Non-BAC Component but not Epidermal Growth Factor Receptor Gene Mutation is Associated with Poor Outcomes in Small Adenocarcinoma of the Lung

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.

Association of postoperative recurrence with radiological and clinicopathological features in patients with stage IA-IIA lung adenocarcinoma

OBJECTIVES

To retrospectively investigate whether radiological and clinicopathological characteristics were associated with the presence of stage IA-IIA lung adenocarcinoma in patients at high risk for a postoperative recurrence.

MATERIALS AND METHODS

Three hundred twelve patients with biopsy-proven node-negative early-stage (IA-IIA) lung adenocarcinoma met the inclusion criteria for this study. Demographics data and histopathological findings were collected from medical records. Computed tomography (CT) performed approximately 1 month before surgery was manually scored using 23 CT descriptors. Univariate analyses were applied to demonstrate an association between clinicopathological and radiological features and 2-/5-year recurrences. Multivariate logistic regression was performed to assess the ability of radiological and clinicopathological features to discriminate low and high-risk factors for recurrence. A ROC curve was used to evaluate prediction performance.

RESULTS

Univariate analysis revealed that the 2-year recurrence was associated with six radiological features and two clinicopathological features, while 5-year recurrence was associated with five radiological features and two clinicopathological features. A multivariate logistic regression model of combined clinicopathological and radiological features showed that stage IIA (OR = 2.87), solid texture (solid part > 50 %: OR = 4.81; solid part = 100 %: OR = 3.61), pleural attachment (OR = 3.97) and bronchovascular bundle thickening (OR = 2.16) were associated with the independent predictors of 2-year recurrence, and stage IIA (OR = 3.52), solid texture (solid part > 50 %: OR = 3.56; solid part = 100 %: OR = 2.44) and pleural attachment (OR = 4.57) were associated with 5-year recurrence. Combined radiological and clinicopathological features could be significant indicators of 2- and 5-year recurrences (AUC = 0.784 and AUC = 0.815, respectively).

CONCLUSIONS

The combination of radiological and clinicopathological features has the potential to help predict postoperative recurrence in patients with stage IA-IIA lung adenocarcinomas and guide oncologists and patients whether to undergo additional treatment after surgery.

Deep learning combined with radiomics may optimize the prediction in differentiating high-grade lung adenocarcinomas in ground glass opacity lesions on CT scans

PURPOSE

Adenocarcinoma (ADC) is the most common histological subtype of lung cancers in non-small cell lung cancer (NSCLC) in which ground glass opacifications (GGOs) found on computed tomography (CT) scans are the most common lesions. However, the presence of a micropapillary or a solid component is identified as an independent predictor of prognosis, suggesting a more extensive resection. The purpose of our study is to explore imaging phenotyping using a method combining radiomics with deep learning (RDL) to predict high-grade patterns within lung ADC.

METHODS

Included in this study were 111 patients differentiated as having GGOs and pathologically confirmed ADC. Four different groups of methods were compared to classify the GGOs for the prediction of the pathological subtypes of high-grade lung ADCs in definitive hematoxylin and eosin stain, including radiomics with gray-level features, radiomics with textural features, deep learning method, and the RDL.

RESULTS

We evaluated the performance of different models on 111 NSCLC patients using 4-fold cross-validation. The proposed RDL has achieved an overall accuracy of 0.913, which significantly outperforms the other methods (p <  0.01, analysis of variation, ANOVA). In addition, we also verified the generality and practical effectiveness of these models on an independent validation dataset of 28 patients. The results showed that our RDL framework with an accuracy of 0.966 significantly surpassed other methods.

CONCLUSION

High-grade lung ADC based on histologic pattern spectrum in GGO lesions might be predicted by the framework combining radiomics with deep learning, which reveals advantage over radiomics alone.

Molecular gene mutation profiles, TMB and the impact of prognosis in Caucasians and east Asian patients with lung adenocarcinoma

Background

The difference in molecular gene mutation profile, tumor mutational burden (TMB) and their prognostic effects in lung adenocarcinoma between different ethnic groups are still unknown. A retrospective analysis was used to investigate the differences in lung adenocarcinoma driver gene mutations, TMB, and their impact on prognosis across different ethnic groups.

Methods

The incidence of epidermal growth factor receptor (EGFR) mutations and follow-up data of 647 Chinese lung adenocarcinoma patients were compared with the data from 522 Caucasian patients in The Cancer Genome Atlas (TCGA) database. Moreover, a comprehensive analysis was performed to compare the differences in gene mutation frequency, signaling pathway variation, and TMB using the whole-exome sequencing (WES) data of Chinese patients with that of Caucasian patients.

Results

A comparison of tumor signaling pathways and gene mutation profiles between Caucasians and Chinese revealed ethnic variations in the incidence of mutations in TGF-β and RTK-RAS signaling pathways, with P values of 0.012 and 0.016, respectively. In the Caucasian population, the mutations in 5 signaling pathways and 18 genes were all significantly correlated with TMB, whereas in the Chinese population, only mutations in the Notch pathway and 6 genes were found to be associated with TMB-high. EGFR mutations showed a better prognosis in Chinese patients with lung adenocarcinoma, while the opposite was found in Caucasians patients.

Conclusions

Variations in the incidence of mutations in signaling pathways involved in lung adenocarcinoma and the correlation of the signaling pathways with TMB may exist across different ethnic groups.

