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An easily overlooked type of abnormality in the colon is the most likely type to turn cancerous, and is more common in this country than previously thought, researchers are reporting.
有学者指出，现在结肠上某种易被忽视的畸变往往更容易转变成癌，并且跟以前相比，该现象越来越常见。
The findings come from a study of colonoscopy, in which a camera-tipped tube is used to examine the lining of the intestine. Generally, doctors search for polyps, abnormal growths that stick out from the lining and can turn into cancer. But another type of growth is much more dangerous, and harder to see because it is flat or depressed and similar in color to healthy tissue.
这一结论是通过对结肠镜检查的研究得到的，结肠镜检查是一种在管子顶端绑上照相机对结肠内部进行检查的一种方法。一般，医生使用结肠镜来检查肠道内部异常增生可能癌变的息肉。但是另外一种类型的增生可能更危险、更难以查出，因为其表面平滑或者略有降低，并且跟正常组织颜色一样。
Japanese researchers became concerned about these flat lesions in the 1980s and ’90s, but studies here had mixed results and American doctors tended to think that flat growths were less common and less dangerous in the United States.
日本学者于80-90年代开始研究这些表面平滑的病灶，但这里所指出的研究结果好坏掺半，美国医生们觉得在美国这种表面平滑的病灶不常见也没那么危险。
The new study, to be published Wednesday in the Journal of the American Medical Association, suggests otherwise.
周三出版的美国医学协会期刊上刊登的一项新的研究显示情况并不如此。
Some doctors in this country were already alert to flat lesions, but the findings will pose a challenge to others, because it takes a trained and vigilant eye to see the growths and special techniques to remove them. The results also mean it is especially important that patients take the harsh laxatives that many dread in advance of the test. The flat lesions, hard to find even under the best conditions, will be impossible to see if any waste is left in the bowel.
在美国一些医生已经开始对这些扁平的病灶提高警惕，但该项发现将引起其他一些方面的变革，因为这需要医生接受培训有锐利的眼神并且还要有移除病灶的特殊技术。该结果还意味着患者需要面临在实验前服用强效泻药的恐惧。这些扁平病灶即使是在最好的诊断条件下也不容易被发现，当肠道内部有任何一点垃圾存在的时候被诊断出来则更不可能了。
Colon cancer is the second-leading cause of cancer death in the United States, after lung cancer, with about 154,000 new cases detected and 52,000 deaths a year. It is one of the few cancers that is totally preventable if precancerous growths are found and removed; it can also be cured with surgery alone if found early enough.
在美国，结肠癌是既肺癌后排名第二的致死癌症因素，每年有154,000患者被诊断出结肠癌，52,000人因结肠癌死亡。
People who have just had a colonoscopy should not rush to schedule another one just to look for the flat growths, doctors said.
医生说，刚刚做过结肠镜检查的患者不用急于再做一次检查扁平病灶的结肠镜。
“I don’t think people have to panic that they’ve somehow been neglected and had poor care,” said Dr. David A. Rothenberger, deputy chairman of surgery at the University of Minnesota.
明尼苏达大学外科主席代表David A. Rothenberger博士说：“我想，人们也不用为结肠镜检查时候扁平病灶被忽略或者没受到重视而惊慌”
But he and other experts emphasized that people should see a doctor any time they have persisting symptoms that could indicate colon cancer, like rectal bleeding or a change in bowel habits — no matter how recently they had a colonoscopy. The test is highly reliable, but not perfect, doctors say.
但是，Rothenberger和其他的研究者强调，无论前一次做结肠镜检查是在什么时候，当患者持续有直肠流血或者肠道习惯改变等结肠癌临床表现的时候，应该立即去医院检查。 该检查虽然不是十全十美，但却很可靠。
Some doctors who perform colonoscopy just are not good at seeing flat lesions, but may improve with training and practice, said Dr. Douglas K. Rex, a gastroenterologist and professor of medicine at Indiana University.
印地安纳大学内科学和肠道学教授Douglas K. Rex博士说：有些做结肠镜检查的医生不擅长查找扁平病灶，但可以通过参加培训和多加练习来精进技术。
“I think there are people who expect everything in there to be shaped like a golf ball,” he said. “It’s not.”
“很多医生希望任何病灶都想高尔夫球那样的形状易于辨认，但实施并不如此。”
Dr. David Lieberman, chief of gastroenterology at Oregon Health and Science University, who wrote an editorial accompanying the study, said: “I think there will be some surprise. There has been in general some skepticism in the United States about how common flat and depressed lesions are and how important they are. So I think this study, coming from the United States and from a good group of investigators, will be a wake-up call to a lot of physicians and will prompt people to be looking for these lesions.”
