LKB1 Loss Correlates with STING Loss and, in Cooperation with ß-Catenin Membranous Loss, Indicates Poor Prognosis in Patients with Operable Non-Small Cell Lung Cancer.

To investigate the incidence and prognostically significant correlations and cooperations of LKB1 loss of expression in non-small cell lung cancer (NSCLC), surgical specimens from 188 metastatic and 60 non-metastatic operable stage I-IIIA NSCLC patients were analyzed to evaluate their expression of LKB1 and pAMPK proteins in relation to various processes. The investigated factors included antitumor immunity response regulators STING and PD-L1; pro-angiogenic, EMT and cell cycle targets, as well as metastasis-related (VEGFC, PDGFRα, PDGFRß, p53, p16, Cyclin D1, ZEB1, CD24) targets; and cell adhesion (ß-catenin) molecules. The protein expression levels were evaluated via immunohistochemistry; the RNA levels of LKB1 and NEDD9 were evaluated via PCR, while KRAS exon 2 and BRAFV600E mutations were evaluated by Sanger sequencing. Overall, loss of LKB1 protein expression was observed in 21% (51/248) patients and correlated significantly with histotype (p < 0.001), KRAS mutations (p < 0.001), KC status (concomitant KRAS mutation and p16 downregulation) (p < 0.001), STING loss (p < 0.001), and high CD24 expression (p < 0.001). STING loss also correlated significantly with loss of LKB1 expression in the metastatic setting both overall (p = 0.014) and in lung adenocarcinomas (LUACs) (p = 0.005). Additionally, LKB1 loss correlated significantly with a lack of or low ß-catenin membranous expression exclusively in LUACs, both independently of the metastatic status (p = 0.019) and in the metastatic setting (p = 0.007). Patients with tumors yielding LKB1 loss and concomitant nonexistent or low ß-catenin membrane expression experienced significantly inferior median overall survival of 20.50 vs. 52.99 months; p < 0.001 as well as significantly greater risk of death (HR: 3.32, 95% c.i.: 1.71-6.43; p <0.001). Our findings underscore the impact of the synergy of LKB1 with STING and ß-catenin in NSCLC, in prognosis.

Excision-repair-cross-complement-1 protein as a prognostic factor in patients with advanced non-small cell lung cancer treated with platinum-based first-line chemotherapy.

Excision-repair-cross-complement-1 (ERCC1) protein expression in tumor cells has been associated with resistance to platinum compounds, the backbone of treatment in NSCLC. In the current study the impact of the tumoral ERCC1 protein expression on the outcome of patients with advanced stage NSCLC treated with platinum-based chemotherapy, was investigated. Ninety-four patients with inoperable stage III-IV NSCLC, treated with platinum-based first-line chemotherapy, were retrospectively analyzed. Pretreatment tumor samples were analyzed for ERCC1 protein expression using immunohistochemistry. Response to treatment, time to tumor progression (TTP), and overall survival (OS) were correlated with patients' clinicopathological characteristics and ERCC1 protein expression on tumor cells. ERCC1 protein low expression was detected in 39 (41.5%) patients and did not correlate with patients' clinicopathological characteristics or response to chemotherapy. However, ERCC1 protein low expression showed a trend for better disease control rate (p = 0.059), longer TTP (5.3 vs. 3.2 months; p = 0.051) and significantly longer OS (18.7 vs. 9.7 months; p = 0.009). ERCC1 could have a role in refining prognosis and thus individualizing chemotherapy for advanced stage NSCLC.