The impact of epidermal growth factor receptor mutations on the prognosis of resected non-small cell lung cancer: a meta-analysis of literatures

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation represents a good response to EGFR-tyrosine kinase inhibitor and an advantageous prognostic factor in advanced-stage non-small cell lung cancer (NSCLC). However, the predictive value of EGFR mutation for prognosis in NSCLC patients after complete surgery, which more reflective of natural process, remains controversial. We sought to examine the predictive value of EGFR mutation in NSCLC. Several studies with small sample sizes have been reported but small studies bring bias especially in a postoperative setting. Therefore, we sought to pool all current evidence to show the true effects.

METHODS

Electronic databases were used to search the relevant articles. Disease-free survival (DFS), which will be less effected by subsequent treatments after recurrence, was the primary endpoint. The DFS between EGFR mutated and wild-type patients were compared focus on stage I patients who are rarely received adjuvant therapy. Besides, the DFS of patients with 19 exon deletion (19del) and 21 exon L858R mutation (L858R) were compared. A random effects model was used.

RESULTS

A total of 19 relevant studies which involved 4,872 cases were enrolled and 2,086 patients were EGFR-mutated. The majority of studies used PCR-based methods to detect EGFR mutations. Through meta-analysis, we observed the DFS of EGFR-mutated patients were similar to wild type patients in overall population (HR 0.93, 95% CI: 0.74 to 1.17). Similar results were observed in stage I subgroup (HR 0.82, 95% CI: 0.50 to 1.33). DFS of 19 del patients were potentially inferior to L858R patients but the difference was not significant (HR 1.38, 95% CI: 0.76 to 2.52).

CONCLUSIONS

There was no significant difference in postoperative DFS between EGFR-mutant patients and wild-type with resected NSCLC. In addition, there is still insufficient evidence to support different postoperative treatment strategies (especially for stage I) for both mutated and wild-type patients. However, 19 del may be a negative factor, which may require more strict management. Thus, we strongly encourage reporting specific prognostic impacts of different mutation types.

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

BACKGROUND

This study was conducted to evaluate the prognostic and recurrent impact of EGFR mutation status in resected pN0M0 lung adenocarcinoma with consideration of the histological subtype.

METHODS

Following retrospective analysis of whole 474 consecutive pathological N0M0 lung adenocarcinoma patients, the prognostic significance of EGFR mutation status was evaluated in limited 394 subjects. Overall survival and recurrence-free interval (RFI) were estimated using the Kaplan-Meier method and compared using a log-rank test. Univariate and multivariate analyses were performed using Cox proportional hazard models.

RESULTS

The five-year RFI was 85.7% and 93.3% for EGFR positive (n = 176) and negative (n = 218) cases, respectively (hazard ratio [HR] 1.992, 95% confidence interval [CI] 1.005-3.982; P = 0.048). Following the exclusion of specific subtypes free from recurrence or EGFR mutation (adenocarcinoma in situ, minimally invasive adenocarcinoma, and invasive mucinous adenocarcinoma), the five-year RFI was obviously poorer in EGFR positive compared to negative cases (80.7% and 92.1%, respectively; HR 2.163, 95% CI 1.055-4.341; P = 0.035). Multivariate analysis excluding the specific subtypes confirmed that male sex, age, current or Ex-smoking status, pleural invasion, and EGFR-positive status were independently associated with shorter RFI. No significant differences in five-year overall survival were found between the EGFR mutation positive and negative groups (88.7% and 93.7%, respectively; HR 1.630, 95% CI 0.787-3.432; P = 0.2).

CONCLUSION

EGFR mutations are associated with recurrence in pN0M0 lung adenocarcinoma. EGFR mutation status and histological subtype should be considered when evaluating the risk of recurrence in resected lung adenocarcinoma patients.

Prognostic value of EGFR and KRAS in resected non-small cell lung cancer: a systematic review and meta-analysis

Background

The prognostic value of EGFR and KRAS mutations in resected non-small cell lung cancer (NSCLC) has been reported. However, conflicting results were reported in these studies. The effect of mutations in these two genes in resected NSCLC remains controversial.

Methods

We searched Internet databases for studies reporting disease-free survival (DFS) and overall survival (OS) in resected NSCLC patients with EGFR or KRAS mutations. A meta-analysis calculating the pooled hazard ratio (HR) for DFS and OS was used to measure the association of EGFR or KRAS mutations with the prognosis of patients after surgery.

Results

A total of 9,635 patients from 32 studies were included in this analysis. The combined HR for EGFR mutations on DFS was 0.77 (95% CI 0.66–0.90, p=0.001) and on OS was 0.72 (95% CI 0.66–0.80, p<0.00001). In addition, the combined HR for KRAS mutations on DFS was 1.5 (95% CI 1.15–1.96, p=0.002) and on OS was 1.49 (95% CI 1.28–1.73, p<0.00001). Sensitivity analysis, subgroup analysis, and bias analysis proved the stability of the results.

Conclusion

The analysis showed that EGFR mutations were significantly associated with DFS and OS. These findings indicated that surgically treated NSCLC patients with EGFR mutations were inclined to exhibit a prolonged DFS and OS. In addition, the results indicated that KRAS mutations predicted worse DFS and OS in patients with resected NSCLC.

Factors associated with distant recurrence following R0 lobectomy for pN0 lung adenocarcinoma

OBJECTIVE

We investigated factors associated with distant recurrence, disease-free survival (DFS), and overall survival (OS) following R0 lobectomy for pathologic node-negative (pN0) lung adenocarcinoma.

