Enhanced capture system for mesenchymal­type circulating tumor cells using a polymeric microfluidic device 'CTC­Chip' incorporating cell­surface vimentin.

CellSearch, the only approved epithelial cell adhesion molecule (EpCAM)­dependent capture system approved for clinical use, overlooks circulating tumor cells (CTCs) undergoing epithelial­mesenchymal transition (EMT­CTCs), which is considered a crucial subtype responsible for metastasis. To address this limitation, a novel polymeric microfluidic device 'CTC­chip' designed for the easy introduction of any antibody was developed, enabling EpCAM­independent capture. In this study, antibodies against EpCAM and cell surface vimentin (CSV), identified as cancer­specific EMT markers, were conjugated onto the chip (EpCAM­chip and CSV­chip, respectively), and the capture efficiency was examined using lung cancer (PC9, H441 and A549) and colon cancer (DLD1) cell lines, classified into three types based on EMT markers: Epithelial (PC9), intermediate (H441 and DLD1) and mesenchymal (A549). PC9, H441 and DLD1 cells were effectively captured using the EpCAM­chip (average capture efficiencies: 99.4, 88.8 and 90.8%, respectively) when spiked into blood. However, A549 cells were scarcely captured (13.4%), indicating that EpCAM­dependent capture is not suitable for mesenchymal­type cells. The expression of CSV tended to be higher in cells exhibiting mesenchymal properties and A549 cells were effectively captured with the CSV­chip (72.4 and 88.4% at concentrations of 10 and 100 µg/ml, respectively) when spiked into PBS. When spiked into blood, the average capture efficiencies were 27.7 and 46.8% at concentrations of 10 and 100 µg/ml, respectively. These results suggest that the CSV­chip is useful for detecting mesenchymal­type cells and has potential applications in capturing EMT­CTCs.

Prognostic impact of PD-L1 and TIGIT expression in non-small cell lung cancer following concurrent chemo-radiotherapy.

We investigated the effect of preoperative therapy for non-small cell lung cancer on programmed death-ligand 1 (PD-L1), programmed death-1 (PD-1), poliovirus receptor (CD155), and T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) expression and prognosis with the cases of 28 patients received preoperative concurrent chemo-radiotherapy (cCRT) and 27 received preoperative drug therapy. The post-treatment PD-L1 expression was higher in cCRT group than in the drug therapy (50.0% vs 5.0%, p = 0.000), whereas that of CD155 did not significantly differ (40.0% vs 60.0%, p = 0.131). The PD-1 expression was not significantly different between the cCRT and drug therapy groups (51.1% vs 42.9%, p = 0.076), while the TIGIT was significantly higher in the cCRT group (41.5% vs 34.0%, p = 0.008). The patients who received cCRT resulted in elevated PD-L1and TIGIT values had a worse prognosis (p = 0.008). The PD-L1 and TIGIT expression after cCRT was significantly higher than after drug treatment. The cCRT population with high expression of both had a significantly poorer prognosis, indicating elevation of PD-L1 and TIGIT after cCRT as a negative prognostic factor. Combination therapy with anti-PD-L1 and anti-TIGIT antibodies after cCRT may contribute to an improved prognosis.

Adaptive resistance to lorlatinib via EGFR signaling in ALK-rearranged lung cancer.

Anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitors rarely elicit complete responses in patients with advanced ALK-rearranged non-small cell lung cancer (NSCLC), as a small population of tumor cells survives due to adaptive resistance. Therefore, we focused on the mechanisms underlying adaptive resistance to lorlatinib and therapeutic strategies required to overcome them. We found that epidermal growth factor receptor (EGFR) signaling was involved in the adaptive resistance to lorlatinib in ALK-rearranged NSCLC, activation of which was induced by heparin-binding EGF-like growth factor production via c-Jun activation. EGFR inhibition halted ALK-rearranged lung cancer cell proliferation by enhancing ALK inhibition-induced apoptosis via suppression of Bcl-xL. Xenograft models showed that the combination of EGFR inhibitor and lorlatinib considerably suppressed tumor regrowth following cessation of these treatments. This study provides new insights regarding tumor evolution due to EGFR signaling after lorlatinib treatment and the development of combined therapeutic strategies for ALK-rearranged lung cancer.

CD155 expression and its clinical significance in non-small cell lung cancer.

