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美国国家公共电台 NPR--A new kind of blood test can screen for many cancers — as some pregnant people learn

时间:2023-10-18 02:28:52

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(单词翻译)

A new kind of blood test can screen for many cancers — as some pregnant people learn

Transcript1

When Kathleen Aukstikalnis was expecting her first baby, she turned to a common prenatal test that a lot of her friends had gotten done during their pregnancies2.

The simple blood test looks at DNA3 that's floating freely in a pregnant person's bloodstream. It searches for bits released by cells in the placenta, which should have the same genetic4 make-up as the fetus5.

Over the last decade, this kind of genetic test has become the go-to method for screening pregnancies for chromosomal6 abnormalities like Down syndrome7, and it's reduced the number of invasive amniocentesis procedures dramatically. Aukstikalnis hoped the test would provide peace of mind, and was also excited that the test would reveal her baby's sex.

"That's really all that I was expecting," she says. "I didn't know that you could find out something about yourself from it."

But she did find out something about herself. In fact, this test sent her on a medical odyssey8, one that shows the promise – and challenges – of blood tests that can potentially zero in on DNA released by cancer cells.

A cancer moonshot

An expectant mother's bloodstream doesn't just contain bits of free-floating DNA associated with the fetus. It's also chock full of DNA released by her own cells. And if some of those cells are malignant9, that can affect the test results – acting10 as a kind of unasked-for cancer screening.

A blood test that can screen for multiple cancers at once by looking at DNA has been something that researchers have been working towards for years. It's currently a major focus of President Biden's Cancer Moonshot research initiative.

"Imagine a simple blood test during an annual physical that could detect cancer early, when the chances of a cure are best," Biden said recently, adding that the National Cancer Institute is planning a large clinical trial to explore this approach.

One such cancer screening test is even commercially available – but no medical association recommends this kind of testing and no such tests have been approved by the Food and Drug Administration.

That's because although there's some data suggesting that certain blood tests that target free DNA might be very good at detecting cancer, there's no definitive11 studies showing that using them for screening will actually improve people's health outcomes, says Lori Minasian, deputy director for the division of cancer prevention at the National Cancer Institute.

"Do we really understand that in all of these different cancers at the earliest stages, they're releasing this DNA in a way that is reproducible, that we can measure and understand that it's early or late?" asks Minasian. "There's so much we don't know about this. We need to do the trials so we can get the information."

'I wasn't thinking about myself'

In the meantime, pregnant people like Aukstikalnis can be blindsided by information that they never expected as they seek out a test that they thought would just tell them something about the pregnancy12.

After she'd gotten blood drawn13 and sent it off for testing of the free-floating DNA in her blood, a nurse called and said there'd been some kind of error and the test hadn't produced reportable results. So Aukstikalnis went in and had her blood drawn again.

"It ended up being the same kind of scenario," she says.

Her nurse-midwife said she'd never had a patient who got this kind of inconclusive result, and recommended a consultation14 with a genetic counselor15 to figure out what might be going on.

"I wasn't thinking anything about myself, really, at all," recalls Aukstikalnis. "I was more worried about the baby."

She and her husband, Andrew, talked with the counselor, who told her that the oddities seen in her blood sample were so rare, no one knew for sure what might be causing them. Physicians had observed, though, that pregnant people who got these kinds of test results sometimes later were diagnosed with benign16 or malignant tumors.

"So that was really difficult to wrap my head around," says Aukstikalnis.

A genetic needle in a DNA haystack

Doctors already have some experience with looking for the DNA of cancer cells in the blood, because they occasionally do so for patients who are known to have advanced cancer. In those cases, these tests help to make decisions about how to best treat these patients.

It isn't hard to detect malignant DNA in these patients, because their bodies usually have a lot of cancerous cells that are shedding DNA, explains Colin Pritchard, professor of laboratory medicine and pathology at the University of Washington.

But catching17 cancers early with a blood test? That's another story.

"Early detection is so much harder. It's really a beast," says Pritchard, adding that trying to spot DNA released into the blood by a small number of cancerous cells is a needle-in-the-haystack problem.

To him, it seemed like an unlikely way to screen for cancer. But recent technological18 advances have made him reconsider.

"I went from being a huge skeptic," says Pritchard, "to being like, 'Well, okay, this is a viable19 approach and this could work.'"

The trouble is, "we don't know who should be tested," he adds. "How old should you be? Should you only be tested if you have a family history of cancer?"

And if the screening test indicates the possible presence of a malignancy, what kind of follow-up testing needs to be done? Insurance companies may balk20 at paying for expensive tests to hunt for cancers that might not even exist, based on the results of a new-fangled screening strategy that hasn't been proven cost-effective.

