Malignant Pleural Mesothelioma : Rationale for a New TNM Classification

BACKGROUND

Malignant pleural mesothelioma (MPM) is a rare but aggressive thoracic malignancy with a poor prognosis. In this regard, a well-defined staging system is of utmost importance in order to correctly diagnose and assign an appropriate treatment to the patient.

METHODS

The current TNM-staging system (7th edition) enables to either clinically or pathologically stage the severity of the disease according to extension of the tumor (T), number of nodes (N) and presence of metastases (M). Patients with stage I-III are considered for surgery, while palliative treatment is indicated for stage IV patients according to the current classification.

RESULTS

Despite its widespread use, the validity of this staging system is questioned due to the low prevalence, histological variety and retrospective nature of the previous study design. In addition, the role of specific treatment modalities including surgery, has yet to be determined, especially for treatment of early-stage disease. In this regard, the International Association for the Study of Lung Cancer (IASLC) initiated the multi-centre, prospective "Mesothelioma Staging Project" in order to address limitations of the 7th edition and to optimize the staging system in accordance to current needs.

CONCLUSIONS

An improved staging system will contribute to the design of prospective multi-institutional clinical trials investigating novel treatment strategies for mesothelioma. In this way comparison of outcome between different medical centres also becomes feasible.

TNM-classification for lung cancer: from the 7th to the 8th edition

Most tumors are staged according to the Tumor-Node-Metastasis (TNM) classification. For lung cancer a new edition was introduced in 2009 and generally applied since 2010. This 7th TNM-classification is based on a large, international retrospective database. Important changes were made regarding the T, N, M factors and specific subcategories were added. However, this 7th edition is still purely based on anatomical information. Other prognosticators such as laboratory results, histology, tumor markers and molecular genetic factors are not yet considered. To prepare the 8th TNM classification a prospective database developed by the International Association for the Study of Lung Cancer (IASLC), is currently enrolling patients from all continents. In this way, more precise and reliable data will become available on specific subdivisions of the T, N and M factors. If proven to be prognostically valid, other parameters will be included as histology, demographic data and specific biochemical and molecular predictive and prognostic factors. All centers with a large experience in thoracic oncology are encouraged to participate in this prospective database.

TNM-Classification for Lung Cancer: From the 7(th) to the 8(th) Edition

Most tumors are staged according to the Tumor-Node-Metastasis (TNM) classification. For lung cancer a new edition was introduced in 2009 and generally applied since 2010. This 7(th) TNM-classification is based on a large, international retrospective database. Important changes were made regarding the T, N, M factors and specific subcategories were added. However, this 7(th) edition is still purely based on anatomical information. Other prognosticators such as laboratory results, histology, tumor markers and molecular genetic factors are not yet considered. To prepare the 8(th) TNM classification a prospective database developed by the International Association for the Study of Lung Cancer (IASLC), is currently enrolling patients from all continents. In this way, more precise and reliable data will become available on specific subdivisions of the T, N and M factors. If proven to be prognostically valid, other parameters will be included as histology, demographic data and specific biochemical and molecular predictive and prognostic factors. All centers with a large experience in thoracic oncology are encouraged to participate in this prospective database.

A novel method for making human monoclonal antibodies

We have developed a B cell immortalization method for low B cell numbers per well using simultaneous B cell stimulation by CpG2006 and B cell infection by Epstein-Barr virus (EBV), followed by an additional CpG2006 and interleukin-2 (IL-2) stimulus. Using this method, immunoglobulin G (IgG)-producing immortalized B cell lines were generated from peripheral blood IgG⁺CD22⁺ B cells with an efficiency of up to 83%. Antibody can already be obtained from the culture supernatant after 3–4 weeks. Moreover, clonality analysis demonstrated monoclonality in 87% of the resulting immortalized B cell lines. Given the high immortalization efficiency and monoclonality rate, evidence is provided that no further subcloning is necessary. An important application of this B cell immortalization method is the characterization of (autoreactive) antibodies from patients with autoimmune disease. This could eventually lead to the identification of new autoantigens, disease markers or targets for therapy.

Quality control in diagnostic molecular pathology in the Netherlands; proficiency testing for patient identification in tissue samples

AIMS

To describe the evolution of proficiency testing for molecular diagnostic pathology with respect to determining unambiguously the patient identity of tissue samples by microsatellite analysis.

METHOD

Four rounds of quality control exchanges of samples from different patients were sent with the purpose of identifying the correct origin of these samples. The samples were either paraffin wax embedded sections on glass, sections in tubes, or isolated DNA. Blinded samples were distributed to all participating laboratories. No restrictions to the method and short tandem repeat markers used for identification were imposed.

RESULTS

In four subsequent rounds the number of participating laboratories increased from three to 10. The numbers of samples tested increased in time from five to 12. The microsatellite markers used by the different laboratories showed little overlap. In the first three rounds, in which isolated DNA was provided, all samples were accurately classified irrespective of the microsatellite markers used. In the last round, which also included paraffin wax embedded sections, a small number of laboratories experienced problems, either with amplification or incorrect classification of a few samples.

CONCLUSION

Proficiency testing was useful, and showed country wide high quality and correct identification of (patient) samples with molecular techniques for diagnostic purposes.