CD155 serves an important role in tumor progression by promoting cell proliferation and migration. CD155 is also involved in the immune evasion of tumor cells, which may cause the development and progression of tumors. Accordingly, CD155 has emerged as a novel target in cancer immunotherapy; however, its expression in lung cancer remains unclear. To assess CD155 expression and its prognostic significance, 96 patients with completely resected pathologic stage I adenocarcinoma of the lung were retrospectively reviewed. Immunohistochemical staining was performed to evaluate CD155 expression on tumor cells. Expression levels of programmed death-ligand 1 (PD-L1), another molecule participating in immune evasion, were also evaluated immunohistochemically. CD155 expression was positive in 37 patients (38.5%). CD155-positivity was associated with aggressive tumor behavior, such as pleural invasion and vascular invasion. In addition, CD155-positivity was a significant factor to predict a poor prognosis (5-year overall survival (OS) rate, 63.3% for CD155-positive patients vs. 93.1% for CD155-negative patients; P<0.001). Patients harboring tumors with positive CD155 and PD-L1 expression showed the poorest prognosis (5-year OS rate, 44.4% for both-positive patients vs. 85.4% for the other patients; P<0.001). The positive expression status of both CD155 and PD-L1 was a significant and independent unfavorable prognostic factor (hazard ratio, 3.86; 95% confidence interval, 1.51-9.89; P=0.004; in a multivariate analysis). In conclusion, CD155-positivity was associated with aggressive tumor behavior, and was a factor to predict a poor prognosis. Its prognostic impact was enhanced when combined with PD-L1 expression status. These results should be validated in a large-scale study.

HER3 activation contributes toward the emergence of ALK inhibitor-tolerant cells in ALK-rearranged lung cancer with mesenchymal features.

Anaplastic lymphoma kinase-tyrosine kinase inhibitors (ALK-TKIs) have shown dramatic efficacy in patients with ALK-rearranged lung cancer; however, complete response in these patients is rare. Here, we investigated the molecular mechanisms underlying the emergence and maintenance of drug-tolerant cells in ALK-rearranged lung cancer. Cell based-assays demonstrated that HER3 activation and mesenchymal-to-epithelial transition, mediated through ZEB1 proteins, help maintain cell survival and induce the emergence of ALK-TKI-tolerant cells. Compared with ALK-TKIs alone, cotreatment with pan-HER inhibitor afatinib and ALK-TKIs prevented tumor regrowth, leading to the eradication of tumors in ALK-rearranged tumors with mesenchymal features. Moreover, pre-treatment vimentin expression in clinical specimens obtained from patients with ALK-rearranged lung cancer was associated with poor ALK-TKI treatment outcomes. These results demonstrated that HER3 activation plays a pivotal role in the emergence of ALK-TKI-tolerant cells. Furthermore, the inhibition of HER3 signals combined with ALK-TKIs dramatically improves treatment outcomes for ALK-rearranged lung cancer with mesenchymal features.

Prognostic impact of circulating tumor cells detected with the microfluidic "universal CTC-chip" for primary lung cancer.

Detecting rare circulating tumor cells (CTCs) in the bloodstream is extremely challenging. We had previously developed a novel polymeric microfluidic device, "CTC-chip," for capturing CTCs and have shown high capture efficiency in lung cancer cell lines by conjugating Abs against epithelial cell adhesion molecules (EpCAM). This study aimed to optimize the EpCAM-chip and clarify the prognostic impact of CTCs in lung cancer patients. Of 123 patients with pathologically proven lung cancer, both progression-free survival (P = .037) and cancer-specific survival (P = .0041) were predominantly poor when CTCs were detected before treatment. After classification into surgical and chemotherapy groups, progression-free survival was worse in CTC-positive patients in both groups (surgery, P = .115; chemotherapy, P = .012), indicating that the detection of baseline CTCs is a risk factor for recurrence and progression. Furthermore, we recovered captured CTCs using micromanipulators and undertook mutation analysis using PCR. Thus, the EpCAM-chip is a highly sensitive system for detecting CTCs that contributes to the prediction of recurrence and progression and enables genetic analysis of captured CTCs, which could open new diagnostic, therapeutic, and prognostic options for lung cancer patients.

Inhibition of c-Jun N-terminal kinase signaling increased apoptosis and prevented the emergence of ALK-TKI-tolerant cells in ALK-rearranged non-small cell lung cancer.

