The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for Revision of the Classification of Residual Tumor After Resection for the Forthcoming (Ninth) Edition of the TNM Classification of Lung Cancer

INTRODUCTION

The goal of surgical resection is to completely remove a cancer; it is useful to have a system to describe how well this was accomplished. This is captured by the residual tumor (R) classification, which is separate from the TNM classification that describes the anatomic extent of a cancer independent of treatment. The traditional R-classification designates as R0 a complete resection, as R1 a macroscopically complete resection but with microscopic tumor at the surgical margin, and as R2 a resection that leaves gross tumor behind. For lung cancer, an additional category encompasses situations in which the presence of residual tumor is uncertain.

METHODS

This paper represents a comprehensive review of evidence regarding these R categories and the descriptors thereof, focusing on studies published after the year 2000 and with adjustment for potential confounders.

RESULTS

Consistent discrimination between complete, uncertain, and incomplete resection is revealed with respect to overall survival. Evidence regarding specific descriptors is generally somewhat limited and only partially consistent; nevertheless, the data suggest retaining all descriptors but with clarifications to address ambiguities.

CONCLUSION

On the basis of this review, the R-classification for the ninth edition of stage classification of lung cancer is proposed to retain the same overall framework and descriptors, with more precise definitions of descriptors. These refinements should facilitate application and further research.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for Revision of the TNM Stage Groups in the Forthcoming (Ninth) Edition of the TNM Classification for Lung Cancer

INTRODUCTION

The TNM classification of lung cancer is periodically revised. The International Association for the Study of Lung Cancer collected and analyzed a new database to inform the forthcoming ninth edition of the TNM classification. The results are herewith presented.

METHODS

After exclusions, 76,518 patients from a total of 124,581 registered patients were available for analyses: 58,193 with clinical stage, 39,192 with pathologic stage, and 62,611 with best stage NSCLC. The proposed new N2 subcategories (N2a, involvement of single ipsilateral mediastinal or subcarinal nodal station, and N2b, involvement of multiple ipsilateral mediastinal nodal stations with or without involvement of the subcarinal nodal station) and the new M1c subcategories (M1c1, multiple extrathoracic metastases in one organ system, and M1c2, multiple extrathoracic metastases in multiple organ systems) were considered in the survival analyses. Several potential stage groupings were evaluated, using multiple analyses, including recursive partitioning, assessment of homogeneity within and discrimination between potential groups, clinical and statistical significance of survival differences, multivariable regression, and broad assessment of generalizability.

RESULTS

T1N1, T1N2a, and T3N2a subgroups are assigned to IIA, IIB, and IIIA stage groups, respectively. T2aN2b and T2bN2b subgroups are assigned to IIIB. M1c1 and M1c2 remain in stage group IVB. Analyses reveal consistent ordering, discrimination of prognosis, and broad generalizability of the proposed ninth edition stage classification of lung cancer.

CONCLUSIONS

The proposed stages for the ninth edition TNM improve the granularity of nomenclature about anatomic extent that has benefits as treatment approaches become increasingly differentiated and complex.

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.

EBUS-TBNA for mediastinal staging of centrally located T1N0M0 non-small cell lung cancer clinically staged with PET/CT

BACKGROUND AND OBJECTIVE

To evaluate the diagnostic accuracy and clinical usefulness of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for mediastinal staging of centrally located T1N0M0 non-small cell lung cancer (NSCLC) clinically staged with positron emission tomography/computed tomography (PET/CT).

METHODS

We conducted a study that included patients with centrally located T1N0M0 NSCLC, clinically staged with PET/CT who underwent EBUS-TBNA for mediastinal staging. Patients with negative EBUS-TBNA underwent mediastinoscopy, video-assisted mediastinoscopic lymphadenectomy (VAMLA) and/or lung resection with systematic nodal dissection, that were considered the gold standard. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), overall accuracy of EBUS-TBNA for diagnosing mediastinal metastases (N2 disease) and the number needed to treat (NNT: number of patients needed to undergo EBUS-TBNA to avoid a case of pathologic N2 disease after resection) were calculated.

