Does lung cancer surgery cause circulating tumor cells?-A multicenter, prospective study

Persistent and novel changes in plasma microRNA profiles in patients with non-small cell lung cancer following tumour resection

Background

Non-small cell lung cancer (NSCLC) accounts for 80% of lung cancers, the leading cause of cancer mortality. microRNAs (miRNA, miR) have emerged as important components of carcinogenesis and promising biomarkers. We aimed to analyse global plasma miRs in NSCLC patients before and at least one year after tumour resection.

Methods

Plasma was collected from the peripheral blood of 24 donors without cancer and of NSCLC patients before surgery (n=36) and at least 1 year after surgery (n=12). Next-generation sequencing (NGS)-based miR profiling was performed. Patients were followed-up for 4 to 12 years after surgery to assess disease recurrence.

Results

Untreated NSCLC patients exhibited significant changes in plasma miR levels compared to cancer-free donors (48 up- and 17 down-regulated miRs). miR profiles in patients with adenocarcinoma (ADC) (n=18) and squamous cell carcinoma (SCC) significantly differed (16 and 86 miRs up-, and 15 and 16 miRs down-regulated, respectively). A subset of pre-surgery deregulated miRs was found to be associated with recurrence (49 miRs). Six miRs were shown to have independent prognostic value. After tumour resection, some pre-surgery miR alterations returned to control levels (18 miRs), some others persisted (27 miRs), while also novel plasma miR changes emerged (75 miRs) in patients with no clinical evidence of recurrence.

Conclusions

Untreated NSCLC patients present deregulated plasma miRs, some of which may have a potential of prognostic markers. After tumour excision plasma miR profiles change, some miR levels normalise, some changes persist and novel miR changes are observed despite no clinical symptoms of recurrence. Plasma miR profiles in NSCLC patients may suggest systemic abnormalities predisposing to lung cancer and/or reflect a systemic response to pre-cancer/dormant cancer cells.

Circulating Tumor Cells from Surgical Manipulation Predict Recurrence and Poor Prognosis in Non-Small Cell Lung Cancer

Background/Objectives: In our previous multicenter prospective controlled study (UMIN000018602), we investigated the impact of surgical manipulation on circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC). CTCs were detected after surgery in four patients (4/29, 13.8%), although CTCs were not present before surgery. These four patients had tumor cells leaked into their bloodstream by surgeons' manipulation. We aimed to clarify long-term outcomes according to the presence of CTCs. Methods: Patients with cT1b-2N0M0 NSCLC scheduled for lobectomy were enrolled, based on the selection criteria of a consolidation-to-ground-glass opacity ratio (over 50%). Peripheral blood samples (≥3 mL) were collected before surgery (for pre-CTCs), during surgery, and immediately after pulmonary vein dissection (for post-CTCs). CTCs were isolated from these samples using ScreenCell®'s size-selective method. Results: From July 2015 to January 2016, 29 patients were enrolled, yielding paired pre- and post-CTC samples for all patients. Thirteen patients were pre-CTC positive, and post-CTCs were detected in 17 patients. Survival analysis revealed a statistically significant difference in recurrence-free survival between patients with and without post-CTCs (p = 0.043), while pre-CTCs status had no significant impact on recurrence (p = 0.226). Patients with post-CTCs had a significantly higher recurrence rate than those without (p = 0.043). Half of patients with post-CTCs but without pre-CTCs had recurrence within 5 years after surgery. Conclusions: Post-CTCs emerged as a significant predictor of recurrence following lobectomy; however, it could be possible for thoracic surgeons to prevent recurrence by improving surgical techniques for NSCLC patients with post-CTCs but without pre-CTCs.

Advantages and rational application of indocyanine green fluorescence in pulmonary nodule surgery: a narrative review

Background and Objective

The early detection and early treatment of high-risk pulmonary nodules directly affect the long-term survival rate of patients. However, conventional nodule localization methods, such as hook-wire, technetium-99m, and methylene blue are associated with issues such as a high-frequency of complications, low patient tolerance, serious side effects, and inability to identify pigmented lungs. For patients who require segmentectomy, there is often a lack of effective path planning, resulting in insufficient resection margins or excessive loss of lung function. Therefore, effective and rational nodule localization and surgical approaches are crucial. This narrative review aimed to evaluate the advantages of indocyanine green (ICG) fluorescence in pulmonary nodule surgery and clarify its application in various types of patients.

