediastinal Lymph Node Dissection for Early-Stage Lung Adenocarcinoma With Consolidation Tumor Ratio Over 0.5

INTRODUCTION

Surgery is the most effective treatment for early-stage lung cancer. This study will propose a personalized plan for mediastinal lymph node dissection in early-stage lung adenocarcinoma to reduce the risk of surgery and improve the quality of life.

METHODS

This study retrospectively analyzed the patients underwent lobectomy and lymph node dissection in the Department of Thoracic Surgery, Zhongshan Hospital, Fudan University. Clinical stage I lung adenocarcinoma patients with solid component ratio (CTR) between 0.5 and 1 were included. Patients were divided into systematic (S-MLND) and lobe-specific (L-MLND) mediastinal lymph node dissection groups. The days of hospitalization, the presence or absence of complications, the recurrence-free survival rate, and the overall survival rate were calculated to evaluate the postoperative quality and operation risk of the patients.

RESULTS

210 patients (138 L-MLND and 72 S-MLND) were included. 2 lymph node metastases appeared in the S-MLND group while none in the L-MLND group (P = .049). No differences were shown in age, tumor site, size, solid component, degree of tumor invasion, and stage. The proportion of patients with severe postoperative cough and the length of hospital stay in the L-MLND group decreased. The 5-year OS of the entire cohort was 98.1%, 98.6% in L-MLND, compared with 97.2% in S-MLND; RFS was 94.8%, 95.7% in L-MLND, compared with 93.0% in S-MLND.

CONCLUSION

For cIA lung adenocarcinoma, according to the Thin-slice CT within 1 month before the operation, if the main lesion was less than 3 cm and CTR over 0.5, L-MLND is as effective as S-MLND.