楼主对西医在肿瘤治疗上的了解确实有限。

来源: 2009-07-10 14:02:12 [博客] [旧帖] [给我悄悄话] 本文已被阅读:

西医除了手术、化疗、放疗三板斧外,对不同的癌症是有不同的方法处理的。只是还有一些肿瘤,其机制还没搞清楚,或还没有找到对应的方法而已。另外,许多外行人说的一种肿瘤,在西医里,是有不同的机制的,所以,对应的治疗方法可以是完全不同的。随着研究的深入,对应的治疗方法会找出来的。

以我以前研究的乳腺癌为例,它初分为ER阳性和阴性。前者除了你说的三板斧之外,更多的是Tamoxifen和aromotase inhibitor来对付的。这种治疗一般能有2-3年的效果。对阴性,除了三板斧,其他办法不多。主要是机制太复杂。

有很多药物,针对特定的肿瘤。查一下大的制药公司的产品就知道了。只是这些药物只能针对几种特定的肿瘤中的一些亚型。肿瘤起源的机制太复杂,所以,没有一种特效药(化疗除外)对付所有的肿瘤。所以,肿瘤的诊断(分型)也是目前的研究重点。

化疗是利用肿瘤细胞生长快的特点来设计的。但这种疗法的特点是副作用太大--人体里正常细胞也要生长,也会被除掉。这就是新一代肿瘤药物要克服的问题。

谈到中(草)药和西药的结合,要先了解过去几十年西药研究的历史。在药物筛选(High throughput screening)上,一直是用简单的化合物。人工合成的化合物,结构是不可能太复杂的。而自然界里的一些化合物,尤其在植物里,其结构要复杂得多。但没有目标的分离纯化成千上万的化合物供药物筛选可不容易。但有不少(尤其是当年前苏联分离纯化的)已经进入药物筛选系统。估计越来越多的天然化合物会进入药物筛选库。西方在肿瘤的知了上,近年在抗体上华了不少功夫,我没有太跟踪,对其前景不熟习,不敢评论。

中医要进步,科学化是必不可免的。靠传统的经验是不会有进步的。必须用科学的办法找出中药中起作用的化学成分,作用机制,在加以完善。其实中西结合的最好例子在中国--中国治疗malari疟疾的药物开发,就是从中药里指导一种植物有效,然后分离这个化学成分,然后在化学结构上加以修饰,合成了更好的抗疟疾的药物。

这是俺当年作的研究,被新闻报道过的:

New inhibitors of breast cancer cells identified

By Megan Rauscher Wednesday, Jun. 18, 2008; 3:33 AM

NEW YORK (Reuters Health) - A team of U.S. scientists has identified a new family of compounds that block the ability of estrogen to stimulate the growth of breast cancer cells.

"The lead inhibitor is quite effective in breast cancer cells that are resistant to tamoxifen," Dr. David J. Shapiro noted at the Endocrine Society's annual meeting underway in San Francisco.

"We are hopeful that as we proceed with further development that these compounds may ultimately lead to therapeutics that are clinically useful against some breast cancers that are resistant to current therapies," added Shapiro, a biochemist at the University of Illinois at Urbana-Champaign.

Currently available treatment for breast cancer driven by estrogen either interfere with estrogen production (e.g., aromatase inhibitors such as letrozole) or block estrogen's ability to bind to estrogen receptors on breast cancer cells (e.g., tamoxifen).

"We targeted a different step in the pathway of estrogen action," Shapiro said, "one that is not targeted by current therapeutics" -- namely, the expression of genes within cell that are controlled by estrogen receptor activity and that contribute to cancer growth.

The researchers found that a compound called TPBM blocked the estrogen-dependent growth of human breast cancer cells that carried estrogen receptors -- even cells resistant to tamoxifen treatment. If cells did not carry estrogen receptors (i.e., ER negative), they were not affected.

"Even at very high concentrations, TPBM has no effect on ER-negative cells, so it is not toxic to these cells at all," Shapiro said. "This gives us a lot of confidence as we go to animal studies that TPBM will not damage human cells."

He noted that while tamoxifen therapy is effective initially, "in essentially all patients, the tumors eventually become resistant to tamoxifen and resume their growth." This fact "underscores the importance of identifying new classes of therapeutic agents that will act outside of the hormone-binding pocket on the estrogen receptor."