Methods

We searched the PubMed and Web of Science databases from January 2010 to January 2024 using the terms "localization of pulmonary nodules", "localization of pulmonary nodules AND indocyanine green", "localization of pulmonary nodules AND complication", "localization of pulmonary nodules AND surgical planning", and "localization of pulmonary nodules AND underlying lung disease". Information used to write this narrative review was from clinical phenomena, statistical data, and authors' conclusions.

Key Content and Findings

The commonly used localization methods of pulmonary nodule such as computed tomography (CT)-guided percutaneous placement of hook-wire are accompanied with serious complications: including hemopneumothorax and ache. Meanwhile, routine dye commonly fails to localize the nodules in patients with anthracosis. ICG with the enhanced permeability and retention (EPR) effect can be used effectively for preoperative and intraoperative localization of pulmonary nodules and its nature of allowing the observance of the condition of pulmonary blood vessels has gradually become a hotspot of research in this field.

Conclusions

For nodules with a depth of less than 1 cm, no penetration depth problem is encountered when ICG fluorescence is used. Percutaneous puncture can effectively identify the location of nodules at low cost. Compared with other localization methods, it can effectively avoid problems such as pain, radiation exposure, marker displacement, and the existence of anthrax lesions in the lungs. For patients on whom it is difficult to locate nodules due to tissue results, virtual bronchoscopy or electromagnetic navigation bronchoscopy can effectively identify nodules and reduce complications such as pneumothorax. For patients whose operation is postponed due to fever, sudden cardiovascular and cerebrovascular diseases, there is no risk of nodule localization material detachment by using ICG. ICG can also be used in patients with pulmonary physiological or pathological diseases. Meanwhile, in patients with deep pulmonary nodules, ICG fluorescence can help plan the surgical path, ensure the margin of resection, reduce lung function damage, and prevent bronchial fistula. Therefore, the rational use of ICG fluorescence technology can effectively locate nodules, assist surgeons in planning surgical methods, potentially reducing complications and ultimately improving patient prognosis.

Perioperative Inflammatory Response and Cancer Recurrence in Lung Cancer Surgery: A Narrative Review

While surgical resection is the gold standard treatment for solid tumors, cancer recurrence after surgery is common. Immunosurveillance of remnant tumor cells is an important protective mechanism. Therefore, maintenance of anti-tumor cell activity and proper levels of inflammatory mediators is crucial. An increasing body of evidence suggests that surgery itself and perioperative interventions could affect these pathophysiological responses. Various factors, such as the extent of tissue injury, perioperative medications such as anesthetics and analgesics, and perioperative management including transfusions and methods of mechanical ventilation, modulate the inflammatory response in lung cancer surgery. This narrative review summarizes the pathophysiological mechanisms involved in cancer recurrence after surgery and perioperative management related to cancer recurrence after lung cancer surgery.

Circulating Tumor Cells and the Non-Touch Isolation Technique in Surgery for Non-Small-Cell Lung Cancer

Circulating tumor cells (CTCs) are dislodged from the primary tumor into the bloodstream, travel within the bloodstream to distant organs, and finally extravasate and proliferate as epithelial metastatic deposits. The relationship between the existence of CTCs and tumor prognosis has been demonstrated by many researchers. In surgery for malignancies, the surgical manipulation of tumors and tissues around the tumor may lead to the release of CTCs into the bloodstream. The non-touch isolation technique (NTIT) has been advocated to prevent the release of CTCs during surgery. The concept of NTIT is the prevention of intraoperative increment of CTCs from the primary tumor by the early blockade of outflow vessels, and ‘pulmonary vein (PV)-first lobectomy’ during surgery for non-small-cell lung cancer (NSCLC) corresponds to this technique. The concept of PV-first lobectomy is well known among thoracic surgeons, but evidence of its efficacy for preventing the increase of intra- and postoperative CTCs and for improving postoperative prognosis is still uncertain. Our study summarizes evidence regarding the relationship between NTIT and CTCs in NSCLC and suggests the need for further research on CTCs and CTC-detecting modalities.

Effect of intraoperative needle biopsy on the survival of nonsmall cell lung cancer patients: a propensity score matching analysis

Purpose

It is unknown whether intraoperative needle biopsy (INB) predisposes to the postoperative recurrence of lung cancer and compromises the prognosis of these patients. We conducted this study to identify the effect of INB before lobectomy on the postoperative recurrence rate and prognosis of patients with nonsmall cell lung cancer (NSCLC).

