BACKGROUND: Sex steroid exposure during early human development 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 closely related 
to carcinogenesis. Digit ratio could act as a possible marker for cancer 
predisposition.
AIMS: The aim of this study is to investigate the possible correlations between 
right hand, left hand and right minus left (R-L) 2D:4D and gastric cancer (GCA) 
in men and women and assess the correlations with tumor staging and histological 
diagnosis.
METHODS: Digital images of the right and left hand palms of patients diagnosed 
with GCA (n=57, 42 males, 15 females) and age and sex-matched controls (n=59, 41 
males, 18 females) were obtained. Means for 2D:4D were compared. Data were 
analyzed by repeated-measures one-way ANOVA and Student's t-test for finger 
measurements and group comparisons and Pearson's and Spearman's tests for 
correlations with tumor staging (α=0.05).
RESULTS: GCA group presented significantly higher left 2D:4D, but significantly 
lower R-L in comparison to healthy controls, particularly so for males. Digit 
ratio did not correlate to clinical staging or TNM staging. However, low R-L was 
significantly related to adenocarcinomas.
CONCLUSIONS: Early developmental conditions, including prenatal testosterone 
seem to play a role on the malignant transformation of gastric lesions. The 
2D:4D pattern found for gastric cancer parallels that earlier described for 
breast 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 gastric cancer.