Use of the Proposals of the International Association for the Study of Lung Cancer in the Forthcoming Edition of Lung Cancer Staging System to Predict Long-Term Prognosis of Operated Patients

The diagnostic value of metabolic, morphological and heterogeneous parameters of 18F-FDG PET/CT in mediastinal lymph node metastasis of non-small cell lung cancer

OBJECTIVES

To investigate the value of PET/CT metabolic, morphological and heterogeneous parameters in the diagnosis of 18F-FDG positive mediastinal lymph node metastasis in non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

A total of 156 patients with pathologically diagnosed NSCLC and underwent 18F-FDG PET/CT scans were enrolled in this study. Mediastinal lymph nodes with 18F-FDG uptake greater than the mediastinum were analyzed. The metabolic parameters of maximum and mean standardized uptake value (SUVmax, SUVmean), SUVratio (node SUVmax/mediastinum SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), morphological parameters of maximum short diameter (Dmin), CT values and metabolic heterogeneity parameter of coefficient of variation (COV) were measured. The performance of each parameter and their combinations for diagnosis of lymph node metastasis was evaluated through receiver operating characteristic (ROC) curves and binary logistic regression analysis.

RESULTS

There were 206 lymph nodes with pathological evidence included in the study, including 103 metastatic and 103 nonmetastatic nodes. The SUVmax, SUVmean, SUVratio, TLG, COV and Dmin of metastatic lymph nodes were significantly higher/greater than those in nonmetastatic ones (P < 0.05). ROC curve analysis revealed that the combination of SUVratio, Dmin and COV showed the highest diagnostic efficacy among all single and combined parameters, the area under the curve (AUC) was 0.907 (P = 0.000), these three parameters all increased the risk of lymph node metastasis, with odds ratios of 1.848, 1.293 and 1.258, respectively (all P < 0.05).

CONCLUSION

Heterogeneity parameter was helpful for the accurate distinction of mediastinal lymph node metastasis in NSCLC. The combination of the SUVratio, Dmin and COV could improve the diagnostic accuracy. Multiple-parameters analysis plays an important complementary role in the diagnosis of lymph node metastasis.

Identification of an Individualized Immune-Related Prognostic Risk Score in Lung Squamous Cell Cancer

Background: Lung squamous cell carcinoma (LUSC) is one of the most common histological subtypes of non-small cell lung cancer (NSCLC), and its morbidity and mortality are steadily increasing. The purpose of this study was to study the relationship between the immune-related gene (IRGs) profile and the outcome of LUSC in patients by analyzing datasets from The Cancer Genome Atlas (TCGA). Methods: We obtained publicly available LUSC RNA expression data and clinical survival data from The Cancer Genome Atlas (TCGA), and filtered IRGs based on The ImmPort database. Then, we identified risk immune-related genes (r-IRGs) for model construction using Cox regression analysis and defined the risk score in this model as the immune gene risk index (IRI). Multivariate analysis was used to verify the independent prognostic value of IRI and its association with other clinicopathological features. Pearson correlation analysis was used to explore the molecular mechanism affecting the expression of IRGs and the correlation between IRI and immune cell infiltration. Results: We screened 15 r-IRGs for constructing the risk model. The median value of IRI stratified the patients and there were significant survival differences between the two groups (p = 4.271E-06). IRI was confirmed to be an independent prognostic factor (p < 0.001) and had a close correlation with the patients' age (p < 0.05). Interestingly, the infiltration of neutrophils or dendritic cells was strongly upregulated in the high-IRI groups (p < 0.05). Furthermore, by investigating differential transcription factors (TFs) and functional enrichment analysis, we explored potential mechanisms that may affect IRGs expression in tumor cells. Conclusion: In short, this study used 15 IRGs to build an effective risk prediction model, and demonstrated the significance of IRGs-based personalized immune scores in LUSC prognosis.

Prognostic Value of EZH2 in Non-Small-Cell Lung Cancers: A Meta-Analysis and Bioinformatics Analysis

Background

The prognosis of non-small-cell lung cancer (NSCLC) has not been significantly improved. In the past several years, research on epigenetics is in full swing. There is a focus on the gene EZH2; however, its role as a predictor of the prognosis of NSCLC is in the debate.

Objective

To clarify if the expression level of EZH2 can influence the prognosis of NSCLC and explain its prognostic value.

