Abstract 89P
Background
Despite an adequate preoperative staging, unexpected nodal metastases after surgery are detected in a relevant number of cases. Given the promising role of novel neoadjuvant treatments, the definition of predictive factors for nodal metastases is critical. In this study we aim to analyze the clinical and molecular factors associated with upstaging in patients with early stage LUAD without evidence of nodal disease in the preoperative staging who underwent lobectomy and radical lymphadenectomy.
Methods
Patients who underwent radical treatment for early stage LUAD without evidence of nodal disease at the preoperative staging with available molecular targets evaluation were evaluated. Univariable and multivariable logistic regression was used to quantify the association between clinical and biological variables and the risk of unforeseen nodal metastasis, in addition to odds ratios and their 95% confidence intervals. A nomogram to predict unexpected nodal metastasis was computed based on the results of the multivariable model.
Results
A total of 359 patients were included. The variables that showed a significant correlation with the upstaging rate at the univariate analysis were the PD-L1 status, ALK rearrangement, number of resected lymph nodes and the tumor diameter. This result was confirmed in the multivariate analysis, with an OR of 8.052 (3.123–20.763, p = 0.00001) for ALK rearrangements, 1.895 (1.093–3.286, p = 0.02) for PD-L1 status, 1.087 (1.048–1.127, p = 0.0001) for the number of resected nodes and 1.817 (1.214–2.719, p = 0.004) for cT status. Using the nomogram, we classified the patients into three classes: the lower risk group with a rate of unexpected nodal metastasis of 13.6% the intermediate group with a rate of 33.6% and the high group with a rate of 81.8%.
Conclusions
Our results showed that in patients with clinical node-negative early stage LUAD the presence of ALK rearrangements, PD-L1 status, number of resected lymph nodes and tumor diameter can predict unforeseen nodal metastasis after surgical resection. The established nomogram could assess the risk of nodal metastases in patients with early stage NSCLC eligible for surgical resection.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.