RESULTS

One-hundred eighteen patients were included. EBUS-TBNA proved N2 disease in four patients. In the remaining 114 patients who underwent mediastinoscopy, VAMLA and/or resection there were two cases of N2 (N2 prevalence 5.1%). The sensitivity, specificity, NPV, PPV and overall accuracy for diagnosing mediastinal metastases (N2 disease) were of 66%, 100%, 98%, 100% and 98%, respectively. The NNT was 31 (95% CI: 15-119).

CONCLUSION

EBUS-TBNA in patients with central clinically staged T1N0M0 NSCLC presents a good diagnostic accuracy for mediastinal staging, even in a population with low prevalence of N2 disease. Therefore, its indication should be considered in the management of even these early lung cancers.

IASLC Lung Cancer Staging Project: The New Database to Inform Revisions in the Ninth Edition of the TNM Classification of Lung Cancer

In the past 20 years, the International Association for the Study of Lung Cancer (IASLC) has been working on a global project to revise the TNM classification of lung cancer. The first and second phases of the staging projects proposed recommendations for revision of the TNM classification, which were adopted by the Union for International Cancer Control and the American Joint Committee on Cancer as their seventh and eighth editions of the TNM classifications of lung cancer. For the third phase of the IASLC Staging Project, a new database of lung cancer cases diagnosed between January 2011 and December 2019 has been established. The Staging and Prognostic Factors Committee of the IASLC is in charge of the process of proposing new recommendations. The newly established database consisted of 124,581 cases. The data were obtained from Asia and Australia (56.0%), Europe (24.7%), North America (15.7%), South/Central America (3.4%), and Africa and the Middle East (0.1%). After cases with incomplete data are excluded, 87,043 cases were enrolled in the analysis, of which 52,069 (59.8%) were invasive adenocarcinoma and 15,872 (18.2%) were squamous cell carcinoma. Both clinical and pathologic stages were available in 44,831 (51.5%) cases. Analyses of this database are expected to provide proposals for changing the TNM classification toward the ninth edition, which is scheduled to be in use in January 2024. This newly established global database on lung cancer is described to provide fundamental elements for revisions of the TNM rules for staging lung cancer.

Case report: Primary pleural squamous cell carcinoma in a 68-year-old male

Introduction

Primary pleural squamous cell carcinoma (PPSCC) is a sporadic disease that is rarely reported in the literature. Due to its low incidence, the pathogenesis of PPSCC is unknown.

Case summary

We report a case of a 68-year-old male with PPSCC and sizable pulmonary bullae. Two months after complete resection of both lesions, a total dose of 50 Gy radiotherapy was administered over the operative field. After more than a year of follow-up, the patient is in steady condition without any sign of recurrence.

Conclusion

Since PPSCC is rarely reported, our case proposed that complete surgical resection combined with radiotherapy may be a promising therapeutic approach.

The Lung ART adjuvant radiotherapy phase 3 randomized trial: Impact of quality of resection in stage IIIAN2 patients

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Background: Lung ART is an international phase 3 trial whose main objective was to evaluate the impact of post-operative conformal radiotherapy (PORT) on disease-free survival (DFS) in patients with completely resected pathologically proven N2 non-small cell lung cancer (NSCLC), with or without neo- or adjuvant chemotherapy. Previously communicated results showed no impact of PORT on DFS. However, as quality of surgical resection and extent of lymph node dissection were expected to be critically important in the interpretation of results, surgical and pathological reports were centrally reviewed by a surgical committee. Methods: A surgical advisory committee composed of 4 expert thoracic surgeons reviewed anonymized surgical and pathological reports of all included patients. Pre-defined classification rules were defined using published guidelines from the International Association for the Study of Lung Cancer and the European Society of Thoracic Surgeons. Tumor resection was defined as complete (no residual tumor and adequate lymph node assessment), uncertain (highest mediastinal nodal station involved, incomplete nodal exploration, involved N2 removed in fragments) or incomplete (presence of residual tumor). Nodal exploration was classified as sampling, selective dissection or extensive dissection. Results: 501 patients were included in the Lung ART trial. Before surgical committee review intervention, all patients except 2 had complete resection. 496 patients’ reports were analyzed by the surgical advisory committee. The basic characteristics are specified in the following table: Conclusions: Monitoring of the quality of nodal exploration and of resection should be implemented in randomized studies evaluating peri-operative strategies in NSCLC in order to provide reliable and generalizable results. Clinical trial information: NCT00410683. [Table: see text]

