The Association of Digit Ratio (2D : 4D)‎ with Cancer: A Systematic Review and Meta-Analysis

Abstract EN

Objective.

Intrauterine sex hormone environment as indicated by the second to the fourth digit ratio (2D : 4D) can be associated with cancer risk.

This systematic review and meta-analysis aimed to evaluate the association of 2D : 4D with cancer diagnosis, malignancy, and age at presentation.

Methods.

Studies that evaluated the association of 2D : 4D with cancer risk were collected from Pubmed/MEDLINE and Clarivate Analytics databases.

Nineteen studies were included in the qualitative analysis.

Results.

The 2D : 4D ratio was studied in prostate cancer, breast cancer, testicular cancer, gastric cancer, oral cancer, brain tumors, and cervical intraepithelial neoplasia.

Low 2D : 4D was associated with prostate cancer, gastric cancer, and brain tumors, while high 2D : 4D, with breast cancer risk and cervical dysplasia.

The 2D : 4D ratio was not associated with prostate, breast, and gastric cancer stage.

Greater 2D : 4D ratio was associated with younger presentation of breast cancer and brain tumors.

The meta-analyses demonstrated that testicular cancer was not associated with right-hand 2D : 4D ratio (p=0.74) and gastric cancer was not associated with right-hand (p=0.15) and left-hand (p=0.95) 2D : 4D ratio.

Conclusions.

Sex hormone environment during early development is associated with cancer risk later in life.

Further studies exploring the link between intrauterine hormone environment and cancer risk are encouraged.