5189 - Association between serum HGF levels and neutrophil counts in small cell lung cancer and their impact on survival

Background

Small cell lung cancer (SCLC) is a highly lethal disease. Recently, immunotherapy has demonstrated a benefit for a subgroup of patients beyond the second-line and in the first-line setting combined with chemotherapy. However, the majority of patients will not benefit and predictive biomarkers are urgently needed. High baseline neutrophil count (NC) and neutrophil-to-lymphocyte ratio (NLR) are unfavorable prognostic factors in SCLC and might also predict for lack of response to immunotherapy. There is data suggesting that activation of the HGF/MET pathway might contribute to the recruitment of immunosuppressor neutrophils in the tumor. Our aim was to evaluate the association between HGF serum levels (sHGF) and NC in SCLC and their impact on outcome.

Methods

Serum samples from SCLC patients were obtained before starting first-line treatment. We used the Quantikine Human HGF Immunoassay to quantify sHGF. All samples were run in duplicates. NC and NLR were obtained from blood test reports before treatment initiation. Statistical analysis was carried out using SPSS 22.0 and Prism 8.1.0. Correlation of variables was assessed by the Spearman’s correlation coefficient. Multivariate analysis was performed with the Cox regression method.

Results

Samples from 105 patients diagnosed with SCLC at our institution were included. 79.1% of the cases were male, 73.3% with extensive stage, and 31.4% had an ECOG score of ≥ 2. Median sHGF, NC and NLR were 1875.38pg/ml, 6440/µl and 5.1 respectively. Patients with baseline NLR > 4 or NC above median had worse median overall survival (mOS), with 7.9 vs 15.3 months (m) (p < 0.001) and 7.2 vs 15.3m (p < 0.001) respectively. sHGF above median values was also correlated with worse mOS (7.6 vs 12.8 m; p = 0.005). Baseline sHGF levels were positively correlated with NC (r = 0.34, p < 0.001). In the multivariate analysis for OS, sHGF and NC remained independently associated with poor outcome (HR 1.094; p = 0.001 and HR 1.18; p = 0.003 respectively).

Conclusions

Baseline HGF levels correlate with NC in SCLC, reinforcing the hypothesis of a plausible interplay between HGF/MET axis and the immune system. The role of these parameters as predictive biomarkers of response to immunotherapy in SCLC warrants further investigation.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

E. Arriola: Speaker Bureau / Expert testimony: BMS; Speaker Bureau / Expert testimony: Roche; Speaker Bureau / Expert testimony: MSD; Speaker Bureau / Expert testimony: Pfizer; Speaker Bureau / Expert testimony: Lilly; Speaker Bureau / Expert testimony: AstraZeneca; Research grant / Funding (institution): BMS; Research grant / Funding (institution): Roche; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): PGDx; Travel / Accommodation / Expenses: BMS; Travel / Accommodation / Expenses: MSD; Travel / Accommodation / Expenses: Roche; Travel / Accommodation / Expenses: Lilly. All authors have declared no conflicts of interest.