Increased risk of recurrence in resected EGFR-positive pN0M0 invasive lung adenocarcinoma

The Prognostic Impact of Epidermal Growth Factor Receptor Mutation in Clinical Stage I Lung Adenocarcinoma

BACKGROUND

This study investigated the prognostic impact of epidermal growth factor receptor (EGFR) mutation in clinical stage I lung adenocarcinoma patients.

METHODS

Data for 952 patients who received surgical resection and underwent detection of oncogenic driver mutations were retrospectively collected. Recurrence-free survival (RFS) and overall survival (OS) were estimated by the Kaplan-Meier method and compared using the log-rank test. The adjusted hazard ratio (aHR) with 95% CI of the prognosticator was calculated by Cox proportional hazards model, and cumulative incidence function was measured by competing risk regression model.

RESULTS

EGFR mutation was detected in 581 patients (61.0%) and was more frequent in women (63.9%), nonsmokers (85.5%), and those with ground-glass nodules (GGNs; 56.6%). EGFR mutation was not associated with recurrence and death in the entire cohort or GGN cohort. However, for patients with radiologic pure-solid appearance, EGFR mutation was an independent risk factor for RFS (aHR, 1.623; 95% CI, 1.192-2.210) and distant recurrence (aHR, 1.863; 95% CI, 1.311-2.650), but not OS. Subsequently, subgroup analysis based on EGFR mutation subtypes, including exon 19 deletions (19-Del), exon 21 L858R substitution (L858R), and rare mutations in patients with radiologic pure-solid appearance, revealed that all 3 subtypes have poorer RFS (19-Del: aHR, 1.424; 95% CI, 0.991-2.047; L858R: aHR, 1.708; 95% CI, 1.172-2.490; rare mutations: aHR, 2.500; 95% CI, 1.400-4.465) and higher prevalent distant recurrence (19-Del: aHR, 1.595; 95% CI, 1.061-2.400; L858R: aHR, 2.073; 95% CI, 1.371-3.140; rare mutations: aHR, 2.657; 95% CI, 1.397-5.050) compared with wild-type.

CONCLUSIONS

In clinical stage I lung adenocarcinoma, EGFR mutation was associated with worse RFS and higher prevalent distant recurrence in patients with radiologic pure-solid appearance but not in patients with GGN.

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

BACKGROUND

We aimed to clarify the risk factors for postoperative recurrence in patients with epidermal growth factor receptor (EGFR)-mutated stage I lung adenocarcinoma, using EGFR wild-type adenocarcinoma as a comparator, to select optimal candidates for adjuvant therapy with EGFR tyrosine kinase inhibitor (TKI).

METHODS

Data of patients with pathologic stage I EGFR-mutated (n = 713) and wild-type (n = 673) adenocarcinoma who did not receive adjuvant therapy were retrospectively analyzed. The cumulative incidence of recurrence (CIR) was estimated using Gray's method, and multivariable Fine-Gray competing risk models identified independent risk factors associated with recurrence.

RESULTS

The CIR did not differ significantly between patients with EGFR-mutated and wild-type adenocarcinoma (P = .32). Multivariable analysis revealed that greater size (cm) of invasive tumor (hazard ratio 1.539; 95% CI, 1.077-2.201), lymphovascular invasion (hazard ratio 5.180; 95% CI, 2.208-12.15), pleural invasion (hazard ratio 3.388; 95% CI, 1.524-7.533), and high-grade histologic subtype (hazard ratio 4.295; 95% CI, 1.539-11.99) were independent risk factors for recurrence in patients with EGFR-mutated adenocarcinoma. The 5-year CIR was significantly higher among patients with these factors (tumor size greater than 2 cm, 15.9%; lymphovascular invasion, 26.9%; pleural invasion, 39.3%; and high-grade subtype, 44.4%) than among patients without them (4.4%, 2.2%, 3.9%, and 5%, respectively; P < .001). For patients with EGFR wild-type adenocarcinoma, independent risk factors for recurrence were invasive tumor size, lymphovascular invasion, and pleural invasion, but not histologic subtypes.

CONCLUSIONS

Even for patients with EGFR-mutated stage I lung adenocarcinoma, recurrence risk is stratified. Adjuvant therapy may be considered if they have high-risk factors for recurrence.