Radicality of lymphadenectomy in lung cancer resections by thoracotomy and video-assisted thoracoscopic approach: A prospective, multicentre and propensity-score adjusted study

OBJECTIVE

To analyse differences in intraoperative nodal assessment in patients undergoing lung cancer resection by thoracotomy and video-assisted thoracoscopy (VATS) in the Spanish Video-Assisted Thoracic Surgery Group (GEVATS).

METHODS

Prospective multicentre cohort study of anatomic pulmonary resections (n = 3533) performed from December 2016 to March 2018. Main surgical, clinical and oncological variables related with lymphadenectomy were compared according to surgical approach. Corresponding tests for homogeneity were performed. Multiple logistic regression analyses were used to determine the odds ratio (OR) and 95% confidence interval (95%CI). Covariate adjustment using the propensity score (PS) was performed to reduce confounding effects.

RESULTS

After exclusions, 2532 patients were analysed. Systematic nodal dissection (SND) was performed in 65%, with a median of resected/sampled lymph nodes (LN) of 7 (IQR 4-12) and pathologic (p) N2 and uncertain (u) pNu rates of 9.4% and 28.9%, respectively. At multivariate analysis, the following were associated with thoracotomy (OR; 95%CI): SND (1.4; 1.08-1.96; p = 0.014), staging mediastinoscopy (2.6; 1.59-4.25; p < 0.001), tumor > 3 cm (2.1; 1.66-2.78; p < 0.001), central tumor (2.5; 1.90-3.24; p < 0.001); pN1 (1.8; 1.25-2.67; p < 0.002), pN2 (1.8; 1.18-2.76; p = 0.006), lower FEV1 (0.9; 0.98-0.99; p < 0.001), squamous cell carcinoma (1.5; 1.16-1.98; p = 0.002) and inexperienced surgeons in VATS (compared with > 100 VATS experience) (37.6; 13.55-104.6; p < 0.001). After PS adjustment, SND maintained the OR, but in the limit of signification (1.4; 1-1.98; p = 0.05). Nodal upstaging was significantly higher in the thoracotomy group. Complication rates of SND and no SND were similar.

CONCLUSIONS

Thoracotomy was associated with a more thorough lymphadenectomy in GEVATS. Therefore, intraoperative lymph node evaluation performed at VATS should be improved to have better prognostic information and more solid grounds to indicate adjuvant therapy.

How do we Classify a Central Tumor? Results of a Multidisciplinary Survey from the SEPAR Thoracic Oncology Area

INTRODUCTION

In patients with non-small cell lung cancer (NSCLC) and normal mediastinal imaging tests, centrally located tumors have greater occult mediastinal involvement. Clinical guidelines, therefore, recommend invasive mediastinal staging in this situation. However, definitions of centrality in the different guidelines are inconsistent. The SEPAR Thoracic Oncology area aimed to evaluate the degree of familiarity with various concepts related to tumor site among professionals who see patients with NSCLC in Spain.

METHODS

A questionnaire was distributed to members of Spanish medical societies involved in the management of NSCLC, structured according to the 3 aspects to be evaluated: 1) uniformity in the definition of central tumor location; 2) uniformity in the classification of lesions that extend beyond dividing lines; and 3) ability to delineate lesions in the absence of dividing lines.

RESULTS

A total of 430 participants responded. The most voted definition of centrality was «lesions in contact with hilar structures» (49.7%). The lines most often chosen to delimit the hemitorax were concentric hilar lines (89%). Most participants (92.8%) classified tumors according to the side of the dividing line that contained most of their volume. Overall, 78.6% were able to correctly classify a central lesion in the absence of dividing lines.

