--- title: Most Types of Cancer Just "Bad Luck" description: Researchers have found that bad luck plays a major role in determining two-thirds of cancer types. canonical: https://time.com/3651785/cancer-bad-luck/ author: Helen Regan article:opinion: false article:content_tier: free article:published_time: 2015-01-02T05:22:31.000Z article:modified_time: 2026-02-22T03:13:37.005Z article:section: Health og:title: Most Cancer Types Just 'Bad Luck' og:description: Biological misfortune explains two-thirds of cancers. og:url: https://time.com/3651785/cancer-bad-luck/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt6b82b3be7503d869/698777d755a85956ada850bd/488635633.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: 488635633 og:type: article twitter:card: summary_large_image twitter:title: Most Cancer Types Just 'Bad Luck' twitter:description: Biological misfortune explains two-thirds of cancers. twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt6b82b3be7503d869/698777d755a85956ada850bd/488635633.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  # Most Types of Cancer Just 'Bad Luck,' Researchers Say by [Helen Regan](https://time.com/author/helen-regan/) ## Helen Regan Jan 2, 2015 5:22 AM UTC  Lymphocytes and cancer cell Lymphocytes and cancer cellJUAN GARTNER—Getty Images/Science Photo Library RF by [Helen Regan](https://time.com/author/helen-regan/) ## Helen Regan Jan 2, 2015 5:22 AM UTC Researchers have found that bad luck plays a major role in determining most types of [cancer](http://www.reuters.com/article/2015/01/01/us-health-cancer-luck-idUSKBN0KA1S320150101), rather than genetics or risky lifestyle choices such as smoking. The [results](http://www.sciencemag.org/content/347/6217/78), published in the journal _Science_ on Thursday, found that random DNA mutations that amass in the body when stem cells divide into various tissues cause two thirds of cancers. After examining 31 cancer types, researchers found 22 were from mutations in stem cells that could not be prevented. Cancers that could be explained with biological bad luck included pancreatic, leukemia, bone, testicular, ovarian and brain cancer. But the researchers say lifestyle choices such as avoiding smoking, eating healthily and staying out of the sun will help to prevent certain cancers, just not all of them. _Read next:_ [_Medicine Is About to Get Personal_](http://time.com/3643841/medicine-gets-personal/?xid=time%5Freadnext) [_Listen to the most important stories of the day._](http://time.com/newsletter/the-brief/?sl%5Fautoplay=true&xid=spl-fullbrief-article) ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/3651785/cancer-bad-luck/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/3651785/cancer-bad-luck/"},"headline":"Most Types of Cancer Just 'Bad Luck,' Researchers Say","datePublished":"2015-01-02T05:22:31.000Z","dateModified":"2026-02-22T03:13:37.005Z","description":"Two thirds of cancers could be explained as biological misfortune","url":"https://time.com/3651785/cancer-bad-luck/","keywords":["Cancer","DNA","Genetics","Stem Cells","Research","health","Lifestyle"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt6b82b3be7503d869/698777d755a85956ada850bd/488635633.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Helen Regan","jobTitle":null,"url":"https://time.com/author/helen-regan/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt6b82b3be7503d869/698777d755a85956ada850bd/488635633.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"488635633","caption":"488635633","creditText":"JUAN GARTNER—Getty Images/Science Photo Library RF","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/cancer/","name":"Cancer"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/3651785/cancer-bad-luck/","name":"Most Types of Cancer Just 'Bad Luck,' Researchers Say"}}]}] ```