Detection of Occult Micrometastases in Patients With Clinical Stage I Non-Small-Cell Lung Cancer: A Prospective Analysis of Mature Results of CALGB 9761 (Alliance)

Can cell-free DNA (cfDNA) in pleural lavage serve as a predictive and prognostic biomarker among surgically treated Stage I-III a nonsmall cell lung cancer (NSCLC)? A pilot study

BACKGROUND AND OBJECTIVES

The role of cell-free DNA (cfDNA) in operable nonsmall cell lung cancer (NSCLC) is unclear. This study was aimed to evaluate the feasibility for identification of cfDNA in pleural lavage fluid and its correlation with plasma in resectable NSCLCs.

METHODS

Consecutively resected NSCLCs were evaluated for cfDNA levels in preoperative plasma (PLS1), intraoperative pleural-lavage (PLV) and postoperative (at 1 month) plasma sample (PLS2). CfDNA was isolated and measured quantitatively by qPCR in a TaqMan probe-detection approach using the human β-actin gene as the amplifying target.

RESULTS

All (n = 34) except one were negative for malignant cells in PLV cytology. CfDNA could be isolated from all the three samples (PLS1, PLV, and PLS2) successfully in each patient. The median cfDNA levels in PLS1, PLV and PLS2 were 118 ng/mL (IQR 61-158), 167 ng/mL (IQR 59.9-179.9) and 103 ng/mL (IQR 66.5-125.4) respectively. The median follow-up was 34.1 months (IQR 25.2-41.6). A significant overall-survival (OS) and disease-free survival (DFS) were recorded for patients with cfDNA level cut-offs at 125, 170, and 100 ng/mL, respectively for PLS1, PLV, and PLS2. Patients with raised cfDNA in PLS1 (>125 ng/mL) and PLV (>170 ng/mL) had significantly poorer 2-year OS, p = 0.005 and p = 0.012, respectively. The hazards (OS) were also higher for those with raised cfDNA in PLV (HR = 5.779, 95% CI = 1.162-28.745, p = 0.032). PLV (>170 ng/mL) had increased pleural recurrences (p = 0.021) and correlated significantly with poorer DFS at 2-years (p = 0.001) with increased hazards (HR = 9.767, 95% CI = 2.098-45.451, p = 0.004). Multivariable analysis suggested higher cfDNA in PLV as a poor prognostic factor for both OS and DFS.

CONCLUSIONS

Among patients with operable NSCLC, it is feasible to identify cfDNA in pleural lavage and correlate PLV cfDNA with pleural recurrences and outcomes.

Prognostic role of lymph node micrometastasis in pN0 esophageal cancer: A meta-analysis

BACKGROUND

To further identify the association between the lymph node micrometastasis (LNM) and long-term survival among pN0 esophageal cancer patients receiving the surgery.

METHODS

Several databases were searched for relevant studies up to June 22, 2023. The primary and secondary outcomes were separately overall survival (OS) and relapse-free survival (RFS) and hazard ratios (HRs) with 95% confidence intervals (CIs) were combined. Subgroup analysis based on pathological type and source of HR was further performed. All statistical analyses were conducted by STATA 15.0 software.

RESULTS

A total of 20 studies involving 1830 pN0 patients were included in this meta-analysis. The pooled results demonstrated that the presence of LNM indicated significantly worse OS (HR = 2.19, 95% CI = 1.77-2.70, P < .001) and RFS (HR = 2.15, 95% CI = 1.65-2.80, P < .001). Besides, subgroup analysis for the OS and RFS stratified by the pathological type (squamous cell carcinoma vs mixed esophageal cancer) and source of HR (reported vs estimated) further identified the significant relationship of LNM with prognosis in surgical esophageal cancer.

CONCLUSION

The presence of LNM indicated significantly poorer long-term survival among operated pN0 esophageal cancer patients. LNM could serve as a novel and reliable prognostic indicator in surgical esophageal cancer.

Frequency and predictive factors of nodal micro-metastasis (NMM) in resectable non-small cell lung cancer

Background

The frequency of lymph nodal micrometastasis (NMM) in resectable non-small cell lung cancer (NSCLC) is frequently underestimated when relying solely on standard hematoxylin and eosin staining during pathological examination.

Methods

This is a retrospective cross-sectional diagnostic research. Medical records of resectable pN0 NSCLC patients who underwent curative resection in Maharaj Nakorn Chiang Mai Hospital between January 2006 to December 2017 were retrospectively reviewed. Immunohistochemistry (IHC) staining using cytokeratin AE1/AE3, p53 and BerEP4 markers was employed to detect NMM. Primary objective of this study was to determine frequency of NMM in pN0 resectable NSCLC.