All this uncertainty21 is what hit Aukstikalnis and her spouse22 when they spoke23 with the genetic counselor. The counselor suggested that they might consider enrolling24 in a clinical trial at the National Institutes of Health that was seeking people who had gotten these ambiguous test results when seeking information about their pregnancies.

The trial, called IDENTIFY, was designed to figure out the full range of what these results might mean, so that doctors in the future would have a better sense of what to tell their patients.

Each participant in the trial would get an all-expense-paid trip to the NIH's clinical center, the biggest research hospital in the world, for a wide array of diagnostic tests including a full-body MRI scan, which is safe to do during pregnancy.

"It was kind of like a no-brainer for me that we were going to go with NIH and see what they could find out about it," says Aukstikalnis, "and go from there."

What to do with these results

Not everyone facing that choice made that decision. After all, most of the people getting these inconclusive prenatal test results are young, apparently25 healthy, and pregnant, notes Amy Turriff, a genetic counselor at the NIH.

"I think to the average person, if you have cancer, you don't feel well, you have some lump, bump, some sort of scary symptom," says Turriff, "and that's just not the experience of the people being referred to us."

Some people have declined to participate in the study because they've gotten the idea from their doctor, or even a cancer specialist, that the test results most likely don't mean anything.

Diana Bianchi, director of the National Institute of Child Health and Human Development, says that she and her colleagues faced that kind of skepticism when they started the IDENTIFY study.

"Everyone thought we were a little bit crazy in the beginning," recalls Bianchi, who says the general attitude was that "there's no way these healthy women are going to have cancer."

But that's not what their trial's results suggest so far, says Bianchi, who hopes to publish interim26 findings from the study, which is still enrolling participants, in 2024.

"Of the ones who have been enrolled27 and have had the full workup, over half of them do have a tumor," says Bianchi. "So this is not a trivial finding. Our take home message is, this really needs to be taken seriously."

The researchers have found a variety of malignancies. "What we've found most commonly is lymphoma. But we found extremely rare cancers as well, like 1-in-a-million type of cancers," says Bianchi. One woman had a cancerous mass in her abdomen28 the size of a grapefruit.

These findings are similar to those of a new study out of the Netherlands, which followed up 48 pregnant women who had suspicious results from one of the cell-free DNA prenatal tests. Eighteen of the women turned out to have malignancies, most often lymphomas.

An overwhelming experience

When Aukstikalnis and her spouse went to the NIH clinical center in July of 2021, to get their slew29 of tests, they hadn't expected to hear the results right away. And she still didn't really think the tests would find that she was sick.

But at the end of the day, a team of doctors sat them down and said that it looked like she likely had lymphoma. The news came as a shock.

"Hearing that news that you have cancer, it's hard to describe. It's just such, like, an overwhelming experience," she says. "And then you're also pregnant at the same time. Your emotions are kind of all over the place. It was definitely really difficult."

The NIH team helped get her set up with caregivers in her home state, and a biopsy confirmed the diagnosis30.

She started chemotherapy even before her baby was born--something that can be done completely safely--and got a lot of help from family and friends, plus online support communities for pregnant women with cancer such as Hope for Two.

In November of last year, her family welcomed a baby girl named McKenna.

"Everything went really smoothly31 with delivery and she was perfectly32 normal, she is perfectly healthy," says Aukstikalnis. "That was always something I was nervous about, was it the right decision to get treatment while I was pregnant, you know, could it still end up causing issues? And it didn't. She is doing really well."

When Kathleen Aukstikalnis was expecting her first baby, she turned to a common prenatal test meant to screen for chromosomal abnormalities and reveal the baby's sex. Inconclusive results led Aukstikalnis to undergo a series of other tests, with results suggesting that she likely had lymphoma. She was able to start chemotherapy before her baby was born, who then entered the world healthy.

Tasharazzi Photography Inc.

Unfortunately, even though Aukstikalnis had what appeared to be a clear scan after the first-line treatment that often puts people in remission, a subsequent scan showed that the lymphoma had likely returned.

She ultimately underwent a stem cell transplant this autumn that required a 26-day hospital stay, during which she wasn't able to see her husband or daughter except over twice-daily video chats.

Now that she's finally home with her family, she's trying to take it easy while her immune system slowly recovers.

"It's like being a newborn baby, all over again," she says. "It's going to take a long time, but I've made it this far, so I know that we can get there."

She hopes that her participation33 in the IDENTIFY study will help other women who face uncertain test results that might mean cancer.

