In the U.S., nearly all sexually active women have used a form of birth control at some point in their lives, and 11 million women rely on the pill.

在美国，几乎所有有性生活的女性都会在生命的某个阶段采取避孕措施，1100万名女性依赖药物避孕。

In a new study published in JAMA Oncology, researchers explore how oral contraceptives, which affect women's hormone¹ levels to prevent pregnancy², affect cancer risk. They found that women taking the pill lowered their risks of ovarian and endometrial cancer-a known benefit of the pill. The researchers also analyzed³ other factors that might affect the risk, including obesity⁴, smoking status and physical activity levels.

JAMA Oncology期刊上发表了一项新研究，研究人员探索了口服避孕药是如何影响癌症风险的，这种避孕药通过影响女性的激素水平防止她们怀孕。他们发现服用避孕药的女性降低了她们患卵巢癌和子宫内膜癌的风险--这是避孕药的一个已知益处。研究人员还分析了其它可能影响患病风险的因素，包括肥胖、抽烟状况和身体活动水平。

In addition to finding that the risk of endometrial and ovarian cancers were lower among women who used the pill, the study found that the longer women were on oral contraceptives, the lower their risk was. For those taking the pill for 10 years or more, the risk of ovarian cancer was 40% lower compared to women who had never used the pill or used them for less than a year, and 34% lower for endometrial cancer.

除了发现服用避孕药的女性有较低的患子宫内膜癌和卵巢癌的风险，研究还发现：口服避孕药的时间越长，患这两种癌症的风险越低。相比那些从没口服过避孕药或口服不足一年的女性，那些服药10年及以上者，她们患卵巢癌的风险要低40%，患子宫内膜癌的风险要低34%。

That confirms what earlier studies found, but the current study also delved⁵ deeper into how oral contraceptives and cancer risk differed among women with different risk factors for cancer. When the scientists looked at lifestyle factors that might affect the cancer risk among pill users, for example, they found that women who used the pill and were obese⁶, smoked or did not exercise had among the lowest ovarian cancer rates. It's not clear why, but the researchers speculate that in the case of smokers⁷, there may be some interaction among the hormones⁸ associated with oral contraceptives and tobacco.

这证明了早期的研究发现，但目前的研究更加深入，探讨了口服避孕药和癌症风险因人而异，因为不同女性患癌的风险因素也不尽相同。当科学家研究生活方式因素时，这一因素可能会影响服药者的癌症风险，比如，他们发现：服用药物、肥胖、抽烟或不运动的女性患卵巢癌的风险最低。目前原因尚不清楚，但研究人员推测，就吸烟者而言，口服避孕药激素和烟草激素可能会产生一些反应。

"We found long-term oral contraceptive use reduced ovarian cancer risk universally - it didn't matter how healthy you were later in life or if you had a family history of the disease; all women experienced the benefit," said Britton Trabert, the study's senior author and epidemiologist from the division of cancer epidemiology and genetics at the National Cancer Institute (NCI).

"我们发现长期口服避孕药能普遍降低患卵巢癌的风险--不管你后来的生活状况是否健康、也不管你是否有这种疾病的家庭史，所有女性都能从中获益，"Britton Trabert说道，他是该研究的资深作者，也是美国癌症研究所癌症流行病学和遗传学部门的流行病学家。

For endometrial cancer, women who were obese and used the pill for 10 years or more lowered their risk of developing the cancer, while women who were normal weight and used oral contraceptives did not.

至于子宫内膜癌，肥胖且服用药物10年及以上的女性患该种癌症的风险降低，而体重正常且口服避孕药的人却没有降低患癌风险。