Prognosis of recurrence after complete resection in early-stage lung adenocarcinoma based on molecular alterations: a systematic review and meta-analysis

Molecular biomarkers have the potential to predict the recurrence risk of early-stage lung adenocarcinoma (LUAD) after complete resection, but the study results are controversial. We aimed to clarify the association of molecular alterations with disease-free survival (DFS) and recurrence-free survival (RFS) in early-stage LUAD with R0 resection. Comprehensive searches were conducted in PubMed/MEDLINE, Web of Science, and Cochrane Library for this systematic review and meta-analysis with date restrictions from 2012 to 2022. In the 18 included studies, data from a total of 7417 participants in 11 studies and 4167 participants in 9 studies were collected for the EGFR and KRAS meta-analyses, respectively. Two studies were assessed as having a moderate risk of bias, and the others were all assessed as having a high individual risk of bias. The molecular alterations in KRAS rather than EGFR, were associated with a high risk of recurrence for early-stage LUAD patients suffering from R0 resection, especially for those in pStage I, the pooled hazard ratios (HRs) of KRAS were 2.71 (95% CI, 1.81-4.06; I2 = 22%; P < 0.00001) and 1.95 (95% CI, 1.25-3.20; I2 = 57%; P = 0.003) with small interstudy heterogeneity in univariate and multivariate analyses, respectively. This finding suggests that molecular alterations in KRAS that could be detected by polymerase chain reaction techniques would provide new insight into stratifying risk and personalizing patient postoperative follow-up.

Distribution and prognostic impact of EGFR and KRAS mutations according to histological subtype and tumor invasion status in pTis-3N0M0 lung adenocarcinoma

BACKGROUND

The prognostic impact of EGFR mutation as major targetable somatic gene variant on lung adenocarcinoma is controversial. KRAS is another major somatic variant in lung adenocarcinoma, and a therapeutic agent for KRAS G12C became available in clinical settings. These mutations represent clinicopathological features of lung adenocarcinoma and can guide the treatment choice after recurrence. We evaluated the prognostic impact of EGFR and KRAS mutations by considering other clinicopathological recurrence risks in resected pTis-3N0M0 lung adenocarcinoma.

METHODS

Clinicopathological features related to recurrence and genetic status were estimated in consecutive 877 resected cases. Recurrence-free survival (RFS), cumulative recurrence rate (CRR), and overall survival (OS) were compared. Uni- and multivariate analyses for RFS were performed after excluding cases with little or no recurrence risks.

RESULTS

EGFR mutation was more likely to be harbored in female, never-smoker, or patients accompanied by > 5% lepidic component. KRAS mutation was more likely to be harbored in patients with current/ex-smoking history, International Association for the Study of Lung Cancer (IASLC) grade 3, or accompanied lymphatic or vascular invasion. In IASLC grade 2 and 3 patients, EGFR or KRAS mutation cases had significantly worse 5-year RFS than wild type patients (76.9% vs. 85.0%, hazard ratio [HR] = 1.55, 95% confidence interval [CI] = 1.62-6.41, P < 0.001). EGFR or KRAS mutation cases had significantly higher 5-year CRR than wild type patients (17.7% vs. 9.8%, HR = 1.69, 95% CI = 1.44-6.59, P = 0.0038). KRAS mutation cases had higher 5-year CRR than EGFR mutation cases (16.7% vs. 21.4%, HR = 1.62, 95% CI = 0.96-7.19, P = 0.061). There was no significant difference in OS between cohorts. Multivariate analysis revealed that a positive EGFR/KRAS mutation status was risk factor for worse RFS (HR = 2.007, 95% CI = 1.265-3.183, P = 0.003).

CONCLUSION

Positive EGFR and KRAS mutation statuses were risk factors for recurrence in resected IASLC grade 2 and 3 patients. KRAS mutations were more likely to be confirmed in cases with an increased risk of recurrence. EGFR and KRAS mutation statuses should be evaluated simultaneously when assessing the risk of recurrence.

Factors affecting outcome in resected EGFR-mutated lung cancer

INTRODUCTION

Long-term data on disease trajectory of EGFR-mutated early-stage non-small cell lung cancer (NSCLC) is still limited. This is relevant in the context of the recently approved introduction of adjuvant EGFR-targeting therapy, specifically osimertinib in resected stage II-III EGFR-mutated NSCLC.