"I'm incredibly grateful that I found out when I did and then found out I could get treatment at an early stage," she says. "Even though things have been really difficult, I would also say there have been a lot of positive experiences. It really shifted my focus to the things that matter most."


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1 transcript JgpzUp     
n.抄本,誊本,副本,肄业证书
参考例句:
  • A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
  • They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。
2 pregnancies 2fedeb45162c233ee9e28d81888a2d2c     
怀孕,妊娠( pregnancy的名词复数 )
参考例句:
  • Since the wartime population needed replenishment, pregnancies were a good sign. 最后一桩倒不失为好现象,战时人口正该补充。
  • She's had three pregnancies in four years. 她在四年中怀孕叁次。
3 DNA 4u3z1l     
(缩)deoxyribonucleic acid 脱氧核糖核酸
参考例句:
  • DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
  • Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
4 genetic PgIxp     
adj.遗传的,遗传学的
参考例句:
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
5 fetus ekHx3     
n.胎,胎儿
参考例句:
  • In the fetus,blood cells are formed in different sites at different ages.胎儿的血细胞在不同时期生成在不同的部位。
  • No one knows why a fetus is not automatically rejected by the mother's immune system. 没有人知道为什么母亲的免疫系统不会自动排斥胎儿。
6 chromosomal 13a3145acf874e52d34a5554025f79c6     
adj.染色体的
参考例句:
  • Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样,都是染色体DNA的转录产物。 来自辞典例句
  • In mammalian species, a variety of chromosomal rearrangements are known to exist. 在哺乳类的物种中,已知有许多类型的染色体内部重新排列。 来自辞典例句
7 syndrome uqBwu     
n.综合病症;并存特性
参考例句:
  • The Institute says that an unidentified virus is to blame for the syndrome. 该研究所表示,引起这种综合症的是一种尚未确认的病毒。
  • Results indicated that 11 fetuses had Down syndrome. 结果表明有11个胎儿患有唐氏综合征。
8 odyssey t5kzU     
n.长途冒险旅行;一连串的冒险
参考例句:
  • The march to Travnik was the final stretch of a 16-hour odyssey.去特拉夫尼克的这段路是长达16小时艰险旅行的最后一程。
  • His odyssey of passion, friendship,love,and revenge was now finished.他的热情、友谊、爱情和复仇的漫长历程,到此结束了。
9 malignant Z89zY     
adj.恶性的,致命的;恶意的,恶毒的
参考例句:
  • Alexander got a malignant slander.亚历山大受到恶意的诽谤。
  • He started to his feet with a malignant glance at Winston.他爬了起来,不高兴地看了温斯顿一眼。
10 acting czRzoc     
n.演戏,行为,假装;adj.代理的,临时的,演出用的
参考例句:
  • Ignore her,she's just acting.别理她,她只是假装的。
  • During the seventies,her acting career was in eclipse.在七十年代,她的表演生涯黯然失色。
11 definitive YxSxF     
adj.确切的,权威性的;最后的,决定性的
参考例句:
  • This book is the definitive guide to world cuisine.这本书是世界美食的权威指南。
  • No one has come up with a definitive answer as to why this should be so.至于为什么该这样,还没有人给出明确的答复。
12 pregnancy lPwxP     
n.怀孕,怀孕期
参考例句:
  • Early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
  • Smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。
13 drawn MuXzIi     
v.拖,拉,拔出;adj.憔悴的,紧张的
参考例句:
  • All the characters in the story are drawn from life.故事中的所有人物都取材于生活。
  • Her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。
14 consultation VZAyq     
n.咨询;商量;商议;会议
参考例句:
  • The company has promised wide consultation on its expansion plans.该公司允诺就其扩展计划广泛征求意见。
  • The scheme was developed in close consultation with the local community.该计划是在同当地社区密切磋商中逐渐形成的。
15 counselor czlxd     
n.顾问,法律顾问
参考例句:
  • The counselor gave us some disinterested advice.顾问给了我们一些无私的忠告。
  • Chinese commercial counselor's office in foreign countries.中国驻国外商务参赞处。
16 benign 2t2zw     
adj.善良的,慈祥的;良性的,无危险的
参考例句:
  • The benign weather brought North America a bumper crop.温和的气候给北美带来大丰收。
  • Martha is a benign old lady.玛莎是个仁慈的老妇人。
17 catching cwVztY     
adj.易传染的,有魅力的,迷人的,接住
参考例句:
