Desensitizing Effect of Intra-Tumoral GDF-15 on Immunotherapy in Patients With Advanced Non-Small Cell Lung Cancer

Abstract

Background: Serum growth/differentiation factor 15 (GDF-15) suppresses anti-tumor immunity and predicts prognosis in several malignancies. Elevated GDF-15 levels are linked to cancer cachexia, characterized by weight loss and systemic inflammation, adversely affecting patient outcomes and therapy response. However, serum GDF-15 is not always derived from tumor tissues but also from multiple organs. Therefore, we evaluated whether intra-tumoral GDF-15 could be used as a biomarker for immunotherapy and its potential association with cancer cachexia.

Method: We retrospectively evaluated patients with advanced non-small cell lung cancer (NSCLC) who underwent treatment with programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) inhibitors at the Shizuoka Cancer Center between 2017 and 2021. Patients with histologically confirmed NSCLC (stage III-IV or postoperative recurrence) who had undergone biopsy or surgery within 6 months prior to initiating immunotherapy were included. Expression of tumor-derived GDF-15 was evaluated using immunohistochemical staining of archival biopsy and surgical specimens. We analyzed the correlation between intra-tumoral GDF-15 expression and the incidence of cancer cachexia, as well as its impact on progression-free survival (PFS) and overall survival (OS).

Result: In 6 of 35 cases, tumor cells highly expressed GDF-15. Patients with high intra-tumoral GDF-15 expression had a higher incidence of cancer cachexia (100% vs. 41.4%, p < 0.05), shorter PFS (3.4 vs. 13.4 months, p < 0.05), and shorter OS (9.5 vs. 26.5 months, p < 0.05) than those with low intra-tumoral GDF-15 expression.

Conclusion: Intra-tumoral GDF-15 expression may predict the presence of cancer cachexia and the efficacy of PD-1/PD-L1 inhibitors in patients with advanced non-small cell lung cancer.

Keywords: GDF‐15; PD‐1/PD‐L1 inhibitors; cachexia; non‐small cell lung cancer; survival.

FIGURE 1

The upper panel shows Chinese hamster cells stained with antibodies against GDF‐15. ExpiCHO‐S were transfected with the GDF15 expression vector as a positive control and mock transfectant with an empty expression vector as a negative control. The lower panel shows GDF15 expression in human‐derived cells, where MKN45, which endogenously expresses GDF‐15, was used as a positive control, and A549, which does not express GDF‐15, was not stained, as in the negative control.

FIGURE 2

Representative images of the intensity of GDF‐15 expression in immunohistochemistry graded as strong (2+), moderate (1+), and negative (0). (B) Scoring system for GDF‐15 expression combined of the staining intensity and proportion of positive cells. (C) Classification of GDF‐15 expression into high or low grade using the scoring system.

FIGURE 3

Flow diagram of patient enrollment. In total, 285 patients were enrolled in this study. However, 250 patients were excluded for the following reasons: 45 patients were excluded for having an interval > 6 months between biopsy and the initiation of PD‐1/PD‐L1 inhibitor therapy, 47 had any kind of driver oncogenes, 28 had ECOG‐PS ≧ 2, 85 did not have data regarding PD‐L1 status, 34 did not have their weight changes examined over a 6‐month duration, and 11 had only small tissue biopsied using TBLB. CT, computed tomography; PD‐1, programmed cell death 1; PD‐L1, programmed death‐ligand 1; PS, performance status; TBLB, transbronchial lung biopsy.

FIGURE 4

Representative GDF‐15 immunostaining of clinical samples from adenocarcinoma patients. (A) A part of the tissue with strong GDF‐15 expression (strong [2+]). (B) A part of the tissue with little GDF‐15 expression (negative [0]). GDF‐15 expression was heterogeneous within the same tissue, with most tissues expressing GDF‐15 in some regions. Magnification × 40, scale bar represents 2.5 mm, rabbit anti‐human GDF15 polyclonal antibody (ATLAS ANTIBODIES, HPA01119) was used for immunostaining.

FIGURE 5

(A) Kaplan–Meier curves of PFS stratified by GDF‐15 expression. (B) Kaplan–Meier curves of OS stratified by GDF‐15 expression. OS, overall survival; PFS, progression‐free survival.