Methods

The subjects of this retrospective study were 953 patients with pathological stage I–III NSCLC who underwent lobectomy between 2001 and 2016. The patients were divided into two groups: the INB group (n = 94) and the non-INB group (n = 859). After propensity score matching (PSM), we compared the postoperative cumulative recurrence rate, recurrence-free survival (RFS), disease-specific survival (DSS), and overall survival (OS) between the two groups.

Results

After PSM, 94 patient pairs were matched. The cumulative recurrence rate was significantly higher in the INB group than in the non-INB group (P = 0.01). The 5-year RFS rate was significantly lower in the INB group than in non-INB group (48% vs 68%), as were the 5-year DSS (76% vs 92%) and 5-year OS rates (67% vs 84%) (all P < 0.05).

Conclusions

The findings of this analysis suggest that INB before lobectomy may increase the cumulative recurrence rate and worsen the prognosis of patients with resectable NSCLC. Thus, we believe that INB should be avoided unless a lung lesion cannot be diagnosed by another type of biopsy.

The matrix-dependent 3D spheroid model of the migration of non-small cell lung cancer: a step towards a rapid automated screening

In vitro 3D cell culture systems utilizing multicellular tumor spheroids (MCTS) are widely used in translational oncology, including for studying cell migration and in personalized therapy. However, early stages of cellular migration from MCTS and cross-talk between spheroids are overlooked, which was addressed in the current study. Here, we investigated cell migration from MCTS derived from human non-small cell lung cancer (NSCLC) cell line A549 cultured on different substrates, collagen gel or plastic, at different time points. We found that migration starts at 4–16 h time points after the seeding and its speed is substrate-dependent. We also demonstrated that co-culture of two NSCLC-derived MCTS on collagen gel, but not on plastic, facilitates cell migration compared with single MTCS. This finding should be considered when designing MCTS-based functional assays for personalized therapeutic approach and drug screenings. Overall, our work characterizes the in vitro 3D cell culture model resembling NSCLC cell migration from the clusters of CTCs into surgical wound, and describes microscopy-based tools and approaches for image data analysis with a potential for further automation. These tools and approaches also might be used to predict patterns of CTCs migration based on ex vivo analysis of patient biopsy in a 3D culture system.

Circulating tumor cells counts are associated with CD8+ T cell levels in programmed death-ligand 1-negative non-small cell lung cancer patients after radiotherapy: A retrospective study

This study aimed to explore the dynamics of circulating tumor cells (CTCs) and CD8+ T cells in stage II-III non-small cell lung cancer patients with CTCs in different programmed death-ligand 1 (PD-L1) status treated with radiotherapy and evaluate the correlation between CTCs and CD8+ T cells.This study was a retrospective study which reviewed 69 stage II-III non-small cell lung cancer patients underwent postoperative radiotherapy and peripheral blood tests of CTCs and T lymphocyte were available before radiation, 1 week after radiation and 1 month after radiation.In this study, 25 patients had PD-L1 positive CTCs and 44 patients had PD-L1 negative CTCs. The CTCs count was significantly decreased compared with baseline in patients with different PD-L1 status CTCs at 1 week and 1 month after radiotherapy. The proportion of CD8+ T cells was significantly increased at 1 month after radiotherapy compared with baseline in the total population (mean change, 7.24 ± 2.12; P < .05) and patients with PD-L1 negative CTCs (mean change, 7.17 ± 2.65; P < .05). One month after radiotherapy, the proportion of CD8+ T cells was negatively correlated with the CTCs count in the total population (r = -0.255, P = .034) and PD-L1 negative patients (r = -0.330, P = .029). In patients with PD-L1 negative CTCs, the CTCs count 1 week after radiotherapy (hazard ratio, 0.150 [95% confidence intervals., 0.027-0.840], P = .031) and the proportion of CD8+ T cells 1 month after radiotherapy (hazard ratio, 7.961 [95% confidence intervals, 1.028-61.68], P = .047) were independent prognostic factors for disease recurrence.After radiotherapy, only PD-L1-negative patients had a significant increase in the CD8+ T cell levels, while it was negatively correlated with CTCs count and was an independent prognostic factors of disease recurrence.

Circulating tumor cells detected only after surgery for non-small cell lung cancer: is it a predictor of recurrence?

