Relationships between blood cadmium concentration and risk of nine cancers: evidence from the NHANES 1999-2018 and Mendelian randomization analyses.

BACKGROUND

Previous observational studies examining the relationship between cadmium exposure and various cancers have yielded conflicting results. This study aims to comprehensively clarify the relationship between blood cadmium concentration (BCC) and nine specific cancers.

METHODS

A retrospective analysis of National Health and Nutrition Examination Survey (NHANES) 1999-2018 identified 36,991 participants. Multivariable logistic regression was used to assess the association between BCC and the risk of nine specific cancers. Additionally, Mendelian randomization (MR) analyses were conducted to investigate potential causal relationships.

RESULTS

Multivariable logistic regression analysis of the NHANES data indicated a positive association between BCC and the risk of bladder and lung cancers (P < 0.05) and a negative association with the risk of kidney and prostate cancers (P < 0.05). The MR analyses demonstrated a causal relationship between BCC and kidney cancer (P < 0.05). Additionally, it uncovered causal associations with breast, cervical, and colon cancers (P < 0.05).

CONCLUSION

Elevated BCC was associated with an increased risk of bladder and lung cancers while demonstrating an inverse relationship with kidney and prostate cancers. MR analysis revealed that cadmium exposure may act as a protective factor against breast, cervical, colon, and kidney cancers, that must be confirmed with new studies.