CONCLUSIONS

In our survey, the most widely accepted definition of centrality is not one of the proposals specified in the clinical guidelines. The results reflect wide variability in the classification of tumor lesions.

SRC-homology 2 domain-containing phosphatase 2 (SHP2) in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma (LUAD)

9540

Background: Epidermal growth factor (EGFR)-mutant lung adenocarcinomas (LUADs) display impaired phosphorylation of extracellular signal-regulated kinase (ERK) and SRC-homology 2 domain-containing phosphatase 2 (SHP2) in comparison with EGFR wild-type LUADs. However, the function of SHP2 in early EGFR-mutant LUADs and EGFR wild-type LUADs has not been reported. We posit that SHP2 mRNA expression could be a predictive marker in resected EGFR-mutant LUADs versus EGFR wild-type patients (pts). Methods: We examined 267 resected LUADs from Japan and Spain. mRNA expression levels of AXL, MET, CDCP1, STAT3, YAP1 and SHP2 were analyzed by quantitative reverse transcriptase polymerase chain reaction (PCR). EGFR mutant cell lines were investigated for their activity of SHP2. Results: Among the 267 enrolled pts, 100 (37.3%) were EGFR-mutant LUADs. Five-year recurrence-free survival (RFS) and overall survival (OS) were lower for EGFR-mutant LUADs with high SHP2 mRNA levels (hazard ratio = 1.83 and 2.28, respectively. p = 0.03 and p = 0.04). However, SHP2 was not associated with RFS nor OS in the 167 wild-type EGFR LUADs. In EGFR-mutant cells, RMC-4550 (SHP2 inhibitor) plus erlotinib showed synergism via inhibition of AKT (S473) and ERK1/2 (T202/Y204). While erlotinib translocates SHP2 (Y542) into the nucleus, either RMC-4550 alone, or in combination with erlotinib, relocalizes SHP2 into the cytoplasm membrane, limiting AKT and ERK activation. Conclusions: High SHP2 mRNA is related to shorter RFS and OS in EGFR-mutant LUADs, but not in EGFR wild-type LUADs. The findings indicate that the addition of SHP2 inhibitors could improve adjuvant therapy in EGFR-mutant LUADs.

Nodal size ranking as a predictor of mediastinal involvement in clinical early-stage non-small cell lung cancer

In non-small cell lung cancer (NSCLC) patients, the recommended minimum requirement for an endoscopy-based mediastinal staging procedure is sampling the largest lymph node (LN) in right and left inferior paratracheal, and subcarinal stations. We aimed to analyze the percentage of cases where the largest LN in each mediastinal station was malignant in a cohort of NSCLC patients with mediastinal metastases diagnosed in the lymphadenectomy specimen. Furthermore, we investigated the sensitivity of a preoperative staging procedure in a hypothetical scenario where only the largest LN of each station would have been sampled.Prospective data of patients with mediastinal nodal metastases diagnosed in the lymphadenectomy specimens were retrospectively analyzed. The long-axis diameter of the maximal cut surface of all LNs was measured on hematoxylin and eosin-stained sections.Seven hundred seventy five patients underwent operation and 49 (6%) with mediastinal nodal disease were included. A total of 713 LNs were resected and 119 were involved. Sixty seven nodal stations revealed malignant LNs: in these, the largest LN was malignant in 39 (58%). In a "per patient" analysis, a preoperative staging procedure that sampled only the largest LN would have attained a sensitivity of 0.67; and if the largest and the second largest were sampled, sensitivity would be 0.87.In patients with NSCLC, nodal size ranking is not reliable enough to predict malignancy. In clinical practice, regardless of the preoperative staging method, systematic thorough sampling of all visible LNs is to be recommended over selective random samplings.