Anaplastic lymphoma kinase-tyrosine kinase inhibitors (ALK-TKIs) have improved clinical outcomes in non-small cell lung cancer (NSCLC) harboring ALK- rearrangements. However, a small population of tumor cells survives due to adaptive resistance under drug pressure and ultimately acquires drug resistance. Thus, it is necessary to elucidate the mechanisms underlying the prevention of drug resistance to improve the prognosis of patients with ALK-rearranged NSCLC. We identified novel adaptive resistance, generated through c-Jun N-terminal kinase (JNK)/c-Jun signaling, to initial ALK-TKIs-alectinib and brigatinib-in ALK-rearranged NSCLC. Inhibition of JNK/c-Jun axis showed suppression of growth and promotion of apoptosis induced by ALK-TKIs in drug-tolerant cells. JNK inhibition, in combination with the use of ALK-TKIs, increased cell apoptosis through repression of the Bcl-xL proteins, compared with ALK-TKI monotherapy. Importantly, combination therapy targeting JNK and ALK significantly delayed the regrowth following cessation of these treatments. Together, our results demonstrated that JNK pathway activation plays a pivotal role in the intrinsic resistance to ALK-TKIs and the emergence of ALK-TKI-tolerant cells in ALK-rearranged NSCLC, thus indicating that optimal inhibition of tolerant signals combined with ALK-TKIs may potentially improve the outcome of ALK-rearranged NSCLC.

Novel circulating tumor cell-detection chip combining conventional podoplanin and EGFR antibodies for all histological malignant pleural mesothelioma.

In our previous study, a microfluidic system was developed based on podoplanin detection for capturing circulating tumor cells (CTCs), derived from malignant pleural mesothelioma (MPM). However, non-epithelioid MPM shows low podoplanin protein expression compared with that in epithelioid MPM; thus, some CTC populations may be missed. To overcome this limitation, a new CTC-detection chip was developed by combining the conventional podoplanin antibody (clone: NZ-1.2) with an epidermal growth factor receptor (EGFR)-targeted antibody (cetuximab). The cell-capture efficiency of the Cocktail-chip reached 100% in all the histological MPM cell lines. The median CTC-counts from 19 patients with MPM (epithelioid/non-epithelioid: 10/9) with the NZ-1.2- and Cocktail-chips were 1 and 3 (P=0.311) in 1 ml peripheral blood, 1.5 and 2 (P=0.332) in epithelioid MPM, and 1 and 3 (P=0.106) in non-epithelioid MPM, respectively. Overall, the Cocktail-chip showed an improved ability to detect more CTCs in patients with non-epithelioid MPM compared with that in the conventional NZ-1.2-chip, showing non-significant, but higher CTC detection. Furthermore, CTC-counts, determined using the Cocktail-chip were significantly correlated with the clinical stage of non-epithelioid MPM. In epithelioid MPM, the Cocktail-chip achieved a CTC-detection efficiency equivalent to that in the conventional NZ-1.2-chip. The Cocktail-chip enabled sensitive CTC detection of all histological MPM, including the non-epithelioid subtype, which may provide a foundation for the diagnosis, treatment, and prognosis of MPM progression.

Detection of Circulating Tumor Cells (CTCs) in Malignant Pleural Mesothelioma (MPM) with the "Universal" CTC-Chip and An Anti-Podoplanin Antibody NZ-1.2.

Circulating tumor cell (CTC) is a potentially useful surrogate of micro-metastasis, but detection of rare tumor cells contaminated in a vast majority of normal hematologic cells remains technical challenges. To achieve effective detection of a variety of CTCs, we have developed a novel microfluidic system (CTC-chip) in which any antibody to capture CTCs is easily conjugated. In previous studies, we employed an antibody (clone E-1) against podoplanin that was strongly expressed on mesothelioma cells. The CTC-chip coated by the E-1 antibody (E1-chip) provided a modest sensitivity in detection of CTCs in malignant pleural mesothelioma (MPM). Here, to achieve a higher sensitivity, we employed a novel anti-podoplanin antibody (clone NZ-1.2). In an experimental model, MPM cells with high podoplanin expression were effectively captured with the CTC-chip coated by the NZ-1.2 antibody (NZ1.2-chip). Next, we evaluated CTCs in the peripheral blood sampled from 22 MPM patients using the NZ1.2-chip and the E1-chip. One or more CTCs were detected in 15 patients (68.2%) with the NZ1.2-chip, whereas only in 10 patients (45.5%) with the E1-chip. Of noted, in most (92.3%, 12/13) patients with epithelioid MPM subtype, CTCs were positive with the NZ1.2-chip. The CTC-count detected with the NZ1.2-chip was significantly higher than that with the E1-chip (p = 0.034). The clinical implications of CTCs detected with the NZ1.2-chip will be examined in a future study.

Prognostic impact of PD-L1 expression in correlation with neutrophil-to-lymphocyte ratio in squamous cell carcinoma of the lung.

