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.

The IASLC Mesothelioma Staging Project: Proposals for Revisions of the T Descriptors in the Forthcoming Eighth Edition of the TNM Classification for Pleural Mesothelioma

INTRODUCTION

The current T component for malignant pleural mesothelioma (MPM) has been predominantly informed by surgical data sets and consensus. The International Association for the Study of Lung Cancer undertook revision of the seventh edition of the staging system for MPM with the goal of developing recommendations for the eighth edition.

METHODS

Data elements including detailed T descriptors were developed by consensus. Tumor thickness at three pleural levels was also recorded. An electronic data capture system was established to facilitate data submission.

RESULTS

A total of 3519 cases were submitted to the database. Of those eligible for T-component analysis, 509 cases had only clinical staging, 836 cases had only surgical staging, and 642 cases had both available. Survival was examined for T categories according to the current seventh edition staging system. There was clear separation between all clinically staged categories except T1a versus T1b (hazard ratio = 0.99, p = 0.95) and T3 versus T4 (hazard ratio = 1.22, p = 0.09), although the numbers of T4 cases were small. Pathological staging failed to demonstrate a survival difference between adjacent categories with the exception of T3 versus T4. Performance improved with collapse of T1a and T1b into a single T1 category; no current descriptors were shifted or eliminated. Tumor thickness and nodular or rindlike morphology were significantly associated with survival.

CONCLUSIONS

A recommendation to collapse both clinical and pathological T1a and T1b into a T1 classification will be made for the eighth edition staging system. Simple measurement of pleural thickness has prognostic significance and should be examined further with a view to incorporation into future staging.

The IASLC Lung Cancer Staging Project: Methodology and Validation Used in the Development of Proposals for Revision of the Stage Classification of NSCLC in the Forthcoming (Eighth) Edition of the TNM Classification of Lung Cancer

INTRODUCTION

Stage classification provides a consistent language to describe the anatomic extent of disease and is therefore a critical tool in caring for patients. The Staging and Prognostic Factors Committee of the International Association for the Study of Lung Cancer developed proposals for revision of the classification of lung cancer for the eighth edition of the tumor, node, and metastasis (TNM) classification, which takes effect in 2017.

METHODS

An international database of 94,708 patients with lung cancer diagnosed in 1999-2010 was assembled. This article describes the process and statistical methods used to refine the lung cancer stage classification.

RESULTS

Extensive analysis allowed definition of tumor, node, and metastasis categories and stage groupings that demonstrated consistent discrimination overall and within multiple different patient cohorts (e.g., clinical or pathologic stage, R0 or R-any resection status, geographic region). Additional analyses provided evidence of applicability over time, across a spectrum of geographic regions, histologic types, evaluative approaches, and follow-up intervals.

CONCLUSIONS

An extensive analysis has produced stage classification proposals for lung cancer with a robust degree of discriminatory consistency and general applicability. Nevertheless, external validation is encouraged to identify areas of strength and weakness; a sound validation should have discriminatory ability and be based on an independent data set of adequate size and sufficient follow-up with enough patients for each subgroup.

The IASLC Lung Cancer Staging Project: Proposals for Coding T Categories for Subsolid Nodules and Assessment of Tumor Size in Part-Solid Tumors in the Forthcoming Eighth Edition of the TNM Classification of Lung Cancer

This article proposes codes for the primary tumor categories of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) and a uniform way to measure tumor size in part-solid tumors for the eighth edition of the tumor, node, and metastasis classification of lung cancer. In 2011, new entities of AIS, MIA, and lepidic predominant adenocarcinoma were defined, and they were later incorporated into the 2015 World Health Organization classification of lung cancer. To fit these entities into the T component of the staging system, the Tis category is proposed for AIS, with Tis (AIS) specified if it is to be distinguished from squamous cell carcinoma in situ (SCIS), which is to be designated Tis (SCIS). We also propose that MIA be classified as T1mi. Furthermore, the use of the invasive size for T descriptor size follows a recommendation made in three editions of the Union for International Cancer Control tumor, node, and metastasis supplement since 2003. For tumor size, the greatest dimension should be reported both clinically and pathologically. In nonmucinous lung adenocarcinomas, the computed tomography (CT) findings of ground glass versus solid opacities tend to correspond respectively to lepidic versus invasive patterns seen pathologically. However, this correlation is not absolute; so when CT features suggest nonmucinous AIS, MIA, and lepidic predominant adenocarcinoma, the suspected diagnosis and clinical staging should be regarded as a preliminary assessment that is subject to revision after pathologic evaluation of resected specimens. The ability to predict invasive versus noninvasive size on the basis of solid versus ground glass components is not applicable to mucinous AIS, MIA, or invasive mucinous adenocarcinomas because they generally show solid nodules or consolidation on CT.