Transcervical videomediastino-thoracoscopy

Although technical advances in non-invasive and minimally invasive approaches to lung and pleural cancer diagnosis and staging have become more widely available and accurate, surgical techniques remain the gold standard in assessing the extent of loco-regional involvement. Precise surgical staging of lung or pleural tumours is pivotal in the selection of surgical candidates and for predicting survival. In some patients, both mediastinal and pleural exploration may be needed for many different reasons. Transcervical videomediastino-thoracoscopy (VMT) combines simultaneously the exploration of both the mediastinum and the pleural cavities through a single cervical incision, allowing for biopsies or sampling of the mediastinal lymph nodes, lymphadenectomy and pleuropulmonary assessment (mainly pleural effusions, tumour involvement of the visceral and parietal pleura and pulmonary nodules). Thoracic surgeons should be aware of this combined surgical approach and completely familiar with classical indications and technical details of the transcervical approach to the mediastinum and thoracoscopic exploration of the pleural cavities.

Subxiphoid video-thoracoscopy

Surgical procedures of pleural cavity are crucial to complete the diagnoses or planning treatment of pleural effusions with an unknown aetiology. Traditionally, the transthoracic approach has been the most used procedure to study the pleural cavity. The subxiphoid video-thoracoscopy is becoming an alternative to the transthoracic approach. Subxiphoid video-thoracoscopy is a minimally invasive technique that allows us to study both pleural cavities with a single subxiphoid incision. In the supine decubitus, through a small subxiphoid incision, a rigid video-mediastinoscope is introduced. Once all the tissues are dissected, mediastinal pleura can be identified and incised. A 30° thoracoscopy is then inserted into the pleural cavity through the video-mediastinoscope to obtain samples of pleural fluid and biopsies of the parietal pleura and lung nodules if present. Subxiphoid approach has some advantages compared with the traditional transthoracic approach. On the one hand, contrary to traditional thoracoscopy, in subxiphoid video-thoracoscopy it is not necessary to do a transthoracic approach even for the insertion of a chest tube. Avoidance of intercostal ports probably decreases the risk of post-operative pain and the patients can be discharged 24 hours after surgery with no increase in surgical risk. On the other hand, we can explore both pleural cavities at the same time through a single incision, in case of bilateral pleural effusion. If malignancy is confirmed by frozen-section or by macroscopic evidence of intrapleural tumour infiltration or implants, a pleurodesis to avoid recurrence can be performed prior to tube insertion and closure.

Clinical implications of the innovations in the primary tumour and metastasis of the 8th edition of the TNM classification for lung cancer

The 8th edition of the tumour, node and metastasis (TNM) classification for lung cancer introduced two new categories to accommodate adenocarcinoma in situ (AIS)-Tis(AIS)-and minimally invasive adenocarcinoma-T1mi; subdivided T1 into T1a (≤1 cm), T1b (>1-2 cm) and T1c (>2-3 cm); and T2 into T2a (>3-4 cm) and T2b (>4-5 cm); reclassified tumours >5-7 cm as T3, and those >7 cm as T4; reclassified endobronchial location <2 cm from the carina and total atelectasis/pneumonitis as T2a; and reclassified invasion of the diaphragm as T4. Regarding metastasis, the 7^th edition M1a category remained the same, but M1b is now redefined to include single extrathoracic metastasis; and a new category, M1c, has been created for multiple extrathoracic metastases in one or in several organs. Tumours with worse prognosis than that assigned in previous editions, such as T3-4N2M0 and T3-4N3M0, were grouped in stages IIIB and IIIC, respectively. Stage IV was subdivided into IVA, for intrathoracic and single extrathoracic metastasis (M1a and M1b, respectively) and IVB, for multiple extrathoracic metastases (M1c). From the clinical point of view, these innovations will demand a more precise registration of tumour size, a thoughtful assessment of locally advanced tumours at multidisciplinary discussions, and a thorough search of extrathoracic metastases because the number of the metastatic sites has prognostic relevance and may influence therapy.