METHODS

Long-term data on patients with resected adenocarcinoma of the lung and known EGFR-status were analysed with focus on site of relapse and detailed cause of death. Patients resected in the period 2006 to 2018 were included.

RESULTS

Of 503 patients (286 (57%) females, median age 67.3 years), 62 (12%) harboured an EGFR-mutation, 286 (57%) were in stage I. After a median follow-up of 8.0 years, 241 (48%) patients relapsed. Recurrence occurred in 30% and 53% of EGFR-positive stage IA and IB patients, respectively. Median overall survival was longer in EGFR-mutated versus non-mutated patients (128 versus 88 months). The recurrence rate, time to recurrence and rate of brain metastases was not different between EGFR-mutated and non-mutated groups. Median time from recurrence to death was longer in EGFR-mutated patients (31 months) compared with non-mutated patients (15 months). More patients without EGFR-mutation succumbed to non-cancer related death (18%) compared to patients with EGFR-mutations (8%).

CONCLUSIONS

The recurrence pattern in EGFR-mutated and non-mutated NSCLC-patients is similar and the rate is high in early stages. Time from recurrence to death and overall survival is longer in the EGFR-mutated group, due to lower risk of non-lung cancer deaths, and efficient treatment upon relapse.

Real-World Survival Outcomes Based on EGFR Mutation Status in Chinese Patients With Lung Adenocarcinoma After Complete Resection: Results From the ICAN Study

Introduction

The adjuvant treatment of patients with resected lung adenocarcinoma (LUAD) remains unstandardized. We analyzed the survival outcomes of these patients based on EGFR mutation status and adjuvant chemotherapy treatment.

Methods

This noninterventional real-world study (ICAN) enrolled Chinese patients with resected stages I to III LUAD from April 8, 2010, to December 31, 2010. Tumor EGFR mutation status and 3-year disease-free survival (DFS) were determined. The extension phase provided long-term follow-up with overall survival (OS) as the primary end point. Secondary end points included DFS and prognostic factors of survival. Survival outcomes based on adjuvant chemotherapy treatment, EGFR mutation status, and postoperative stage were analyzed post hoc.

Results

Among 568 patients in the ICAN cohort, 472 continued to the extension phase and remained eligible. The 3-year DFS rate was 58.8%. In the extension cohort, 260 patients (55.1%) had EGFR-mutant disease and 207 (43.9%) received adjuvant chemotherapy. At a median follow-up of 109.0 (95% confidence interval [CI]: 106.6–111.4) months, median OS and DFS were 103.3 (95% CI: 101.7–104.9) and 67.4 (95% CI: 49.7–85.2) months, respectively. The 5-year OS and DFS rates were 68.9% (95% CI: 64.3–73.6) and 52.9% (95% CI: 48.2–57.7), respectively. EGFR wild-type disease was a significant independent predictor of worse OS (HR = 1.24, 95% CI: 1.07–1.44, p= 0.004) based on the Cox regression analysis of common factors. Post hoc subgroup analysis revealed that survival outcomes were not significantly different with adjuvant chemotherapy regardless of EGFR mutation status across all postoperative stages.

Conclusions

EGFR mutations are common in operable LUAD, and recurrence and mortality after resection were considerable. Adjuvant chemotherapy did not improve survival outcomes, regardless of EGFR mutation status and postoperative stage.

Association of Clinicopathologic and Molecular Tumor Features With Recurrence in Resected Early-Stage Epidermal Growth Factor Receptor-Positive Non-Small Cell Lung Cancer

IMPORTANCE

The recently published ADAURA study has posed a significant dilemma for clinicians in selecting patients for adjuvant osimertinib. Risk factors for recurrence in early-stage epidermal growth factor receptor (EGFR)-positive non-small cell lung cancer (NSCLC) also remain undefined.

OBJECTIVE

To determine clinicopathologic characteristics and recurrence patterns of resected early-stage EGFR-positive NSCLC, using wildtype EGFR as a comparator cohort, and identify features associated with recurrence.