俄勒冈健康与科学大学肠道学科带头人David Lieberman，写了一篇关于此研究的社论，他说：“我认为会有一些令人惊讶的反对声音。在美国，普遍就存在这样一种怀疑，到底这种扁平病灶或者略为凹陷的病灶有多常见、多严重？因此，美国的精英研究人员进行的这项研究将会给许多内科医生以警醒，并促使他们仔细寻找这种病灶。”
The study, of 1,819 military veterans, mostly men, found that 9.35 percent had flat lesions, and those lesions were five times as likely as polyps to contain cancerous or precancerous tissue. Depressed or indented lesions were the least common but the most risky. Together, the flat or depressed lesions accounted for only 15 percent of the potentially cancerous growths found in the study, but were involved in half of the cancers. Once the doctors spotted the flat lesions, they sprayed a bluish dye on them to see their outlines better and remove them completely.
以1819名退伍军人（绝大多数是男性）为研究对象，发现9.35%有扁平病灶，而这些扁平病灶的癌变的几率是息肉癌变或者癌前组织癌变几率的5倍。凹陷或者锯齿状的病灶是最不常见但危险性最高的病灶。总体来看，该研究中扁平或者凹陷的病灶导致潜在癌细胞的生长只有15%被发现，但一半的结肠癌与其有关。一旦医生发现了扁平病灶，他们将会对病灶喷射蓝色染料，以便更好观察病灶外轮廓并完全清除病灶。
The first author of the study, Dr. Roy M. Soetikno of the Veterans Affairs Palo Alto Health Care System said, “The message for doctors is, Here is a large amount of data showing that these precursors of cancer, always believed to be a Japanese disease, are actually a disease here, and are important, because they are much more likely to be cancerous, and doctors need to spend the time to provide quality colonoscopy.”
该研究的带头人，退伍士兵事务Palo Alto健康关怀系统的Roy M. Soetikno博士说：“对医生来说，这一讯息总是被认为是一种日本病。有大量数据显示这些癌前病变其实就是一种疾病，是非常重要的，因为它们很可能就是癌细胞，医生应该在结肠镜检查上多花一些时间仔细检查。”
The message to patients, Dr. Soetikno said, is that when preparing for colonoscopy, they must follow instructions to the letter and take the hated laxatives to make sure their bowels are empty so that doctors can see the lining.
对病人来说，准备做结肠镜检查前，要严格按照要求服用强效的泻药以保证将肠道完全排空，医生能看清肠道内壁。
If any waste remains, flat lesions will be buried by it. Studies have shown that in about a quarter of all colonoscopies, the bowel preparation is inadequate.
如果有粪便遗留的话，扁平病灶将被覆盖住。该研究中大约就有1/4的结肠镜检查前的准备工作不够充分。
Dr. Rex said that male veterans tended to have more precancerous colon growths than other groups, so the rate of flat lesions in women or the general population might not be quite as high as those in the study.
Rex说，与其他群体相对比，男性退伍军人癌前结肠增生更多。女性或者普通群体扁平病灶发生率也不像男性退伍军人那么高。
Dr. Soetikno and his colleagues started an exchange program with doctors in Japan to learn their techniques for recognizing and removing the flat lesions.
Soetikno和他的同事开始与日本医生呼唤交流，学习日本的鉴别和移除扁平病灶的技术。
American doctors should learn from overseas colleagues more often, Dr. Rothenberger said, adding, “We tend to get very smug about our abilities.”
Rothenberger说，美国医生需要经常向海外的同僚学习，我们对于自己的能力太自以为是了。
The quality of colonoscopy has become a delicate issue, because an article in The New England Journal of Medicine in December 2006 found that some doctors were 10 times better than others at finding precancerous polyps. A major factor in their success was taking enough time to examine the colon thoroughly, as opposed to rushing through the procedure. Doctors who miss polyps would almost certainly miss flat lesions as well because they are harder to see. The new study underscores the need for careful examinations, because the flat lesions are more dangerous.
结肠镜检查的质量变成了一件敏感的事情，因为在2006年12月新西兰医学期刊表明，某些医生结肠镜检查癌症前期病变息肉的技术比其他人高明10倍。他们技术高明的主要原因就是对结肠内壁进行彻底仔细的检查，反对草草了事。那些检查中忽略了息肉的医生，同样也忽略了扁平病灶，因为扁平病灶本身就很难发现。此新研究强调了要仔细进行结肠镜检查，因为扁平病灶具有更高的危险性。
The study also raises doubts about whether “virtual colonoscopy,” performed by a CT scanner, will ever be able to take the place of the colonoscope inserted into the rectum, as many patients had hoped. The problem is that CT scans use X-rays to reveal shapes, and find polyps because they stick out. Flat lesions are unlikely to show up in such scans.
