Resection of calcified lymph nodes confers clinical benefit in patients with non-small cell lung cancer

The aim of the present study was to compare the metastatic ratio between calcified lymph node stations (CLNS) and non-CLNS (NCLNS) and to explore the impact of CLNS on surgical outcomes. Consecutive patients with non-small cell lung cancer (NSCLC) scheduled to receive surgical treatment between June and December 2020 were included in the present study. Their clinical and radiological data were prospectively collected and analyzed. A total of 91 patients with NCLNS and 64 patients with CLNS were enrolled in the present study. Out of the 91 patients, 38 (24.516%) patients had 61/343 (17.784%) lymph node stations (LNS) that were metastasized. On a per-patient basis, the differences in the LNS metastatic ratio were not significant between the CLNS with NCLNS groups. However, on a per-nodal station basis, all differences in the LNS metastatic ratio between the groups were significant not only in the all-LNS group (P=0.004), but also in the LNS group which in patients with solely CLNS or NCLNS (P=0.009) and in the patients with CLNS (P=0.010). Pathology, T stage and calcification were independent predictive factors for LNS metastasis (P=0.002, P=0.021 and P=0.044, respectively). More patients with CLNS than patients with NCLNS received thoracotomy or conversion from video-assisted thoracoscopic surgery to thoracotomy (P=0.006). The operating time and blood loss were significantly higher in patients with CLNS than in those without (P<0.001 and P<0.001, respectively). Although CLNS are a risk reduction factor for metastasis and their dissection is time- and blood-consuming in patients with NSCLC, their thorough removal is advisable, since metastases were identified in ~15% of patients and 9% of CLNS.