Oncology Frontier: In the global breast cancer session last evening， where you spoke， there was one distinction in one Asian country and that is Japan， who has adopted many western ways， they still have a breast cancer rate which is not equal in western women. Can you talk about that?

　　《肿瘤瞭望》：在昨晚举行的全球乳腺癌日程中，您曾提到亚洲的日本采用了很多西方方法，但其乳腺癌发病率仍无法达到与西方相当的水平。能否请您谈一下这个问题？

　　Dr. Anderson: There is an ongoing global discussion about differences between women of Asian descent and women of European descent. Women of African descent seem to be more similar to the Europeans than to the Chinese. We see somewhat similar patterns in China， Korea， and Japan. The issue is that globally when breast cancer rates are very low， in those same countries we typically have very advanced disease and the survival rates are low， so when countries have very low rates often it is because there is no surveillance rates for breast cancer and you do not find it until it is very advanced and it takes people’s lives. As countries make transitions and I believe China is in transition. The healthcare system starts to rev up for being ready to make these diagnoses and so you see these rapidly raising rates of incidence. In that transition mortality tends to rise in a similar way， so I think China is in that sort of phase as is Japan and Korea. What Japan and Korea have not yet seen and this is different from Europe， they have not yet seen the plateau in breast cancer mortality and they are beginning to drop. Mortality for breast cancer started to drop in the United States in about 1991 and that was presumably related to the combination of population based screening and use of effective therapies. The Asian countries have not yet adopted population based screening strategies. Mammography is the test that has been shown in randomized trials to improve survival but mammography has not been accepted in China， Japan， and Korea in the same way that it has been in western countries. It might be because there is something cultural about it that makes it not as acceptable and it might be because it does not work as well in Asian women. The point is often made that Asian women are built differently， they are typically very slender， they have small breasts， it is difficult to get the breast between the plates， and when you do it the breast tissue looks quite dense and makes it hard to see through. It might be that mammography is not as effective in Asian women as it is in others. It also might be that it is as effective， it just has not been accepted. That is not a question that has been well addressed， we do not have any large screening mammography trials that have been done in reliable ways that you can really answer this question well， but it is notable that countries that have decreasing mortality rates at a population level， essentially all of them have taken on mammography. This is an important question for China， what are they going to do. There is the point of maybe a combination of clinical breast examination in ultrasound could be used in China with similar effect that remains in question. It has not yet been evaluated in a way that the data has proven it to work. The ultrasound is different from mammography， because it evaluates masses. Masses are almost always invasive cancer whereas mammography can find calcifications， which commonly can represent DCIS. DCIS is preinvasive cancer. If you find it at that point， mortality approaches zero. It may be that an ultrasound strategy might work in Chinese woman， but it also might be that then you still have a higher fraction of women with invasive cancer where good outcomes are still difficult to achieve. I think it is terribly important for China to consider organized， thoughtful strategies for early detection， and that they measure their outcomes. Without those measurements， it would be very difficult to know what it is that is making improvements.

　　Anderson教授：现在正在进行一个有关亚裔女性与欧洲女性乳腺癌差异的全球性探讨。结果发现，与华裔女性相比，非洲裔女性与欧洲女性更类似。而中国、韩国及日本的乳腺癌发病在一定程度上有类似模式。但问题是，当全球乳腺癌发病率非常低的时候，上述国家的乳腺癌通常都非常晚期，生存率也非常低，因此当一些国家乳腺癌发病率非常低的时候，往往因缺乏对乳腺癌发病率的监控而无法及时发现，一旦发现已处于非常晚期，导致死亡率增加。很多国家都处于转型期，我认为中国也如此。医疗系统正在加快运转从而为乳腺癌诊断作准备，因此，乳腺癌发病率会出现快速增加。同时，在转型期间，死亡率也会以类似方式增加。所以，我认为中国与日本及韩国正面临类似情况。目前，与欧洲不同，日本及韩国还未发现其乳腺癌发病率及死亡率已处于平台期并开始下降。大约1991年开始，美国乳腺癌死亡率出现下降，究其原因可能与当时以人群为基础的筛查方法及有效治疗方法的联合应用有关。但是，目前亚洲国家尚未应用以人群为基础的乳腺癌筛查策略。随机试验显示，乳腺钼靶检查可改善乳腺癌患者生存率，但与西方国家不同，在中国、日本及韩国，乳腺钼靶检查均未得到广泛接受和应用。这可能与某些文化差异导致中国、日本及韩国人不太愿意接受乳腺钼靶检查有关，也可能与其在亚洲女性中筛查效果并不是非常好有关。通常人们认为，与西方女性相比，亚洲女性的乳腺解剖结构有所不同，其乳腺通常更细、更小，乳腺组织相对更密集，因此行钼靶检查很难早期发现乳腺癌，可能是与其他人群相比，乳腺钼靶检查在亚洲女性中不是特别有效的原因。但也有一种可能，即与西方人群相比，在亚洲女性中乳腺钼靶检查同样有效，只是尚未被普遍接受。目前我们还未能找到亚洲国家乳腺钼靶检查未能广泛应用的原因，尚未在可靠方式下开展任何大型乳腺钼靶检查试验从而真正解答这个问题。但值得注意的是，人群水平上乳腺癌死亡率呈现降低的国家基本上都推广应用了乳腺钼靶检查。推广乳腺钼靶检查是中国需要做的一件非常重要的事。乳腺临床超声检查与乳腺钼靶检查联用能否对中国乳腺癌的发病率及死亡率产生同样影响仍有待解答。目前尚无这方面证据显示两者联用有非常好的效果。与乳腺钼靶检查不同，乳腺超声检查能评估和发现团块，而团块通常是浸润癌；而乳腺钼靶检查可发现钙化，钙化通常代表的是导管原位癌（DCIS），属于浸润前癌。如能早期发现，乳腺癌死亡率接近于零。因此，超声筛查乳腺癌策略可能会对中国女性有效，但仍可能有很大部分浸润性癌女性难以实现良好预后。我认为，中国要考虑应用非常有组织、周到的乳腺癌早期检测策略并评估患者预后，否则很难知道患者乳腺癌情况是否有所改善。