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

Colorectal cancer and dormant metastases: Put to sleep or destroy?

After reading the review by An et al "Biological factors driving colorectal cancer metastasis", which covers the problem of the metastasis of colorectal cancer (CRC), I had a desire to discuss with readers one of the exciting problems associated with dormant metastases. Most deaths from CRCs are caused by metastases, which can be detected both at diagnosis of the primary tumor and several years or even decades after treatment. This is because tumor cells that enter the bloodstream can be destroyed by the immune system, cause metastatic growth, or remain dormant for a long time. Dormant tumor cells may not manifest themselves throughout a person's life or, after some time and under appropriate conditions, may give rise to the growth of metastases. In this editorial, we will discuss the most important features of dormant metastases and the mechanisms of premetastatic niche formation, as well as factors that contribute to the activation of dormant metastases in CRCs. We will pay special attention to the possible mechanisms involved in the formation of circulating tumor cell complexes and the choice of therapeutic strategies that promote the dormancy or destruction of tumor cells in CRCs.

Re-appraisal of bronchus-first right upper lobectomy as an alternative routine procedure

OBJECTIVES

Postoperative air leakage is a major complication of lung resection, particularly right upper lobectomy. However, various surgical procedures can reduce postoperative complications and shorten the drainage period. The current study aimed to analyse the utility of bronchus-first right upper lobectomy as an alternative routine procedure.

METHODS

We retrospectively analysed the data of 225 (53.7%) patients who underwent bronchus-first right upper lobectomy and 194 (46.3%) patients who underwent the conventional bronchus-last right upper lobectomy at our institution from 2015 to 2022. In patients with incomplete fissures who underwent bronchus-first right upper lobectomy, the bronchus was dissected 1st, followed by the pulmonary artery and vein, and then, the interlobar fissure was divided. We compared the outcomes of 2 procedures and analysed the surgical utility of bronchus-first right upper lobectomy.

RESULTS

The surgical outcomes and postoperative morbidity comparing bronchus-first and bronchus-last procedure were as follows: median operation time (min) 103/126 (P < 0.001), median bleeding amount (ml) 28/55 (P = 0.003), incomplete lobulation rate (%) 35.1/24.2 (P = 0.02), incidence of prolonged air leakage (%) 2.2/3.1 (P = 0.76) and rate of fellow surgeon's operation (%) 28.0/4.6 (P < 0.001). The procedure was associated with a decreased incidence of prolonged air leakage. The 4-year overall survival rates did not significantly differ between the 2 groups (P = 0.24).

CONCLUSIONS

Bronchus-first right upper lobectomy can prevent postoperative air leakage in patients with incomplete fissure. Additionally, as an alternative routine procedure, it is associated with a shorter surgical duration and a lower volume of blood loss regardless of interlobar fissure and operator's experience.

The influence of different sequences of vessel ligation on long-term survival during video-assisted thoracoscopic lobectomy for non-small cell lung cancer: A matched cohort study

In lobectomy of patients with lung cancer, the principle of operation is to cut off the pulmonary vein first, but it is often not taken seriously in clinical practice. We conducted this research to compare the impact of different sequences of pulmonary vessel ligation on the long-term survival of patients. This cohort study included 1239 patients treated surgically with video-assisted thoracoscopic lobectomy from January 2015 to December 2019 at The Second Affiliated Hospital of Nanchang University. Survival and perioperative indicators were compared between a Vein-first group (VF) and an artery-first group. After matching, 364 patients were included in each group for analysis. VF was associated with better overall survival (hazard ratio: 1.96 [1.4~2.74], P < .0001) and disease-free survival (hazard ratio: 1.65 [1.22~2.24], P = .0011). Meanwhile, the survival advantage of VF was achieved in almost all subgroups, particularly in the pathological tumor node metastasis stage I-II group and squamous cell carcinoma group. We obtained no significant differences in perioperative indications (operation time, hospital stay, etc) between VF and artery-first group. With better overall survival and disease-free survival, especially for pathological stage I-II squamous cell carcinoma, vein-first ligation should be strictly observed in lobectomy for patients with non-small cell lung cancer.

Risk factors for postoperative cerebral infarction in Lung Cancer patients: a retrospective study

BACKGROUND

Postoperative cerebral infarction is a rare but serious complication after lung cancer surgery. We aimed to investigate the risk factors and evaluate the efficiency of our devised surgical procedure to prevent cerebral infarction.

METHODS

We retrospectively examined 1,189 patients who underwent a single lobectomy for lung cancer at our institution. We identified the risk factors for cerebral infarction and investigated the preventive effects of performing resection of the pulmonary vein as the last step of the surgical procedure during left upper lobectomy.