Background

Surgical manipulation of a tumor can lead to shedding of tumor cells that can enter the circulation and lead to metastasis. The present study evaluated the clinical relevance of circulating tumor cells (CTCs) that were identified immediately after non-small cell lung cancer resection in patients without preoperative CTCs, and whether postoperative CTC detection was associated with recurrence.

Methods

Immediate preoperative testing for CTCs was performed for 147 patients with pulmonary nodules. This study included 81 lung cancer patients (55.1%) with negative preoperative results for CTCs and who completed postoperative testing for CTCs. The clinical relevance of postoperative CTC detection was evaluated based on the clinicopathological characteristics and recurrence patterns.

Results

Among the eligible patients, the postoperative CTC results were none detected in 58 patients (71.6%, “Group N”), only a single CTC detected in 6 patients (7.4%, “Group S”), and CTC clusters detected in 17 patients (21.0%, “Group C”). The presence of postoperative CTCs was associated with tumor vessel invasion, lymph duct invasion, and pleural invasion. Distant metastasis was very common in cases with postoperatively detected CTC clusters. The 2-year recurrence-free survival rates were 94.6% for Group N, 62.5% for Group S, and 52.9% for Group C (P<0.01). Multivariate analysis revealed that recurrence was independently related to the postoperative detection of single CTCs and CTC clusters.

Conclusions

In cases without preoperative CTCs, we postoperatively detected CTCs and the postoperative CTC results were an independent predictor of recurrence.

Prognostic significance of spread through air spaces in pulmonary metastases from colorectal cancer

OBJECTIVES

Surgical resection for pulmonary metastases from colorectal cancer could provide long-term survival in selected patients, and it is commonly performed in practice. However, surgical margin relapse sometimes occurs and is a problematic issue to resolve. Spread through air spaces (STAS) is one of the invasion forms in primary lung cancer and is associated with local recurrence and a poor prognosis. The aim of this study was to evaluate the prognostic significance of STAS for pulmonary metastases from colorectal cancer and to assess the predictability of STAS with preoperative clinical information.

METHODS

A total of 96 pulmonary metastatic lesions from colorectal cancer in 37 patients who underwent metastasectomy at our institution from January 2008 to December 2013 were retrospectively analyzed.

RESULTS

STAS was identified in 41.6 % of the 96 lesions. Surgical margin relapse was found in 8 lesions (8.3 %) from 7 patients (18.9 %). The distance of STAS was identified as an independent risk factor for surgical margin relapse on multivariable analysis (p =  0.033). The patients with STAS showed significantly worse overall survival than those without (5-year overall survival rate: 30.3 % vs. 76.9 %; p =  0.002). On multivariable analysis, patients with STAS had a significantly higher risk of death than those without (p =  0.019). An elevated pre-metastasectomy serum carcinoembryonic antigen level was independently correlated with STAS on multivariable analysis (p =  0.049).

CONCLUSION

STAS was related to a poor prognosis and surgical margin relapse in pulmonary metastases from colorectal cancer.

Gauging the Impact of Cancer Treatment Modalities on Circulating Tumor Cells (CTCs)

The metastatic cascade consists of multiple complex steps, but the belief that it is a linear process is diminishing. In order to metastasize, cells must enter the blood vessels or body cavities (depending on the cancer type) via active or passive mechanisms. Once in the bloodstream and/or lymphatics, these cancer cells are now termed circulating tumor cells (CTCs). CTC numbers as well as CTC clusters have been used as a prognostic marker with higher numbers of CTCs and/or CTC clusters correlating with an unfavorable prognosis. However, we have very limited knowledge about CTC biology, including which of these cells are ultimately responsible for overt metastatic growth, but due to the fact that higher numbers of CTCs correlate with a worse prognosis; it would seem appropriate to either limit CTCs and/or their dissemination. Here, we will discuss the different cancer treatments which may inadvertently promote the mobilization of CTCs and potential CTC therapies to decrease metastasis.

Ultrasound location of pulmonary nodules in video-assisted thoracoscopic surgery for precise sublobectomy

BACKGROUND

We investigated the clinical value of accurate sublobectomy of pulmonary nodules using video-assisted thoracoscopy (VATS). In June 2017 to June 2019, single lung nodule patients who accepted thoracoscopic resection were included. Palpation and intraoperative ultrasound (IU) were used to localize lung nodules, and the success rate, location time and safety compared. Performance of lung nodule ultrasound was assessed. The success rate of IU localization of pulmonary nodules with different properties was studied.