Results

This study included 98 patients with pN0 NSCLC, of which 47 were male and 51 were female. NMM was detected in 21 of 98 patients (21.43%). Lymph node station 10 and 7 were the most common site of micrometastasis among patients with N1 and N2 micrometastasis, respectively. Cytokeratin AE1/AE3 was the most sensitive antibody in detecting micrometastasis in lymph nodes, identifying 25 out of 27 positive lymph nodes. Tumor size greater than 4 cm was a statistically significant predictive factor for NMM with risk ratio 6.69 [95% confidence interval (CI): 2.38-18.85, P<0.001].

Conclusions

NMM was identified in 21.43% of pN0 resectable NSCLC patients and tumor size greater than 4 cm is predictive factor for NMM.

The possibility of mutations of RAS signaling genes and/or TP53 in combination as a negative prognostic impact on pathological stage I non-small cell lung cancer

BACKGROUND

The recurrence rate of non-small cell lung cancer (NSCLC) is as high as 30%, even in the cancer with pathological stage I disease. Therefore, identifying factors predictive of high-risk pathological recurrence is important. However, few studies have examined the genetic status of these tumors and its relationship to prognosis.

MATERIALS AND METHODS

A cohort of 328 cases of primary lung cancer that underwent complete resection at Tokyo Medical and Dental University (TMDU) was screened for 440 cancer-associated genes using panel testing. Further analyses included 92 cases of pathological stage I NSCLC who did not receive adjuvant chemotherapy. Ridge regression was performed to identify association studies mutational status and postoperative recurrence. These data were then validated using clinical and genetic data from 56 patients in The Cancer Genome Atlas (TCGA).

RESULTS

Mutations in TP53, RAS signaling genes KRAS and HRAS, and EGFR were recurrently detected. Ridge regression analysis relevant to recurrence, as well as survival analysis, performed using data from the TMDU cohort revealed significantly shorter relapse-free survival (RFS) for patients with RAS signaling or TP53 gene mutations than for those without (log-rank test, p = 0.00090). This statistical trend was also suggested in the TCGA cohort (log-rank test, p = 0.10).

CONCLUSION

Mutations in RAS signaling genes and/or TP53 could be useful for the prediction of shorter RFS of patients with stage I NSCLC.

Combination of CEACAM5, EpCAM and CK19 gene expressions in mediastinal lymph node micrometastasis is a prognostic factor for non-small cell lung cancer

BACKGROUND

Lung cancer is known as the most common and highly metastatic form of cancer worldwide. Tumour node metastasis (TNM) staging is the gold standard classification system for the decision-making process for appropriate treatment. Particularly N status has the most important prognostic value in the absence of distant metastasis. Traditional diagnostic methods are capable of detecting metastasis; however, they may fail to detect micrometastasis, which plays a role in disease recurrence and patients' long-term survival. Occult micrometastasis can change the tumour's TNM staging and, consequently, the patient's treatment regimen.

METHODS

The median number of three lymph node tissues were collected from 30 patients who underwent surgery for non-small cell lung cancer. Lymph node tissues were collected from different lymph node stations according to the location of the patient's tumour. CK19, EpCAM and CEACAM5 gene expressions were analysed in tissues using quantitative real-time polymerase chain reaction to detect micrometastasis in distant lymph nodes.

RESULTS

Triple positivity was seen in 26 out of 30 patients which 19 patients were upstaged from N0 to N2. While survival was not significantly affected between upstaged and non-upstaged patients, patients upstaged with multiple-station N2 had a significantly higher recurrence and lower survival compared to single-station N2.

CONCLUSION

A combination of CK19, EpCAM and CEACAM5 gene expressions in lymph nodes can be used to identify micrometastasis which postoperatively may be used as a tool to predict patients' recurrence and survival.

Systematic review and meta-analysis of the prognostic impact of lymph node micrometastasis and isolated tumour cells in patients with stage I-IIIA non-small cell lung cancer

Lymph node micrometastases could be one of the reasons for the high recurrence rate after complete surgical resection in stage I-IIIA non-small cell lung cancer (NSCLC). The standard evaluation of a single haematoxylin and eosin (H&E) slide of a paraffin-embedded section of a lymph node is insufficient for the detection of micrometastases, and there is a need for additional histopathological evaluation. The association of lymph node micrometastases with survival remains as yet unresolved. The aim of this systematic review and meta-analysis is to investigate if lymph node micrometastases and isolated tumour cells in patients with stage I-IIIA NSCLC, detected with multiple sectioning and/or immunohistochemistry (IHC) and/or reverse transcriptase polymerase chain reaction (RT-PCR), are associated with overall survival (OS) and disease-free survival (DFS) after surgical resection. We performed a meta-analysis of time-to-event outcomes based on 15 articles using ancillary techniques to detect micrometastases. We extracted the OS and DFS every 3-6 months after surgery, for patients with and without occult lymph node micrometastasis, from the survival curves published in each article. These data were used to reconstruct OS and DFS for 'micrometastasis' and 'no micrometastasis' groups. Based on all included studies that used IHC, serial sectioning, or RT-PCR, we found a 5-year OS of 55% (micrometastasis) vs. 75% (no micrometastasis), and a 5-year DFS of 53% (micrometastasis) vs. 75% (no micrometastasis). Patients with stage I-IIIA NSCLC with lymph node micrometastases detected by ancillary histopathological and molecular techniques have a significantly poorer OS and DFS compared to patients without lymph node micrometastases.