RESULTS

Among the 1,189 patients, we identified 5 male patients (0.4%) with postoperative cerebral infarction. All five underwent left-sided lobectomy including three upper and two lower lobectomies. Left-sided lobectomy, a lower forced expiratory volume in 1 s, and lower body mass index were associated with postoperative cerebral infarction (Ps < 0.05). The 274 patients who underwent left upper lobectomy were stratified by two procedures: lobectomy with resection of the pulmonary vein as the last step of the surgical procedure (n = 120) and the standard procedure (n = 154). The former procedure significantly shortened the length of the pulmonary vein stump when compared with the standard procedure (mean stump length: 15.1 vs. 18.6 mm, P < 0.01), and the shorter pulmonary vein might possibly prevent postoperative cerebral infarction (frequency: 0.8% vs. 1.3%, Odds ratio: 0.19, P = 0.31).

CONCLUSIONS

Resecting the pulmonary vein as the last step during the left upper lobectomy enabled the length of the pulmonary stump to be significantly shorter, which may contribute to preventing cerebral infarction.

Does Primary Tumor Resection Induce Accelerated Metastasis in Breast Cancer? A Review

INTRODUCTION

Over a century of cumulative experimental results and clinical data have suggested that surgical procedures of primary tumors promote tumor progression and metastasis in breast cancer and other cancer patients, suggesting a potential interplay linking primary tumors and distant lesions that lead to metastasis development triggered by primary tumor removal. Such evidence may generate a departure in terms of our attitude toward the surgery. However, the reliability and prognostic benefits of tumor surgery, especially for chemotherapy-resistant patients, are indisputable. Thus, it is important to explore the mechanism underlying this surgery-induced cancer progression to guide individual clinical treatment and improve tumor control.

MATERIALS AND METHODS

We conducted a comprehensive review in PubMed in October 2021 to determine the article outline. Non-English and repetitive articles were excluded. The year, topic, key findings, and opinions of each article were gathered.

RESULTS

This review not only comprehensively summarizes the potential mechanisms of primary tumors interacting with the growth of metastases but also discusses whether and how surgical resection of primary lesions can trigger tumor metastasis and development. At the same time, this article also provides our understanding of clinical findings and future directions on this topic. In addition, the combination of surgery and some potentially beneficial therapeutic interventions for postoperative tumor metastasis control was also mentioned.

CONCLUSIONS

There are viewpoints supporting an acceleration of metastasis after surgery for breast cancer and fundamental research on relevant therapies, although controversial. Further attention should be focused on the gap between current preclinical data and the complicated clinical therapeutic combination during surgery in metastatic breast cancer patients.

Circulating Tumor Cells as a Predictive Biomarker in Resectable Lung Cancer: A Systematic Review and Meta-Analysis

Background: In breast, prostate, and other epithelial tumors, circulating tumor cells (CTC) in peripheral blood may predict survival. Our study evaluated the prognostic significance of baseline and postoperative CTC in patients with early non-small cell lung cancer (NSCLC) through a meta-analytic approach. Methods: Prospective studies comparing survival outcomes between positive (CTC+) and negative CTC (CTC−) patients were systematically searched. Primary outcomes were overall (OS) and disease-free survival (DFS) with hazard ratio (HR) and 95% confidence interval (CI) as the effect measure. Pooled HR determined the prognostic role under a fixed-effect or random-effect model depending on heterogeneity. Results: Eighteen studies with 1321 patients were eligible. CTC+ patients were associated with an increased risk of death (HR 3.53, 95% CI 2.51−4.95; p < 0.00001) and relapse (HR 2.97, 95% CI 2.08−4.22; p < 0.00001). Subgroup analysis results were consistent in different subsets, including time points (baseline and postoperative) and sources (peripheral and pulmonary vein) of blood collection, detection methods (label-free, label-dependent, and RT-PCR), and follow-up duration. Conclusion: Our meta-analysis revealed that CTC is a promising predictive biomarker for stratifying survival outcomes in patients with early-stage NSCLC. However, future studies are required to validate these findings and standardize detection methods.

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.