Methods

We have systematically searched PubMed, Web of Science, and Cochrane library, screened relevant articles, and conducted a meta-analysis on the expression level of EZH2 in NSCLC. We collected the hazard ratio (HR) and the 95% confidence interval (CI) and used STATA 12.0 to calculate the combined result of EZH2 overall survival. In addition, we conducted subgroup analyses, a sensitivity analysis, and a funnel plot to test the reliability of the results. We further validated these meta-analysis results using the Kaplan-Meier plotter database and The Cancer Genome Atlas (TCGA) database. In addition, we have investigated the correlation between EZH2 expression and EGFR expression, KRAS expression, BRAF expression, and smoking in TCGA database to further explore the mechanism behind the influence of high EZH2 expression on lung cancer prognosis.

Results

13 studies including 2180 participants were included in the meta-analysis. We found that high expression of EZH2 indicates a poor prognosis of NSCLC (HR = 1.65 and 95% CI 1.16-2.35; p ≤ 0.001). Subgroup analyses showed high heterogeneity in stages I-IV (I ² = 85.1% and p ≤ 0.001) and stages I-III (I ² = 66.9% and p = 0.029) but not in stage I (I ² = 0.00% and p = 0.589). In the Kaplan-Meier plotter database, there was a high expression in 963 cases and low expression in 964 cases (HR = 1.31 and 95% CI 1.15-1.48; p < 0.05). Further analysis found that the high expression of EZH2 was statistically significant in lung adenocarcinoma (HR = 1.27and 95% CI 1.01-1.6; p = 0.045), but not in lung squamous cell carcinoma (HR = 1.03 and 95% CI 0.81-1.3; p = 0.820). The results of the TCGA database showed that the expression of EZH2 in normal tissues was lower than that in lung cancer tissues (p < 0.05). Smoking was associated with high expression of EZH2 (p < 0.001). EZH2 was also highly expressed in lung cancers with positive KRAS expression, and the correlation was positive in lung adenocarcinoma (r = 0.3129 and p < 0.001). The correlation was also positive in lung squamous cell carcinoma (r = 0.3567 and p < 0.001). EZH2 expression was positively correlated with BRAF expression (r = 0.2397 and p < 0.001), especially in lung squamous cell carcinoma (r = 0.3662 and p < 0.001). In lung squamous cell carcinoma, a positive yet weak correlation was observed between EZH2 expression and EGFR expression (r = 0.1122 and p < 0.001).

Conclusions

The high expression of EZH2 indicates a poor prognosis of NSCLC, which may be related to tumor stage or cancer type. EZH2 may be an independent prognostic factor for NSCLC. EZH2 high expression or its synergistic action with KRAS and BRAF mutations affects the prognosis of non-small-cell lung cancer.

Validation of the 8th lung cancer TNM classification and clinical staging system in a German cohort of surgically resected patients

OBJECTIVES

The updated 8th edition of the tumor, node, metastases (TNM) classification system for non-small cell lung cancer (NSCLC) attempts to improve on the previous 7th edition in predicting outcomes and guiding management decisions. This study sought to determine whether the 8th edition was more accurate in predicting long-term survival in a European population of surgically treated NSCLC patients.

METHODS

We scanned the archives of the Heckeshorn Lung Clinic for patients with preoperative clinical stages of IIIA or lower (based on the 7th edition), who received surgery for NSCLC between 2009 and 2014. We used pathologists' reports and data on tumor size and location to reassign tumor stages according to the 8th edition. We then analyzed stage specific survival and compared the accuracy of the two systems in predicting long-term survival. We excluded patients with neoadjuvant treatment, incomplete follow-up data, tumor histologies other than NSCLC, or death within 30 days of surgery.

RESULTS

The final analysis included 1,013 patients. Overall five-year survival was 47.3%. The median overall survival (OS) was 63 months (range 1-222), and the median disease-free survival (DFS) was 50 months (0-122). The median follow-up time for non-censored patients was 84 months (range 60-122).

CONCLUSIONS

We found significant survival differences between the newly defined stages 1A1, 1A2 and 1A3 (previously 1A). We also found that the 8th edition of TMN classification was a significantly better predictor of long-term survival, compared to the 7th edition.