Long Noncoding RNA SNHG7 Is a Diagnostic and Prognostic Marker for Colon Adenocarcinoma

Numerous studies have shown that long noncoding RNAs (lncRNAs) play a critical role in the malignant progression of cancer. However, the potential involvement of lncRNAs in colon adenocarcinoma (COAD) remains unexplored. In this study, the expression of lncRNA SNHG7 in colon cancer tissues and its correlation with clinical characteristics were analyzed based on data from The Cancer Genome Atlas (TCGA) database. SNHG7 was found to be highly expressed in 17 types of cancer, including COAD. Next, TCGA data were further investigated to identify differentially expressed genes, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed. In addition, the relationship between SNHG7 expression and clinical features were analyzed. SNHG7 expression was found to be a potentially valuable indicator for COAD diagnosis and prognosis. Finally, gene set enrichment analysis showed that SNHG7 may affect lupus erythematosus and reactome cellular senescence, possibly influencing the prognosis of patients with COAD. Altogether, these results suggest that SNHG7 may be associated with the occurrence and development of COAD, having potential diagnostic and prognostic value.

Lymph node micrometastasis in non-small cell lung cancer

Lung cancer has some of the highest morbidity and mortality rates of all cancers, and an important risk factor for mortality in patients with lung cancer is tumor metastasis. Even if a tumor is completely removed at an early stage of the disease, quite a number of patients still have the risk of recurrence. With the advent of molecular diagnostic and therapeutics, more and more studies have found that a poor prognosis may be related to lymph node micrometastasis. However, clinicians still find that predicting the prognosis and choosing the type of surgery and postoperative adjuvant chemotherapy are still challenging. Thus, this article reviews the current research status of lymph node micrometastasis in non-small cell lung cancer, envision to provide some updates and insights in this area.

Oncogenic Alterations in Histologically Negative Lymph Nodes Are Associated with Prognosis of Patients with Stage I Lung Adenocarcinoma

Simple Summary

Lymph nodes (LNs) metastasis is one of the most important factors affecting the outcome of non-small cell lung. The aim of this study is to explore whether presence of oncogenic alterations in histologically-negative lymph nodes (LNs) can be of prognostic significance in stage I lung adenocarcinoma (LUAD). We confirmed that presence of oncogenic alterations in regional LN may be associated with higher risks of postsurgical recurrence of Stage I LUAD, particularly for certain molecular subgroups. These results warranted future studies on larger cohort of NSCLC patients using more comprehensive cancer gene panels to establish the clinical impact of molecular LN occult metastasis for localized NSCLC and identify Stage I patients at high risks for recurrence for appropriate adjuvant therapy.

Abstract

Background: Survival of patients with stage I non-small cell lung cancer (NSCLC) varies greatly. We sought to explore whether presence of oncogenic alterations in histologically-negative lymph nodes (LNs) can be of prognostic significance in stage I lung adenocarcinoma (LUAD). Methods: Genomic analysis of oncogenic alterations was applied to 123 stage I LUAD tumors. The same genomic variants identified in primary tumors were examined in corresponding histologically-negative LNs. Results: A total of 102 (82.9%) patients had at least one canonical oncogenic alteration detected in primary tumors, and 57 LNs from 12 patients (11.8%) were found to carry the identical oncogenic alterations detected in the corresponding primary tumor tissues, including EGFR mutations (six cases), KRAS mutations (three cases), ALK fusion (one case), BRAF mutation (one case) and HER2 & NRAS co-mutations (one case). None of these LNs was found to have occult tumor cells by routine pathological assessment or immunohistochemistry staining using antibodies against pan-cytokeratins (AE1/AE3) and the epithelial marker Ber-EP4. The detection rate of oncogenenic alterations in LN was significantly higher in RAS-mutant tumors than EGFR mutant tumors (36.36% verse 7.41%, p = 0.017). Patients with oncogenic alterations in LN showed inferior disease-free survival (DFS, p = 0.025) and overall survival (OS, p = 0.027). Furthermore, patients with RAS-mutations detected in LN had the worst DFS and OS (p = 0.001). Among the 11 patients with RAS mutation in primary tumors, DFS and OS in the four patients with mutations detected in LN were significantly shorter than the remaining seven patients without mutations LN (DFS, p = 0.001, OS, p = 0.002). Conclusions: Genomic analysis has the potential to detect oncogenic alterations in regional LNs for localized LUAD and presence of oncogenic alterations in regional LN may be associated with inferior clinical outcome of stage I LUAD, particularly for certain molecular subgroups. ClinicalTrials.gov ID NCT04266691