METHODS

We performed a retrospective analysis of a prospectively maintained database of patients with pT1-3N0M0 non-small cell lung cancer. Exclusion criteria included metachronous lung cancer, sublobar/incomplete resection, nonadenocarcinoma histology, and induction/adjuvant therapy. The primary outcome was distant recurrence; secondary outcomes were DFS and OS. Associations between variables and outcomes were assessed by Fine-Gray competing-risk regression for distant recurrence and Cox proportional hazard models for DFS and OS.

RESULTS

Of 2392 patients identified with pT1-3N0M0 lung adenocarcinoma, 893 met the inclusion criteria. Median follow-up was 35.0 months (range, 0.1-202 months). Thirteen percent of patients developed recurrence (n = 115), of which 86% (n = 99) were distant. The 5-year cumulative incidence of distant recurrence was 14% (95% confidence interval [CI], 11%-17%). On multivariable analysis, pT2a (hazard ratio [HR], 2.84; 95% CI, 1.56-5.16; P = .001) and pT2b/3 (HR, 6.53; 95% CI, 3.17-13.5; P < .001) tumors were associated with distant recurrence. Recent surgery was associated with decreased distant recurrence (HR, 0.43; 95% CI, 0.20-0.91; P = .028), and lymphovascular invasion was strongly associated with distant recurrence (HR, 1.62; 95% CI, 1.00-2.63; P = .05). DFS was independently associated with pT stage (P < .001) and lymphovascular invasion (P = .004).

CONCLUSIONS

In patients undergoing R0 lobectomy with pN0 lung adenocarcinoma, pT stage and lymphovascular invasion were associated with distant recurrence and decreased DFS. These observations support the inclusion of these patients in future clinical trials investigating adjuvant targeted and immunotherapies.

Prognostic implication of EGFR gene mutations and histological classification in patients with resected stage I lung adenocarcinoma

Introduction

The prognostic value of epidermal growth factor receptor (EGFR) mutations and the correlation between EGFR mutations and the new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histological classification remain controversial. The current study aimed to investigate the pure prognostic role of EGFR mutations in treatment-naïve patients with resected stage I lung adenocarcinoma.

Methods

We retrospectively reviewed 373 patients with stage I pulmonary non-small-cell lung cancer who underwent complete surgical resection between January 2010 and May 2014. The tumors were classified according to IASLC/ATS/ERS criteria. EGFR mutation status was determined by established methods.

Results

A total of 120 patients were included for analysis; 87 had tumors with EGFR mutations and 33 had wild-type tumors. More low- and intermediate-grade tumors had EGFR mutations, and nearly half of the high-grade tumors were wild-type (75.7% versus 46.2%, p = 0.041). Patients with low-grade tumors had significantly greater median disease-free survival (DFS) (76.8 versus 13 months, p < 0.0001) and better overall survival (OS) (median OS not reached, p = 0.0003) than those with intermediate- and high-grade tumors. Tumor recurrence was 41.4% and 30.3% in mutant and wild-type patients. The 5-years survival rate was 54% and 71.2%. Multivariate analysis revealed that the new histological classification and the pathologic stage were independent predictors of both DFS and OS. EGFR mutation status had no prognostic implications.

Conclusion

Low grade tumors according to IASLC/ATS/ERS histological classification and the pathologic stage IA tumors of resected stage I lung adenocarcinomas independently predict better DFS and OS. EGFR mutations were frequently seen in histologically low- and intermediate-grade tumors but not a prognostic factor.

The Association of EGFR Mutations with Stage at Diagnosis in Lung Adenocarcinomas

Background

The prognostic role of epidermal growth factor receptor (EGFR) mutations in patients with lung adenocarcinomas remains controversial and the association between EGFR mutations and stage at the time of the initial diagnosis is debatable. In this study, we evaluated the association of EGFR mutations with stage at diagnosis in lung adenocarcinomas.

Materials and Methods

We retrospectively analyzed 1004 consecutive patients who were diagnosed with lung adenocarcinomas and tested for EGFR mutations between June 2011 and December 2014.

Results

EGFR mutations were detected in 49.2% of 1004 patients with lung adenocarcinomas. In multivariable analysis, EGFR mutations were significantly associated with early stage disease (stage I to II) at diagnosis (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.49–0.87; P = 0.003). When adjusted for age, sex, smoking status, and screening, the adjusted proportion of EGFR mutations significantly decreased according to stage. The adjusted proportions of EGFR mutations were 57.6% (95% CI, 51.7%–63.3%) for stage I, 47.9% (95% CI, 36.9%–59.0%) for stage II, 47.5% (95% CI, 39.6%–55.5%) for stage III, and 43.4% (95% CI, 38.3%–48.6%) for stage IV (P = 0.0082).

Conclusions

The presence of EGFR mutations is significantly associated with early stage disease at initial diagnosis in lung adenocarcinomas after adjusting for age, sex, smoking status, and screening. This finding implies that EGFR mutations may play a role as a positive prognostic marker.

Comparison of outcomes for patients with lepidic pulmonary adenocarcinoma defined by 2 staging systems: A North American experience

OBJECTIVE

Application of the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) classification of lepidic adenocarcinomas in conjunction with American Joint Committee on Cancer (AJCC) staging has been challenging. We aimed to compare IASLC/ATS/ERS and AJCC classifications, to determine if they could be integrated as a single staging system.

