Digit Ratio is Associated with Colorectal Cancer

Abstract

Background: Prenatal testosterone and estrogen exposure may influence disease susceptibility. Digit ratio (2D:4D) is a putative marker for prenatal hormone exposure and sensitivity, as well as the action of genes related to malignancies. Therefore, 2D:4D could act as a marker for cancer predisposition. Aims: Investigate the possible correlation between R2D:4D, L2D:4D and right minus left. 2D:4D (Δr-l) and colorectal cancer (CRC) in men and women and assess correlations with tumor staging and histological diagnosis. Methods: Digital images of the right and left hand palms of patients diagnosed with CRC (n=139) and age and sex-matched controls (n=139) were used to measure the 2nd and 4th fingers. Means for 2D:4D were compared. Data were analyzed by intraclass correlation coefficient, Student's t-test, Kendall’s tau b and Spearman’s rho (α=0.05). Results: CRC group presented significantly higher right and left 2D:4D (p=0.00001 and p=0.00005, respectively) in comparison to healthy controls. R2D:4D was negatively correlated to tumor differentiation (p=0.02) while L2D:4D was positively correlated to tumor size (p=0.03). Conclusions: Prenatal estrogen and testosterone seem to play a role on the malignant transformation and progression of colorectal cancer. The findings suggest that 2D:4D could add to the list of etiological factors and be a putative marker for the screening of patients’ susceptibility to develop colorectal cancer.