The prognostic impact of tumoral programmed death-ligand 1 (PD-L1) expression in correlation with neutrophil-to-lymphocyte ratio (NLR) was retrospectively assessed in 83 patients with completely resected stage I squamous cell carcinoma of the lung, as PD-L1 is a potent regulator of cancer immunity and NLR is a potential surrogate of immune status. Forty-three patients (51.8%) had tumor with positive PD-L1 expression. There was no significant correlation between PD-L1 expression and NLR. PD-L1-positivity failed to provide a significant prognostic impact (overall survival [OS] rate at 5 years, 53.0% in PD-L1-positive patients versus 70.1% in PD-L1-negative patients; P = 0.117). Among NLR-low (<2.2) patients, however, PD-L1-positivity was significantly correlated with a poor prognosis (OS rate at 5 years, 46.1% versus 86.0%; P = 0.020). In contrast, among NLR-high (≥2.2) patients, PD-L1-positivity provided no prognostic impact (P = 0.680). When NLR status and tumoral PD-L1 status were combined, "NLR-low and PD-L1-negative" was a significant and independent factor to predict a favorable recurrence-free survival (hazard ratio, 0.237 [95% confidence interval, 0.083 to 0.674]; P = 0.007) and OS (hazard ratio, 0.260 [0.091 to 0.745]; P = 0.012). These results suggest the prognostic impact of tumoral PD-L1 expression might be influenced by the status of NLR.

Difficulty of treatment for pleural epithelioid hemangioendothelioma: a report of a case.

We herein report the case of a 62-year-old man who underwent extrapleural pneumonectomy (EPP) for pleural epithelial hemangioendothelioma (EHE) diagnosed by a pleural biopsy. Pre-operative computed tomography revealed diffuse pleural thickening and pleural effusion in the right thoracic cavity, although metastasis to neither the lymph nodes nor distant organs was detected. We decided to perform EPP based on surgical findings that the tumor had invaded the lung parenchyma. A pathological examination revealed tumor invasion of the lung parenchyma, blood vessel, pericardium, diaphragm and bronchial wall. Despite aggressive treatment, tumor recurrence was detected about 1 month after surgery. Although we controlled the tumor progression using pazopanib, the patient ultimately died 3.5 months after the operation. Pleural EHE is a very rare disease that has a poor prognosis due to its high malignant potential. It is important to formulate strategies matched to individual cases based on disease progression and invasiveness of treatment.

The impact of perioperative heparin bridging therapy in lung cancer surgery.

PURPOSE: The impact of perioperative heparin bridging (HB) for lung surgery in patients on anti-clotting drugs remains unclear. We performed a retrospective study to assess its effect on surgical safety by comparing HB and non-HB groups. METHODS: This study included 274 consecutive patients on anti-clotting drugs who underwent surgery for lung cancer. Of these, 77 received HB and 197 did not. Propensity score matching extracted 124 patients, consisting of 62 patients with HB and 62 patients without HB. Endpoints were surgical safety. RESULTS: There was no statistically significant difference in the outcomes of surgical safety outcomes between the HB and non-HB group after propensity-score matching, operative time (172 vs. 203 min, p = 0.131), volume of blood loss (60 vs. 70 ml, p = 0.335), need for intraoperative RBC transfusion (3.2 vs. 6.5%, p = 0.680), chest tube drainage volume on the 1st postoperative day (200 vs. 200 ml, p = 0.796), and chest tube placement duration (3 vs. 3 days, p = 0.606). CONCLUSIONS: The influence of perioperative HB on postoperative thromboembolic or bleeding events in lung cancer surgery is not obvious, but its surgical safety appears to be acceptable.

Perioperative pirfenidone treatment for lung cancer patients with idiopathic pulmonary fibrosis.

PURPOSE: To assess the efficacy and feasibility of perioperative pirfenidone treatment (PPT) in lung cancer patients with idiopathic pulmonary fibrosis (IPF). METHODS: The subjects of this retrospective review were 100 patients diagnosed with IPF, who underwent surgical resection for primary lung cancer between January 2011 and April 2018 at our institution. We compared the clinical outcomes of patients treated with pirfenidone (PPT group; n = 28) and those of patients not treated with pirfenidone (non-PPT group; n = 72). RESULTS: The Japanese Association for Chest Surgery (JACS) risk score was significantly higher in the PPT group (p = 0.020, 10.9 vs. 9.4); therefore, we subdivided the groups based on JACS risk score. In the low-risk group, the incidence of postoperative acute exacerbation (AE) both within the postoperative day (POD) 30 and 90 was 0.0% (0/6) and 6.5% (2/31) in the PPT and non-PPT groups, respectively (p = 0.522). In the intermediate/high-risk group, the incidence of postoperative AE was 4.5% (1/22) and 19.5% (8/41) within POD 30 (p = 0.106) and 4.5% (1/22) and 24.4% (10/41) within POD 90 (p = 0.048) in the PPT and non-PPT groups, respectively. No serious pirfenidone-related complications were observed. CONCLUSIONS: Based on our findings, PPT is an effective and feasible prophylactic treatment to reduce postoperative AE.

