Continuing yesterday's theme, I thought I'd write a few blogs on one of my favorite subjects: precancer. Precancers are probably the most important lesion of humans. If you prevent, treat or excise a precancer, the cancer never develops. Even if you simply lengthen the precancer phase of carcinogenesis (which precedes the invasive cancer), you can greatly reduce the number of cancer-related deaths.
Many people, including cancer researchers, mistakenly believe that precancers are merely small or early cancers. This is not true. Precancers have biological properties that differ from invasive cancers.
Here they are:
1. Precancers can be defined and studied as biological entities.
2. Precancers are more prevalent than cancers. (Corollary: many precancers regress or fail to progress).
3. On average, precancers develop in younger individuals than do cancers.
4. If a precancer is eradicated, the cancer cannot develop.
5. Every cancer has a precancer (Corollary: if all precancers were eradicated, there would be no cancers).
6. It is easier to treat a precancer than to treat a cancer.
7. A single precancer may develop into any one of several closely related cancers (Corollary: There are more types of cancers than there are types of precancers.)
8. Precancers contain the characteristic genetic abnormality that distinguish one class of cancrer from another class of cancer. Corollary: Agents that target an essential pathway in a particular cancer will also target the same pathway in the precancer for the cancer and for all of the closely related cancers.
9. Precancers can be distinguished from the cancers into which they develop. (Corollary: precancers can be diagnosed and studies).
10. Precancers can be sensibly classified into classes of lesions that share biological properties.
11. Precancers that progress will progress into cancers and no other type of lesion.
12. All agents that cause cancers will also cause precancers.
- Copyright (C) 2008 Jules J. Berman
key words: intraepithelial neoplasia, premalignant, premalignancy, preneoplasia, pre-cancer, preneoplastic, cancer precursor, incipient neoplasia, neoplasm