Tumour invasion and dissemination

Activating invasion and metastasis are one of the primary hallmarks of cancer, the latter representing the leading cause of death in cancer patients. Whilst many advances in this area have been made in recent years, the process of cancer dissemination and the underlying mechanisms governing invasion are still poorly understood. Cancer cells exhibit multiple invasion strategies, including switching between modes of invasion and plasticity in response to therapies, surgical interventions and environmental stimuli. The ability of cancer cells to switch migratory modes and their inherent plasticity highlights the critical challenge preventing the successful design of cancer and anti-metastatic therapies. This mini-review presents current knowledge on the critical models of tumour invasion and dissemination. We also discuss the current issues surrounding current treatments and arising therapeutic opportunities. We propose that the establishment of novel approaches to study the key biological mechanisms underlying the metastatic cascade is critical in finding novel targets that could ultimately lead to complete inhibition of cancer cell invasion and dissemination.

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.

aBVA Procedure by Uniportal Video-Assisted Thoracoscopic Surgery for Right Upper Peripheral Lung Cancer: A Randomized Trial

Objective

This study aims to determine the optimal dividing order of anatomic pulmonary resection under uniportal video-assisted thoracoscopic surgery (uni-VATS) for patients with right upper peripheral lung cancer.

Methods

Patients who met the eligibility criteria were randomly allocated into the aBVA and VAB groups. In the aBVA group, the surgical procedure proceeded from the posterior to the anterior region (from the deeper to the superficial site). In the VAB group, the dissection orders were vein first followed by arterial branches, followed by the bronchus. Clinical data were collected and analyzed.

Results

Sixty patients were randomly allocated to the aBVA group (n = 30) and the VAB group (n = 30). The operation time in the aBVA group (230.500 ± 68.360 min) was significantly shorter than that in the VAB group (305.600 ± 107.821 min) (p = 0.01). The blood loss in the aBVA group (104.000 ± 70.935 ml) was significantly lower than that in the VAB group (391.000 ± 625.175 ml) (p = 0.01). Two patients in the VAB group underwent conversion to 2-portal VATS. The number of lymph nodes (13.367 ± 5.436 vs. 10.333 ± 7.279, p = 0.072) and lymph node stations (5.067 ± 1.574 vs. 4.467 ± 2.345, p = 0.567) were comparable between the two groups. The differences in the postoperative drainage tube time (5.033 ± 3.113 vs. 6.467 ± 4.447 days, p = 0.278) and hospital stay (8.233 ± 3.390 vs. 9.433 ± 4.523 days, p = 0.361) were not significantly different between the two groups.

Conclusion

Compared with the VBA procedure, aBVA is easier for patients with right upper peripheral lung cancer who undergo uni-VATS lobectomy.

Surgical Trauma-induced CCL2 Upregulation Mediates Lung Cancer Progression by Promoting Treg Recruitment in Mice and Patients

Surgical removal of the tumor is currently the first-line treatment for lung cancer, but the procedure may accelerate cancer progression through immunosuppression. However, whether CCL2 (C-C motif chemokine ligand 2) enhances cancer progression by affecting regulatory T cells (Tregs) remains unknown. We found that the volume and weight of tumors were larger in the surgical trauma group than in the control group. CCL2 expression and Treg abundance were increased in tumor tissues after surgical trauma, and CCL2 expression was positively associated with Treg abundance. These results demonstrated that surgical trauma contributes to lung cancer progression by increasing CCL2 expression, thus promoting Treg recruitment.

Vein-first versus artery-first ligation procedure for lung cancer surgery: An updated review

Background

The optimal sequence of pulmonary vessel interruption during lung cancer resection remains controversial. This review aimed to elucidate the association of vein-first versus artery-first ligation and survival of the patients.

Methods

We searched PubMed, Web of Science, Scopus, Embase, Cochrane Library and Google Scholar from their inception to September 2021 for published articles that compared vein-first (the pulmonary vein was interrupted first) and artery-first procedure (the pulmonary artery was ligated first) during lung cancer surgery.

Results

Finally, a total of 13 full articles were obtained. First, 7 studies with survival information were included for meta-analyses. As compared with the artery-first ligation, vein-first approach did not decrease the risk of local recurrence (risk ratio [RR] 0.92 in favour of vein-first; 95% confidence interval [CI] 0.61–1.39, p = 0.68) or distant metastasis (RR 0.92; 95% CI 0.30–2.85, p = 0.89); but it was associated with better disease-free survival (RR 0.52; 95% CI 0.37–0.73, p < 0.01) as well as 5-year overall survival (RR 0.60; 95% CI 0.41–0.86, p < 0.01). In addition, the operative time, intraoperative blood loss, total complications, and length of postoperative stay were mainly comparable between the two groups. Second, 7 studies provided the data of tumor cells indicated by different biomarkers and detection methods; and 3 of these reports showed that vein-first ligation decreased the extent of intraoperative tumor dissemination. However, a quantitative meta-analysis was not possible due to the significant heterogeneity.

