Are all the different cancers really that different or is it all just cancer and we just specify where it formed?
In: Biology
If I’m not mistaken…We don’t even really know what cancer (really) is or what causes it. So, it could all be the same thing and we just don’t know enough to find the connection between all of them. OR They could all be completely separate different diseases that are caused by completely separate different things. Which is now the single most terrifying thought I’ve ever had.
So to ELI5, cancer is your body’s cells that were once good but have now turned bad. Those bad cells can turn at any moment, anywhere in the body. Depending on the where in the body those cells turned bad, that will determine the type of cancer a person gets. Your body also has super hero cells to fight the bad cells, but sometimes those bad cells are too strong for the super hero cells and those super hero cells need help. Much like in Star Wars, when Luke is trying to destroy the Death Star and then Han shows up with the Millennium Falcon to help. It’s that help we hope will lead to the destruction of the Death Star (one’s cancer).
Okay…
Read a few comments didn’t find the correct answer..
I am a med student myself.
Our Tissues are made of layers of cells…
Each layer with different type of cell …
For Example taking a three layer tissue..
With different cells in all three
Cancer – Uncontrolled Proliferation (multiplication) of cells
Now Cells of any one (or all) can become cancer cells..
And then your disease is classified according to that (i.e Sarcoma, Adenoma etc..where -oma means cancer)
Now further it is classified on the basis if it is confined to that tissue only or it is spreading to other parts of the body (called metastasis then termed as Carcinoma ). Also there is a third category where we check if it is invasive or not , meaning if it invades into blood vessels and/or surrounding tissues.
If you’re interested in this subject, I really like the treatment by Siddhartha Mukherjee in the “Emperor of All Maladies,” as you’ll get a sense of how understanding of this developed. Originally, it was hoped that cancer was one disease caused by a virus or from some other cause. Unfortunately, this turned out to not be quite right, although cancers can be caused by viruses (HPV for example). Cancers share one common feature: DNA mutation. What this means is that the mutation causes cells to behave improperly, with things like tumor suppressor genes turned off (uncontrolled replication, as other commenters have mentioned). While there are common mutations in many types of cancer, there is also a diversity of pathways that result in cancer. There can be very common genes that are mutated (BRCA2 is a classic example in breast cancer), but overall, this is very complicated unfortunately, which is why some treatments are common, but all treatments don’t work against all types of cancer. People with one defective copy of a gene at birth can be more susceptible because they have no backup if the other copy also gets mutated.
Tumors are actually named by the cells that are forming. A common example is a Hematoma medical term for a bruise Hemat meaning blood oma meaning a collection of cells .. another common example is Carcinoma Carcin means lung. But there are types of Cancer that can form outside where the cells are normally found
With the caveat that its been nearly 20 years since I’ve worked as a cancer researcher, this is what I learned:
YES all cancers are different. But they follow patterns of behavior that let us have a good guess as to how aggressive they will be and what drugs will work against them. And knowing what kind of cell the cancer started out as can give us good clues.
Every cell in your body has a job to do and it has a special shape to let it do its job and special proteins that it makes to let itself do its job. Its important that every cell stay in place and do Only the one job it is supposed to do. Nerves are nerve shaped and send electric signals, pancreas cells are round and secrete insulin, etc. And the cells all constantly send chemical signals to each other that say “stay alive, stay in place, stay the right shape and size, only do your own job, and DO NOT GROW AND DIVIDE to make more cells like you unless directed. Cells that obey these commands are ‘differentiated’.
Some cells are ‘allowed’ to divide: like the cells in a growing embryo, or the cells in your bone marrow that make fresh blood for your body, or the cells near a wound that is in the process of healing.
If you take a cell from one organ and stick it into another, it will fail to receive the correct “stay alive” signal and it will commit suicide (apotosis). Also, there are immune cells wandering the body, looking for and executing rogue ‘pre-cancerous’ cells. And there are other failsafes too. Your whole body is constantly policing every cell, to look for dangerous cells that are getting out of line.
But if these fail-safes don’t work, and an individual cell starts to lose its special shape, to divide out of control and make millions of new cells like itself, that is cancer.
Cancer starts growing wherever the original mutant cell was. The lump of millions of overgrown mutant cells is called a tumor.
The millions of decendants of the original cancer cell often develop new mutations that allow them to leave the original tumor and slip into the bloodstream and migrate to new parts of the body to make new tumors.