RESULTS

A total of 33 cases with single pulmonary nodules were included in the study, and 32 cases (97%) were successfully located by IU as opposed to 16 cases (48.5%) located by palpation (P < 0.05). Clear hypoechoic ultrasound images of nodules were obtained in all 32 cases, and the diameter of pulmonary nodules on ultrasound and CT were found to have a significant correlation (R = 0.860, P = 0.000). The average positioning time of IU was lower than that of the palpation group (P < 0.05). No complications occurred during ultrasound examination. The success rate of intraoperative ultrasonic localization between the pure ground-glass opacity (p-GGO) group and the mixed-ground-glass opacity (m-GGO) group was 90%, 100% (P = 0.526).

CONCLUSIONS

In thoracoscopic surgery, IU can locate pulmonary nodules accurately, efficiently and safely, and also has a high degree of accuracy in locating different types of pulmonary nodules.

Premetastatic niches, exosomes and circulating tumor cells: Early mechanisms of tumor dissemination and the relation to surgery

The physiological stress response to surgery promotes wound healing and functional recovery and includes the activation of neural, inflammatory and proangiogenic signaling pathways. Paradoxically, the same pathways also promote metastatic spread and growth of residual cancer. Human and animal studies show that cancer surgery can increase survival, migration and proliferation of residual tumor cells. To secure the survival and growth of disseminated tumor cells, the formation of premetastatic niches in target organs involves a complex interplay between microenvironment, immune system, circulating tumor cells, as well as chemical mediators and exosomes secreted by the primary tumor. This review describes the current understanding of the early mechanisms of dissemination, as well as how surgery may facilitate disease progression.

Analysis of Released Circulating Tumor Cells During Surgery for Non-Small Cell Lung Cancer

PURPOSE

Tumor cells from patients with lung cancer are expelled from the primary tumor into the blood, but difficult to detect in the peripheral circulation. We studied the release of circulating tumor cells (CTCs) during surgery to test the hypothesis that CTC counts are influenced by hemodynamic changes (caused by surgical approach) and manipulation.

EXPERIMENTAL DESIGN

Patients undergoing video-assisted thoracic surgery (VATS) or open surgery for (suspected) primary lung cancer were included. Blood samples were taken before surgery (T0) from the radial artery (RA), from both the RA and pulmonary vein (PV) when the PV was located (T1) and when either the pulmonary artery (T2 open) or the PV (T2 VATS) was dissected. The CTCs were enumerated using the CellSearch system. Single-cell whole-genome sequencing was performed on isolated CTCs for aneuploidy.

RESULTS

CTCs were detected in 58 of 138 samples (42%) of 31 patients. CTCs were more often detected in the PV (70%) compared with the RA (22%, P < 0.01) and in higher counts (P < 0.01). After surgery, the RA but not the PV showed less often CTCs (P = 0.02). Type of surgery did not influence CTC release. Only six of 496 isolated CTCs showed aneuploidy, despite matched primary tumor tissue being aneuploid. Euploid so-called CTCs had a different morphology than aneuploid.

CONCLUSIONS

CTCs defined by CellSearch were identified more often and in higher numbers in the PV compared with the RA, suggesting central clearance. The majority of cells in the PV were normal epithelial cells and outnumbered CTCs. Release of CTCs was not influenced by surgical approach.

Circulating tumor cells in the pulmonary vein increase significantly after lobectomy: A prospective observational study

Background

It has been reported that there are more circulating tumor cells (CTCs) in the pulmonary vein (PV) than in the peripheral blood; however, it is unclear whether the CTC count changes in the PV after resection of a lung lobe.

Methods

Thirty‐three lung cancer patients were recruited for the study, including 17 who underwent lobectomy via video‐assisted thoracoscopic surgery and 16 via open thoracotomy. Sixty‐six blood specimens were sampled from the PV before the PV was interrupted and after lobectomy. The CTCs were quantified using the oHSV1‐hTERT‐GFP method.

Results

Before PV interruption, the CTC (pre‐CTC) detection rate was 79.0% (26/33), the mean number of CTCs was 3.36 (median 2, range: 0–18), and there was no significant relationship between the pre‐CTC count and clinical factors, such as histologic findings and pathological T stage (P > 0.05). After lobectomy, the CTC (post‐CTC) detection rate was 100% (33/33), the average number of CTCs was 14.88 (median 11, range: 1–69), and the post‐CTC count was significantly higher in patients in whom the PV was interrupted prior to the pulmonary artery (PA) than in patients in whom the PA was interrupted before the PV (P = 0.016). Overall, the CTC count was significantly higher following surgery (P < 0.001).