Validation of the 8th edition of the TNM staging system in 3,950 patients with surgically resected non-small cell lung cancer

BACKGROUND

The International Association for the Study of Lung Cancer introduced the 8th edition of the tumor, node, and metastasis (TNM) staging system for lung cancer. In this study, we validated the 8th edition of the TNM staging system and compared its discrimination power with that of the previous 7th edition.

METHODS

A retrospective analysis was carried out on patients who underwent complete resection with systematic lymph node dissection for non-small cell lung cancer (NSCLC) between 2006 and 2015 at a tertiary referral center in Seoul, South Korea. Cox regression model was used to identify significant differences between adjacent TNM stage groupings. The Concordance index (C-index), Akaike Information Criterion (AIC), and R2 measure were utilized to evaluate the discrimination ability of the staging systems.

RESULTS

A total of 3,950 patients (2,440 male, median age: 63 years) were analyzed. Median follow-up was 59 months (interquartile ranges, 38-88 months). According to the 8th edition, survival curves of overall survival (OS) and recurrence-free survival (RFS) within adjacent stage groupings showed significant differences except for IIA vs. IIB. Compared with the 7th edition, the 8th edition showed higher C-index (0.753 vs. 0.751), lower AIC (17,517 vs. 17,543), and higher R2 (0.178 vs. 0.171) values, indicating better discrimination ability.

CONCLUSIONS

Stratification based on the 8th edition of the TNM staging system showed favorable prognostic validity compared with the 7th edition. The 8th edition also had superior discrimination ability in terms of OS and RFS.

Validation of the AJCC 8th lung cancer staging system among patients with small cell lung cancer

BACKGROUND

The current study tried to validate the prognostic significance of the 8th American Joint Committee on Cancer (AJCC) staging system among small cell lung cancer (SCLC) patients recorded within the surveillance, epidemiology, and end results (SEER) database.

PATIENTS AND METHODS

SEER database (2004-2014) has been queried through SEER*Stat program, and both AJCC 7th and 8th edition stages were constructed. Cancer-specific and overall survival analyses according to both editions were performed through Kaplan-Meier analysis. The cause-specific Cox regression hazard for both AJCC editions (adjusted for age, gender, race, and surgery) was calculated and pair-wise comparisons of hazard ratios were conducted.

RESULTS

A total of 39,286 patients with SCLC were recruited in the period from 2004 to 2014. For overall and cancer-specific survival assessment, according to the AJCC 7th edition, P values for all pair-wise comparisons among different stages were significant (<0.0001) except for the comparisons between stage IB vs. stage IIA, and stage IIB vs. stage IIIA. For overall survival assessment, according to AJCC 8th, P values for all pair-wise comparisons were significant (<0.05) except for IA2 vs. IA3, IA3 vs. IB, IB vs. IIA, IIA vs. IIB, and IIIB vs. IIIC. For cancer-specific survival, according to AJCC 8th, P values for all pair-wise comparisons among different stages were significant (<0.05) except IA1 vs. IA2, IA2 vs. IA3, and IIA vs. IIB. When conducting pair-wise hazard ratio comparisons among different AJCC stages (for both editions), similar findings to the Kaplan-Meier analyses were reported.

CONCLUSION

While there is a clear improvement for both the AJCC 7th and 8th systems compared to the old veterans' administration system, there is a modest improvement for the 8th compared to the 7th system among patients with SCLC.

Multi-institutional analysis of T3 subtypes and adjuvant radiotherapy effects in resected T3N0 non-small cell lung cancer patients

Purpose

We evaluated the prognostic significance of T3 subtypes and the role of adjuvant radiotherapy in patients with resected the American Joint Committee on Cancer stage IIB T3N0M0 non-small cell lung cancer (NSCLC).

Materials and Methods

T3N0 NSCLC patients who underwent resection from January 1990 to October 2009 (n = 102) were enrolled and categorized into 6 subgroups according to the extent of invasion: parietal pleura chest wall invasion, mediastinal pleural invasion, diaphragm invasion, separated tumor nodules in the same lobe, endobronchial tumor <2 cm distal to the carina, and tumor-associated collapse.