METHODS

We reviewed patients from 2001-2013 who had AJCC stage I lepidic adenocarcinomas, and categorized them according to IASLC/ATS/ERS guidelines: adenocarcinoma in situ (AIS); minimally invasive adenocarcinoma (MIA); or invasive adenocarcinoma (IA). We integrated the 2 classification systems by separating AIS and MIA as being stage 0, and routinely classifying IA as stage I.

RESULTS

Median follow-up was 52 months in 138 patients. The IASLC/ATS/ERS classification demonstrated a higher disease-free survival (DFS) in AIS (100%) and MIA (96%) versus IA (80%) (P = .022), and higher overall survival (OS): 100% for AIS and MIA, versus 90% for IA (P = .049). The AJCC classification identified a DFS of 87% and an OS of 94% for stage I patients. Integration of the 2 systems demonstrated higher DFS in stage 0 (98%) versus I (80%) (P = .006), and higher OS: 100% for stage 0 versus 90% for stage I (P = .014).

CONCLUSIONS

The IASLC/ATS/ERS classification better discriminates AIS and MIA compared with current AJCC staging; however, integration suggests that these categories may be collectively classified in AJCC staging, based on similarly favorable outcomes and distinctive survival rates.

Expression and prognostic value of GalNAc-T3 in patients with completely resected small (≤2 cm) peripheral lung adenocarcinoma after IASLC/ATS/ERS classification

Background

GalNAc-T3 catalyzes initial glycosylation of mucin-type O-linked protein involved in proliferation, adhesion, and migration of tumor cells. This study was performed to explore the relationships of the expression of GalNAc-T3 in small peripheral lung adenocarcinoma, especially as an indicator of prognosis.

Materials and methods

A retrospective analysis of the patients with small peripheral lung lesions, including 106 adenocarcinoma and two precancerous lesions (atypical adenomatous hyperplasia and adenocarcinoma in situ) after complete surgical resection, was launched. Expression of GalNAc-T3 was examined using immunohistochemistry staining on primary tumor specimens, and the tumors were reclassified in light of the IASLC/ATS/ERS (International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society) adenocarcinoma classifications followed by grading and scoring. Moreover, reverse transcription polymerase chain reaction and Western blot were used to study the expression of GalNAc-T3 in vivo.

Results

The low expression of GalNAc-T3 was found in the cytoplasm of tumor cells in 56 of 108 patients (51.9%) and was associated with IASLC/ATS/ERS classification of high risk groups (P=0.007), high Sica score (P=0.036), poorly differentiated tumor (P=0.023), poor tumor-node-metastasis (TNM) stage (P=0.007), pleural invasion (P=0.007), and vascular invasion (P<0.001) by Pearson’s chi-squared test, but not with sex, age, smoking status, concentration of carcinoembryonic antigen, and lymph node metastasis. In logistic regression analysis, low GalNAc-T3 expression was only correlated with high-ranking TNM stage (odds ratio [OR] =8.975, 95% confidence interval [CI]: 1.797–44.661), vascular invasion (OR =5.668, 95% CI: 1.827–17.578), and the higher risk grade (low risk grade: OR =0.141, 95% CI: 0.027–0.719; moderate risk grade: OR =0.122, 95% CI: 0.017–40.871). The low expression of the GalNAc-T3 usually in adenocarcinoma cell lines was compared with normal bronchial epithelium cell line. Based on the univariate and multivariate analysis, poor TNM stage (P<0.001), pleural invasion (hazard ratio [HR]: 7.958, P=0.021), vascular invasion (HR: 2.403, P=0.040), and low GalNAc-T3 expression (HR: 3.317, P=0.016) were shown to be independently associated with an unfavorable prognosis. However, IASLC/ATS/ERS classification of risk groups and Sica score (P=0.034 and P=0.032, respectively) was correlated with overall survival on Kaplan–Meier method but not Cox regression model.

Conclusion

GalNAc-T3 expression was correlated with the IASLC/ATS/ERS classification and also associated with prognosis of patients with completely resected small (≤2 cm) peripheral lung adenocarcinoma.

Radiologic Evaluation of Small Lepidic Adenocarcinomas to Guide Decision Making in Surgical Resection

BACKGROUND

The International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification of pulmonary adenocarcinomas identifies indolent lesions associated with low recurrence, superior survival, and the potential for sublobar resection. The distinction, however, is determined on the pathologic evaluation, limiting preoperative surgical planning. We sought to determine whether preoperative computed tomography (CT) characteristics could guide decisions about the extent of the pulmonary resection.

METHODS

We reviewed the preoperative CT scans for 136 patients identified to have adenocarcinomas with lepidic features on the final pathologic evaluation. The solid component on CT was substituted for the invasive component, and patients were radiologically classified as adenocarcinoma in situ, 3 cm or less with no solid component; minimally invasive adenocarcinoma, 3 cm or less with a solid component of 5 mm or less; or invasive adenocarcinoma, exceeding 3 cm or solid component exceeding 5 mm, or both. Analysis of variance, t test, χ(2) test, and Kaplan-Meier methods were used for analysis.

