Detection of occult tumor cells in regional lymph nodes is associated with poor survival in pN0 non-small cell lung cancer: a meta-analysis

Ex vivo expansion of lung cancer-derived disseminated cancer cells from lymph nodes identifies cells associated with metastatic progression

The cellular basis of the apparent aggressiveness in lung cancer is poorly understood but likely associated with functional or molecular features of disseminated cancer cells (DCCs). DCCs from epithelial cancers are mostly detected by antibodies directed against histogenetic markers such as cytokeratin or EpCAM. It has been argued that marker-negative metastatic founder cells might escape detection. We therefore used ex vivo sphere formation for functional detection of candidate metastasis founders. We generated cell suspensions from 199 LN samples of 131 lung cancer patients and placed them into non-adherent cell culture. Sphere formation was associated with detection of DCCs using EpCAM immunocytology and with significantly poorer prognosis. The prognostic impact of sphere formation was strongly associated with high numbers of EpCAM-positive DCCs and aberrant genotypes of expanded spheres. We also noted sphere formation in patients with no evidence of lymphatic spread, however such spheres showed infrequent expression of signature genes associated with spheres from EpCAM-positive samples and displayed neither typical lung cancer mutations (KRAS, TP53, ERBB1) nor copy number variations, but might be linked to disease progression >5 years post curative surgery. We conclude that EpCAM identifies relevant disease-driving DCCs, that such cells can be expanded for model generation and that further research is needed to clarify the functional and prognostic role of rare EpCAM-negative sphere forming cells.

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.

Ex-vivo exploration of an endobronchial sentinel lymph node procedure in lung cancer for optimizing workflow and evaluating feasibility of novel imaging tools

Background

Early-stage lung cancer is treated with curative intent by surgery or radiotherapy. However, upstaging is frequently seen after surgery in clinical N0 lung cancer patients, and despite curative intent, 2-year recurrence rates of 9-28% are reported. A sentinel lymph node (SLN) procedure could improve the staging accuracy. We explored the feasibility of performing a navigation bronchoscopy based SLN procedure in human ex-vivo lung cancer specimens to optimize procedural parameters and assess a novel injection tool.

Methods

Ten lung resection specimens were included and allocated to either peri- or intratumoral injection of a tracer combining ^99mTc-nanocolloid and indocyanine green (ICG) while varying the injection volume. A Pioneer Plus catheter with a pre-angulated 24G needle and an ultrasound (US)-element was used to perform real-time US guided transbronchial injections at multiple locations. Thereafter, single photon emission computed tomography/computed tomography (SPECT/CT)-scanning was performed to image injection depots and to assess their location relative to the tumor.

Results

An average volume of 0.7 mL (range, 0.3-1.2 mL) with an average activity of 89.5 MBq ^99mTc (range, 35.4-188.0 MBq) was injected. Intratumoral injections in non-solid and solid tumors were successful in 100% and 64.3% respectively, while 100% of peritumoral injections in solid tumors were successful. The US-element of the catheter allowed real-time imaging and was able to visualize all tumors and 67.4% of all injections. SPECT/CT-scanning visualized 76.7% of the injection depots.

Conclusions

A navigation bronchoscopy mediated SLN procedure seems technically feasible. The Pioneer Plus is a suitable catheter to place tracer depots at multiple intra-/peri-tumoral sites, while receiving real-time feedback on the needle localization in relation to the tumor. The next step of in-vivo injections will determine if tracer drainage to the SLN can also be detected on pre- and per-operative imaging.

Lymph node sampling-what are the numbers?

Lung cancer is a deadly disease. Lymph node staging is the most important prognostic factor, and lymphatic drainage of the lung is complex. Major advances have been made in this field over the last several decades, but there is much left to understand and improve upon. Herein, we review the history of the lymphatic system and the creation of lymph node maps, the evolution of tumor, node, and metastasis lung cancer classification, the importance of lung cancer staging, techniques for lymph node dissection, and our recommendations regarding a minimum number of nodes to sample during pulmonary resection.

Sentinel Lymph Node in Non-Small Cell Lung Cancer: Assessment of Feasibility and Safety by Near-Infrared Fluorescence Imaging and Clinical Consequences

Occult micrometastases can be missed by routine pathological analysis. Mapping of the pulmonary lymphatic system by near-infrared (NIR) fluorescence imaging can identify the first lymph node relay. This sentinel lymph node (SLN) can be analyzed by immunohistochemistry (IHC), which may increase micrometastasis detection and improve staging. This study analyzed the feasibility and safety of identifying SLNs in thoracic surgery by NIR fluorescence imaging in non-small cell lung cancer (NSCLC). This was a prospective, observational, single-center study. Eighty adult patients with suspected localized stage NSCLC (IA1 to IIA) were included between December 2020 and May 2022. All patients received an intraoperative injection of indocyanine green (ICG) directly in the peri tumoural area or by electromagnetic navigational bronchoscopy (ENB). The SLN was then assessed using an infrared fluorescence camera. SLN was identified in 60 patients (75%). Among them, 36 SLNs associated with a primary lung tumor were analyzed by IHC. Four of them were invaded by micrometastases (11.1%). In the case of pN0 SLN, the rest of the lymphadenectomy was cancer free. The identification of SLNs in thoracic surgery by NIR fluorescence imaging seems to be a feasible technique for improving pathological staging.