Alteration in tumoural PD-L1 expression and stromal CD8-positive tumour-infiltrating lymphocytes after concurrent chemo-radiotherapy for non-small cell lung cancer.

BACKGROUND: Consolidation treatment with an anti-PD-L1 antibody, durvalumab, following concurrent chemo-radiotherapy (cCRT) has become a new standard of care for locally advanced non-small cell lung cancer (NSCLC). The rationale of PD-L1 blockade after cCRT is based on preclinical evidence suggesting that chemotherapy and radiotherapy up-regulate tumoural PD-L1 expression, which has not been shown in clinical studies. METHODS: To examine alteration in tumoural PD-L1 expression (tumour proportion score, TPS) and density of stromal CD8-positive tumour-infiltrating lymphocytes (CD8 + TILs) after cCRT, paired NSCLC samples obtained before and after cCRT were reviewed in comparison with those obtained before and after drug therapy. RESULTS: PD-L1 expression was significantly up-regulated after cCRT (median TPS, 1.0 at baseline versus 48.0 after cCRT; P < 0.001), but not after drug therapy. There was no significant correlation between baseline TPS and post-cCRT TPS. CD8 + TIL density was significantly increased after cCRT (median, 10.6 versus 39.1; P < 0.001), and higher post-cCRT CD8 + TIL density was associated with a higher pathologic response and with a favourable survival (P = 0.019). CONCLUSION: Tumoural PD-L1 expression was up-regulated after cCRT, which provides pathologic rationale for PD-L1 blockade following cCRT to improve prognosis. Stromal CD8 + TIL density was also increased after cCRT, and higher post-cCRT CD8 + TIL density was a favourable prognostic indicator.

Treatment of Non-small Cell Lung Cancer with EGFR-mutations.

The discovery of activating mutations in the epidermal growth factor receptor (EGFR) gene and development of tyrosine kinase inhibitors (TKIs) of EGFR have achieved a paradigm shift in treatment strategy of non-small cell lung cancer (NSCLC). For advanced NSCLC harboring activating EGFR mutations, an EGFR-TKI is preferably prescribed as it provides a superior survival benefit over platinum-based chemotherapy. To further improve the therapeutic outcomes, more potent EGFR-TKIs through irreversible inhibition of tyrosine kinase have been developed. In a recent clinical trial, an irreversible EGFR-TKI (osimertinib) showed a superior survival benefit with lower toxicity profile. In addition, combination treatments such as an EGFR-TKI plus platinum-based chemotherapy may achieve a long-term survival. For earlier-stage resectable NSCLC with EGFR-mutations, several clinical trials to assess the efficacy of EGFR-TKIs in pre-operative induction setting and in postoperative adjuvant setting are now ongoing. Here we review and discuss the current status and future perspectives of treatment for EGFR-mutated NSCLC.

Salvage surgery combined with descending aorta resection for lung cancer.

BACKGROUND: Recent retrospective studies have shown that salvage surgery can improve survival with acceptable adverse events, and this procedure has been adapted for lung cancer. However, there are no reports demonstrating the efficacy of salvage surgery combined with aortic resection. CASE PRESENTATION: A 73-year-old man had received definitive concurrent chemoradiotherapy (carboplatin/paclitaxel, 70 Gy) for lung cancer originated from the left upper lobe and infiltrating the thoracic aorta (cT4N1M0 stage IIIA). Although the tumor has shrunk significantly (ycT4N0M0 stage IIIA), radiation pneumonitis occurred. Due to the steroid therapy, radiation pneumonitis was relieved; however, re-enlargement of the primary tumor was observed during steroid tapering. Nonetheless, the lymphatic and distant metastases were controlled. Moreover, aortic invasion was localized to the periphery of the third branch, and the tumor was considered to be resectable. Intraoperatively, we observed macroscopic evidence of aortic invasion in the periphery of the third branch; thus, left upper lobectomy combined with descending aorta resection was performed under partial extracorporeal circulation. The patient is currently active without any recurrence 21 months post-surgery. CONCLUSIONS: No clear consensus exists regarding salvage surgery combined with aortic resection for primary lung cancer. However, we believe that this surgery may improve the survival of carefully selected patients.