Abstract Background: Although clinical N1 (cN1) non-small cell lung cancer (NSCLC) is considered to be locoregional, the postoperative outcome is disappointing, with a 5-year survival of less than 50%. One possible reason may underline that cN1disease diagnosed by current standard imaging modalities often contain unexpected N2 disease. This study was conducted to evaluate the surgical and pathological results of cN1 NSCLC patients.
Methods: Among 1782 NSCLC patients who underwent intended curative resection from 1993 to 2003, 143 patients were identified to have cN1 disease and were enrolled in this study. The clinico-pathological records and CT films of each patient were retrospectively reviewed to identify predictors for pN2-3 disease. Results: The pathological nodal status was pN0 in 23% (n = 33); pN1 in 47% (n = 67); and pN2-3 in 30% (n = 43). Patients with pN2-3 showed a significantly worse 5-year survival rate of 38% compared with pN0 (68%) and pN1 (60%) patients (p = 0.017 and 0.007, respectively). Multivariate analysis showed that adenocarcinoma histology was a significant predictor for pN2-3 disease (odds ratio [OR], 3.312; 95% confidence interval [CI], 1.439-7.784; p = 0.005). The presence of N1 node separate from the main tumour on CT scans tended to predict pN2-3 disease although it did not reach statistical significance (OR, 2.103; 95% CI, 0.955-4.693; p = 0.066). Pathological N2-3 disease was found in 53% of adenocarcinoma patients with separate N1 pattern and only in 12% of non-adenocarcinoma patients with continuous N1 pattern.
Conclusions: The diagnosis of N1 status by contrast-enhanced CT scans is unsatisfactory with a high rate of unexpected pN2 disease. To avoid infertile lung resection, CT-diagnosed N1 adenocarcinoma patients, especially with separate N1 pattern on CT, should be considered to undergo additional invasive node biopsy modalities, including mediastinoscopy.
- lymph node
- non-small cell lung cancer