Cancers Can Vanish Without Treatment, but How?

[Christa]

Call it the arrow of cancer. Like the arrow of time, it was supposed to point in one direction. Cancers grew and worsened.

But as a paper in The Journal of the American Medical Association noted last week, data from more than two decades of screening for breast and prostate cancer call that view into question. Besides finding tumors that would be lethal if left untreated, screening appears to be finding many small tumors that would not be a problem if they were left alone, undiscovered by screening. They were destined to stop growing on their own or shrink, or even, at least in the case of some breast cancers, disappear.

“The old view is that cancer is a linear process,” said Dr. Barnett Kramer, associate director for disease prevention at the National Institutes of Health. “A cell acquired a mutation, and little by little it acquired more and more mutations. Mutations are not supposed to revert spontaneously.”

So, Dr. Kramer said, the image was “an arrow that moved in one direction.” But now, he added, it is becoming increasingly clear that cancers require more than mutations to progress. They need the cooperation of surrounding cells and even, he said, “the whole organism, the person,” whose immune system or hormone levels, for example, can squelch or fuel a tumor.

Full article here:

http://www.nytimes.com/2009/10/27/health/27canc.html?_r=1&ref=science

[mzmolly]

1. Fascinating research.

The earlier a cell is in its path toward an aggressive cancer, researchers say, the more likely it is to reverse course. So, for example, cells that are early precursors of cervical cancer are likely to revert. One study found that 60 percent of precancerous cervical cells, found with Pap tests, revert to normal within a year; 90 percent revert within three years.

I hope researchers can pinpoint the mechanism involved and create interventions.

[kestrel91316]

2. Every once in a while, a cancer grows and then the body's

immune system SUDDENLY realizes it's there and says "Holy shit, WTF is THIS thing doing here??", and zaps it and it disappears.

Wish it happened more often.

ETA: I belong to a very tiny group of people who just might all happen to have circulating antibodies to malignant melanoma - we have "halo" moles. The medical journal Lancet noted in the 70's that patients with halo moles had detectible anti-melanoma antibodies. I have been curious ever since then as to whether it might actually confer protection against future melanomas, or at least deter their metastasis if they occur......

[trotsky]

4. The holy grail of cancer research...

is to figure out how to make the immune system do that for every cancer. Because as you say, for many of them, it does just that once in a while. Not nearly often enough, though.

[sharp_stick]

3. The complexity of the cell replication machinery is

nothing short of amazing. The fact that we don't all die of cancer is an amazing testament to how well we work. There are backup systems to backup systems that check the cell and make sure it's functioning properly.

[laughingliberal]

5. My favorite cancer question is in this article.

From my earliest days as an oncology nurse, I remember a doctor who said to me, "The question is not why some people get cancer but why do some people not get it?" Not nearly enough research, IMHO, going in that direction.