DESIGN, SETTING, AND PARTICIPANTS

This is a cohort study including patients diagnosed with AJCC7 Stage IA to IIIA NSCLC between January 1, 2010, and June 30, 2018, who underwent curative surgical procedures at a specialist cancer center in Singapore. The cutoff for data analysis was October 15, 2020. Patient demographic characteristics, treatment history, and survival data were collated. In exploratory analysis, whole-exome sequencing was performed in a subset of 86 patients. Data were analyzed from September 3, 2020, to June 6, 2021.

EXPOSURES

Adjuvant treatment was administered per investigator's discretion.

MAIN OUTCOMES AND MEASURES

The main outcome was 2-year disease-free survival (DFS).

RESULTS

A total of 723 patients were included (389 patients with EGFR-positive NSCLC; 334 patients with wildtype EGFR NSCLC). There were 366 women (50.6%) and 357 men (49.4%), and the median (range) age was 64 (22-88) years. A total of 299 patients (41.4%) had stage IA NSCLC, 155 patients (21.4%) had stage IB NSCLC, 141 patients (19.5%) had stage II NSCLC, and 125 patients (17.3%) had stage IIIA NSCLC. Compared with patients with wildtype EGFR NSCLC, patients with EGFR-positive NSCLC were more likely to be women (106 women [31.7%] vs 251 women [64.5%]) and never smokers (121 never smokers [36.2%] vs 317 never smokers [81.5%]). At median (range) follow up of 46 (0-123) months, 299 patients (41.4%) had cancer recurrence. There was no statistically significant difference in 2-year DFS for EGFR-positive and wildtype EGFR NSCLC (70.2% [95% CI, 65.3%-74.5%] vs 67.6% [95% CI, 62.2%-72.4%]; P = .70), although patients with EGFR-positive NSCLC had significantly better 5-year overall survival (77.7% [95% CI, 72.4%-82.1%] vs 66.6% [95% CI, 60.5%-72.0%]; P = .004). Among patients with EGFR-positive NSCLC, 2-year DFS was 81.0% (95% CI, 74.0%-86.3%) for stage IA, 78.4% (95% CI, 68.2%-85.6%) for stage IB, 57.1% (95% CI, 43.7%-68.4%) for stage II, and 46.6% (95% CI, 34.7%-57.7%) for stage IIIA. Overall, 5-year DFS among patients with stage IB through IIIA was 37.2% (95% CI, 30.1%-44.3%). Sites of disease at recurrence were similar between EGFR-positive and wildtype EGFR NSCLC, with locoregional (64 patients [16.5%] vs 56 patients [16.8%]), lung (41 patients [10.5%] vs 40 patients [12.0%]), and intracranial (37 patients [9.5%] vs 22 patients [6.6%]) metastases being the most common. A risk estimation model incorporating genomic data and an individual patient nomogram using clinicopathologic features for stage I EGFR-positive NSCLC was developed to improve risk stratification.

CONCLUSIONS AND RELEVANCE

This cohort study found that recurrence rates were high in early-stage EGFR-positive NSCLC including stage IA, yet 37.2% of patients with stage IB through IIIA were cured without adjuvant osimertinib. Further studies are needed to elucidate individualized surveillance and adjuvant treatment strategies for early-stage EGFR-positive NSCLC.

Clinicopathologic features and prognostic value of epidermal growth factor receptor mutation in patients with pT1a and pT1b invasive lung adenocarcinoma after surgical resection

Background

Previous studies have evaluated the prognostic value of epidermal growth factor receptor (EGFR) mutation in different subgroups of lung adenocarcinoma, but there remains controversial on this issue. We conduct this study aimed to reveal the prognostic value of EGFR mutation in patients with pT1a and pT1b invasive lung adenocarcinoma.

Methods

From August 2009 to February 2015, 338 patients with pT1a and pT1b invasive lung adenocarcinoma who underwent EGFR mutation analysis were enrolled into this study. According to clinicopathologic and radiologic characteristics, survival analysis was conducted in different subgroups using Kaplan-Meier methods and Cox regression models.

