October is breast cancer awareness month, and thankfully it seems quite a few Americans are aware of it. Mortality from breast cancer has dropped by 43% over the past 30 years, according to a new report by the American Cancer Society (acs). This is largely thanks to earlier detection and better treatments. All told, the improvement adds up to 460,000 lives saved over the past three decades.

10月是乳腺癌宣傳月，值得慶幸的是，似乎相當(dāng)多的美國人意識到了這一點(diǎn)。根據(jù)美國癌癥協(xié)會的一份新報告，乳腺癌的死亡率在過去30年下降了43%。這在很大程度上要?dú)w功于更早的發(fā)現(xiàn)以及更好的治療?？偟膩碚f，在過去的30年里，這些改善挽救了46萬人的生命。

Most public-health news from America is gloomy. About 100,000 people die each year from drug overdoses. Life expectancy, which used to creep steadily up year after year, has gone into reverse: America is unusual among rich countries in that life expectancy has fallen back to a level it was last at in the mid-1990s. Within that overall picture though, there have been improvements. Breast cancer joins lung cancer, the most prevalent cause of death from cancer, colorectal, and prostate cancer in becoming less lethal over the past three decades. Since deaths avoided tend to be rather neglected relative to deaths caused, it is worth considering what has gone right.

大多數(shù)來自美國的公共衛(wèi)生新聞都令人沮喪。每年大約有10萬人死于藥物過量。曾經(jīng)年復(fù)一年穩(wěn)步增長的預(yù)期壽命已經(jīng)開始逆轉(zhuǎn):在發(fā)達(dá)國家中，美國的預(yù)期壽命已經(jīng)回落到上世紀(jì)90年代中期的水平，這是不尋常的。不過，在整體情況下，情況有所改善。在過去的30年里，乳腺癌與肺癌(最常見的導(dǎo)致死亡的癌癥)、結(jié)腸直腸癌和前列腺癌一起變得不那么致命。由于與造成的死亡相比，避免的死亡往往被忽視，因此值得考慮哪些是正確的。

According to the Centres for Disease Control and Prevention, about 264,000 cases of breast cancer are diagnosed among American women each year, and about 42,000 women die. Men are susceptible too, though male breast cancer is very rare: each year about 2,400 men are diagnosed with breast cancer and 500 die. Early diagnosis is key to survival. Today someone diagnosed with breast cancer that has not spread to any other body part has a 99% chance of living for at least five more years. That compares with 29% for breast cancer that has spread throughout the body.?

根據(jù)美國疾病控制與預(yù)防中心的數(shù)據(jù)，美國女性中每年約有26.4萬例乳腺癌確診病例，其中約4.2萬例死亡。男性也易受影響，盡管男性乳腺癌非常罕見: 每年約有2400名男性被診斷患有乳腺癌，其中500人死亡。早期診斷是生存的關(guān)鍵。今天，被診斷患有乳腺癌但沒有擴(kuò)散到身體其他部位的人至少有99%的機(jī)會再活5年。相比之下，擴(kuò)散到全身的乳腺癌的這一比例為29%。

How has this improvement come about? Three-quarters of women with health insurance have regular mammograms, which result in earlier detection. Treatments have also become more targeted. Doctors are now able to divide breast cancer diagnoses into subtypes based on whether the cancer contains oestrogen and progesterone receptors, which means they are sensitive to hormones, and whether they have high levels of her2 protein, which stimulates cell growth. These classifications allow for more specific, and therefore effective, treatment.

這種改善是如何產(chǎn)生的? 有醫(yī)療保險的女性中，有四分之三定期進(jìn)行乳房x光檢查，這樣可以更早發(fā)現(xiàn)。治療也變得更有針對性。醫(yī)生現(xiàn)在可以根據(jù)癌癥是否含有雌激素和孕激素受體(這意味著它們對激素敏感)，以及是否有高水平的HER2蛋白(刺激細(xì)胞生長)，將乳腺癌診斷分為亞型。這些分類允許更具體的，因此有效的治療。

While mortality rates have decreased, the prevalence of breast cancer has risen in the past 40 years—and not just because more people are being screened. The increase is probably due to high obesity rates and declining fertility among women, says Rebecca Siegel, an author of the acs report. Breast cancer and obesity are linked because fat cells synthesise oestrogen production in post-menopausal women, and higher oestrogen levels are associated with breast cancer. As for fertility, having children at a later age and not having children at all is associated with increased risk of breast cancer. “It’s not fully understood why, but it’s thought to be related to exposure to oestrogen,” says Ms Siegel.

雖然死亡率下降了，但在過去的40年里，乳腺癌的患病率卻上升了，不僅僅是因為更多的人接受了篩查。美國癌癥學(xué)會報告的作者麗貝卡·西格爾稱，乳腺癌患病率的增加可能是由于女性的高肥胖率和生育率的下降。乳腺癌和肥胖是有關(guān)聯(lián)的，因為在絕經(jīng)后的女性中，脂肪細(xì)胞會合成雌激素，而雌激素水平較高與乳腺癌有關(guān)。至于生育能力，晚育和不生育都與患乳腺癌的風(fēng)險增加有關(guān)。西格爾女士稱:“ 原因還不完全清楚，但人們認(rèn)為這與暴露于雌激素有關(guān)?！?/p>

Still, the news is mostly good. As ever there are racial gaps in outcomes, and people without health insurance are much less likely to get a mammogram. But with the exception of Native Americans, all racial groups have seen mortality rates from breast cancer decline.

盡管如此，大部分消息還是好的。結(jié)果一如既往地存在種族差異，沒有醫(yī)保的人做乳房x光檢查的可能性要小得多。但除了印第安人，所有種族的乳腺癌死亡率都在下降。