An extensive review of the current literature, encompassing epidemiological evidence, systemic and peripheral oestrogen concentrations, 17β-hydroxysteroid dehydrogenase (17β-HSD) and aromatase in CRC, steroid sulphatase (STS)/oestrone sulphotransferase (EST) and in vitro and in vivo genomic effects was therefore undertaken.
We explored the effect modification of MHT-associated CRC risk in postmenopausal women by 47 polymorphisms with known or putative functional relevance in 16 candidate genes related to hormone metabolism (COMT, CYP1A1, CYP1A2, CYP1B1, CYP2C9, CYP2C19, CYP3A4, CYP17A1, GSTP, and HSD17B1), transport (ABCB1), and signaling (ESR1, ESR2, SHBG, PGR, and NR1I2).
These findings implicate a role of ESR2 in the risk for developing CRC in women and suggest that HSD17B1, ABCB1, and SHBG genes may contribute to sex steroid-mediated effects on CRC development.
We found a significant decrease in HSD17B1 transcript (p = 0.0016) and protein (p = 0.0028) levels in colorectal cancer (CRC) from the proximal but not distal colon and rectum.