For example, if someone discovers they have breast cancer or cancer in the liver or something, does that mean that they always had cancer but it was not able to be detected until they discovered they had it? Or is that something that is formed later, and wasn’t always in that person’s body?
In: Biology
it forms at some point, but it can lay dormant/not affecting the human for a while. it’s why we do screening for breast cancer, for example. it’s a build up over time
cancer is always the persons cells dividing incorrectly.
so yes? No? the cells have always been there (or grew from something that has always been there) but the division problems arent necessarily always there.
No, they didn’t always have cancer. It happened later. (Though many types of cancer don’t start generating symptoms and getting noticed until *years* after the person gets them.)
There are several different mutations that have to happen for tissue to become cancerous: it has to deactivate the gene for “only grow when needed”, deactivate the gene for “self-destruct if you notice yourself growing out of control”, activate the gene for “don’t age”, and a couple others that I forget.
The tissue itself—the breast, liver, or whatever—will have been present all along, and sometimes one of the mutations will have been there all along too (there’s a gene that famously raises women’s chances of getting breast cancer from like 5% to 50%, because it gives their breasts a head start to turning into cancer), but the other mutations happen as a result of the tissue being damaged and repairing itself incorrectly.
Your cells are always dividing in order to keep up with cell death and loss.
The DNA in your cells is also under constant bombardment from oxidation, UV rays, and toxic chemicals (alcohol etc) that end up creating DNA damage.
Most of the time this DNA damage is either a) not important b) important but gets repaired or c) so critical that it results in the death of the cell (either cause it can’t survive or because it starts expressing weird proteins which your immune system kills).
Over time, your cells accumulate more and more of this non-lethal DNA damage (this is, arguably, *why* our body ages). Most of the damage just means the cell doesn’t do it’s job as well.
Rarely however, the DNA damage can effect genes that do not kill the cell but cause serious issues. Such as controlling growth regulation.
When these mutations occur, you can end up with cells that are the trifecta, resulting in cancer: a) unregulated replication b) loss of function and c) still recognized as “normal” by your immune system (so not killed).
There are many different causes of cancer. Cancer isn’t a single disease with a single cause. Just like you might have a sore throat because of a virus (like a cold), or from yelling at concert, or from bacteria.
Cancer can occur due to chemicals you are exposed to (carcinogens) like tobacco smoke. It can be caused by radiation like sun burns leading to skin cancer. Cancer can be caused by a virus like some cervical cancers. Some cancers can be genetic meaning that the tendency is in you from your birth or due to some mutation (change in your genes) during your life (radiation can cause these mutations). It may get triggered very young (childhood cancers) or you might live your whole life with the genes that give you a greater chance of getting cancer but you never actually get cancer.
So cancers that are caused by chemicals aren’t in you your whole life. Cancers caused by radiation aren’t in you your whole life. (I’m ruling out that you were exposed to the radiation or chemicals while you were in your mother’s womb). Cancers that occur to viruses aren’t in you your whole life. Cancers that occur due to a genetic mutation (that wasn’t in your genes at birth) aren’t in you your whole life. You might be born with genes that give you a greater than average chance of getting some types of cancers. You might be born with some very rare cancers.
This is a very long way to say, “well, it depends”. Hope this helps. 🙂
its caused by intentional dna modifications.
some people did not have the cancer genes until later in their life while others were born with them.
the big suspects now are genetically modified bacteria and viruses.
Cancer happens when your cells divide at a rate that isn’t normal for them.
Typically cells divide in an orderly process–everything needs to be in place before the cell decides to divide. Your skin cells are a good example of this–they’re constantly dividing and you’re always sloughing (gross verb, sorry) dead skin cells here and there.
Cancer happens when the genes that control that process get messed up. For example, we have genes that act as the brakes in this process–they tell the cell “Do not divide, do not divide, until I tell you to divide.” We have two copies of those kinds of genes–we inherit one copy from one parent, and the other copy from the other parent.
Say you get a bad sunburn, and the UV radiation causes the DNA for one of those genes to get damaged in one of your skin cells. That skin cell keeps dividing normally, but now it only has *one* copy of that gene protecting it from becoming cancerous.
Say you get another bad sunburn, and the *other* copy of that gene gets damaged as well. Now you have *zero* copies of that gene to put their feet on the brakes, and that cell can divide as much as it wants. This is what causes cancer. This is what we call the “two-hit hypothesis.”
80-90% of the time, cancer is what we call *sporadic*. This means those cancers are caused by these genetic mutations our cells *acquire* or *accumulate* over time, with age being the biggest risk factor–the more years you have under your belt, the more opportunities for your cells to acquire those changes and cause cancer. Because of this, if you have lots of members of your family living into old age, it’s not uncommon to see sporadic cancers here and there.
About 5-10% of the time, however, cancer is caused when a person *inherits* a non-functional gene from a parent that *should* be putting its feet on the brakes, but in actuality isn’t showing up to work in the morning. These people often develop cancer at younger ages, because they only need *one* acquired genetic mutation (such as through a bad sunburn) for that cell to become cancerous. These cancers are what we would call *hereditary*.
Edit: If you have a family history of young cancers, such as breast, colon, or uterine cancer under the age of 50, you could be at a higher risk of carrying a gene that increases your lifetime risk of cancer. A genetic counselor can help you talk through your family history, what your risk may be based on family history, and the benefits and limitations of genetic testing in learning more information. The National Society of Genetic Counselors (NSGC) has a [directory](https://findageneticcounselor.nsgc.org/?reload=timezone) if anyone is interested in learning more about their cancer risk, and the ways that we can manage or even reduce that risk.
To answer your question simply: yes even technically from birth once your cells start dividing and replicating, you have cancerous cells in your body. Technically even fetuses can develop cancerous tumors (although it’s extremely rare).
Because what cancer is at its SIMPLIEST explanation, is a cell that keeps replicating beyond its predetermined number of times it can replicate, and just like how a photocopy degrades the original image over time, eventually with enough replications it’s just a useless mass sucking up energy from the rest of your body
iirc, your body makes cancer cells all the time but your immune system gets rid of them immediately. it becomes “cancer” when it gets big enough and fast enough for your immune system to not be able to get rid of it, or your immune system just didnt detect it at all
Cells have two very important functions. Make more copies of themselves, and self-destruct if they are damaged or unhealthy.
A cell becomes cancerous when the instructions for these two functions gets messed up, causing the cell to make copies of itself very quickly and never self destruct. What you end up with is a big clump of cells (called a tumor) that slowly grows and grows over time. Eventually, pieces of this tumor can break off and spread all over your body, settling down and forming new tumors wherever they landed. Eventually, if the tumors are not treated, they will start messing up all the other parts of your body that keep you alive, leading to your death.
When we do chemotherapy, we’re giving you medicine that attacks your whole body, but especially the cancer cells. That’s why it’s effective at treating cancer, but also makes you feel incredibly sick.
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