你說的沒科學數據支持。實際上美國從1940-1980 發病率是上升的，這我想主要是人的壽命在這段時間逐漸增長，而乳腺癌

在老年的發病率高造成了整體的發病率高（ 如果象原始社會人均壽命30歲人還沒來得及得癌就死掉了肯定發病率低). 1980-200 可能是更年期綜合症激素治療導致乳腺癌增加。 但在2000年後下降了，以後一直比較穩定，沒上升。
http://ww5.komen.org/BreastCancer/Statistics.html

Breast cancer incidence over time From the 1940s until the 1980s, breast cancer incidence (new cases) rates in the U.S. increased by a little over one percent each year. In the 1980s, incidence rose greatly (likely due to increased mammography screening), and then leveled off during the 1990s [41].

The incidence of breast cancer declined in the early 2000s [37-38]. Although mammography screening rates fell somewhat over this same time period, studies show these changes were not likely related to the decline in breast cancer rates [42-43]. The decline appears to be related to the drop in use of menopausal hormone therapy (postmenopausal hormone use) that occurred after the Women's Health Initiative study showed its use increased the risk of breast cancer [37,41-43].

Since 2004, the incidence of breast cancer has remained stable [38].

- See more at: http://ww5.komen.org/BreastCancer/Statistics.html#sthash.0HSlCwfG.dpuf
你還可到下麵這個網頁看一下統計分析圖，從1992-2011 發病率基本穩定，隻是2000年前略有上升，然後馬上又降下來了。死亡率從1992-2011 整體是下降的。

http://seer.cancer.gov/statfacts/html/breast.html

還有這篇文章
Breast Cancer Statistics, 2013
http://onlinelibrary.wiley.com/doi/10.3322/caac.21203/pdf

再看一下這一個，http://www.cancer.org/acs/groups/content/@research/documents/document/acspc-042725.pdf
從1975 到2010， 0-49歲年齡段非常穩定不升，與你說的年輕化不符。另外所有年齡放在一起統計1975-1987略有上升，以後增加也不明顯。但50歲以上的單獨分析1975-2000年增加，然後下降(page 6, figure 4b)。增加主要是由於壽命的增加導致發病率增加，這個統計裏也有圖表說明（見第2頁figure 1)，還有可能與那個時期更年期綜合症激素治療有關。 死亡率1975-1995 是上生的，以後大幅下降（page 7, figure 5b)

總之，你的 “有越研究越高發，越研究越發病年輕化之勢” 沒有充分的統計數據支持。

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• 乳腺癌發病與年齡 -環球醫生001- ♂ (70 bytes) () 01/24/2015 postreply 09:53:54