Do sharks get cancer?

Factual Questions
1

I’ve heard that sharks don’t get cancer. Is this truth, speculation or fiction? Also, if it is true, why?

2

Check out this site:

http://www.hcrc.org/contrib/acsh/articles/sharks.html

The long and short of it is as follows:

  1. Sharks DO (or at least can) get cancer - though it is often introduced in a laboratory setting as opposed to acquired in the wild. Of course, the fact that they don’t get it normally doesn’t mean anything. They may simply die of something else before it can happen. It wasn’t all that long ago that people had never heard of Alzeheimer’s because they didn’t live long enough to get it…

  2. Components of shark cartilage have been shown to inhibit angiogenesis (that is, the formation of new blood vessel networks that can support the growth of tumors)

  3. Clinical in humans of the above have been mostly negative, or (if you’re an optimist) at least inconclusive. I know that there are still a few studies ongoing (I believe at Sloan Kettering) but I wouldn’t hold my breathe for that ‘miracle cure’

  4. Powdered shark cartilage is a big seller on the Internet via the health food stores as a ‘cancer preventer’, but again, research here is inconclusive. Then again, so is taking ground-up rhino horn as a Viagra substitute, but plenty of Chinese people think that’s where it’s at.

3

Or check this out from about a month ago on cnn.com

http://www.cnn.com/2000/HEALTH/cancer/04/06/cancer.sharks.ap/index.html

The article begins…

SAN FRANCISCO (AP) – Researchers announced this week that sharks do get cancer, a discovery that could threaten a small industry based on the belief that shark cartilage contains a cancer-fighting substance.

4
  • … Last scene of all,
    That ends this strange eventful history,
    Is second childishness and mere oblivion,
    Sans teeth, sans eyes, sans taste, sans everything.*
    – Shakespeare

I think it’s safe to say that people back then knew about Alzheimer’s, even if they didn’t have a medical term for it.

5
      • Hmmm . . . .
      • Scavenger Hunt!
      • I had a particular book out to respond to another thread, and just remembered something about cancer in the same book:
  • Isaac Asimov’s Book of Facts, ISBN 0-8038-9347-7, page 232 says that “One group of people, and only one group, has been found to be free of cancer in any of its forms. They are the Hunza people of northwest Kasmir, who are also known for their longevity.”
  • Is it so? I don’t know! Get ready, get set, go! - <C
6
      • Sorry; that should read “Hunza people of Kashmir”, if’n it wasn’t obvious. - MC
7

The latest Scientific american has a short blurb on sharks getting cancer. It just came today so i haven’t actually had a chance to read it yet…
hope the pointer helps.
-luckie