Results

EGFR mutation was detected in 216 (63.9%) patients. In the entire cohort, EGFR mutation was significantly frequent in female (P=0.011), never smoking (P=0.014) patients, patients with part-solid nodules (P=0.005) and patients with lepidic pattern-predominant adenocarcinoma (LPA)/acinar pattern-predominant adenocarcinoma (APA)/papillary pattern-predominant adenocarcinoma (PPA) (P=0.005). No difference in recurrence-free survival (RFS) was seen between patients harboring EGFR mutation and patients without EGFR mutation in the entire cohort (P=0.664) and the subgroup cohorts. Patients with EGFR mutation had a longer overall survival (OS) compared with patients without EGFR mutation in the entire cohort (P=0.005) and the subgroups of N0 stage cohort (P=0.013), N1–2 stage cohort (P=0.033), APA/PPA/invasive mucinous adenocarcinoma (IMA) cohort (P=0.011) and pT1b cohort (P=0.002). Tyrosine kinase inhibitors (TKIs) could significantly prolong the OS in patients with EGFR mutation after recurrence (P=0.04).

Conclusions

EGFR mutation was not a risk factor for recurrence of patients with pT1a and pT1b invasive lung adenocarcinoma.

Prognostic influence of epidermal growth factor receptor mutation and radiological ground glass appearance in patients with early-stage lung adenocarcinoma

OBJECTIVES

The ADAURA demonstrated the efficacy of osimertinib as adjuvant therapy in patients with resected stage IB-IIIA adenocarcinoma harboring epidermal growth factor receptor (EGFR) mutations. However, it is controversial whether adjuvant therapy should be applied to all these patients because of their heterogeneities. This study aimed to examine the influence of GGO and EGFR mutations on the prognosis and to identify optimal targets for the development of perioperative therapy.

MATERIAL AND METHODS

Among the patients who underwent complete resection between 2003 and 2014 and had pathological stage IA3-IIA adenocarcinoma, 505 consecutive patients were examined for EGFR mutation status. The prognosis was analyzed among the clinicopathological factors including EGFR status and presence or absence of GGO.

RESULTS

Of the 489 patients, 193 (39.5%) showed EGFR mutations. The recurrence-free survival (RFS) and overall survival (OS) of the EGFR mutant were slightly better than those of the EGFR wild type. There was no difference in RFS and OS between EGFR mutant and wild type in patients with GGO; however, EGFR mutant showed better OS than EGFR wild type in patients without GGO. The presence of GGO was a strong independent prognostic predictor in OS and RFS, but EGFR mutations was not predictors. In patients without GGO, EGFR mutants showed slightly higher recurrence, especially with a hazard ratio of 1.427 in stage IB.

CONCLUSIONS

Adenocarcinoma with GGO show a very good prognosis, so may not require adjuvant therapy. It will be necessary to further develop perioperative therapy in patients with poor prognosis.

Sensitivity and optimal clinicopathological features for mutation-targeted liquid biopsy in pN0M0 EGFR-mutant lung adenocarcinoma

PURPOSE

Liquid biopsy for early-stage lung cancer diagnosis is challenging, and optimal candidates' clinicopathological features are unknown. We investigated utility and clinicopathological features of optimal candidates in somatic mutation-targeted liquid biopsy using droplet digital polymerase chain reaction (ddPCR) in pN0M0 EGFR mutation-positive lung adenocarcinoma patients.

METHODS

We performed EGFR mutation-targeted ddPCR liquid biopsy in 100 patients with resected pN0M0 invasive lung adenocarcinoma, whose tumor diameter in high-resolution computed tomography (HRCT) was ≤ 5 cm. Peripheral blood-derived serum was collected preoperatively. Two representative EGFR somatic variants (exon 19 [E746-A750 del (2235_2249 del)]; exon 21 (L858R)) were utilized as liquid biopsy targets. Clinicopathological features including radiological appearance, subhistology, and invasive status were compared between ddPCR-positive and ddPCR-negative patients.

RESULTS

Among the 100 patients, 98 showed part-solid or pure-solid appearance in HRCT and 2 showed non-solid appearance; 98 were pathological stage IA1-IB. Of the 66 patients with EGFR mutation detection in ddPCR, 12 were significantly positive and 10 (83.3%, 10/12) exhibited pure-solid appearance in HRCT. Clinical invasive tumor ratio was significantly higher in ddPCR-positive than in ddPCR-negative patients (median: 100% vs. 85.4%, P = 0.0212), whereas other clinicopathological features were not significantly different.