The IASLC Lung Cancer Staging Project: Background Data and Proposals for the Application of TNM Staging Rules to Lung Cancer Presenting as Multiple Nodules with Ground Glass or Lepidic Features or a Pneumonic Type of Involvement in the Forthcoming Eighth Edition of the TNM Classification

INTRODUCTION

Application of tumor, node, and metastasis (TNM) classification is difficult in patients with lung cancer presenting as multiple ground glass nodules or with diffuse pneumonic-type involvement. Clarification of how to do this is needed for the forthcoming eighth edition of TNM classification.

METHODS

A subcommittee of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee conducted a systematic literature review to build an evidence base regarding such tumors. An iterative process that included an extended workgroup was used to develop proposals for TNM classification.

RESULTS

Patients with multiple tumors with a prominent ground glass component on imaging or lepidic component on microscopy are being seen with increasing frequency. These tumors are associated with good survival after resection and a decreased propensity for nodal and extrathoracic metastases. Diffuse pneumonic-type involvement in the lung is associated with a worse prognosis, but also with a decreased propensity for nodal and distant metastases.

CONCLUSION

For multifocal ground glass/lepidic tumors, we propose that the T category be determined by the highest T lesion, with either the number of tumors or m in parentheses to denote the multifocal nature, and that a single N and M category be used for all the lesions collectively-for example, T1a(3)N0M0 or T1b(m)N0M0. For diffuse pneumonic-type lung cancer we propose that the T category be designated by size (or T3) if in one lobe, as T4 if involving an ipsilateral different lobe, or as M1a if contralateral and that a single N and M category be used for all pulmonary areas of involvement.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for the Revision of the Clinical and Pathologic Staging of Small Cell Lung Cancer in the Forthcoming Eighth Edition of the TNM Classification for Lung Cancer

INTRODUCTION

Small cell lung cancer (SCLC) is commonly classified as either limited or extensive, but the Union for International Cancer Control TNM Classification of Malignant Tumours seventh edition (2009) recommended tumor, node, and metastasis (TNM) staging based on analysis of the International Association for the Study of Lung Cancer (IASLC) database.

METHODS

Survival analyses were performed for clinically and pathologically staged patients presenting with SCLC from 1999 through 2010. Prognosis was compared in relation to the TNM seventh edition staging to serve as validation and analyzed in relation to proposed changes to the T descriptors found in the eighth edition.

RESULTS

There were 5002 patients: 4848 patients with clinical and 582 with pathological stages. Among these, 428 had both. Survival differences were confirmed for T and N categories and maintained in relation to proposed revisions to T descriptors for seventh edition TNM categories and proposed changes in the eighth edition. There were also survival differences, notably at 12 months, in patients with brain-only single-site metastasis (SSM) compared to SSM at other sites, and SSM without a pleural effusion showed a better prognosis than other patients in the M1b category.

CONCLUSION

We confirm the prognostic value of clinical and pathological TNM staging in patients with SCLC, and recommend continued usage for SCLC in relation to proposed changes to T, N, and M descriptors for NSCLC in the eighth edition. However, for M descriptors, it remains uncertain whether survival differences in patients with SSM in the brain simply reflect better treatment options rather than better survival based on anatomic extent of disease.

Predicting the prognosis of lung cancer: the evolution of tumor, node and metastasis in the molecular age-challenges and opportunities

The tumor, node and metastasis (TNM) classification of malignant tumors was proposed by Pierre Denoit in the mid-20(th) century to code the anatomic extent of tumors. Soon after, it was accepted by the Union for International Cancer Control and by the American Joint Committee on Cancer, and published in their respective staging manuals. Till 2002, the revisions of the TNM classification were based on the analyses of a database that included over 5,000 patients, and that was managed by Clifton Mountain. These patients originated from North America and almost all of them had undergone surgical treatment. To overcome these limitations, the International Association for the Study of Lung Cancer proposed the creation of an international database of lung cancer patients treated with a wider range of therapeutic modalities. The changes introduced in the 7(th) edition of the TNM classification of lung cancer, published in 2009, derived from the analysis of an international retrospective database of 81,495 patients. The revisions for the 8(th) edition, to be published in 2016, will be based on a new retrospective and prospective international database of 77,156 patients, and will mainly concern tumor size, extrathoracic metastatic disease, and stage grouping. These revisions will improve our capacity to indicate prognosis and will make the TNM classification more robust. In the future the TNM classification will be combined with non-anatomic parameters to define prognostic groups to further refine personalized prognosis.

Impact of inappropriate lymphadenectomy on lung metastasectomy for patients with metastatic colorectal cancer

PURPOSE

To evaluate the characteristics of lymph node assessment in the Spanish Colorectal Metastasectomy Registry (GECMP-CCR) and to analyze and compare the survival of patients with pathological absence or presence of lymph node metastases (LNM) with the survival of those with uncertain lymph node status (uLNs).

METHODS

A total of 522 patients with lung metastases from colorectal carcinoma were prospectively registered from 2008 to 2010. To confirm the pathologic absence of LNM, systematic nodal dissection or systematic sampling was required, or the lymph node status was coded as uncertain. Disease-specific survival and disease-free survival were calculated by the Kaplan-Meier method with the log-rank test for comparisons.

