do metastases also seed just like primary tumors do? - 1271143

kempten
Posts:128

Hello Dr West

I have to ask a really stupid question.

Does each metastasis have the potential to behave like a primary tumor and send out microscopic cells into the periphery just like a primary tumor does?

And If this is not the case, than what is the mechanism that is preventing this from happening?

Thanks so much

Kempten

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catdander
Posts:

Hi Kempten,

There are no stupid questions here. Yours especially because I don't think there's an answer. It seems almost silly to ask what seems like such a simple question but I think it shows just how much we don't know because if I remember correctly we don't have an answer. But lets see if I'm remembering correctly.

Janine

Dr Pennell
Posts: 139

Hi Kempten, Janine is right, we don't really know the answer to that question although it is a really important one. I would say that there certainly is the possibility that metastases can seed other metastases, as certain patients who develop metastatic disease after removal of their primary cancer can continue to develop new metastases over time, which could all have come from the original tumor but could also be coming from the remaining sites. If this wasn't true, then removing the primary cancer might make sense even after the cancer metastasized elsewhere, and we know that generally this doesn't help patients live longer (at least in lung cancer).

There is still a surprising amount we don't know about how cancer metastasizes. I am curious if other faculty have a different perspective on this question.

kempten
Posts: 128

But as pointed out by ACS Scientific Council member Dan Welch, "Fewer than 8% percent of researchers mention the word 'metastasis' in their grant applications, in the context of actually working on the problem,

I just came across these statistics.
As a researcher I would be fascinated by the subject and don't understand how it can be so neglected.

Thanks
Kempten

JimC
Posts: 2753

Hi Kempten,

I think the problem isn't being investigated because with current technology it's difficult or impossible to determine where the cancer cells in a metastasis originated. Scans don't "see" individual cancer cells, only collections of them when they form tumors. At that point it's too late to discern their precise origin; all we know is that there were caner cells in the bloodstream that eventually landed in that spot. At present, if there is a complete response to treatment for stage IV lung cancer, all we can say is that there is no visible evidence of disease. We don't know if there continue to be cancer cells in the bloodstream or where they are beginning to collect until that collection is large enough to see on a scan. Perhaps in the near future someone will devise a way to "tag" or otherwise identify the cells in a metastasis so that it can be determined if they later migrate elsewhere in the body.

JimC
Forum moderator

kempten
Posts: 128

thank you Jim,

Hopefully we will have a better understanding of this very complex issue soon , because it seems to me to be so basic.
How can we try to devise new treatments if we don't even fully understand how cancer spreads.
Here's to science.
Kempten

dr. weiss
Posts: 206

Great question! I sure wish that I knew the answer :-? What we do know thus far is that not all cancer cells are the same. There are some cancer cells that are particularly resistant to chemotherapy and seem to have particular ability to copy themselves and spread; some like to call these "cancer stem cells." Understanding of the heterogeneity of cancer cells, both in terms of their ability to spread and in terms of sensitivity/resistance to treatments will help drive the development of better therapeutics.

cards7up
Posts: 636

There is nothing "basic" about cancer. One tumor can have millions of cells so this thought you're having could prove almost impossible to discern. What matters most right now for those with stage IV LC is finding treatment that works. I'd be more concerned about why some tumors respond to a tx but others may not. As Dr. Weiss is stating, sensitivity/resistance. One person has adeno which has spread to the lymphs and liver. All responds to tx except the liver, why? I'd prefer to see this study.
Take care, Judy

kempten
Posts: 128

Hi Judy,
I agree with you, that my question might not even matter that much, when you look at it from this larger perspective.
And obviously great strides have been made even without knowing the answer to my question.

It is just an overwhelming thought to me, that potentially every cancer cell that ends up to be viable and survived the onslaught from the immune system and the microenvironment in its little niche, can then go on, form a met that then also churns out millions of cancer cells and so on and so on . For some naïve reason I was hoping only the primaries had that capability. And I'm also aware that some tumors do seed and others don't. So it is this thought of never-ending cell production that overwhelms me, and of course we know about the constant mutations that make this so dam difficult to treat.
Thanks
Kempten