Global, regional, and national age–sex specific all-cause and cause-specific mortality for 240 causes of death, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. GBD 2013 Mortality and Causes of Death Collaborators. Estimated cancer incidence, mortality and prevalence worldwide in 2012 v1.0. Further studies exploring the link between intrauterine hormone environment and cancer risk are encouraged. Sex hormone environment during early development is associated with cancer risk later in life. 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. Greater 2D : 4D ratio was associated with younger presentation of breast cancer and brain tumors. The 2D : 4D ratio was not associated with prostate, breast, and gastric cancer stage. 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 studied in prostate cancer, breast cancer, testicular cancer, gastric cancer, oral cancer, brain tumors, and cervical intraepithelial neoplasia. Nineteen studies were included in the qualitative analysis. Studies that evaluated the association of 2D : 4D with cancer risk were collected from Pubmed/MEDLINE and Clarivate Analytics databases. This systematic review and meta-analysis aimed to evaluate the association of 2D : 4D with cancer diagnosis, malignancy, and age at presentation. Intrauterine sex hormone environment as indicated by the second to the fourth digit ratio (2D : 4D) can be associated with cancer risk.

2d 4d ratio equatio