The IASLC Lung Cancer Staging Project: Proposals for the Inclusion of Broncho-Pulmonary Carcinoid Tumors in the Forthcoming (Seventh) Edition of the TNM Classification for Lung Cancer

Objective

In the 2003 Supplement for tumor, node, metastasis (TNM) Staging classification it states that TNM staging “applies to all types of carcinoma including small cell carcinoma; however, it does not apply to carcinoids.” Despite this caveat, most publications on typical and atypical carcinoids use the TNM staging system for nonsmall cell carcinoma and are able to demonstrate prognostic significance for the different stages. For this reason, as the next TNM Staging proposal is being considered, we sought to investigate the carcinoid cases submitted to the International Association for the Study of Lung Cancer (IASLC) database, as well as the National Cancer Institute Surveillance Epidemiology and End Results (SEER).

Materials and Methods

In the data collected for the IASLC Staging Project database over the time period 1990 to 2000, there were 513 broncho-pulmonary carcinoids. A total of 1619 broncho-pulmonary carcinoid cases diagnosed over the period 1990–2002 were analyzed from the SEER database, including 1437 surgical cases. Pathologic slides were not available for histologic review.

Results

Most of tumors in both the IASLC and SEER databases were Stage I (82% and 78%, respectively), as defined by the IASLC proposals for the 7th edition of TNM staging system. T status was a statistically significant predictor of survival for both the SEER data (p < 0.0001) and the IASLC database (p = 0.0156), though for different reasons. N status showed significant survival correlations in both data sets (p < 0.0001). The effect of M status was significant (p < 0.0001) within the SEER data and not studied in the IASLC cases, which were almost exclusively M0. We found that all three T, N, and M categories as defined for non-small cell lung cancer are generally useful for staging of pulmonary carcinoid tumors. Significant differences in survival for overall stages I versus II versus III/IV were identified in both data sets. Patients with multiple same lobe nodules had a 100% 5-year survival, which may be a reason to reevaluate their status in the IIB category in future analyses.

Conclusions

In summary, the IASLC proposals for the 7th edition of TNM are helpful in predicting prognosis for broncho-pulmonary carcinoid tumors. It is the recommendation of the IASLC Staging project that TNM be applied to broncho-pulmonary carcinoid tumors. A prospective collection of data through an International Registry of Pulmonary Neuroendocrine Tumors planned by the IASLC will allow for further detailed analysis of staging data for broncho-pulmonary carcinoids.