Inflammatory proteins in pre‐diagnosis versus at‐diagnosis samples associated with differentiated thyroid cancer

Inflammation is a hallmark of cancer, but its role in thyroid cancer is unclear. We examined the association between 92 inflammatory proteins measured by Olink Target 96 and differentiated thyroid cancer in samples collected 1–8 years before diagnosis (pre‐diagnosis) and <1 year before (at‐diagnosis) from 69 thyroid cancer cases and 69 matched controls matched by sex, age, race/ethnicity, BMI, and sample collection year from BioMe, a medical record‐linked biobank. The at‐diagnosis group included 46 cases and 46 controls, while the pre‐diagnosis group included 23 cases and 23 controls. The association between the inflammatory proteins and thyroid cancer was assessed using logistic and generalized weighted quantile sum regressions. Eleven inflammatory proteins were negatively associated with thyroid cancer diagnosis: one in the at‐diagnosis group (OPG) and ten in the pre‐diagnosis group (CCL20, CXCL6, FGF‐21, IL20‐RA, TSLP, CST5, IL7, MCP‐3, MMP‐1, and TNF). There was a negative association between the mixture effect of the proteins (constrained in the negative direction) and thyroid cancer diagnosis only in the pre‐diagnosis group. Overall, we found a difference in inflammatory proteins negatively associated with thyroid cancer in the at‐ versus the pre‐diagnosis group. These findings highlight that inflammation potentially has a dual role in thyroid carcinogenesis.