Abstract 29P
Background
Surgery holds curative potential in non-small cell lung cancer (NSCLC), but around 50% of the patients will still experience disease recurrence. Natural Killer (NK) cells are important as a part of the host immune defense against cancer, and NK cell activity (NKA) has been suggested as a prognostic biomarker.
Methods
Patients with NSCLC eligible for surgery with curative intent were prospectively enrolled. Blood was sampled at baseline, 2-7 weeks post-operatively, and at the first follow-up. Interferon gamma (IFNg) as a surrogate for NKA was measured using the NK Vue® assays (NKMAX, Seongnam-si, South Korea). A cutoff of >250 pg/mL was used to define a normal test according to the manufacturer’s instructions.
Results
We enrolled 78 patients, who received curatively intended surgery for NSCLC. The median NKA was 569 pg/mL, 357 pg/mL, and 784 pg/mL, respectively, at baseline, 2-7 weeks post-surgery, and follow-up (1-10 months). There was no significant difference in NKA between the time-points. A division of the patients into two groups according to NKA cut-off at baseline resulted in a difference in overall survival (OS) (p=0.014) but not in recurrence free survival (RFS) (p=0.548). A further division according to NKA dynamics resulted in three groups: The NKA-low group had NKA <250 pg/mL at all available time-points (n=19). The NKA-mixed group had NKA of varying levels (n=21). The NKA-high group had NKA >250 pg/mL at all available time-points (n=38). This grouping had a statistically significant prognostic impact on OS (p=0.027), but not on RFS (p=0.728). The hazard ratio was 5.36 (95% CI 1.39-20.64) for the NKA-low group compared to the NKA-high group. Table: 29P
Patient characteristics
| Patient characteristics | Total n=78 n (%) or median (range) |
| Sex, male | 37 (47%) |
| Age, years | 69 (44-85) |
| Histology, adenocarcinoma | 47 (60%) |
| Histology, squamous cell carcinoma | 25 (32%) |
| Histology, other | 6 (8%) |
| Stage I | 39 (50%) |
| Stage II | 23 (29%) |
| Stage III | 16 (21%) |
| Post-operative complications | 21 (27%) |
| Adjuvant chemotherapy | 23 (29%) |
Conclusions
The dynamics of NK cell activity may be used for a prognostic subclassification of NSCLC patients undergoing surgery with curative intent.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Thora og Viggo Groves Mindelegat, AP Møller Fonden, Kleins Mindelegat, and grants within the Department of Oncology, Vejle Hospital.
Disclosure
S.W.C. Wen, L. Nederby, T.F. Hansen, A. Jakobsen, O. Hilberg: Other, Institutional, Product Samples: NK Max.