CONCLUSION

Mutation-targeted liquid biopsy using ddPCR detected lung cancer in 12.0% (12/100) of pN0M0 EGFR-mutant lung adenocarcinoma patients. In 83.3% of the ddPCR-positive patients, tumors showed pure-solid appearance in HRCT. The detection ratio increased to 21.3% (10/47) among patients with pure-solid appearance tumors. Tumor appearance might be useful for better selection of liquid biopsy candidates.

Transition of Treatment for Ground Glass Opacity-Dominant Non-Small Cell Lung Cancer

Lobectomy has been the standard surgical treatment for non-small cell lung cancer (NSCLC). Over the decades, with the dramatic development of radiographic tools, such as high-resolution computed tomography (HRCT), and the widespread practice of low-dose helical CT for screening, the number of cases diagnosed with small-cell lung cancers with ground glass opacity (GGO) at early stages has been increasing. Accordingly, mainly after 2000, many retrospective studies and prospective trials have shown that patients with lung adenocarcinoma with GGO have a good prognosis and may be candidates for sublobar resection. Previous studies indicated that HRCT findings including the maximum diameter of the tumor, GGO ratio, and a consolidation/tumor ratio (CTR) are simple and useful tools to predict tumor invasiveness and prognosis in patients with NSCLC with GGO. Thus, sublobar resection may be considered a “standard therapy” for peripheral GGO-dominant small-cell lung adenocarcinomas. Ultimately, some of such tumors might not require surgical resection. A multicenter, prospective study has just begun in Japan to evaluate the validity of follow-up for small-sized GGO-dominant small-cell lung cancer. Lung cancers that do not require surgery should be identified. This study reviewed retrospective and prospective studies on GGO tumors and discussed the treatment strategies for such tumors.

Development and external validation of a composite immune-clinical prognostic model associated with EGFR mutation in East-Asian patients with lung adenocarcinoma

BACKGROUND

EGFR mutation is a common oncogene driver in East Asians with lung adenocarcinoma (LUAD), conferring a favorable prognosis with effective targeted therapy. However, the EGFR mutation is a weak predictor of long-term survival. Therefore, a powerful predictive tool is urgently needed to estimate disease prognosis and patient survival for East-Asian patients with LUAD.

METHODS

In this first systematic analysis of the relationships among EGFR mutation, immunophenotype, and prognosis in LUAD samples from East-Asian patients, we constructed a prognostic signature consisting of EGFR-associated immune-related gene pairs (EIGPs). The predictive performance for overall survival (OS) and the clinical significance of this signature were then comprehensively investigated.

RESULTS

Based on transcriptome data analysis of a training set, we proposed the EIGP index (EIGPI), represented by five EIGPs, which was significantly associated with the OS of East-Asian patients with LUAD. It was also well validated in a test set. Furthermore, the prognostic performance of the EIGPI was further verified using protein levels in an additional independent set. Stratification analysis and multivariate Cox regression analysis revealed that the EIGPI was an independent prognostic factor. When combined with stage, the composite immune-clinical prognostic model index (ICPMI) showed improved prognostic accuracy in all datasets.

CONCLUSION

This study was the first to systematically investigate the relationships among EGFR mutation, immunophenotype, and prognosis in East Asians with LUAD and develop a composite clinical and immune model associated with EGFR mutation. This model may be a reliable and promising prognostic tool and help further personalize patient management.

Comprehensive analysis of the clinicopathological features, targetable profile, and prognosis of mucinous adenocarcinoma of the lung

PURPOSE

The clinicopathological or genetic features related to the prognosis of mucinous adenocarcinoma are unknown because of its rarity. The clinicopathological or targetable features were investigated for better management of patients with mucinous adenocarcinoma of the lung.

METHODS

We comprehensively evaluated the clinicopathological and genetic features of 60 completely resected mucinous lung adenocarcinomas. Targetable genetic variants were explored using nCounter and polymerase chain reaction, PD-L1 and TTF-1 expression were evaluated using immunohistochemistry. We analyzed the prognostic impact using the Kaplan-Meier method and log-rank test.