RESULTS

Lymphadenectomy was performed in 250 (48%) patients. LNM was found in 25 (10%) of the patients who had lymph node assessment done. The 3- and 5-year disease-specific survival rates according to lymph node status were 73.5 and 58.3% in the absence of LNM, 50.5 and 24.8% when LNM was confirmed, and 69 and 44% for those with uLNs, respectively (p = 0.006).

CONCLUSIONS

The presence of LNM and uLNs is associated with an increased risk of death. The association of nodal assessment at the time of metastasectomy to identify LNM helps us to refine the postoperative prognosis; therefore, its impact should be properly studied in a prospective clinical trial.

Subxiphoid video-pericardioscopy

Pericardial effusion may be associated with many diseases, but sometimes its aetiology is not easy to elucidate. Subxiphoid video-pericardioscopy is useful for the study of the pericardial cavity. Through a subxiphoid approach, the pericardium is incised and a rigid (usually a video-mediastinoscope) or a flexible endoscope (flexible bronchoscope or flexible choledoscope) is inserted into the pericardial cavity. The inner surface of the parietal pericardium and the epicardium can be explored and biopsies can be taken under visual control. In addition, a subxiphoid pericardial window can be developed, and sclerosing agents instilled for pericardiodesis, if a malignant aetiology is confirmed. In case of pericardial effusion associated with lung cancer, video-pericardioscopy helps to confirm the absence or presence of pericardial tumour implant or infiltration, and to establish the resectability of the tumour. Other than transient arrhythmias during the procedure, video-pericardioscopy has no major complications. When compared with surgical pericardial drainage, video-pericardioscopy has higher sensitivity without specific risks. Rigid endoscopes are the best devices to explore the posterior and lateral pericardial surfaces, the pulmonary veins being the posterior limit of the exploration. Big anterior mediastinal masses and pericardial symphysis may render the exploration impossible.

Utility of the transcervical approach in bilateral synchronous lung cancer

Bilateral pulmonary nodules represent a challenge in distinguishing between synchronous bronchogenic carcinomas and metastatic disease. In the case of potentially curable synchronous lung cancer, it is recommended to treat each lesion with curative intent if there is no evidence of mediastinal involvement or extrathoracic disease. In this situation, surgical staging of the mediastinum is recommended. This case shows the utility of a transcervical approach to perform precise mediastinal staging and lymphadenectomy, and to access the pleural cavity to resect a pulmonary nodule. Moreover, video-assisted mediastinoscopic lymphadenectomy combined with video-assisted lobectomy could be a good option for a radical lymphadenectomy.

Mediastinal lymphadenectomy in elderly patients with non-small-cell lung cancer

OBJECTIVES

The progressive ageing of the population is accompanied by an increasing incidence of cancer. Our objective was to compare mediastinal lymphadenectomy performed in the surgical treatment of non-small-cell lung cancer (NSCLC) patients between ≥ 70 and <70.

METHODS

We performed a retrospective single-centre case-control study, including 80 patients ≥ 70 years of age, surgically treated for NSCLC between January 2008 and December 2010, matched 1:1 to 80 younger controls on gender, American Society of Anesthesia score, performance status and histological subtype of the tumour. The number and type of dissected hilar/intrapulmonary and mediastinal lymph node stations as well as the number of resected lymph nodes were compared between the two age groups.

RESULTS

The type of pulmonary resection was significantly different between the two groups (P = 0.03): pneumonectomy 6% (n = 5) for patients ≥ 70 vs 12% (n = 10) for patients <70, lobectomy 85 (n = 68) vs 65% (n = 52), bilobectomy 1 (n = 1) vs 2% (n = 2) and sub-lobar resection 7 (n = 6) vs 20% (n = 16). There was no significant difference in type of mediastinal lymphadenectomy (radical vs sampling; P = 0.6). Elderly patients presented a more advanced N status of lymph node invasion than younger controls (P = 0.02). The number and type of dissected lymph node stations and the number of lymph nodes were not significantly different between the two age groups (P = 0.66 and 0.25, respectively). The mean number of metastatic lymph nodes was higher in patients ≥ 70 (2.3 vs 1.3 in patients <70; P = 0.002). Lymph node ratio between metastatic and resected lymph nodes was higher in elderly patients (0.11 vs 0.07 in younger controls; P = 0.009).

CONCLUSIONS

Lymph node involvement in surgically treated NSCLC was more significant in elderly patients ≥ 70 than in younger patients presenting comparable clinical and histopathological characteristics, and undergoing a similar lymphadenectomy.

Invasive staging of mediastinal lymph nodes: mediastinoscopy and remediastinoscopy

Nodal status in lung cancer is essential for planning therapy and assessing prognosis. The involvement of ipsilateral and contralateral mediastinal lymph nodes is associated with poor prognosis and usually excludes patients from upfront surgical treatment. Mediastinoscopy is a time-honored procedure that allows the surgeon to access the upper mediastinal lymph nodes for either biopsy or removal. Remediastinoscopy is mainly indicated to assess objective tumor response in mediastinal lymph nodes after induction therapy for locally advanced lung cancer and to indicate further therapy.