MCTS1 promotes the development of lung adenocarcinoma by regulating E2F1 expression

Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer that results in the majority of cancer-associated mortality. Multiple copies in T-cell lymphoma-1 (MCTS1) is an oncogene that is expressed at high levels in several types of cancer tissues. However, its exact role and pathomechanism in the development of LUAD remains unknown. Reverse transcription-quantitative PCR analysis was performed to detect MCTS1 expression. Immunohistochemistry analysis was performed to detect MCTS1 expression in LUAD tissues and normal tissues. The MTT, colony formation, EdU, flow cytometry, wound healing and Transwell assays were performed to assess the proliferation, apoptosis, migration and invasion of LUAD cells. Western blot analysis was performed to detect protein expression levels. The present study aimed to investigate the effects of MCTS1 on the progression of LUAD and the potential mechanisms underlying its effects. The results demonstrated that MCTS1 expression was upregulated in LUAD tissues and cells, which was associated with an unfavorable outcome in patients with LUAD. MCTS1 knockdown inhibited LUAD progression by suppressing cell viability and motility, and promoting apoptosis. In addition, E2F1 protein expression was attenuated following MCTS1 knockdown. The silencing MCTS1-induced inhibitory effect on LUAD malignancy was reversed following overexpression of E2F1 by modulating the c-Myc signaling pathway. Taken together, the results of the present study suggest that MCTS1 facilitates cell proliferation and migration, and suppresses apoptosis of LUAD cells by regulating E2F1 expression and the c-Myc signaling pathway.

Intraoperative Detection of Micrometastases in Whole Excised Lymph Nodes Using Fluorescent Paired-Agent Imaging Principles: Identification of a Suitable Staining and Rinsing Protocol

PURPOSE

Correctly identifying nodal status is recognized as a critical prognostic factor in many cancer types and is essential to guide adjuvant treatment. Currently, surgical removal of lymph nodes followed by pathological examination is commonly performed as a standard-of-care to detect node metastases. However, conventional pathology protocols are time-consuming, yet less than 1 % of lymph node volumes are examined, resulting in a 30-60 % rate of missed micrometastases (0.2-2 mm in size).

PROCEDURES

This study presents a method to fluorescently stain excised lymph nodes using paired-agent molecular imaging principles, which entail co-administration of a molecular-targeted imaging agent with a suitable control (untargeted) agent, whereby any nonspecific retention of the targeted agent is accounted for by the signal from the control agent. Specifically, it was demonstrated that by dual-needle continuous infusion of either an antibody-based imaging agent pair (epidermal growth factor receptor (EGFR) targeted agent: IRDye-800CW labeled Cetuximab; control agent: IRDye-700DX-IgG) or an Affibody-based pair (EGFR targeted Affibody® agent: ABY-029; control agent IRDYe-700DX carboxylate) at 0.3 ml/min.

RESULTS

The results demonstrated the possibility to achieve >99 % sensitivity and > 95 % specificity for detection of a single micrometastasis (~0.2 mm diameter) in a whole lymph node within 22 min of tissue processing time.

CONCLUSION

The detection capabilities offer substantial improvements over existing intraoperative lymph node biopsy methods (e.g., frozen pathology has a micrometastasis sensitivity <20 %).

Molecular Nodal Restaging Based on CEACAM5, FGFR2b and PTPN11 Expression Adds No Relevant Clinical Information in Resected Non-Small Cell Lung Cancer

BACKGROUND

The relapse rate in non-small cell lung cancer (NSCLC) is high, even in localized disease, suggesting that the current approach to pathological staging is insufficiently sensitive to detect occult micrometastases present in resected lymph nodes. Therefore, we aimed to determine the prognostic value of the expression of embryonic molecular markers in histologically-negative lymph nodes of completely-resected NSCLC.

METHODS

76 completely-resected NSCLC patients were included: 60 pN0 and 16 pN1. Primary tumors and 347 lymph node were studied. CEACAM5, FGFR2b, and PTPN11 expression levels were evaluated through mRNA analysis using real-time RT-qPCR assay. Statistical analyses included the Kruskal-Wallis test, Kaplan Meier curves, and log-rank tests.

RESULTS

CEACAM5 expression levels were scored as high in of 90 lymph nodes (26%). The molecular-positive lymph nodes lead to the restaging of 37 (62%) pN0 patients as molecular N1 or N2 and 5 (31%) pN1 cases were reclassified as molecular-positive N2. Surprisingly, molecular-positive patients associated with a better OS (overall survival, p = 0,04). FGFR2b overexpression was observed in 41 (12%) lymph nodes leading to the restaging of 17 patients (22%). Again a trend was observed toward a better DFS (disease-free survival) in the restaged patients (p = 0,09). Accordingly, high expression levels of CEACAM5 or FGFR2b in the primary were related to better DFS (p = 0,06; p < 0,02, respectively).