RESULTS

Of the 60 enrolled patients, 13 (21.7%) had adenocarcinoma in situ/minimally invasive adenocarcinoma, and 47 (78.3%) had invasive mucinous adenocarcinoma (IMA). Fifteen patients (25%) showed a pneumonic appearance on computed tomography (CT). CD74-NRG1 fusion, EGFR mutations, and BRAF mutation were detected in three (5%), four (6.7%), and one (1.7%) patient(s), respectively. KRAS mutations were detected in 31 patients (51.7%). Two patients (3.5%) showed immunoreactivity for PD-L1. No in situ or minimally invasive cases recurred. IMA patients with pneumonic appearance had significantly worse recurrence-free survival (RFS) and overall survival (OS) (p < 0.001). Furthermore, IMA patients harboring KRAS mutations had worse RFS (p = 0.211). Multivariate analysis revealed that radiological pneumonic appearance was significantly associated with lower RFS (p < 0.003) and OS (p = 0.012). KRAS mutations served as an unfavorable status for RFS (p = 0.043).

CONCLUSION

Mucinous adenocarcinoma had a low frequency of targetable genetic variants and PD-L1 immunoreactivity; however, KRAS mutations were frequent. Pneumonic appearance on CT imaging and KRAS mutations were clinicopathological features associated with a worse prognosis.

Prognostic value of epidermal growth factor receptor gene mutation in resected lung adenocarcinoma

BACKGROUND

Mutation of the EGFR gene is known as a predictor for the response to EGFR tyrosine kinase inhibitor. Although EGFR mutation status is proposed to be incorporated in the Ninth Edition of the Lung Cancer Staging system, its prognostic value for surgically resected lung adenocarcinoma remains controversial.

METHODS

Data on 1512 patients with completely resected lung adenocarcinoma who underwent EGFR mutation analysis between 2008 and 2015 were collected. The prognostic value of EGFR mutations was determined in patients with lung adenocarcinoma stratified by clinicopathologic and radiologic characteristics. Independent prognostic factors were identified by multivariate analysis using the Cox proportional hazards model. Competing risk model was used to estimate the cumulative incidence.

RESULTS

EGFR mutations were identified in 935 patients (61.8%). In the entire cohort, there was no difference in recurrence-free survival between the EGFR-mutated group and the wild-type group (P = .266). However, Cox multivariate analyses revealed that EGFR mutation was a strong independent prognostic factor for worse recurrence-free survival in patients with radiologic solid tumors (hazard ratio, 1.485; 95% confidence interval, 1.208-1.826; P < .001), histologic acinar pattern-predominant adenocarcinoma/papillary pattern-predominant adenocarcinoma/invasive mucinous adenocarcinoma (hazard ratio, 1.684; 95% confidence interval, 1.330-2.132; P < .001), and pathologic stage II and III (hazard ratio, 1.417; 95% confidence interval, 1.115-1.801; P = .004). Patients with EGFR mutations developed significantly more brain (hazard ratio, 1.827; 95% confidence interval, 1.213-2.766; P = .004) and bone (hazard ratio, 1.724; 95% confidence interval, 1.131-2.631; P = .011) metastases compared with the wild-type cohort.

CONCLUSIONS

EGFR mutation was a strong poor prognostic factor in patients with radiologic solid, histologic acinar pattern-predominant adenocarcinoma/papillary pattern-predominant adenocarcinoma/invasive mucinous adenocarcinoma, and pathologic stage II and III lung adenocarcinomas. After surgery, distinct metastatic patterns were revealed according to EGFR mutation status. These findings have implications for the upcoming new lung cancer staging system.

The role of EGFR mutations in predicting recurrence in early and locally advanced lung adenocarcinoma following definitive therapy

Introduction: Roughly one third of new non-small cell lung cancer (NSCLC) is diagnosed at early stages. While lobectomy can improve mortality in this group, about 30–55% of patients will experience disease recurrence. Increased investigation into the factors affecting recurrence, particularly tumor molecular genetics such as EGFR mutations, is needed.

Materials and Methods: We conducted a single-center retrospective study of 282 patients with early or locally advanced lung adenocarcinoma, with or without EGFR mutations, who underwent definitive therapy. We then assessed recurrence, stage at recurrence, time to recurrence and progression-free survival (PFS).

Results: We identified 142 patients with EGFR-mutated and 140 EGFR-wildtype lung adenocarcinoma. Overall progression between groups was equivalent at ~40% at 5 years; no difference in PFS was observed at any time-point. However, among those who recurred, EGFR-mutated lung cancer had increased rates of metastatic recurrence compared to EGFR-wildtype disease (97% vs 68%, p = 0.007).