RESULTS

The radiologic classification identified 35 adenocarcinomas in situ (26%) and 12 minimally invasive (9%) and 89 invasive adenocarcinoma (65%) lesions. At a 32-month median follow-up, patient outcomes associated with the radiologic classification were similar to the pathologic-based classification: the radiologic classification identified 14 of 16 patients with recurrent disease and all 6 who died of lung cancer. In addition, patients with radiologic adenocarcinoma in situ and minimally invasive adenocarcinoma who underwent sublobar resections had no recurrence and 100% disease-free and overall survival at 5 years.

CONCLUSIONS

The radiologic classification of patients with lepidic adenocarcinomas is associated with similar oncologic and survival outcomes compared with the pathologic classification and may guide decision making in the approach to surgical resection.

Observer Variability for Classification of Pulmonary Nodules on Low-Dose CT Images and Its Effect on Nodule Management

PURPOSE

To examine the factors that affect inter- and intraobserver agreement for pulmonary nodule type classification on low-radiation-dose computed tomographic (CT) images, and their potential effect on patient management.

MATERIALS AND METHODS

Nodules (n = 160) were randomly selected from the Dutch-Belgian Lung Cancer Screening Trial cohort, with equal numbers of nodule types and similar sizes. Nodules were scored by eight radiologists by using morphologic categories proposed by the Fleischner Society guidelines for management of pulmonary nodules as solid, part solid with a solid component smaller than 5 mm, part solid with a solid component 5 mm or larger, or pure ground glass. Inter- and intraobserver agreement was analyzed by using Cohen κ statistics. Multivariate analysis of variance was performed to assess the effect of nodule characteristics and image quality on observer disagreement. Effect on nodule management was estimated by differentiating CT follow-up for ground-glass nodules, solid nodules 8 mm or smaller, and part-solid nodules smaller than 5 mm from immediate diagnostic work-up for solid nodules larger than 8 mm and part-solid nodules 5 mm or greater.

RESULTS

Pair-wise inter- and intraobserver agreement was moderate (mean κ, 0.51 [95% confidence interval, 0.30, 0.68] and 0.57 [95% confidence interval, 0.47, 0.71]). Categorization as part-solid nodules and location in the upper lobe significantly reduced observer agreement (P = .012 and P < .001, respectively). By considering all possible reading pairs (28 possible combinations of observer pairs × 160 nodules = 4480 possible agreements or disagreements), a discordant nodule classification was found in 36.4% (1630 of 4480), related to presence or size of a solid component in 88.7% (1446 of 1630). Two-thirds of these discrepant readings (1061 of 1630) would have potentially resulted in different nodule management.

CONCLUSION

There is moderate inter- and intraobserver agreement for nodule classification by using current recommendations for low-radiation-dose CT examinations of the chest. Discrepancies in nodule categorization were mainly caused by disagreement on the size and presence of a solid component, which may lead to different management in the majority of cases with such discrepancies. (©) RSNA, 2015.

EGFR mutations as a prognostic and predictive marker in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) has entered the age of individual treatment, and increasing point mutations of specific oncogenes and rearrangement of some chromosomes are biomarkers used to predict the therapeutic effect of targeted therapy. At present, there is a consensus among clinicians that epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have shown favorable efficacy in NSCLC patients with EGFR mutation, and some relevant research has suggested that the presence of EGFR mutations is a favorable prognostic marker. However, the association of EGFR mutation status with the responsiveness to conventional chemotherapy agents and survival in NSCLC patients is still unclear. This review provides an overview of and assesses the role of EGFR as a prognostic marker for postoperative patients and as a predictive marker for response to cytotoxic chemotherapy. In addition, we review the comparison of response to chemotherapy between EGFR mutations in exon 19 and in exon 21 and the predictive role of p.T790M mutation.

Prognostic value of epidermal growth factor receptor mutations in resected non-small cell lung cancer: a systematic review with meta-analysis

BACKGROUND

The prognostic value of epidermal growth factor receptor (EGFR) mutations in resected non-small cell lung cancer (NSCLC) remains controversial. We performed a systematic review with meta-analysis to assess its role.

METHODS

Studies were identified via an electronic search on PubMed, Embase and Cochrane Library databases. Pooled hazard ratio (HR) for disease-free survival (DFS) and overall survival (OS) were calculated for meta-analysis.

RESULTS

There were 16 evaluated studies (n  =  3337) in the meta-analysis. The combined HR evaluating EGFR mutations on disease free survival was 0.96 (95% CI [0.79-1.16] P  =  0.65). The combined HR evaluating EGFR mutations on overall survival was 0.86 (95% CI [0.72-1.04] P  = 0.12). The subgroup analysis based on univariate and multivariate analyses in DFS and OS showed no statistically significant difference. There was also no statistically significant difference in DFS and OS of stage I NSCLC patients.

CONCLUSION

The systematic review with meta-analysis showed that EGFR mutations were not a prognostic factor in patients with surgically resected non-small cell lung cancer. Well designed prospective study is needed to confirm the result.

