インタビュー
「General Session VIII：結腸・直腸癌のトランスレーショナル・リサーチ」の座長 Scott Kuwada氏に聞く
| 編集部 | 腫瘍の増殖に関係しているのは，腫瘍組織中に存在する癌幹細胞という一部の細胞だけだということが，基礎研究によって明らかになってきました。この癌幹細胞とはどういったものなのか。また，これは癌の化学療法にどのようなインパクトがあるとお考えですか？ |
| Kuwada氏 |  |
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cancer stem cell：癌幹細胞
give rise to：引き起こす，発生させる
resistant：抵抗性
In this particular session that we had today, I think the main finding is this concept of a cancer stem cell. And the importance of cancer stem cells to tumor biology. So when you think of a big tumor, I think the important thing is, not all of the cells in the tumor are the same. So what Dr. O'Brien was talking about was that there is a very small fraction of the cells in the tumor that are really important for generating all of the cells in the tumor. Just like normal tissue we have stem cells, they give rise to all the rest of the cells, the tumors appears to be the same. Now, if this turns out to be true, the important part of her work is that the tumor stem cells are not responding very well to chemotherapy. And the way we follow responses to chemotherapy is by watching tumor shrink. But what she is showing is that most of those cells are not a problem and that they cannot give rise to new cells. If the cancer stem cell fraction is resistant to therapy then the tumors are shrinking in that patient and then they will come back again. So what we really need to study is how to attack the cancer stem cell.
| 編集部 | 予後予測因子として，循環癌細胞（CTC）も期待されていますが，これは癌幹細胞と何かつながりがあるのでしょうか。また，癌遺伝子KRAS の変異と分子標的治療薬であるEGFR阻害薬の効果も話題となっていましたが，KRAS 変異のある患者では治療効果がみられなかったのでしょうか。 |
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circulating cancer cell：循環癌細胞（CTC:circulating tumor cellと同義）
prognosis：予後
mutation：変異
And Dr. Meropol's work is related in that some of these circulating cancer cells may be the stem cells. And there are animal study showing now that, that the cancer stem cells are the ones that are metastasizing. So it makes his work much more important to, he needs to go back and look now to see what cells are circulating in cancer patients. Are they the stem cells? And if it's the stem cell fraction, does that make the prognosis much worse, in another words, those patients die more quickly than those that don't have circulating stem cells. So I think those are major findings from this and the other major finding that Dr Lenz was talking about and then also Dr. Roth presented ... not Dr. Roth, a model was that if you're using EGF receptor inhibitor for therapy for colon cancer, if you have a KRAS mutation in the tumor, those patients have a less, less chance of responding to EGF receptor inhibitors, so those are from my session.
