Video-assisted mediastinoscopic lymphadenectomy (VAMLA): Mature results for staging non-small cell lung cancer with normal mediastinum

OBJECTIVES

The aim of this study is to analyze the accuracy of video-assisted mediastinoscopic lymphadenectomy (VAMLA) and the unsuspected (u) N2/3 rates in patients with non-small cell lung cancer (NSCLC) and normal mediastinum by integrated positron emission tomography-computed tomography.

METHODS

Prospective observational single-center study of 603 consecutive VAMLAs from 2010 to 2022.

EXCLUSION CRITERIA

other indications (n = 32), tumors different from NSCLC (n = 91), and clinical (c) N2/3 tumors by positron emission tomography-computed tomography (n = 46). Systematic nodal dissection was the gold standard to validate negative VAMLAs. Those patients with negative VAMLA and missing reference standard test were excluded. uN2/3 rates were analyzed in the global series and in the subgroups of tumors according to their clinical nodal and tumor categories. Pathologic findings were reviewed, and staging values were calculated.

RESULTS

Three hundred eighty-three patients with cN0/1 NSCLC underwent VAMLA. Staging values of VAMLA were: sensitivity, 0.98 (95% CI, 0.92-0.99); negative predictive value, 0.99 (95% CI, 0.98-1); and diagnostic accuracy, 0.99 (95% CI, 0.98-1). The uN2/3 rate for the whole series (N = 383) was 18.8%. The uN2/3 rates according to presurgical nodal and tumor categories determined by positron emission tomography computed tomography were: 3.6% (4 out of 111) in cT1N0; 16.3% (18 out of 110) in cT2N0; 10.25% (4 out of 39) in cT3N0; and 32% (7 out of 22) in cT4N0. Forty-two percent (39 out of 93) in cN1; complication rate was 7%.

CONCLUSIONS

This series of NSCLC with normal mediastinum staged by VAMLA demonstrates a high accuracy of this technique and a high rate of uN2/3 disease (specially in cN1 and cT4N0). VAMLA could be considered the reference staging procedure for staging cN0/1 NSCLC.

Mediastinal lymph node removal modulates natural killer cell exhaustion in patients with non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death globally. In this study, the effect of complete removal of mediastinal lymph nodes by video-assisted mediastinoscopic lymphadenectomy (VAMLA) on natural killer (NK) cell phenotype and functions in patients with NSCLC was evaluated. The study included 21 NSCLC patients (cIA-IVA) undergoing VAMLA staging and 33 healthy controls. Mononuclear cells were isolated from peripheral blood of all participants and mediastinal lymph nodes of the patients. NK cells were analyzed by flow cytometry to define NK subsets, expressions of PD-1, CTLA-4, activating/inhibitory receptors, granzyme A, and CD107a. The plasma levels of soluble PD-1, PDL-1, and CTLA-4 were measured by ELISA. Mediastinal lymph nodes of NSCLC patients had increased ratios of exhausted NK cells, increased expression of PD-1 and IL-10, and impaired cytotoxicity. Mediastinal lymph nodes removal increased CD56dimCD16bright cytotoxic effector phenotype and reduced exhausted NK cells. PD-1+ NK cells were significantly more abundant in patients' blood, and VAMLA significantly reduced their ratio as well. The ratio of IL-10 secreting regulatory NK cells was also reduced after VAMLA. Blood NK cells had increased cytotoxic functions and spontaneous IFN-γ secretion, and these NK cell functions were also recovered by VAMLA. Mediastinal lymph node removal reversed NK cell exhaustion, reduced regulatory NK cells, and improved antitumoral functions of NK cells. Tumor-draining lymph nodes may contribute to tumor evasion from antitumoral immune responses. The role of their removal needs to be further studied both to better understand this mechanism and as a potential immunotherapeutic approach.

Mediastinal lymph node removal ameliorates cytotoxic T-lymphocyte functions in patients with non-small cell lung cancer

INTRODUCTION

Mediastinal lymph node (MLN) removal by video-assisted mediastinoscopic lymphadenectomy (VAMLA) for preoperative cancer staging was reported to be associated with increased survival. The aim of this study was to evaluate the immunologic effects of complete MLN removal by VAMLA on cytotoxic T lymphocyte (CTL) phenotype and function.

METHODS

Seventeen patients with non-small cell lung cancer (NSCLC) (stage cT1-4N0-3M0-1A) and 20 healthy participants were included in this study. Blood samples were collected before and 4 weeks after the procedure. Lymphocytes were isolated from the removed MLNs. CTL phenotypes and functions were evaluated by flow cytometry. Plasma levels of soluble programmed cell death protein 1 (sPD-1), soluble programmed cell death protein 1 ligand, and soluble CTL antigen 4 (sCTLA-4) were measured with enzyme-linked immunosorbent assay.

RESULTS

The ratio of the immunosenescent CTLs (CD3⁺CD8⁺CD28^-) was increased in peripheral blood and MLNs of the patients with NSCLC compared to controls (p = 0.037), and MLN removal did not change this ratio. PD-1 and CTL antigen 4 expressions were significantly reduced in peripheral blood CTLs after MLN removal by VAMLA (p = 0.01 and p = 0.01, respectively). Granzyme A expression was significantly reduced in the peripheral blood CTLs of the patients compared to controls (p = 0.006) and MLN removal by VAMLA significantly improved Granzyme A expression in CTLs (p = 0.003). Plasma concentrations of sPD-1 and sCTLA-4 remained unchanged after VAMLA.

CONCLUSION

CTLs in the MLNs and peripheral blood of the patients with NSCLC had an immunosenescent phenotype, increased immune checkpoint receptor expression, and impaired cytotoxicity. MLN removal by VAMLA improved these phenotypic and functional characteristics of CTLs. These changes may explain the potential contribution of VAMLA to improved survival.