Comparison of recurrence risk between patients with clinically node-positive and -negative stage I non-small cell lung cancer following surgery: A propensity score matching analysis

Background

Identifying patients with stage I non‐small cell lung cancer (NSCLC) at increased risk of tumor recurrence following surgery remains a major challenge. The current study aimed to compare disease‐free survival (DFS) rates after surgery between patients with clinically node‐positive (cN+) and ‐negative (cN0) stage I NSCLC.

Methods

Patients with pathological stage I resected NSCLC were identified from the lung cancer database of Changhua Christian Hospital in Taiwan. Patients with clinical N status 1 or 2 and pathological N status 0 were identified as the cN+/pN0 cohort, whereas others were identified as the cN0/pN0 cohort. Propensity score matching (PSM) was used to balance the baseline characteristics between both cohorts. Kaplan–Meier method and Cox proportional hazards model were used to evaluate DFS.

Results

From January 2010 to July 2019, 754 eligible patients were enrolled into the study, among whom 41 (5.4%) were cN+/pN0. The median follow‐up time was 43.4 months. Before PSM, the 5‐year DFS rate was 79.0% and 90.3% in cN+/pN0 and cN0/pN0 cohorts (log‐rank test, p = 0.009), respectively. After a 1:4 PSM, multivariate analysis showed that the cN+/pN0 cohort still had a poorer DFS compared to the cN0/pN0 cohort in (hazard ratio, 3.17; p = 0.040).

Conclusion

Among patients with stage I resected NSCLC, cN+ patients had a worse DFS compared to cN0 patients. Surgeons should therefore consider more aggressive adjuvant therapy or frequent follow‐up in patients with surgically resected stage I NSCLC with cN+ status.

RGD-modified nanoliposomes containing quercetin for lung cancer targeted treatment

Purpose

The aim of this study was to prepare RGD-modified nanoliposomes containing quercetin (QCT) distearoyl-L-a-phosphatidylethanolamine-polyethylene glycol 2000-RGD-liposomes ([DSPE]-PEG2000-RGD-LPs/QCT) for lung cancer targeting treatment.

Methods

The physicochemical parameters of (DSPE)-PEG2000-RGD-LPs/QCT were characterized in terms of the particle size, zeta potential, morphology, entrapment efficiency, drug loading, and in vitro release behavior. In vivo, pharmacokinetics and antitumor studies of prepared formulations were also evaluated.

Results

In this study, QCT was found to be easily dispersed in lipid solution and entrapped by the thin-film hydration method. The encapsulation ratio and drug loading of prepared LPs were 89.2%±7.4% and 9.2%±1.3% and the mean diameter was 93.4±7.2 nm from 3 batches. The results of in vitro experiments showed that the particle size of liposomes was suitable for the fenestrated vasculatures of cancer tissues via the enhanced permeability retention effect. In vitro, a relatively slow QCT release profile was observed in (DSPE)-PEG2000-RGD-LPs, and the release mechanism fit with the Higuchi equation better. In vivo imaging results indicated that RGD-modified LPs had very good tumor targeting ability. (DSPE)-PEG2000-RGD-LPs/QCT showed a significant antitumor activity in mice with A549 tumors.

Conclusion

Through this study, it was found that the RGD-modified LPs loaded with QCT could potentially be a very promising lung-targeted preparation.

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.

Ultrastructural changes during lung carcinogenesis-modulation by curcumin and quercetin

The aim of the present study was to examine the effectiveness of curcumin and quercetin in modulating ultrastructural changes during lung carcinogenesis. A total of 24 male laka mice were divided into the normal control, benzo[a]pyrene (BP)-treated, BP+curcumin-treated, BP+quercetin- treated, and BP+curcumin+quercetin-treated groups (n=6 per group). Lung carcinogenesis was induced by a single intraperitoneal injection of BP [100 mg/kg of body weight (b.wt.)]. Curcumin was supplemented to mice at a dose level of 60 mg/kg of b.wt. in drinking water and quercetin was given at a dose level of 40 mg/kg of b.wt. in drinking water. The ultrastructure of BP-treated mice revealed disruptions in cellular integrity together with nuclear deformation and premature mitochondrial aging. Notably, supplementation with phytochemicals individually resulted in improvement of the ultra-histoarchitecture of BP-treated mice although the improvement was much greater with combined supplementation of phytochemicals. Furthermore, BP treatment revealed alterations in lung histoarchitecture, which, however, were improved appreciably following combined supplementation with curcumin and quercetin. The results of the present study show that, combined supplementation with curcumin and quercetin effectively preserved the histoarchitecture as well as ultra-histoarchitecture during BP-induced lung carcinogenesis in mice.