Prognostic value of epidermal growth factor receptor mutations in resected lung adenocarcinomas

The purpose of this study was to evaluate the association between epidermal growth factor receptor (EGFR) mutations and prognosis in patients with completely resected lung adenocarcinoma. A total of 131 patients were included in this study. EGFR mutation status in exons 18-21 of the tyrosine kinase-binding domain was detected using nested PCR amplification of individual exon. The χ (2) test was used to analyze the associations between EGFR mutations and the different variables. The log-rank test and Cox regression model were used to evaluate the factors influencing disease-free survival (DFS) and overall survival (OS). EGFR mutations in 18-21 exons were detected in 58 of the 131 patients (44.3 %). Smoking status (P = 0.029), N stage (P = 0.021), and pathologic stage (P = 0.048) were significantly associated with EGFR mutations. The median DFS in mutant EGFR and wild-type EGFR groups was 36.6 and 25.7 months, respectively (P = 0.533). No significant correlation was observed between EGFR mutations and OS (P = 0.564). However, patients with exon 19 mutation tended to have longer DFS than those with exon 21 mutation (46.2 vs. 21.9 months, P = 0.056), and the 1-, 2-, and 3-year OS rates were significantly higher in patients with exon 19 mutation compared to patients with exon 21 mutation (100, 96.7, 93.3 vs. 91.3, 82.6, 60.9 %, respectively, P = 0.01). Our data demonstrated that EGFR mutations do not have significant prognostic value in primary resected lung adenocarcinomas, but patients with exon 19 mutation tended to have better prognostic value compared to patients with exon 21 mutation.

Cribriform and fused glands are patterns of high-grade pulmonary adenocarcinoma

The 2011 International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society classification of pulmonary adenocarcinoma recognizes the prognostic significance of different histologic patterns but does not address the issue of tumor grade. We previously developed an objective and prognostic grading system for pulmonary adenocarcinomas that is based on associating patterns with their metastatic potential. The best prognostic stratification was achieved by summing the grades of the 2 most predominant patterns (histologic score). Here, we extend this work by evaluating the prognostic importance of variant patterns of adenocarcinoma, which are not recognized by the new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification. Pathologic specimens from 249 resected stage I adenocarcinomas were reviewed. The proportions of standard and nonstandard patterns (cribriform and fused glands) were recorded for each case. The associations between the presence of standard and nonstandard patterns, tumor histologic score, and disease-free survival were evaluated. Cribriform and fused gland patterns were observed in 15% and 29% of tumors, respectively. These nonstandard patterns each composed 10% to 100% of the entire tumors but were the predominant pattern in only 5% and 7% of tumors, respectively. The presence of complex glandular patterns was associated with solid pattern (P < .001) and high histologic score (P < .0001). Disease-free survival for tumors with predominant complex glandular patterns was similar to that for high-grade tumors (P = .932) and was significantly worse than that for low- and intermediate-grade tumors (P = .0025). Complex glandular patterns have a significant prognostic value and should be considered patterns of high-grade adenocarcinoma.

The presence of mutations in epidermal growth factor receptor gene is not a prognostic factor for long-term outcome after surgical resection of non-small-cell lung cancer

BACKGROUND

The presence of mutation in EGFR gene is known as a predictive marker for the response to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment. However, whether or not these EGFR mutations are prognostic factors for non-small-cell lung cancer (NSCLC) is debatable.

METHODS

We retrospectively collected a series of samples from patients whose EGFR mutation status had been tested, and analyzed their survival. The pathologic cell types of 863 patients (520 men, 343 women) were squamous cell carcinoma in 227, adenocarcinoma in 636 patients.

RESULTS

EGFR mutations were detected in 354 patients and it was frequently observed in adenocarcinoma in younger, early-stage, female never-smokers. In univariate analysis of younger, early-stage, never-smoker women, bronchioloalveolar carcinoma pattern and the presence of EGFR mutation showed better long-term survival. However, in multivariate analysis, age, pathologic stage, and smoking status remained significant prognostic factors, whereas EGFR mutation was not. For recurrence, pathologic stage was the only independent prognostic factor. After recurrence, smoking status was the only significant risk factor that affected postrecurrence survival. However, when EGFR TKIs were used in EGFR-mutated patients, survival was longer than for those treated with conventional chemotherapy.

CONCLUSIONS

Although the EGFR mutation is a predictive marker for EGFR TKI response, it is not a prognostic factor in NSCLC. The clinical observation that patients with EGFR mutation seem to survive longer may be because EGFR mutation is more frequently associated with other good prognostic factors. Once there is a recurrence, administration of EGFR TKI for patients with EGFR mutation may increase survival.

Recommendations for the management of subsolid pulmonary nodules detected at CT: a statement from the Fleischner Society

This report is to complement the original Fleischner Society recommendations for incidentally detected solid nodules by proposing a set of recommendations specifically aimed at subsolid nodules. The development of a standardized approach to the interpretation and management of subsolid nodules remains critically important given that peripheral adenocarcinomas represent the most common type of lung cancer, with evidence of increasing frequency. Following an initial consideration of appropriate terminology to describe subsolid nodules and a brief review of the new classification system for peripheral lung adenocarcinomas sponsored by the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS), six specific recommendations were made, three with regard to solitary subsolid nodules and three with regard to multiple subsolid nodules. Each recommendation is followed first by the rationales underlying the recommendation and then by specific pertinent remarks. Finally, issues for which future research is needed are discussed. The recommendations are the result of careful review of the literature now available regarding subsolid nodules. Given the complexity of these lesions, the current recommendations are more varied than the original Fleischner Society guidelines for solid nodules. It cannot be overemphasized that these guidelines must be interpreted in light of an individual's clinical history. Given the frequency with which subsolid nodules are encountered in daily clinical practice, and notwithstanding continuing controversy on many of these issues, it is anticipated that further refinements and modifications to these recommendations will be forthcoming as information continues to emerge from ongoing research.