Conclusion

Post‐CTC counts were significantly higher than pre‐CTC counts, suggesting that surgical manipulation may potentially dislodge tumor cells into the PV. Interrupting the PV prior to the PA during lobectomy may prevent partial CTC entry into the circulation.

The prognostic roles of circulating ALDH1+ tumor cell in the patients with non-small cell lung cancer

Circulating tumor cells can provide important diagnostic and prognostic information of the patients with non-small cell lung cancer (NSCLC). Aldehyde dehydrogenase 1 (ALDH1), a cancer stem cell marker, has been used in various tumors, including NSCLC. In the present study, we isolated the circulating ALDH1+ tumor cells from the NSCLC patients using ALDH1 as a potential marker. Higher percentage of ALDH1+ tumor cells was identified in blood samples from the NSCLC patients compared with normal controls. ALDH1+ cells were correlated with the poor prognosis of these patients by using Kaplan-Meier analysis. In the last, the tumorigenic properties of ALDH1+ tumor cells were determined in vitro and in vivo by using sphere assay and xenograft tumor mouse models. Our in vitro and in vivo experiments demonstrated that ALDH1 could drive the stemness of circulating NSCLC cells. Circulating ALDH1+ cells could be used as a prognostic marker for NSCLC.

[Effects of minimally invasive versus open esophagectomy on circulating tumor cells in patients with esophageal cancer]

OBJECTIVE

To investigate the effects of minimally invasive esophagectomy (MIE) and open esophagectomy (OE) on the level of circulating tumor cells (CTCs) in patients with esophageal cancer (EC).

METHODS

A total of 73 patients with EC undergoing MIE (n=38) or OE (n=35) in our department between October, 2015 and October, 2017 were enrolled, with 10 patients with benign esophagus disease and 10 healthy volunteers as controls. The levels of CTCs in the peripheral blood of the participants were detected using CanPatrolTM technique and analyzed for their association with the operation methods and perioperative complications.

RESULTS

CTCs were detected in 60.3% (44/73) of the EC patients but in none of the control subjects. CTC level after the surgery was significantly higher than that during the surgery, and CTC level during the surgery was significantly higher than that before surgery (P<0.001). The preoperative and intra-operative CTC levels were not significantly different between MIE and OE groups (P>0.05), but the postoperative CTC level was significantly lower in MIE group than in OE group, and postoperative increment of CTC level (from the preoperative level) was significantly lower in MIE group than in OE group (P<0.001). The total incidence of postoperative complications was significantly lower in MIE group than in OE group (28.9% vs 54.3%, P=0.023), and in both groups, CTC levels in patients with complications were significantly higher than those in patients without complications (P=0.001 and P=0.005 in MIE and OE groups, respectively).

CONCLUSION

MIE may help to reduce the number of peripheral blood CTCs early after the operation, and dynamic monitoring CTCs level assists in evaluation of the prognosis of EC patients. CTC level may serve as an indicator for monitoring the prognosis of EC.

A no-touch technique for pulmonary wedge resection of lung cancer

OBJECTIVE

Many of the surgical patients with lung cancer die by metastasis originated from circulating tumor cells (CTCs) which are seeds of metastases. A ring-shaped catching forceps, which generates the great pressure by compression, may reduce the risk of tumor cell spreading. Here, we investigated the efficacy of such forceps based on CTC occurrence.

METHODS

Twenty-three patients with clinical stage IA lung cancer who underwent a pulmonary wedge resection were investigated in a clinical-pathological manner. They were divided into those treated using ring forceps catching without tumor release (R group) (n = 16) and non-complete use of ring forceps (N group) (n = 7), then were determined circulating tumor cells (CTCs).

RESULTS

Radiographic findings, tumor location, pathological diagnosis, and stapling method were not significantly different between the groups. The risk of detection of CTCs after surgery was significantly lower in group R (12.5 vs. 85.7%, p = 0.02), whereas there were no significant differences found in risk of negative-stapled margin cytology, pre-OP CTC detection, V (+), Ly (+), and Pl (+).

CONCLUSIONS

Patients who underwent pulmonary wedge resection of lung cancer had low chance of CTC detection after surgery when they were treated with ring forceps without tumor release, which might become a no-touch isolation technique.