Risk Factors for Recurrence of Stage I Epidermal Growth Factor Receptor Mutated Lung Adenocarcinoma

Longitudinal Analysis of Recurrence and Risk Factors of Early-Stage Resected Adenocarcinoma With Common EGFR Mutations: A Multicenter Retrospective Cohort Study in South Korea

INTRODUCTION

Despite curative surgery for lung cancer, 30% to 55% of patients experience recurrence or death, which highlights the importance of adjuvant treatment. Adjuvant osimertinib therapy effectively prolongs disease-free and overall survival in patients with lung cancer harboring common epidermal growth factor receptor (EGFR) mutations. To identify potential candidates for adjuvant osimertinib, it is crucial to understand the rates and identify risk factors of recurrence.

METHODS

This multicenter, retrospective cohort study was conducted in the Republic of Korea and enrolled patients who, between 2010 and 2017, underwent resection of stages I-III adenocarcinomas, with common EGFR mutations. The primary outcomes comprised the rate and risk factors of postoperative recurrence.

RESULTS

Among the 759 participants, the overall recurrence rate and median recurrence-free survival were 39.1% and 59.8 (interquartile range [IQR], 26.3-84.2) months, respectively, during a median follow-up of 73.0 (IQR, 55.4-95.0) months. The recurrence rates for stages IA, IB, IIA, IIB, IIIA, and IIIB were 14.7%, 45.5%, 53.8%, 72.5%, 80.3%, and 93.3%, respectively. Multivariate analysis revealed that age ≥ 65 years, body mass index < 18.5 kg/m², the Del19 subtype of EGFR mutation, tumor size ≥ 2.3 cm, N1 involvement, N2 involvement, predominantly micropapillary or solid pattern, and the presence of visceral pleural invasion were independently associated with recurrence.

CONCLUSION

This multicenter cohort study demonstrated that stages I-III EGFR-mutated adenocarcinoma has a postoperative recurrence rate of 39.1%, and identified 7 independent risk factors for recurrence.

Oncological characteristics of epidermal growth factor receptor-mutated clinical stage IA lung adenocarcinoma with radiologically pure-solid appearance

OBJECTIVES

We evaluated the clinicopathological and oncological characteristics of epidermal growth factor receptor-mutated clinical stage IA radiological pure-solid lung adenocarcinoma and compared them with those of a ground-glass opacity component.

METHODS

Between 2008 and 2020, data from 1014 surgically resected clinical stage 0-IA epidermal growth factor receptor-mutated lung adenocarcinomas were evaluated. Oncological outcomes were assessed using multivariable analysis. Overall survival was estimated using Kaplan-Meier analysis and the log-rank test. The cumulative incidence of recurrence was estimated using the Gray's test.

RESULTS

Of these, 233 (23%) were radiologically pure-solid tumors, which demonstrated a higher proportion of nodal metastasis, micropapillary component, spread through alveolar space, and Ex19 subtype compared with those of tumors with ground-glass opacity (P < .001). Multivariable analysis revealed that the presence of ground-glass opacity was an independently significant factor for overall survival (P = .037) and cumulative incidence of recurrence (P < .001). In cases where the oncological outcomes were stratified by the presence of ground-glass opacity component, the 5-year overall survival was excellent at more than 90% in tumors with ground-glass opacity despite clinical-T categories (P = .2044); however, tumor size significantly affected survival only in pure-solid tumors (T1a, 100%; T1b, 77.7%; T1c, 68.5%; P = .0056). Furthermore, the cumulative incidence of recurrence was low in tumors with ground-glass opacity despite the clinical-T categories, whereas tumor size significantly affected the cumulative incidence of recurrence only in pure-solid tumors (5-year cumulative incidence of recurrence: T1a-b, 18.9%; T1c, 41.3%; P < .001).

CONCLUSIONS

Oncologic behavior and prognosis of radiologically pure-solid tumors were significantly poorer than those of tumors with ground-glass opacity among patients with epidermal growth factor receptor-mutated early-stage lung adenocarcinoma. These findings imply distinct tumorigenesis based on the presence of ground-glass opacity, even in tumors with epidermal growth factor receptor mutations.