High Expression of Interleukin-12A and Its Association with the Clinicopathology and Prognosis of Differentiated Thyroid Cancer.

BACKGROUND

The inflammatory microenvironment is closely related to the occurrence and development of cancer. Members of the interleukin-12 (IL-12) cytokine family play synergistic or antagonistic roles in the tumor microenvironment, in the form of classic heterodimers or newly discovered monomers or homodimers.

OBJECTIVE

The purpose of this study was to investigate the association between IL-12A and the clinicopathology and prognosis of differentiated thyroid cancer (DTC).

METHODS

A total of 101 pathologically confirmed DTC patients were included in this study. Immunohistochemistry was performed to assess IL-12A expression in DTC and corresponding paracancerous tissues. The associations of IL-12A with clinicopathology and prognosis were evaluated.

RESULTS

IL-12A was expressed in both normal thyroid tissues and DTC, but its expression level was significantly higher in DTC than in normal thyroid tissues (p < 0.001). IL-12A was positively correlated with tumor size (p = 0.027), risk stratification (p = 0.020), and TNM (Tumor-Node-Metastasis) stage (p = 0.024), but not with age, sex, pathological type, multifocality, extrathyroid extension, lymph node metastasis, and distant metastasis (all p > 0.05). Lymphocytic thyroiditis was found in 26/101 patients (25.7%), which was negatively associated with IL-12A expression (p = 0.018). Multivariate logistic regression analysis showed that risk stratification was the significant independent predictor of IL-12A expression. The rate of disease persistence or recurrence (P&R) was 13/101 (12.9%), and a positive relationship was found between IL-12A expression and P&R (p = 0.020). Disease-free survival was affected by factors such as tumor size, extrathyroid extension, tumor stage (T stage), and IL-12A expression, with p values of 0.006, 0.048, 0.002, and 0.012, respectively. Multivariate Cox proportional-hazards analysis showed that tumor size ≥2 cm (hazard ratio [HR] = 4.041 [95% CI: 1.144-14.274], p = 0.031) and high IL-12A expression (HR = 4.027 [95% CI 1.014-15.994], p = 0.049) were independent predictors of prognosis of DTC patients.

CONCLUSIONS

IL-12A is highly expressed in DTC and is associated with disease aggressiveness. In addition, IL-12A is an independent predictor of the outcome of DTC.