该研究也增加了这样一种疑问，是否应该如许多病人希望的那样，用CT扫描来取代实质上的结肠镜检查。但问题是CT用X线能扫描到息肉的形状是因为他们是突出于肠壁的，而扁平病灶用这样的方法检查不出来。
Studies show that from 0.3 percent to 0.9 percent of patients develop colon cancers within just a few years of having a colonoscopy and polyp removal — exactly what the procedure is supposed to prevent. Some doctors think that flat lesions, missed entirely during the colonoscopy or not fully removed, may account for some of these apparent failures.
研究显示，那些用结肠镜检查并移除息肉的病人术后几年内有0.3％-0.9％患上了结肠癌――严格的说，该手术预防了结肠癌的发生。一些医生认为结肠镜检查遗漏了的或者没有去除完全的扁平病灶可能是导致某些病人术后仍患结肠癌的原因
Dr. Robert Smith, the director of screening for the American Cancer Society, said flat lesions were “a vexing issue” that had provoked a lot of arguments among doctors.
美国癌症协会的主任Robert Smith说，扁平病灶是一个恼人的问题，已经在医生中挑起了很多的争论。
“This paper shows they’re more prevalent than we believed, and also quite serious with regard to the presence of features associated with an elevated risk of cancer,” Dr. Smith said.
该报告显示，扁平病灶比我们想像的要普遍的多，同样它们的存在也是患癌症的高风险因素。
The difficulty facing patients is how to be sure their doctors are doing a good job. Professional groups have issued guidelines about the best way to perform a colonoscopy, but they are recommendations, not rules. The groups also urge doctors to track their own success rates at finding precancerous growths to see how they measure up to standards, but even if they do keep track, the doctors do not have to share the data with anyone. And many people are loath to ask about it. The doctor wielding the scope is the last person most patients would want to offend.
病人们面临的最大问题是如何确定给他们看病的医生在结肠镜检查上具有优秀的职业技能。专业人士已经提出了如何更好履行结肠镜检查的建议，只是建议，不是规则。专业人士也呼吁临床医生对自己检查出的癌前增生的成功率做一下追踪统计，看他们是如何达到标准的。然而即使医生们坚持追踪统计，他们也不会跟任何人分享该数据。医生所能掌控的范围仅限于他们最近的一个病人，对于其他的大部分病人，他们不愿意得罪。
“The patient really has no way to act as an informed consumer,” Dr. Smith said. “You can’t call up a facility and say, ‘By the way, is my doctor any good?’ or, ‘Tell me who the best one is.’ ”
Smith说：“患者如论如何都不可能是见多识广的消费者，不可能打电话直接问：我的医生是最好的医生么？或者谁是最好的医生？”
He added: “For some physicians there is an expectation of trust, and it is offputting to have a patient request documentation of competence. However, some physicians know patients are hearing about these issues and are not offended by questions about performance and errors.”
他补充说：“对于一些医生来说，患者的信任也是他们所希望的，那些质疑他们诊断的病人令人生气。但是，有些医师知道病人听到这些问题，并没有被这些质疑他们能力和过错的问题所激怒。\"
编译
通过结肠镜检查结肠内壁上异常的增生和可能癌变的息肉，并即使清除是预防结肠癌的一种有效的方式，然而近期的研究发现跟息肉不同的病变，例如扁平的或者略为凹陷的病灶更有可能致癌，尤其这种类型的病灶容易被结肠壁上没有清理干净的粪便等垃圾给掩盖住，在结肠镜下不易被检查出来。这要求医生在做结肠镜检查的时候要用心、仔细，不能着急。
在80-90年代，日本学者就提出了该种扁平病灶容易被遗漏致癌的说法，但是没有得到更多人的认可，现在看来，是美国的医学研究者太自大了，应该谦虚，多多跟其他国家的学者交流，促进研究的发展。
专业机构呼吁临床医生对自己检查出的癌前增生的成功率做一下追踪统计，看他们的结肠镜检查是否达到标准。但很少有人相应。即使医生们坚持进行追踪统计，他们也不会跟任何其他人分享该数据。医生所能掌控的范围仅限于他们最近的一个病人，对于其他的大部分病人，他们不愿意得罪，多一事不如少一事。 |
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发表于 2008-3-10 16:26:11