Editing Combined oral contraceptive pill (section)

====Decreased risk of ovarian, endometrial, and colorectal cancers====
Usage of combined oral concetraption decreased the risk of [[ovarian cancer]], [[endometrial cancer]],<!--
 --><ref name="Speroff 20052"/> and [[colorectal cancer]].<ref name=IARC2007/><ref name="pmid18710356"/><ref name="pmid17302189">{{cite book |vauthors=Bast RC, Brewer M, Zou C, Hernandez MA, Daley M, Ozols R, Lu K, Lu Z, Badgwell D, Mills GB, Skates S, Zhang Z, Chan D, Lokshin A, Yu Y | chapter = Prevention and Early Detection of Ovarian Cancer: Mission Impossible? | title = Cancer Prevention | volume = 174 | pages = 91–100 | year = 2007 | pmid = 17302189 | doi = 10.1007/978-3-540-37696-5_9 | isbn = 978-3-540-37695-8 | series = Recent Results in Cancer Research }}</ref> Two large cohort studies published in 2010 both found a significant reduction in adjusted relative risk of ovarian and endometrial cancer mortality in ever-users of OCs compared with never-users.<ref name="Hannaford 2010">{{cite journal | vauthors = Hannaford PC, Iversen L, Macfarlane TV, Elliott AM, Angus V, Lee AJ | title = Mortality among contraceptive pill users: cohort evidence from Royal College of General Practitioners' Oral Contraception Study | journal = BMJ | volume = 340 | pages = c927 | date = March 2010 | pmid = 20223876 | pmc = 2837145 | doi = 10.1136/bmj.c927 }}</ref><ref name="Vessey 2010">{{cite journal | vauthors = Vessey M, Yeates D, Flynn S | title = Factors affecting mortality in a large cohort study with special reference to oral contraceptive use | journal = Contraception | volume = 82 | issue = 3 | pages = 221–9 | date = September 2010 | pmid = 20705149 | doi = 10.1016/j.contraception.2010.04.006 }}</ref> The use of oral contraceptives (birth control pills) for five years or more decreases the risk of ovarian cancer in later life by 50%.<ref name="pmid17302189"/><ref>{{cite journal |last1=Nappi |first1=Rossella E. |last2=Pellegrinelli |first2=Alice |last3=Campolo |first3=Federica |last4=Lanzo |first4=Gabriele |last5=Santamaria |first5=Valentina |last6=Suragna |first6=Alessandro |last7=Spinillo |first7=Arsenio |last8=Benedetto |first8=Chiara |date=2 January 2015 |title=Effects of combined hormonal contraception on health and wellbeing: Women's knowledge in northern Italy |journal=The European Journal of Contraception & Reproductive Health Care |volume=20 |issue=1 |pages=36–46 |doi=10.3109/13625187.2014.961598 |issn=1362-5187 |pmid=25317952|s2cid=26048792 }}</ref> Combined oral contraceptive use reduces the risk of [[ovarian cancer]] by 40% and the risk of [[endometrial cancer]] by 50% compared with never users. The risk reduction increases with duration of use, with an 80% reduction in risk for both ovarian and endometrial cancer with use for more than 10 years. The risk reduction for both ovarian and endometrial cancer persists for at least 20 years.<!--
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