P-186 Morphological and molecular characteristics in surgically-treated NSCLC tumors and matched lymph nodes

Hintergrund

Curative surgical resection is the treatment of choice for early-stage and locally advanced non-small cell lung cancer (NSCLC). Locoregional N1 and N2 lymph nodes (LNs) are a site of antigen presentation and T- and B-cell activation. They are removed during surgery and provide a snapshot of the immune cell composition at the time of lymph node removal. We investigated immune cell populations in the primary tumor and matched tumor-bearing (tb) LNs, N2 non-tb (ntb) LNs and N1 ntbLNs in surgically treated NSCLC patients.

Material und Methode

We retrospectively collected archived tissue from patients with NSCLC treated between 1999 and 2019 at the Ludwig-Maximilians University in Munich, Germany. For each patient, material from the primary NSCLC tumor and matched tbLNs, N2 ntbLNs and N1 ntbLNs was obtained. H&E stainings of all samples were analyzed for morphological changes and qPCR for selected immune markers was performed. We used Cox regression models with forward selection to identify morphological factors associated with OS and PFS.

Ergebnis

151 NSCLC patients were included in this study: 71 with long-term disease-free survival (no local or distant recurrence for three years after surgery) and 80 patients with relapse within three years after surgery. CD4 expression in N1 (HR=0.72; p=0.02) and N2 (HR=0.91; p=0.04) ntbLNs was correlated with PFS and OS, respectively. Morphological assessment showed sinus histiocytosis and tumor-infiltrating lymphocyte density to be associated with PFS and OS, respectively.

Schlussfolgerung

We found CD4 expression levels, tumor-infiltrating lymphocytes, as well as the presence of increased sinus histiocytosis to be beneficial for prolonged survival in this cohort. These findings should be investigated in patients treated with radiation, chemotherapy or checkpoint inhibition.

Publication History

Article published online:
06 September 2021