Video-assisted mediastinoscopic lymphadenectomy (VAMLA): A video vignette

Mediastinal staging in potentially resectable non-small cell lung cancer is of paramount importance since it impacts the survival of the patient. With increasing nodal stage, survival was noted to precipitously decline. Nodal status also determined the use of neoadjuvant/adjuvant therapy and other treatment modalities. Various methods of obtaining lymphatic tissue from the mediastinum for staging purposes have been described in the literature, although mediastinoscopic lymph node evaluation remains the gold standard. Endoscopic methods of mediastinal staging, like the endobronchial ultrasound guided and esophageal ultrasound guided fine-needle aspiration techniques, although minimally invasive, provide the highest levels of accuracy when used in conjunction with surgical mediastinal staging. Video-assisted mediastinoscopic lymphadenectomy (VAMLA) provides clear advantages, as far as ergonomics and training are concerned, over conventional mediastinoscopy. Access to stations 2R, 2L, 4R, 4L, and 7 is feasible with VAMLA. In this video vignette, we present the step-by-step technique of a standard VAMLA, with an overview of relevant anatomical relationships, for the effective and safe clearance of lymph node stations for the purposes of staging and defining appropriate therapy.

The learning curve of video-assisted mediastinoscopic lymphadenectomy for staging of non-small-cell lung carcinoma

OBJECTIVES

The objective of this study was to define the learning process of video-assisted mediastinoscopic lymphadenectomy (VAMLA) by the assessment of consecutive procedural metrics.

METHODS

We conducted a single-centre retrospective observational study of all consecutive VAMLAs performed between 2011 and 2018 for the staging of non-small-cell lung carcinoma. Learning curves were assessed using non-risk adjusted cumulative observed minus expected (CUSUM) failure charts of complications. Boundary lines were defined by the acceptable and unacceptable complication rates of 4.5% and 15.0%. The Kruskal-Wallis test with post hoc analysis was used to assess trends in operation time and blood loss.

RESULTS

Two-hundred-thirty-six unique VAMLAs by 4 surgeons performing their first procedures were evaluated. CUSUM charts of surgeons A and B showed a typical learning curve with an initial incline, followed by a turning point towards lower complications rates after 16-17 cases, whereas surgeons C and D showed an average performance. The median time between consecutive VAMLAs was shorter for surgeons A and B (13.0 vs 28.5-38.0 days for surgeons C and D). Overcoming the learning curve, complication rates of surgeons A and B decreased from 19% to 3% and from 18% to 5%, respectively. Operation time and blood loss showed a significant improvement after, respectively, 81-100 and 61-80 procedures compared to the first 20 procedures.

CONCLUSIONS

VAMLA is a safe procedure to adopt and perform with acceptable complication rates from the first operation onward, regardless of the caseload. To overcome its learning curve, 16-17 cases are required, preferably at least 1 per 2 weeks.

Tailored management of stage IIIa non-small-cell lung cancer in the era of the 8th edition of the TNM classification for lung cancer

Stage IIIA is a very heterogeneous group encompassing locally advanced disease with T3 and T4 tumors without any nodal involvement and very small T1a primary tumors with unilateral mediastinal lymphatic disease. Tailored management defines interdisciplinary management requiring board decisions, which can sometimes be difficult particularly in stage IIIa non-small-cell lung cancer (NSCLC). Lobectomy still is standard of care even for stage I NSCLC, which increasingly is implemented using minimally invasive surgical technique. On the other hand even locally extended tumors are today safely resected with low morbidity and mortality. According to the 2015 guidelines of the European Society of Thoracic Surgeons any kind of anatomical lung resection for lung cancer with curative intent has to be accompanied by formal mediastinal lymph node dissection. The transcervical route for complete bilateral mediastinal lymphadenectomy offers improved completeness of resection without the need for single lung ventilation and ideally supports the concept of minimally invasive surgery.

Video-assisted mediastinoscopic lymphadenectomy is associated with better survival than mediastinoscopy in patients with resected non-small cell lung cancer

OBJECTIVES

We aimed to analyze the accuracy of video-assisted mediastinoscopic lymphadenectomy (VAMLA) as a tool for preoperative staging and the impact of the technique on survival in patients with non-small cell lung cancer (NSCLC) undergoing pulmonary resection.

METHODS

Between May 2006 and December 2010, 433 patients underwent pulmonary resection for NSCLC, 89 (21%) had VAMLA before resection and 344 (79%) had standard mediastinoscopy. The patients who had negative VAMLA/mediastinoscopy results underwent anatomic pulmonary resection and systematic lymph node dissection.

RESULTS

The median and mean numbers of resected lymph node stations were 5 and 4.9 in the VAMLA group and 4 and 4.2 in the mediastinoscopy group (P = .9). The mean number of lymph nodes per biopsy specimen using standard mediastinoscopy was 10.1, whereas it was 30.4 using VAMLA (P < .001). VAMLA unveiled N2 or N3 disease in 30 (33.7%) and in 6 (6.7%) of patients, respectively. The negative predictive value, sensitivity, false-negative value, and accuracy of VAMLA were statistically higher in the VAMLA groups compared with those of standard mediastinoscopy. The 5-year survival was 90% for VAMLA patients and 66% for mediastinoscopy patients (P = .01). By multivariable analysis, VAMLA was associated with better survival (odds ratio, 1.34; 95% confidence interval, 1.1-3.2; P = .02).

CONCLUSIONS

VAMLA was associated with improved survival in NSCLC patients who had resectional surgery.