Prognostic significance of the IASLC/ATS/ERS classification in Chinese patients-A single institution retrospective study of 292 lung adenocarcinoma

BACKGROUND

A new classification of pulmonary adenocarcinoma has been recently proposed by the International Association for the Study of Lung Cancer, American Thoracic Society and European Respiratory Society (IASLC/ATS/ERS). This study was undertaken in an attempt to explore the clinical implication of this new classification in Chinese patients.

METHODS

Two hundred ninety-two lung adenocarcinomas were reclassified strictly according to the IASLC/ATS/ERS classification by two pathologists, independently. Kaplan-Meier and Cox regression analyses were used to analyze the correlation between the new classification and patients' prognosis.

RESULTS

We confirmed three groups with different outcomes. Both AIS and MIA had 100% 5-year disease-free survival rate and 100% 5-year overall survival rate. Lepidic, acinar, and papillary as well as variants of invasive adenocarcinoma had intermediate prognosis. Solid and micropapillary cases had poor prognosis (DFS: P < 0.001, OS: P = 0.002). After controlling the clinicopathological factors, the new classification was identified as an independent prognostic factor in patients' disease-free survival and overall survival.

CONCLUSIONS

We have demonstrated a valuable prognostic role of the new classification in Chinese patients. This new classification is valuable of screening out patients with high risk of recurrence to receive postoperative adjuvant therapy.

Solitary pulmonary nodular lung adenocarcinoma: correlation of histopathologic scoring and patient survival with imaging biomarkers

PURPOSE

To evaluate the usefulness of histopathologic scoring for survival prediction in patients with solitary pulmonary nodular (SPN) lung adenocarcinomas and to correlate the histopathologic scoring with the results of computed tomography (CT) and fluorine 18 fluorodeoxyglucose positron emission tomography (PET)/CT.

MATERIALS AND METHODS

This retrospective study was institutional review board approved and the requirement for informed consent was waived. A total of 148 patients with SPN lung adenocarcinoma underwent PET/CT and CT. Correlations between histopathologic scores estimated by using two predominant histologic subtypes from each surgically resected specimen and the mass of the nodule at CT or maximum standardized uptake value (SUV(max)) at PET/CT were assessed. Disease-free survival (DFS) was estimated by using the Kaplan-Meier method, and the log-rank test was used to evaluate differences in each histopathologic subtype.

RESULTS

In 135 (91%) patients, tumors had a mixed subtype. The most frequently observed histologic subtypes, in decreasing order, were acinar (51%), lepidic (18%), solid (10%), and papillary (9%). DFS rates at 5 years were higher than 90% for the group of patients with nodules that showed the lepidic growth pattern, and 50% for patients with nodules that showed the micropapillary pattern. The pathologic score proved to be a significant predictor of DFS (P < .001). Both SUV(max) and the mass of the nodule were closely correlated with pathologic score.

CONCLUSION

Pathologic scoring appears to help predict DFS in patients with SPN lung adenocarcinoma and shows close correlation with imaging biomarkers including the mass of the nodule at CT and SUV(max) at PET/CT.

Ground-glass nodules on chest CT as imaging biomarkers in the management of lung adenocarcinoma

OBJECTIVE

The purpose of this article is to review the clinical significance of ground-glass nodules (GGNs) in the management of lung adenocarcinoma.

CONCLUSION

GGNs can serve as imaging biomarkers that represent the bronchioloalveolar carcinoma component in adenocarcinoma on histology and indicate a better prognosis in patients with lung adenocarcinoma. The evolution of GGNs reflects the multistep progression of adenocarcinoma. Despite the high probability of malignancy of GGNs, the possibility of overdiagnosis should be considered in the management of GGNs.

A grading system of lung adenocarcinomas based on histologic pattern is predictive of disease recurrence in stage I tumors

Currently no objective grading system for pulmonary adenocarcinomas exists. To determine whether specific histologic patterns or combinations thereof could be linked to an objective grading system, the histologic patterns in metastatic tumor deposits was compared with the patterns seen in the corresponding 73 primary tumor to determine whether a specific pattern had higher propensity to metastasize. The concordance of the predominant histologic pattern in the primary tumor and the metastases was of 100% for micropapillary, 86% for solid, 42% for acinar, and 23% for papillary types of adenocarcinoma. Informed by these results, a 3-tier grading system based on the histologic subtypes was established. Grade I, a pattern with low metastatic potential (BAC); Grade II, patterns with intermediate metastatic potential (acinar and papillary); and Grade III, patterns with high metastatic potential (solid and micropapillary). These grades were combined into a number of different scoring systems, whose ability to predict recurrence or death from disease was tested in 366 stage 1 adenocarcinomas. A score based on the 2 most predominant grades was able to stratify patients into low-to-high risk for recurrence or death of disease (P=0.001). The 5-years disease-free survival for patients in the highest score group was of 0.73, compared with 0.84 and 0.92 in the intermediate and lowest score groups. Concordance probability estimate was 0.65 (95% confidence interval 0.57-0.73). Therefore, this scoring system provides valuable information in discriminating patients with different risk of disease-recurrence in a highly homogeneous population of patients with stage I cancer.