Results

The median overall survival (OS) and disease-free survival (DFS) were 55.3 months and 51.2 months, respectively. In postoperative T3N0M0 patients, the tumor size was a significant prognostic factor for survival (OS, p = 0.035 and DFS, p = 0.035, respectively). Patients with endobronchial tumors within 2 cm of the carina also showed better OS and DFS than those in the other T3 subtypes (p = 0.018 and p = 0.016, respectively). However, adjuvant radiotherapy did not cause any improvement in survival (OS, p = 0.518 and DFS, p = 0.463, respectively). Only patients with mediastinal pleural invasion (n = 25) demonstrated improved OS and DFS after adjuvant radiotherapy (n = 18) (p = 0.012 and p = 0.040, respectively).

Conclusion

The T3N0 NSCLC subtype that showed the most favorable prognosis is the one with endobronchial tumors within 2 cm of the carina. Adjuvant radiotherapy is not effective in improving survival outcome in resected T3N0 NSCLC.

Lung cancer prognosis before and after recurrence in a population-based setting

BACKGROUND

Population-based estimates of absolute risk of lung cancer recurrence, and of mortality rates after recurrence, can inform clinical management.

METHODS

We evaluated prognostic factors for recurrences and survival in 2098 lung cancer case patients from the general population of Lombardy, Italy, from 2002 to 2005. We conducted survival analyses and estimated absolute risks separately for stage IA to IIIA surgically treated and stage IIIB to IV non-surgically treated patients.

RESULTS

Absolute risk of metastases exceeded that of local recurrence in every stage and cell type, highlighting the systemic threat of lung cancer. In stage I, the probability of dying within the first year after diagnosis was 2.7%, but it was 48.3% within first year after recurrence; in stage IV, the probabilities were 57.3% and 80.6%, respectively. Over half the patients died within one year of first metastasis. Although in stages IA to IB about one-third of patients had a recurrence, stage IIA patients had a recurrence risk (61.2%) similar to stage IIB (57.9%) and IIIA (62.8%) patients. Risk of brain metastases in stage IA to IIIA surgically treated non-small cell lung cancer patients increased with increasing tumor grade. Absolute risk of recurrence was virtually identical in adenocarcinoma and squamous cell carcinoma patients.

CONCLUSIONS

This population-based study provides clinically useful estimates of risks of lung cancer recurrence and mortality that are applicable to the general population. These data highlight the need for more effective adjuvant treatments overall and within specific subgroups. The estimated risks of various endpoints are useful for designing clinical trials, whose power depends on absolute numbers of events.

The solitary pulmonary nodule in patients with previous cancer history: results of surgical treatment

BACKGROUND

The present study was carried out to evaluate the characteristics of solitary pulmonary nodule (SPN) in patients with previous cancer(s) and to analyse the outcome of its surgical treatment.

METHODS

We retrospectively analysed 131 patients with history of previous malignancy submitted to lung surgery for new identified SPN between January 2004 and December 2009.

RESULTS

The diagnosis was metastasis in 65 patients, primary lung cancer in 57, benign lesion in 9. Primary lung cancers were significantly larger, had higher maxSUV at CT-PET scanning, occurred after a longer disease-free interval in patients older and with worse lung function when compared with metastatic lesions. Overall survival at 5-year was 67% for benign lesions, 62% for primary lung cancer, 48% for metastatic disease. Histological subtype, SPN diameter less than 2 cm and DFI >36 months were factors influencing long-term prognosis of metastatic patients. Histological subtype and pathological staging were factors influencing long-term outcome of primary lung cancer patients.

DISCUSSION

Surgical resection of solitary pulmonary nodule is essential in patients with history of previous cancer to rule out benign lesions, to offer diagnostic confirmation and local control of the disease in metastatic tumours and to correctly stage and treat primary lung cancer.

Survival, classifications, and desmosomal plaque genes in non-small cell lung cancer