CONCLUSION

Molecular nodal restaging based on expression levels of CEACAM5 and/or FGFR2b, does not add relevant clinical information to pathological staging of NSCLC likely related to the better prognosis of their overexpression in primary tumors.

Prognostic value of occult lymph node metastases in patients with completely resected esophageal squamous cell carcinoma

To investigate the prognostic value of occult lymph node metastases (OLNMs) in patients with pathologically lymph node negative (pN0) esophageal squamous cell carcinoma (ESCC). OLNMs were detected in 516 pN0 ESCC patients by immunohistochemical staining. The correlation between the clinicopathological features and OLNM, and the prognostic value of OLNM was explored. Eighty-eight patients (17.1%) had OLNMs, including 37 patients with isolated tumor cells (ITCs), 49 patients with micrometastases, and 2 patients with macrometastases (> 2 mm). The OLNM-positive group had poorer differentiation and a more advanced pT category. The 5-year overall survival and disease-free survival for patients with OLNMs were significantly worse than those of IHC-negative patients (P < 0.001), but similar to those of the pN1 patients (P > 0.05). The multivariate analysis showed that OLNM was an independent prognostic factor. In subgroup analyses, the IHC-negative patients had significant survival advantages compared with the ITC group and the micrometastasis group, whereas the survival for the ITC group was similar to that of the micrometastasis group. IHC staining in pN0 ESCC patients might help to identify patients at high risk of death after resection, and ITCs in the lymph nodes appear to have a prognostic value equal to that of micrometastases.

An Externally-Validated Dynamic Nomogram Based on Clinicopathological Characteristics for Evaluating the Risk of Lymph Node Metastasis in Small-Size Non-small Cell Lung Cancer

Background: Lymph node metastasis (LNM) status is of key importance for the decision-making on treatment and survival prediction. There is no reliable method to precisely evaluate the risk of LNM in NSCLC patients. This study aims to develop and validate a dynamic nomogram to evaluate the risk of LNM in small-size NSCLC.

Methods: The NSCLC ≤ 2 cm patients who underwent initial pulmonary surgery were retrospectively reviewed and randomly divided into a training cohort and a validation cohort as a ratio of 7:3. The training cohort was used for the least absolute shrinkage and selection operator (LASSO) regression to select optimal variables. Based on variables selected, the logistic regression models were developed, and were compared by areas under the receiver operating characteristic curve (AUCs) and decision curve analysis (DCA). The optimal model was used to plot a dynamic nomogram for calculating the risk of LNM and was internally and externally well-validated by calibration curves.

Results: LNM was observed in 12.0% (83/774) of the training cohort and 10.1% (33/328) of the validation cohort (P = 0.743). The optimal model was used to plot a nomogram with six variables incorporated, including tumor size, carcinoembryonic antigen, imaging density, pathological type (adenocarcinoma or non-adenocarcinoma), lymphovascular invasion, and pleural invasion. The nomogram model showed excellent discrimination (AUC = 0.895 vs. 0.931) and great calibration in both the training and validation cohorts. At the threshold probability of 0–0.8, our nomogram adds more net benefits than the treat-none and treat-all lines in the decision curve.

Conclusions: This study firstly developed a cost-efficient dynamic nomogram to precisely and expediently evaluate the risk of LNM in small-size NSCLC and would be helpful for clinicians in decision-making.

Exploiting the folate receptor α in oncology

Folate receptor α (FRα) came into focus as an anticancer target many decades after the successful development of drugs targeting intracellular folate metabolism, such as methotrexate and pemetrexed. Binding to FRα is one of several methods by which folate is taken up by cells; however, this receptor is an attractive anticancer drug target owing to the overexpression of FRα in a range of solid tumours, including ovarian, lung and breast cancers. Furthermore, using FRα to better localize effective anticancer therapies to their target tumours using platforms such as antibody-drug conjugates, small-molecule drug conjugates, radioimmunoconjugates and, more recently, chimeric antigen receptor T cells could further improve the outcomes of patients with FRα-overexpressing cancers. FRα can also be harnessed for predictive biomarker research. Moreover, imaging FRα radiologically or in real time during surgery can lead to improved functional imaging and surgical outcomes, respectively. In this Review, we describe the current status of research into FRα in cancer, including data from several late-phase clinical trials involving FRα-targeted therapies, and the use of new technologies to develop FRα-targeted agents with improved therapeutic indices.

miR-134-5p Promotes Stage I Lung Adenocarcinoma Metastasis and Chemoresistance by Targeting DAB2