The way a cell turns cancerous is that it has many random bits of damage its DNA that happen to ruin its ability to recognize and respond to the chemical signals that tell it to behave. There are multiple layers of anti-cancer back up systems for each type of cell, so it takes about six or more different mutations to turn a healthy cell into cancer.
A pre-cancerous cell divides and grows and makes decendants. Some of those cells gain new mutations that make them more dangerous. And some of their offspring have even more dangerous mutations.
Each mutation lets the cell gain a new bad behavior until it has enough bad behaviors to grow into a large mass. Some of these bad behaviors: grow too fast, start ordering nearby blood vessels to give more blood to me, learn how to move from one place to another in the body, learn how to hide from cells that detect pre-cancerous cells, learn how to ignore when other cells tell me that I’m growing in the wrong place.
Each type of cell in the body has different types of signals and controls that keep its cells from becoming cancer, so the path to turning into cancer is different for every type of cell.
Every cancer is as unique as the random mutations that created it, but cancer cells still have some of the traits of whatever original kind of cell they started out as. We have found certain medicines that work well for cancers that started out in certain regions of the body. There are special drugs for lung cancer and breast cancer and bone marrow cancer.
We can now do tests that give us a lot of very good information on what type of cell the cancer started as and even what types of mutations it has. This tells what bad behaviors it is likely to have and what drugs will thwart it.
Cancer describes the class of diseases caused by a multitude of different mutations that cause cells to grow uncontrolled and without normal limitations. Most cancers are caused by more than one mutation, since your cells actually have quite a few protective and diagnostic measures to prevent cancer, or at least kill themselves if they become cancerous. You need mutations in growth genes and cancer control genes to get cancer (this is a broad generalization).
Beyond these basic factors, every cancer is different. The mutations that cause a specific cancer might be drastically different from a another cancer, even in two people with the same type of cancer.
Because the cells responsible are your own, they can be affected by all sorts of aspects of your biology, such as your diet, metabolism, activity, etc. Where the cancer formed is important because different types of cells have different abilities, and certain parts of your body are more important. Kidney cancer? You might just remove the affected kidney. Brain cancer? Can’t just remove the brain.
Tl;dr: cancers are extremely diverse in both their causes, effects, and susceptibilities to treatments. Cancer is more a class of diseases that share some general characteristics (just like viral or bacterial infections have general similarities and treatments) than a specific disease. This is why the “cure for cancer” is such a big deal; it’s kinda like searching for the “universal vaccine” or “ubiquitous antibiotic.”
Love to add my two cents. I have always liked to describe cancer as an evolutionary process on a rapid scale. You can think of the cells like an individual organism and whole cancer like an ecosystem. Because one of the main distinctions in cancer is genetic instability due to rapid proliferation you begin to see a “survival of the fittest” emerge. In later stages, it’s not hard to believe that you start getting different cancers that develop traits that make them more adapted to their niche. This process is shaped by all the unique environmental stress which can change from person to person and organ to organ.
Furthermore, even in each individual tumor, there are subpopulations. Previously we would take a whole-tumor mass and say it’s one phenotype. I believe this would be like taking all the biomass in the woods and say the only thing living there would be trees. It fails to incorporate the complexities and interactions of the other organisms. Pretty recently we have had the technology now to isolate the populations and characterize them leading to a better understanding of the complexities of cancer.
One of the many ways that cancers behave differently, and can respond to different treatments, can be due to an inherited genetic mutation. Even patients with the same type of cancer can have drastically different responses to treatment if the cancer is based on different mutations. A great example is the BRCA mutation, which affects much more than breast cancer, which it is commonly known for.
For example, I work on clinical trials for prostate cancer. I test patients with the same “type” (stage, location, etc) of prostate cancer for genetic mutations, and provide treatment specific to those mutations.
Cancer is when 2 things in a cell break. One is the part that controls growth, that part has to break in a way that makes the growth go out of control. The other is the part that controls something called apoptosis, which is a process where a cell that is malfunctioning will actually kill itself to protect the organism as a whole. When both of these things break, the cell multiplies out of control and won’t kill itself, and this is cancer. However, since this can happen in almost any cell in your body, and there are a myriad of ways those processes can break, different cancers have wildly different characteristics and may need wildly different treatments to be dealt with. Cancer cells that started off as bone marrow tissue are going to behave very different from cancers that started off as lung tissue.
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