Conclusions: EGFR-mutated disease may be associated with a higher risk of metastatic recurrence. Molecular testing may be a promising tool for risk stratification and surveillance following definitive management for early stage disease. Future prospective, multi-center cohort studies are needed to confirm these findings and improve our understanding of how EGFR mutation contributes to prognosis and clinical outcomes.

Positive EGFR mutation status is a risk of recurrence in pN0-1 lung adenocarcinoma when combined with pathological stage and histological subtype: A retrospective multi-center analysis

OBJECTIVES

Recurrence risk of resected lung adenocarcinoma is represented by pathological stage (pStage), histological subtype, and potentially by EGFR mutation. However, the relationship among these factors and their combined impact on prognosis are unclear.

MATERIALS AND METHODS

Using a multicenter database, we retrospectively investigated the prognostic impact of EGFR mutation status in relation to pStage and histological subtype in resected pN0-1M0 lung adenocarcinoma.

RESULTS

Among 1155 pN0-1M0 adenocarcinoma cases, pStage 0 and IA1-IB were confirmed predominantly in EGFR-positive cases. AIS, MIA, and lepidic predominant adenocarcinoma were also more frequently found in EGFR-positive cases and showed no/little recurrence regardless of EGFR mutation status. The 5-year recurrence-free survival (RFS) of papillary, acinar, solid, and micropapillary predominant adenocarcinoma was stratified by pStage (IA1-IB, IIA-IIIA) or histological malignant subtype (intermediate or high malignant subtype), and more finely subdivided by EGFR mutation status. Positive EGFR mutation cases showed worse RFS in both classifications. Low malignant subtype and pStage IA1-IB intermediate malignant subtype showed low frequency of recurrence. Whereas, in pStage IA1-IB high malignant subtype and pStage IIA-IIIA cases, EGFR-positive cases showed poorer 5-year RFS than EGFR-negative (49.6% and 75.6%, respectively, hazard ratio [HR] = 1.84, 95% CI = 1.38-7.42, p <  0.01) and multivariate analysis indicated positive EGFR mutation status was significantly related to poorer PRF (HR = 2.005, 95% CI = 1.029-3.906, p =  0.041).

CONCLUSION

EGFR mutation harbored primarily in early-stage or low-malignant histological subtypes with no/little recurrence. In pN0-1M0 adenocarcinoma with higher risk of recurrence, positive EGFR mutation cases showed worse RFS. EGFR mutation status enables better stratification of recurrence risk when considering pStage and histological malignant subtype.

Synchronicity of genetic variants between primary sites and metastatic lymph nodes, and prognostic impact in nodal metastatic lung adenocarcinoma

PURPOSE

Nodal positive lung adenocarcinoma includes wide range of survival. Several methods for the classification of nodal-positive lung cancer have been proposed. However, classification considering the impact of targetable genetic variants are lacking. The possibility of genetic variants for the better stratification of nodal positive lung adenocarcinoma was estimated.

METHODS

Mutations of 36 genes between primary sites and metastatic lymph nodes (LNs) were compared using next-generation sequencing. Subsequently, mutations in EGFR and BRAF, rearrangements in ALK and ROS1 were evaluated in 69 resected pN1-2M0 adenocarcinoma cases. Recurrence-free survival (RFS), post-recurrence survival (PRS), and overall survival (OS) were evaluated with respect to targetable variants and tyrosine kinase inhibitor (TKI) therapy after recurrence.

RESULTS

About 90% of variants were shared and allele frequencies were similar between primary and metastatic sites. In 69 pN1-2M0 cases, EGFR/ALK were positive in primary sites of 39 cases and same EGFR/ALK variants were confirmed in metastatic LNs of 96.7% tissue-available cases. Multivariate analyses indicated positive EGFR/ALK status was associated with worse RFS (HR 2.366; 95% CI 1.244-4.500; P = 0.009), and PRS was prolonged in cases receiving TKI therapy (no post-recurrence TKI therapies, HR 3.740; 95% CI 1.449-9.650; P = 0.006). OS did not differ with respect to targetable variants or TKI therapy.

CONCLUSIONS

Cases harbouring targetable genetic variants had a higher risk of recurrence, but PRS was prolonged by TKI therapy. Classification according to the targetable genetic status provides a basis for predicting recurrence and determining treatment strategies after recurrence.