Impact of HIF-1α+ Cellular Subpopulations on Lymph Node Metastasis and Prognosis in Non-Small Cell Lung Cancer

Objective This study investigates the differential densities of hypoxia-inducible factor-1α (HIF-1α)-expressing tumor cells, CD4+ T cells, and CD8+ T cells in primary lesions of non-small cell lung cancer (NSCLC) patients, and evaluates their association with lymph node metastasis and clinical outcomes.Methods We retrospectively collected 256 formalin-fixed paraffin-embedded primary tumor specimens from NSCLC patients who underwent radical resection at Shandong Cancer Hospital between January 1, 2014 and December 31, 2018, constructed tissue microarrays containing both tumor center (TC) and invasive margin (IM) regions, and performed multiplex immunofluorescence staining (HIF-1α/CD4/CD8/DAPI) to quantitatively analyze the densities of HIF-1α-expressing tumor cells (HIF-1α+CK+), HIF-1α+CD4+ T cells, and HIF-1α+CD8+ T cells, with Mann-Whitney U tests used to compare cellular density differences between N0 versus N1-N2 groups and N1 versus N2 subgroups, while Cox proportional hazards regression models were employed to identify critical recurrence-associated factors.Results The study ultimately included 256 patients with stage IA-IIIB NSCLC, with a median follow-up duration of 37.05 months, during which 87 cases (34.0%) experienced recurrence. Comparative analysis revealed that in both tumor center (TC) and invasive margin (IM) regions, the N1-N2 group exhibited significantly higher densities of HIF-1α+CK+ cells (P values: 0.039 and 0.000, respectively) and lower densities of HIF-1α+CD8+ cells (both P values: 0.000) compared to the N0 group, while no statistically significant differences were observed in the densities of HIF-1α+CK+, HIF-1α+CD4+, or HIF-1α+CD8+ cells between N1 and N2 subgroups within either TC or IM regions (all P>0.05). Multivariate Cox regression analysis incorporating pTNM stage and clinical/immunological parameters with P<0.05 in univariate analysis demonstrated that low HIF-1α+CD8+ cell density in TC region served as an independent risk factor for recurrence in N0 patients (HR=1.993, 95%CI:1.076-3.692, P=0.028), whereas among N1 or N2 patients, neither HIF-1α+CK+, HIF-1α+CD4+, nor HIF-1α+CD8+ cell densities in TC or IM regions showed significant associations with tumor recurrence.Conclusions In patients with NSCLC, the N1-N2 group demonstrated significantly higher HIF-1α+CK+ cell density and lower HIF-1α+CD8+ cell density compared to the N0 group, with the reduced HIF-1α+CD8+ cell density in the primary tumor's tumor center (TC) region being particularly associated with postoperative recurrence in N0 patients, showing an inverse correlation where lower HIF-1α+CD8+ cell density corresponded to higher recurrence risk, suggesting these findings could potentially guide adjuvant therapy decisions for N0 patients following curative resection.