Conclusion

Vein-first ligation in lung cancer surgery may be associated with improved survival of the patients, which might be ascribed to potentially lower risk of tumor cell dissemination. Well-designed, large-scale trials are warranted to clarify these occasional findings.

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.

Neuroimmune Regulation of Surgery-Associated Metastases

Surgery remains an essential therapeutic approach for most solid malignancies. Although for more than a century accumulating clinical and experimental data have indicated that surgical procedures themselves may promote the appearance and progression of recurrent and metastatic lesions, only in recent years has renewed interest been taken in the mechanism by which metastasizing of cancer occurs following operative procedures. It is well proven now that surgery constitutes a risk factor for the promotion of pre-existing, possibly dormant micrometastases and the acceleration of new metastases through several mechanisms, including the release of neuroendocrine and stress hormones and wound healing pathway-associated immunosuppression, neovascularization, and tissue remodeling. These postoperative consequences synergistically facilitate the establishment of new metastases and the development of pre-existing micrometastases. While only in recent years the role of the peripheral nervous system has been recognized as another contributor to cancer development and metastasis, little is known about the contribution of tumor-associated neuronal and neuroglial elements in the metastatic disease related to surgical trauma and wound healing. Specifically, although numerous clinical and experimental data suggest that biopsy- and surgery-induced wound healing can promote survival and metastatic spread of residual and dormant malignant cells, the involvement of the tumor-associated neuroglial cells in the formation of metastases following tissue injury has not been well understood. Understanding the clinical significance and underlying mechanisms of neuroimmune regulation of surgery-associated metastasis will not only advance the field of neuro–immuno–oncology and contribute to basic science and translational oncology research but will also produce a strong foundation for developing novel mechanism-based therapeutic approaches that may protect patients against the oncologically adverse effects of primary tumor biopsy and excision.

Wedge Resection of Tumor Before Lobectomy for Lung Cancer Could Be a No-touch Isolation Technique

BACKGROUND/AIM

Circulating tumor cells (CTCs) can be a surrogate biomarker of prospective prognosis. Surgical manipulation can promote the dissemination of CTCs. Prognosis improvement is expected with the no-touch isolation technique (NTIT), preventing surgical manipulation. The Wedge resection of the tumor site before lobectomy could prevent surgical manipulation during lobectomy for non-small cell lung cancer (NSCLC) and reduce the shedding of tumor cells, similar to a NTIT. This study aimed to evaluate the effect of wedge resection technique.

PATIENTS AND METHODS

A total of 624 resected NSCLC patients were retrospectively analyzed. Patients were divided in two groups: Wedge and Non-Wedge. Overall survival (OS) curves were plotted using the Kaplan-Meier method.

RESULTS

The 5-year OS rates were 89.9% and 84.0% in the Wedge and Non-Wedge groups, respectively (p=0.033).

CONCLUSION

The OS in the Wedge group was significantly better than that in the Non-Wedge group. Wedge resection technique for NSCLC may be a NTIT.

Possible role of circulating tumor cells in early detection of lung cancer

The prognosis of lung cancer varies highly depending on the disease stage at diagnosis, from a 5-year survival rate close to 90% in stage I, to 10% or less in stage IV disease. The enhancement of early diagnosis of this malignancy is mandatory to improve prognosis, because lung cancer patients stay long asymptomatic or few symptomatic after disease onset. Nowadays, liquid biopsy has emerged as a minimally-invasive tool to address the urgent need for real time monitoring, stratification, and personalized treatment of malignancies, including lung cancer. Liquid biopsy refers to a class of biomarkers, including circulating tumor cells (CTCs), cell-free circulating tumor DNA (ctDNA) and tumor-derived extracellular vesicles (tdEV). Since CTCs represent a crucial step in disease progression and metastasis, we reviewed here the scientific literature about the use of CTCs in early diagnosis of lung cancer; different techniques, and different strategies (e.g., source of analysis sample or high-risk groups of patients) were discussed showing the potential of implementing liquid biopsy in the clinical routine of non-metastatic lung cancer.

Surgical stress and cancer progression: the twisted tango

Surgical resection is an important avenue for cancer treatment, which, in most cases, can effectively alleviate the patient symptoms. However, accumulating evidence has documented that surgical resection potentially enhances metastatic seeding of tumor cells. In this review, we revisit the literature on surgical stress, and outline the mechanisms by which surgical stress, including ischemia/reperfusion injury, activation of sympathetic nervous system, inflammation, systemically hypercoagulable state, immune suppression and effects of anesthetic agents, promotes tumor metastasis. We also propose preventive strategies or resolution of tumor metastasis caused by surgical stress.