Management of clinical stage IIIA primary lung cancers in the National Cancer Database

Background: Clinical stage IIIA (cStage IIIA) non-small cell lung cancer (NSCLC) resulting from mediastinal lymph node disease (stage IIIA-cN2) represents one of the more challenging lung cancer scenarios. Not only is the prognosis disappointing but the accuracy of mediastinal staging is uncertain, the optimal treatment approach is unclear, and the outcomes are variable. In attempt to assess the current state of clinical stage IIIA-cN2 NSCLC in the United States, we examined this controversial cohort in the largest clinical database resource available, the National Cancer Database (NCDB).

Methods: The NCDB was queried for patients diagnosed between 1999 and 2011 with NSCLC, clinically staged to have mediastinal lymph node metastases but not systemic metastases (T1-3, N2, M0, cStage IIIA).

Results: A total of 83,913 cSstage IIIA NSCLC patients with presumed or confirmed mediastinal lymph node metastases were identified. Clinical staging of the mediastinum was variable, as lymph nodes were only biopsied in 23% of patients who were treated without surgery, and in surgical patients clinical N2 status was pathologically confirmed in only 56% of treatment naïve patients. The most common treatment approach was nonsurgical, involving chemotherapy, radiation, or both (69% of patients) followed by surgery (14%). The 5-year survival varied by treatment and was highest for patients treated with surgery in combination with chemotherapy, radiation, or both (38%), followed by surgery alone (30%), nonsurgical treatment (11%), and worst for untreated patients (5%).

Conclusions: There is cause for concern over the accuracy of the clinical staging of the mediastinum among cStage IIIA-cN2 patients in the United States. The use of surgery is relatively low but is associated with an encouraging 5-year survival. Further study is needed to clarify the accuracy of mediastinal staging in the United States for cStage IIIA-cN2 NSCLC.