Novel biomarkers are required to improve prognostic predictions obtained with lung cancer staging systems. This study of 62 surgically-treated Non-Small Cell Lung Cancer (NSCLC) patients had two objectives: i) to compare the predictive value of T-stage classifications between the 6(th) and 7(th) editions of the Tumor, Node, and Metastasis staging system (TNM); and ii) to examine the association of Pkp1 and/or Krt15 gene expression with survival and outcomes. Multivariate and Kaplan-Meier survival analyses were performed, examining the relationship of survival with T-stage, recurrence, and TNM-stage (by each TNM edition) and with the single/combined expression of Pkp1 and/or Krt15 genes. Five-year survival rates only significantly differed as a function of T-stage in patients without recurrence when estimated using the 6(th) edition of the TNM classification and only in patients in pathologic TNM-stage IA using the 7(th). Overall survival for patients with elevated expression of both genes was 13.5 months in those with adenocarcinoma and 34.6 months in those with squamous cell carcinoma. Overall survival was 30.4 months in patients with Pkp1 gene upregulation and 30.9 months in those with Krt15 gene upregulation. In conclusion, survival estimations as a function of T-staging differed between the 6(th) and 7(th) editions of TNM. Overall survival differed according to the expression of Pkp1 and/or Krt15 genes, although this relationship did not reach statistical significance.

Unification of T2a and T2b tumors to T2 tumors in non-small cell lung cancer staging

INTRODUCTION

We investigated the validation of the seventh edition of the TNM staging (2009) system for lung cancer, retrospectively.

METHODS

From January 1990 to March 2004, 1629 patients who underwent lung resection with systemic lymph node dissection for non-small cell lung cancer at Nippon Medical School and Saitama Cancer Center were included. The overall survivals after surgery by each pathological stage according to the 1997 and 2009 systems were statistically analyzed using Kaplan-Meier estimated survival curves, and the significance of the difference was analyzed by the log-rank test.

RESULTS

The 2009 system had significant prognostic distinction between each T descriptor except for T2a and T2b, and between each M descriptor. The 2009 system had better prognostic distinction between each pathological stage except for stages IB and IIA, and stages IIIB and IV. In the simulation, we unified T2a and T2b tumors into T2 tumors, and T2bN0M0 and T2bN1M0 were moved to stages IB and IIA, respectively. This proposed system had significant prognostic distinction between the proposed IB, IIA, and IIB stages.

CONCLUSIONS

The 2009 system provides better patient selection for surgery and prognostic distinction between each stage except for stages IB and IIA, and stages IIIB and IV, compared with the 1997 system. Unification of T2a and T2b tumors to T2 tumors can improve prognostic distinction between stages IB and IIA.

PET/CT imaging in different types of lung cancer: an overview

Lung cancer (LC) still represents one of the most common tumours in both women and men. PET/CT is a whole-body non-invasive imaging procedure that has been increasingly used for the assessment of LC patients. In particular, PET/CT added value to CT is mainly related to a more accurate staging of nodal and metastatic sites and to the evaluation of the response to therapy. Although the most common PET tracer for LC evaluation is 18F-FDG, new tracers have been proposed for the evaluation of lung neuroendocrine tumours (68Ga-DOTA-peptides, 18F-DOPA) and for the assessment of central nervous system metastasis (11C-methionine). This review focuses on the main clinical applications and accuracy of PET/CT for the detection of non-small cells lung cancer (NSCLC), broncho-alveolar carcinoma (BAC), small cells lung cancer (SCLC), lung neuroendocrine tumours (NET) and solitary pulmonary nodules (SPN).

Impact of parenchymal tuberculosis sequelae on mediastinal lymph node staging in patients with lung cancer

Because tuberculous (TB) involvement of mediastinal lymph nodes (LN) could cause false positive results in nodal staging of lung cancer, we examined the accuracy of nodal staging in lung cancer patients with radiographic sequelae of healed TB. A total of 54 lung cancer patients with radiographic TB sequelae in the lung parenchyma ipsilateral to the resected lung, who had undergone at least ipsilateral 4- and 7-lymph node dissection after both chest computed tomography (CT) and fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT were included for the analysis. The median age of 54 subjects was 66 yr and 48 were males. Calcified nodules and fibrotic changes were the most common forms of healed parenchymal pulmonary TB. Enlarged mediastinal lymph nodes (short diameter > 1 cm) were identified in 21 patients and positive mediastinal lymph nodes were identified using FDG-PET/CT in 19 patients. The overall sensitivity and specificity for mediastinal node metastasis were 60.0% and 69.2% with CT and 46.7% and 69.2% with FDG-PET/CT, respectively. In conclusion, the accuracy of nodal staging using CT or FDG-PET/CT might be low in lung cancer patients with parenchymal TB sequelae, because of inactive TB lymph nodes without viable TB bacilli.