Chromosomal and genomic changes in lung cancer

Lung cancer is a complex spectrum of diseases characterized by extensive genomic instability, which can be detected among both histological subtypes and different foci within a tumor. Conventional and cutting edge investigative technologies have uncovered scores of genomic changes in individual specimens that have been used to characterize specific molecular subtypes. Oncogenes with predominant roles in lung cancer include EGFR, MYC and RAS family members, PIK3CA, NKX2-1 and ALK; tumor suppressor genes include TP53, RB1, CDKN2, and a cluster of genes mapped at 3p. MicroRNA regulators also have been linked to lung cancer. The functional role of the recurrent genomic changes in lung tumors has been explored, which has led to a better understanding of cell growth, differentiation and apoptotic pathways. Additionally, this knowledge has supported the development of novel therapeutics and translational tools for selection of patients for personalized therapy.

Update in neoplastic lung diseases and mesothelioma

CONTEXT

Lung cancer is a common disease frequently seen by the surgical pathologist. Although secondary to improvements in screening and radiologic techniques and aggressive resection of small pulmonary nodules, the diagnosis of preneoplastic lesions is increasing in frequency and importance. Consequently, a greater understanding of their role in the development of lung carcinoma is needed for optimal patient care. Two lesions often encountered as small pulmonary nodules are bronchioloalveolar carcinoma and adenocarcinoma, which can be challenging to distinguish. Recently, updates to the TNM classification of non-small cell lung carcinoma have been reported that directly impact prognosis and treatment algorithms. Identification of new molecular targets in pleural mesothelioma and in preneoplastic lesions may lead to improved therapeutic strategies.

OBJECTIVE

To present recent advances in our understanding of neoplastic lung diseases and mesothelioma and to describe how these advances relate to the current practice of pulmonary pathology.

DATA SOURCES

Published literature from PubMed (National Library of Medicine) and primary material from the authors' institution.

CONCLUSIONS

It is important for the surgical pathologist to understand current diagnostic classifications of non-small cell lung cancer and to be aware of the range of preneoplastic lesions, as well as the features useful for distinguishing bronchioloalveolar carcinoma from adenocarcinoma in small pulmonary nodules. Although pleural mesothelioma has distinct features, it can also overlap histologically with adenocarcinoma, and immunohistochemistry can greatly aid in accurate diagnosis. New therapies targeting molecular markers in both non-small cell lung cancer and mesothelioma rely on accurate histopathologic diagnosis of these entities.

Activating mutations within the EGFR kinase domain: a molecular predictor of disease-free survival in resected pulmonary adenocarcinoma

PURPOSE

Although epidermal growth factor receptor (EGFR) tyrosine kinase (TK) mutations are highly predictive of response to EGFR TK inhibitors in advanced non-small-cell lung cancer (NSCLC), a prognostic value of EGFR mutations in resected NSCLC has not been established.

METHODS

We retrospectively reviewed 117 patients with primary lung adenocarcinoma who underwent surgical resection between 1995 and 2005. Nucleotide sequencing of the kinase domain of EGFR (exons 18-21) was performed using nested PCR amplification of individual exons.

RESULTS

Forty-eight patients (41.8%) harbored exon 19 deletion or exon 21 point mutations. EGFR mutations were more frequently found in never-smoker (P = 0.04) or in smaller-sized primary tumor (P = 0.001). A presence of EGFR mutations was significantly associated with longer disease-free survival (DFS) (20.1 vs. 34.4 months in mutated EGFR; P = 0.003). In multivariate analysis of DFS, wild-type EGFR was associated with a higher risk of recurrence, with an adjusted hazard ratio of 1.42 (95% CI, 1.1-2.41, P = 0.04), as compared to mutated EGFR. However, no significant association was observed between EGFR mutations and overall survival (P = 0.39). Isolated brain metastasis as the first recurrence after resection was found more frequently in those patients with tumors bearing EGFR mutations, although the difference was not statistically significant (9 vs. 24% in mutated EGFR, P = 0.15).

CONCLUSIONS

Activating mutations within the EGFR TK domain can be used to predict the risk of recurrence in curatively resected pulmonary adenocarcinoma.

Lung adenocarcinoma as a solitary pulmonary nodule: prognostic determinants of CT, PET, and histopathologic findings

We aimed to retrospectively compare CT, PET, and histopathologic (the extent of bronchioloalveolar carcinoma [BAC] components) findings of solitary pulmonary nodular (SPN) adenocarcinomas of the lung to determine their value as prognostic determinants. We reviewed CT and PET characteristics of tumors and pathologic specimens from 65 consecutive patients who underwent surgical resection for SPN adenocarcinomas. Nodule size and TDR (tumor shadow disappearance rate) were assessed from CT scans, and maximum standardized uptake value (SUVmax) of tumors was measured at PET. On pathologic examination, BAC, non-BAC, and central fibrous scar ratios were quantified. Prognosis was evaluated by noting disease recurrence during a minimum 12-month follow-up period after curative resection. The interrelationships between TDR, SUVmax, BAC, and non-BAC ratio were studied, and relationships between recurrence and various variables were analyzed. The median follow-up time was 33 months, and seven patients (11%) developed disease recurrence after surgical resection. TDR at CT and SUVmax at PET correlated well with pathologic BAC and non-BAC ratios. Between subgroups with and without recurrence, there were significant differences in SUVmax and BAC and non-BAC ratios. Based on univariate survival analyses, pathologic BAC and non-BAC ratios were risk factors significantly related to recurrence, but only high non-BAC ratio remained as an independent factor associated with recurrence in the multivariate analysis (hazard ratio [HR]=0.956, P=0.013). Among the factors examined, pathologic non-BAC ratio is the only independent risk factor for poor prognosis in patients with SPN adenocarcinomas.