Editing Cancer (section)

=== Hormones ===
[[Hormone]]s also play a role in the development of cancer by promoting [[cell growth|cell proliferation]].<ref name=Henderson>{{cite book |vauthors=Henderson BE, Bernstein L, Ross RK |veditors=Bast RC, Kufe DW, Pollock RE |title=Holland-Frei Cancer Medicine |edition=5th |publisher=B.C. Decker |location=Hamilton, Ontario |year=2000 |chapter=Chapter 13: Hormones and the Etiology of Cancer |isbn=978-1-55009-113-7 |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK20759/ |access-date=27 January 2011 | display-editors = etal |url-status=live |archive-url=https://web.archive.org/web/20170910174411/https://www.ncbi.nlm.nih.gov/books/NBK20759/ |archive-date=10 September 2017}}</ref> [[Insulin-like growth factor]]s and their binding proteins play a key role in cancer cell proliferation, differentiation and [[apoptosis]], suggesting possible involvement in carcinogenesis.<ref>{{cite journal |vauthors=Rowlands MA, Gunnell D, Harris R, Vatten LJ, Holly JM, Martin RM |title=Circulating insulin-like growth factor peptides and prostate cancer risk: a systematic review and meta-analysis |journal=International Journal of Cancer |volume=124 |issue=10 |pages=2416–29 |date=May 2009 |pmid=19142965 |pmc=2743036 |doi=10.1002/ijc.24202}}</ref>

Hormones are important agents in sex-related cancers, such as cancer of the breast, [[endometrium]], prostate, ovary and [[testicle|testis]] and also of [[thyroid cancer]] and [[bone cancer]].<ref name=Henderson/> For example, the daughters of women who have breast cancer have significantly higher levels of [[estrogen]] and [[progesterone]] than the daughters of women without breast cancer. These higher hormone levels may explain their higher risk of breast cancer, even in the absence of a breast-cancer gene.<ref name=Henderson/> Similarly, men of African ancestry have significantly higher levels of [[testosterone]] than men of European ancestry and have a correspondingly higher level of prostate cancer.<ref name=Henderson/> Men of Asian ancestry, with the lowest levels of testosterone-activating [[androstanediol glucuronide]], have the lowest levels of prostate cancer.<ref name=Henderson/>

Other factors are relevant: obese people have higher levels of some hormones associated with cancer and a higher rate of those cancers.<ref name=Henderson/> Women who take [[Hormone replacement therapy (menopause)|hormone replacement therapy]] have a higher risk of developing cancers associated with those hormones.<ref name=Henderson/> On the other hand, people who exercise far more than average have lower levels of these hormones and lower risk of cancer.<ref name=Henderson/> [[Osteosarcoma]] may be promoted by [[growth hormone]]s.<ref name=Henderson/> Some treatments and prevention approaches leverage this cause by artificially reducing hormone levels and thus discouraging hormone-sensitive cancers.<ref name=Henderson/>