Lung cancer staging: a concise update

Diagnosis and clinical staging of lung cancer are fundamental to planning therapy. The techniques for clinical staging, i.e anatomic and metabolic imaging, endoscopies and minimally invasive surgical procedures, should be performed sequentially and with an increasing degree of invasiveness. Intraoperative staging, assessing the magnitude of the primary tumour, the involved structures, and the loco-regional lymphatic spread by means of systematic nodal dissection, is essential in order to achieve a complete resection. In resected tumours, pathological staging, with the systematic study of the resected specimens, is the strongest prognostic indicator and is essential to make further decisions on therapy. In the present decade, the guidelines on lung cancer staging of the American College of Chest Physicians and the European Society of Thoracic Surgeons are based on the best available evidence and are widely followed. Recent advances in the classification of the adenocarcinoma of the lung, with the definition of adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic predominant adenocarcinoma, and the publication of the eighth edition of the tumour, node and metastasis classification of lung cancer, have to be integrated into the staging process. The present review complements the latest guidelines on lung cancer staging by providing an update of all these issues.

The IASLC Lung Cancer Staging Project: A Renewed Call to Participation

Over the past two decades, the International Association for the Study of Lung Cancer (IASLC) Staging Project has been a steady source of evidence-based recommendations for the TNM classification for lung cancer published by the Union for International Cancer Control and the American Joint Committee on Cancer. The Staging and Prognostic Factors Committee of the IASLC is now issuing a call for participation in the next phase of the project, which is designed to inform the ninth edition of the TNM classification for lung cancer. Following the case recruitment model for the eighth edition database, volunteer site participants are asked to submit data on patients whose lung cancer was diagnosed between January 1, 2011, and December 31, 2019, to the project by means of a secure, electronic data capture system provided by Cancer Research And Biostatistics in Seattle, Washington. Alternatively, participants may transfer existing data sets. The continued success of the IASLC Staging Project in achieving its objectives will depend on the extent of international participation, the degree to which cases are entered directly into the electronic data capture system, and how closely externally submitted cases conform to the data elements for the project.

Combination video-assisted mediastinoscopic lymphadenectomy and transcervical thoracoscopy

Surgical staging of lung and pleural cancers is crucial for planning treatment and assessing prognosis. In some cases, we need to explore both the mediastinum and the pleural cavity to confirm or rule out tumor dissemination. The combination of video-assisted mediastinoscopic lymphadenectomy (VAMLA) and thoracoscopy through a single transcervical incision allows the surgeon to widen the range of the exploration and improve the staging for lung and pleural cancers.  VAMLA consists of complete removal of the mediastinal fat and lymph nodes of the subcarinal space, the right paratracheal and pretracheal areas, and the left paratracheal space. Once this mediastinal tissue is removed, the right mediastinal pleura can be identified and incised. A 30o thoracoscope is then inserted through the video-mediastinoscope into the pleural cavity to obtain samples of pleural fluid and biopsies of the parietal pleura and lung nodules, if present. In the case of left-sided thoracoscopy the access route to the left pleural cavity is anterior to the aortic arch, as for extended cervical mediastinoscopy. The combination of VAMLA and thoracoscopy is useful for exploring the mediastinum and the pleural space from a single incision and in the same surgical setting as the transcervical approach.

The IASLC Lung Cancer Staging Project: External Validation of the Revision of the TNM Stage Groupings in the Eighth Edition of the TNM Classification of Lung Cancer

INTRODUCTION

Revisions to the TNM stage classifications for lung cancer, informed by the international database (N = 94,708) of the International Association for the Study of Lung Cancer (IASLC) Staging and Prognostic Factors Committee, need external validation. The objective was to externally validate the revisions by using the National Cancer Data Base (NCDB) of the American College of Surgeons.

METHODS

Cases presenting from 2000 through 2012 were drawn from the NCDB and reclassified according to the eighth edition stage classification. Clinically and pathologically staged subsets of NSCLC were analyzed separately. The T, N, and overall TNM classifications were evaluated according to clinical, pathologic, and "best" stage (N = 780,294). Multivariate analyses were carried out to adjust for various confounding factors. A combined analysis of the NSCLC cases from both databases was performed to explore differences in overall survival prognosis between the two databases.

RESULTS

The databases differed in terms of key factors related to data source. Survival was greater in the IASLC database for all stage categories. However, the eighth edition TNM stage classification system demonstrated consistent ability to discriminate TNM categories and stage groups for clinical and pathologic stage.