  • There are those who think eczema is catching.有人就是认为湿疹会传染。
  • Enthusiasm is very catching.热情非常富有感染力。
18 technological gqiwY     
adj.技术的;工艺的
参考例句:
  • A successful company must keep up with the pace of technological change.一家成功的公司必须得跟上技术变革的步伐。
  • Today,the pace of life is increasing with technological advancements.当今, 随着科技进步,生活节奏不断增快。
19 viable mi2wZ     
adj.可行的,切实可行的,能活下去的
参考例句:
  • The scheme is economically viable.这个计划从经济效益来看是可行的。
  • The economy of the country is not viable.这个国家经济是难以维持的。
20 balk RP2y1     
n.大方木料;v.妨碍;不愿前进或从事某事
参考例句:
  • We get strong indications that his agent would balk at that request.我们得到的强烈暗示是他的经纪人会回避那个要求。
  • He shored up the wall with a thick balk of wood.他用一根粗大的木头把墙撑住。
21 uncertainty NlFwK     
n.易变,靠不住,不确知,不确定的事物
参考例句:
  • Her comments will add to the uncertainty of the situation.她的批评将会使局势更加不稳定。
  • After six weeks of uncertainty,the strain was beginning to take its toll.6个星期的忐忑不安后,压力开始产生影响了。
22 spouse Ah6yK     
n.配偶(指夫或妻)
参考例句:
  • Her spouse will come to see her on Sunday.她的丈夫星期天要来看她。
  • What is the best way to keep your spouse happy in the marriage?在婚姻中保持配偶幸福的最好方法是什么?
23 spoke XryyC     
n.(车轮的)辐条;轮辐;破坏某人的计划;阻挠某人的行动 v.讲,谈(speak的过去式);说;演说;从某种观点来说
参考例句:
  • They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
  • The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。
24 enrolling be8b886d0a6622fbb0e477f03e170149     
v.招收( enrol的现在分词 );吸收;入学;加入;[亦作enrol]( enroll的现在分词 );登记,招收,使入伍(或入会、入学等),参加,成为成员;记入名册;卷起,包起
参考例句:
  • They lashed out at the university enrolling system. 他们猛烈抨击大学的招生制度。 来自辞典例句
  • You're enrolling in a country club, Billy. 你是注册加入乡村俱乐部了,比利。 来自辞典例句
25 apparently tMmyQ     
adv.显然地;表面上,似乎
参考例句:
  • An apparently blind alley leads suddenly into an open space.山穷水尽,豁然开朗。
  • He was apparently much surprised at the news.他对那个消息显然感到十分惊异。
26 interim z5wxB     
adj.暂时的,临时的;n.间歇,过渡期间
参考例句:
  • The government is taking interim measures to help those in immediate need.政府正在采取临时措施帮助那些有立即需要的人。
  • It may turn out to be an interim technology.这可能只是个过渡技术。
27 enrolled ff7af27948b380bff5d583359796d3c8     
adj.入学登记了的v.[亦作enrol]( enroll的过去式和过去分词 );登记,招收,使入伍(或入会、入学等),参加,成为成员;记入名册;卷起,包起
参考例句:
  • They have been studying hard from the moment they enrolled. 从入学时起,他们就一直努力学习。 来自《简明英汉词典》
  • He enrolled with an employment agency for a teaching position. 他在职业介绍所登了记以谋求一个教师的职位。 来自《简明英汉词典》
28 abdomen MfXym     
n.腹,下腹(胸部到腿部的部分)
参考例句:
  • How to know to there is ascarid inside abdomen?怎样知道肚子里面有蛔虫?
  • He was anxious about an off-and-on pain the abdomen.他因时隐时现的腹痛而焦虑。
29 slew 8TMz0     
v.(使)旋转;n.大量,许多
参考例句:
  • He slewed the car against the side of the building.他的车滑到了大楼的一侧,抵住了。
  • They dealt with a slew of other issues.他们处理了大量的其他问题。
30 diagnosis GvPxC     
n.诊断,诊断结果,调查分析,判断
参考例句:
  • His symptoms gave no obvious pointer to a possible diagnosis.他的症状无法作出明确的诊断。
  • The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做一次彻底的调查分析。
31 smoothly iiUzLG     
adv.平滑地,顺利地,流利地,流畅地
参考例句:
  • The workmen are very cooperative,so the work goes on smoothly.工人们十分合作,所以工作进展顺利。
  • Just change one or two words and the sentence will read smoothly.这句话只要动一两个字就顺了。
32 perfectly 8Mzxb     
adv.完美地,无可非议地,彻底地
参考例句:
  • The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
  • Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。
33 participation KS9zu     
n.参与,参加,分享
参考例句:
  • Some of the magic tricks called for audience participation.有些魔术要求有观众的参与。
  • The scheme aims to encourage increased participation in sporting activities.这个方案旨在鼓励大众更多地参与体育活动。

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