Abstract:Objective To explore the relationship between the expressions of Fanconi anemia D2 protein (FANCD2) and partner and localizer of BRCA2 (PALB2) and the clinical manifestations and prognosis of patients with non-small cell lung cancer (NSCLC).Methods A total of 194 patients with NSCLC admitted to our hospital from November 2017 to October 2019 were selected. The cancer tissue samples obtained during the surgery were included in the NSCLC group (n = 194), and the corresponding adjacent tissue samples were included in the adjacent group (n = 194). Immunohistochemistry was used to detect the expressions of FANCD2 and PALB2 in NSCLC tissues and adjacent tissues. The relationship between the expressions of FANCD2 and PALB2 and the clinicopathological characteristics of NSCLC patients was analyzed. Kaplan-Meier method was applied to plot survival curves, and the Cox proportional hazard model was used to analyze the factors affecting the prognosis of patients with NSCLC.Results The positive rates of FANCD2 and PALB2 in the NSCLC group were higher than those in the adjacent group (P < 0.05). Spearman correlation analysis revealed that the expression of FANCD2 was positively correlated with that of PALB2 in cancer tissues of NSCLC patients (rs = 0.486, P < 0.05). There was no significant difference in the positive rates of FANCD2 and PALB2 among patients with different age, gender, smoking behavior, histological type of the tumor, and tumor diameter (P < 0.05). The positive rates of FANCD2 and PALB2 in patients with TNM stage III and IV tumors, poorly-differentiated tumors, and lymph node metastasis were higher than those in patients with TNM stage I and II tumors, moderately- and well-differentiated tumors, and no lymph node metastasis (P < 0.05). The multivariable Cox regression analysis exhibited that TNM stage III/IV tumors [H^R = 4.125, (95% CI: 2.187, 10.035) ], poorly-differentiated tumors [H^R = 3.146, (95% CI: 3.115, 9.264) ], lymph node metastasis [H^R = 4.124, 95% CI: 3.005, 13.145) ], FANCD2 positivity [H^R = 5.146, (95% CI: 3.784, 12.689) ], and PALB2 positivity [H^R = 4.563, (95% CI:2.845, 7.398) ] were factors affecting the recurrence in NSCLC patients (P < 0.05), and that TNM stage III/IV tumors [H^R = 3.689, (95% CI: 2.963, 11.254) ], poorly-differentiated tumors [H^R = 2.167, (95% CI: 1.998, 5.996) ], lymph node metastasis [H^R = 5.648, (95% CI: 3.552, 12.953) ], FANCD2 positivity [H^R = 3.886, (95% CI: 2.958, 12.775)], and PALB2 positivity [H^R = 4.633, (95% CI: 1.968, 11.547) ] were factors affecting the prognosis of NSCLC patients (P < 0.05). The survival rates of FANCD2-positive patients were significantly different from those of FANCD2-negative patients (P < 0.05), and the survival rates of PALB2-positive patients were also significantly different from those of PALB2-negative patients (P < 0.05).Conclusions FANCD2 and PALB2 are highly expressed in cancer tissues of NSCLC patients and closely related to TNM stage, tumor differentiation and lymph node metastasis, and can be established as potential biomarkers for evaluating the recurrence and prognosis in NSCLC patients.