Despite surgery and adjuvant therapy, early-stage lung adenocarcinoma (LUAD) treatment often fails due to local or metastatic recurrence. However, the mechanism is largely unknown. Here, we report that increased expression levels of miR-134-5p and decreased levels of disabled-2 (DAB2) were significantly correlated with recurrence in stage I LUAD patients. Our data show that miR-134-5p overexpression or DAB2 silencing strongly stimulated LUAD cell metastasis and chemoresistance. In contrast, inhibition of miR-134-5p or overexpression of DAB2 strongly suppressed LUAD cell metastasis and overcame the insensitivity of chemoresistant LUAD cells to chemotherapy. In addition, we demonstrated that DAB2 is a target of miR-134-5p and that miR-134-5p stimulates chemoresistance and metastasis through DAB2 in LUAD. Taken together, these findings suggest that miR-134-5p and its target gene DAB2 have potential as a biomarker for predicting recurrence in stage I LUAD patients. Additionally, miR-134-5p inhibition or DAB2 restoration may be a novel strategy for inhibiting LUAD metastasis and overcoming LUAD cell resistance to chemotherapy.

[Lung cancer and elective nodal irradiation: A solved issue?]

Lung cancer treatment is a heavy workload for radiation oncologist and that field showed many evolutions over the last two decades. The issue about target volume was raised when treatment delivery became more precise with the development of three-dimensional conformal radiotherapy. Initially based upon surgical series, numerous retrospective and prospective studies aimed to evaluate the risk of elective nodal failure of involved-field radiotherapy compared to standard large field elective nodal irradiation. In every setting, locally advanced non-small cell lung cancer, localized non-small cell lung cancer, localized small cell lung cancer, exclusive chemoradiation or postoperative radiotherapy, most of the studies showed no significant difference between involved-field radiotherapy or elective nodal irradiation with elective nodal failure rate under 5% at 2 years, provided staging had been done with modern imaging and diagnostic techniques (positron emission tomography scan, endoscopy, etc.). Moreover, if reducing irradiated volumes are safe regarding recurrences, involved-field radiotherapy allowed dose escalation while reducing acute and late oesophageal, cardiac and pulmonary toxicities. Consequently, major clinical trials involving radiotherapy initiated in the last two decades and international clinical guidelines recommended omission of elective nodal irradiation in favour of in-field radiotherapy.

Incidence and clinical relevance of non-small cell lung cancer lymph node micro-metastasis detected by staging endobronchial ultrasound-guided transbronchial needle aspiration

Background

Approximately twenty percent of lymph node (LN) negative non-small cell lung cancer (NSCLC) patients who undergo curative intent surgery have pan-cytokeratin immunohistochemistry (IHC)-detectable occult micro-metastases (MMs) in resected LNs. The presence of the MMs in NSCLC is associated worsened outcomes. As a substantial proportion of NSCLC LN staging is conducted using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), we sought to determine the frequency of detection of occult MMs in EBUS-TBNA specimens and to evaluate the impact of MMs on progression-free and overall survival.

Methods

We performed retrospective IHC staining for pan-cytokeratin of EBUS-TBNA specimens previously deemed negative by a cytopathologist based on conventional hematoxylin and eosin staining. The results were correlated with clinical variables, including survival outcomes.

Results

Of 887 patients screened, 44 patients were identified meeting inclusion criteria with sufficient additional tissue for testing. With respect to the time of the EBUS-TBNA procedure, 52% of patients were clinical stage I, 34% clinical stage II, and clinical 14% stage IIIa NSCLC. Three patients (6.8%) were found to have cytokeratin positive MMs. All 3 MMs detected were at N2 LN stations. The presence of MMs was associated with significantly decreased progression-free (median 210 vs. 1,293 days, P=0.0093) and overall survival (median 239 vs. 1,120 days, P=0.0357).

Conclusions

Occult LN MMs can be detected in EBUS-TBNA specimens obtained during staging examinations and are associated with poor clinical outcomes. If prospectively confirmed, these results have significant implications for EBUS-TBNA specimen analyses and possibly for the NSCLC staging paradigm.

[Research Progress of Lymph Node Micrometastasis in Non-small Cell Lung Cancer]

The incidence and mortality of lung cancer rank top in China. One important factor is the occurrence of metastasis. With the development of science technology, the effect of surgical treatment on lung cancer is improved. Moreover, the use of targeted therapy has achieved a new height for the treatment of lung cancer. However, the recurrence rate remains high even the tumor was completely resected at early stage. The occurrence of lymph node micrometastasis is considered as one of the plausible explanations. The difficulty indetecting micrometastasis has been greatly reduced. Although studies dig deeper into the lymph node micrometastasis, there are still some controversies including the selection of surgical procedures, the pathological staging and prognosis about patients with lymph node micrometastasis. This review manages to generalize the latest research progress of lymph node micrometastasis.
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Long-term outcomes after near-infrared sentinel lymph node mapping in non-small cell lung cancer

OBJECTIVE

To report the first analysis of long-term outcomes using near-infrared (NIR) image-guided sentinel lymph node (SLN) mapping in non-small cell lung cancer (NSCLC).