CONCLUSIONS

The IASLC revisions made for the eighth edition of lung cancer staging are validated by this analysis of the NCDB database by the ordering, statistical differences, and homogeneity within stage groups and by the consistency within analyses of specific cohorts.

Lung cancer - major changes in the American Joint Committee on Cancer eighth edition cancer staging manual

Answer questions and earn CME/CNE The revision for the eighth edition of the tumor, node, and metastasis (TNM) classification of lung cancer was based on analyses of the International Association for the Study of Lung Cancer database, which included 77,156 evaluable patients diagnosed with lung cancer from 1999 to 2010. Among tumor (T) descriptors, the following new tumor-size groups were created: T1a, ≤1 cm; T1b, >1 to 2 cm; T1c, >2 to 3 cm; T2a, >3 to 4 cm; T2b, >4 to 5 cm; T3, >5 to 7 cm; and T4, >7 cm. Tis and T1mi were introduced for adenocarcinoma in situ and minimally invasive adenocarcinoma, respectively. Endobronchial tumors located <2 cm from the carina have better prognosis than those with any other T3 descriptor and were classified as T2. Total atelectasis/pneumonitis was classified as a T2 descriptor, because it has a T2 prognosis. Diaphragmatic invasion is now T4. Visceral pleural invasion remains unchanged, and mediastinal pleura invasion, which is seldom used, disappears as a T descriptor. The lymph node (N) component descriptors are unchanged, but the number of involved nodal stations has prognostic impact. For the metastasis (M) component, M1a (intrathoracic metastases) remains unchanged, but extrathoracic metastases are divided into a single extrathoracic metastasis (new M1b) and multiple extrathoracic metastases in a single organ or multiple organs (M1c). Stage IA is now divided into IA1, IA2, and IA3 to accommodate T1a, T1b, and T1cN0M0 tumors, respectively; all N1 disease is stage IIB except for T3-T4N1M0 tumors, which are stage IIIA; a new stage IIIC is created for T3-T4N3M0 tumors; and stage IV is divided into IVA (M1a and M1b) and IVB (M1c). This revision enhances our capacity for prognostication and will have an important impact in the management of patients with lung cancer and in future research. CA Cancer J Clin 2017;67:138-155. © 2017 American Cancer Society.

The IASLC Mesothelioma Staging Project: Proposals for the M Descriptors and for Revision of the TNM Stage Groupings in the Forthcoming (Eighth) Edition of the TNM Classification for Mesothelioma

INTRODUCTION

The M component and TNM stage groupings for malignant pleural mesothelioma (MPM) have been empirical. The International Association for the Study of Lung Cancer developed a multinational database to propose evidence-based revisions for the eighth edition of the TNM classification of MPM.

METHODS

Data from 29 centers were submitted either electronically or by transfer of existing institutional databases. The M component as it currently stands was validated by confirming sufficient discrimination (by Kaplan-Meier analysis) with respect to overall survival (OS) between the clinical M0 (cM0) and cM1 categories. Candidate stage groups were developed by using a recursive partitioning and amalgamation algorithm applied to all cM0 cases.

RESULTS

Of 3519 submitted cases, 2414 were analyzable and 84 were cM1 cases. Median OS for cM1 cases was 9.7 months versus 13.4 months (p = 0.0013) for the locally advanced (T4 or N3) cM0 cases, supporting inclusion of only cM1 in the stage IV group. Exploratory analyses suggest a possible difference in OS for single- versus multiple-site cM1 cases. A recursive partitioning and amalgamation-generated survival tree on the OS outcomes restricted to cM0 cases with the newly proposed (eighth edition) T and N components indicates that optimal stage groupings for the eighth edition will be as follows: stage IA (T1N0), stage IB (T2-3N0), stage II (T1-2N1), stage IIIA (T3N1), stage IIIB (T1-3N2 or any T4), and stage IV (any M1).

CONCLUSIONS

This first evidence-based revision of the TNM classification for MPM leads to substantial changes in the T and N components and the stage groupings.