METHODS

Retrospective analysis of patients with NSCLC enrolled in 2 prospective phase 1 NIR-guided SLN mapping trials, including an indocyanine green (ICG) dose-escalation trial, was performed. All patients underwent NIR imaging for SLN identification followed by multistation mediastinal lymph node sampling (MLNS) and pathologic assessment. Disease-free (DFS) and overall survival (OS) were compared between patients with NIR⁺ SLN (SLN group) and those without (non-SLN group).

RESULTS

SLN detection, recurrence, DFS, and OS were assessed in 42 patients with NSCLC who underwent intraoperative peritumoral ICG injection, NIR imaging, and MLNS. NIR⁺ SLNs were identified in 23 patients (SLN group), whereas SLNs were not identified in 19 patients enrolled before ICG dose and camera optimization (non-SLN group). Median follow-up was 44.5 months. Pathology from NIR⁺ SLNs was concordant with overall nodal status in all 23 patients. Sixteen patients with SLN were deemed pN0 and no recurrences were, whereas 4 of 15 pN0 non-SLN patients developed nodal or distant recurrent disease. Comparing SLN versus non-SLN pN0 patients, the probability of 5-year OS is 100% versus 70.0% (P = .062) and 5-year DFS is statistically significantly improved at 100% versus 66.1% (P = .036), respectively. Among the 11 pN+ patients, 7 were in the SLN group, with >40% showing metastases in the SLN alone.

CONCLUSIONS

Patients with pN0 SLNs showed favorable disease-free and overall survival. This preliminary review of NIR SLN mapping in NSCLC suggests that pN0 SLNs may better represent true N0 status. A larger clinical trial is planned to validate these findings.

Prognostic roles of lymph node micrometastasis in non-small cell lung cancer

OBJECTIVE

This study aimed to confirm the prognostic roles of lymph node (LN) micrometastasis (LNMM) in non-small cell lung cancer (NSCLC) through a meta-analysis.

METHODS

This study included 2026 NSCLC cases without detection of LN metastasis in histologic examination. We investigated the detection rate of LNMM in early-stage NSCLC and analyzed the correlation between LNMM and the rates of recurrence and survival.

RESULTS

The range of detection rates of LNMM was 3.8-68.8% in the eligible studies. The detection rate of LNMM in early-stage NSCLC was 25.3% (95% confidence interval [CI] 19.8-31.6%). In subgroup analysis based on detection method, polymerase chain reaction method had higher detection rate than immunohistochemistry (33.7%, 95% CI 25.5-43.0% vs. 23.1%, 95% CI 18.0-29.0%). The presence of LNMM was significantly correlated with a higher recurrence rate (odds ratio 3.913, 95% CI 1.595-9.600, P=0.003). In addition, there were significant correlations between LNMM and worse overall and disease-free survival rates (hazard ratio [HR] 2.345, 95% CI 1.863-2.951, and HR 1.606, 95% CI 1.170-2.206, respectively).

CONCLUSION

Taken together, our results showed that LNMM was detected in 25.3% of NSCLCs without nodal disease through ancillary test. In addition, the presence of LNMM was significantly correlated with a higher recurrence rate and worse survival rates in early-stage NSCLC.

Relationship of Lymph Node Micrometastasis and Micropapillary Component and Their Joint Influence on Prognosis of Patients With Stage I Lung Adenocarcinoma

This study aimed to investigate the relationship between lymph node micrometastasis and histologic patterns of adenocarcinoma, with a particular focus on their joint effect on prognosis. We retrospectively reviewed 235 patients with stage I adenocarcinoma from January 2009 to December 2009. Lymph node micrometastasis was evaluated by immunohistochemical staining for cytokeratin (AE1/AE3) and thyroid transcription factor-1. A logistic regression model was applied to confirm the predictive factors of micrometastasis. Survival analysis was performed to evaluate the effect of micrometastasis on prognosis. Lymph node micrometastasis was observed in 35 patients (15%). Patients with micrometastasis had significantly worse recurrence-free survival (P<0.001) and overall survival (P<0.001) compared with those without micrometastasis. Micropapillary component was confirmed as an independent predictor of increased frequency of micrometastasis (P<0.001). Among 62 patients with adenocarcinoma with a micropapillary component, 23 (37%) had lymph node micrometastasis. Micropapillary-positive/micrometastasis-positive patients had significantly worse survival compared with micropapillary-positive/micrometastasis-negative patients (RFS, P=0.039; OS, P=0.002) and micropapillary-negative patients (recurrence-free survival, P<0.001; overall survival, P<0.001). Moreover, the presence of micrometastasis correlated with a higher risk of locoregional recurrence (P=0.031) rather than distant recurrence (P=0.456) in micropapillary-positive patients. In summary, lymph node micrometastasis was more frequently observed in adenocarcinoma with a micropapillary component. Moreover, lymph node micrometastasis could provide helpful prognostic information in patients with resected stage I lung adenocarcinoma with a micropapillary component; thus, immunohistochemical detection of micrometastatic tumor cells in lymph nodes should be recommended.

Accuracy of contemporary oesophageal cancer lymph node staging with radiological-pathological correlation

AIM

To evaluate the accuracy of contemporary N-staging and provide radiological-pathological correlation in patients with lymph node metastases (LNMs) that were radiologically staged N0.

MATERIALS AND METHODS

One hundred and twelve patients were included who underwent surgery alone (n=41) or neoadjuvant therapy (n=71) between October 2010 and December 2015. Contrast-enhanced computed tomography (CECT), endoscopic ultrasound (EUS), and combined positron-emission tomography (PET) and CT N-stage were compared to pathological N-stage [node-negative (N0) versus node-positive (N+) groups]. Fifty LNMs from 15 patients preoperatively staged as N0 were measured and the maximum size recorded.

RESULTS

Accuracy, sensitivity, and specificity of N0 versus N+ disease with CECT, EUS, and PET/CT was 54.5%, 39.7% and 77.3%, 55.4%, 42.6% and 75%, and 57.1% 35.3%, and 90.9%, respectively. All techniques were more likely to under-stage nodal disease; CECT (X² 32.890, df=1, p<0.001), EUS (X² 28.471, df=1, p<0.001), and PET/CT (X² 50.790, df=1, p<0.001). PET/CT was more likely to under-stage nodal disease than EUS (p=0.031). Median LNM size was 3 mm, with 41 (82%) of LNMs measuring <6 mm and 22 (44%) classified as micro-metastases (≤2 mm).

CONCLUSION

This study has demonstrated poor N-staging accuracy in the modern era of radiological staging. Eighty-two percent of LNMs measured <6 mm, making direct identification extremely challenging on medical imaging. Future research should focus on investigating and developing alternative surrogate markers to predict the likelihood of LNMs.

A novel technique for tumor localization and targeted lymphatic mapping in early-stage lung cancer

OBJECTIVE

To investigate safety and feasibility of navigational bronchoscopy (NB)-guided near-infrared (NIR) localization of small, ill-defined lung lesions and sentinel lymph nodes (SLN) for accurate staging in patients with non-small cell lung cancer (NSCLC).

METHODS

Patients with known or suspected stage I NSCLC were enrolled in a prospective pilot trial for lesion localization and SLN mapping via NB-guided NIR marking. Successful localization, SLN detection rates, histopathologic status of SLN versus overall nodes, and concordance to initial clinical stage were measured. Ex vivo confirmation of NIR⁺ SLNs and adverse events were recorded.

RESULTS

Twelve patients underwent NB-guided marking with indocyanine green of lung lesions ranging in size from 0.4 to 2.2 cm and located 0.1 to 3 cm from the pleural surface. An NIR⁺ "tattoo" was identified in all cases. Ten patients were diagnosed with NSCLC and 9 SLNs were identified in 8 of the 10 patients, resulting in an 80% SLN detection rate. SLN pathologic status was 100% sensitive and specific for overall nodal status with no false-negative results. Despite previous nodal sampling, one patient was found to have metastatic disease in the SLN alone, a 12.5% rate of disease upstaging with NIR SLN mapping. SLN were detectable for up to 3 hours, allowing time for obtaining a tissue diagnosis and surgical resection. There were no adverse events associated with NB-labeling or indocyanine green dye itself.

CONCLUSIONS

NB-guided NIR lesion localization and SLN identification was safe and feasible. This minimally invasive image-guided technique may permit the accurate localization and nodal staging of early stage lung cancers.

Undetected lymph node metastases in presumed early stage NSCLC SABR patients

INTRODUCTION

Stereotactic body radiation therapy (SBRT, also called stereotactic ablative body radiation SABR) is the treatment of choice for many patients with early-stage non-small cell lung cancer (NSCLC), including those who are unfit for surgery or refuse surgery.

AREAS COVERED

In an effort to develop optimal staging for the evaluation of SBRT candidates, we review the performance of available lymph node staging methods, as well as risk factors for lymph node involvement. Pubmed was searched to identify relevant literature. Current staging methods for NSCLC, including Positron Emission Tomography/Computed Tomography(PET/CT) and endobronchial ultra sound (EBUS), have limited sensitivities. Expert commentary: There are several factors, including primary tumor location, tumor size, and histology that are possibly associated with the sensitivity of PET/CT to detect mediastinal lymph node metastasis. Small lymph node metastases typically remain undetected by PET/CT. Therefore invasive nodal staging procedures are indicated for most presumed early-stage NSCLC patients, but these also have limited sensitivity. Occult lymph node metastasis is associated with adverse outcome in NSCLC. Moreover, there is overwhelming evidence that certain patients who have lymph node metastases detected at the time of surgery derive an overall survival benefit from adjuvant therapies. It remains to be determined if improved detection of lymph node metastases in SABR candidates can indeed improve prognosis.