As the title says, I want to know how does cancer form and expand on the body and why is it so hard to treat sometimes.
Pd: I’m sorry if I wrote something incorrectly, english is not my first language.
In: Biology
Very simplified: your healthy cells normally have a self-destruct mechanism. When this mechanism is broken, those cells don’t get removed and start to grow into a cancer.
And why is it hard to treat: everybody’s cells are different.
**how does cancer form:**
cells become damaged and start to behave abnormally; they pass along this bad code when they divide.
**what causes cancer**
exact cause is unknown – but there are many activities that increase the likelyhood…….smoking cigarettes; too much sun exposure; consuming non-food “stuff”
**why is cancer hard to treat** (lets assume lung cancer)
cancer is usually attached to the rest of the body so you have cancer tissue connected to healthy lung tissue…..this means removing the cancer damages the lung just by removing it. treating the cancer cells usually means damaging surrounding cells.
your cancer is not 100% identical to my cancer. what treatments work for me might have little impact for you
some treatments might damage other aspects of your general health (chemotherapy is very hard for lots of patients)
This is my layman’s knowledge, I’m sure there are professionals that can answer better. But:
Your cells have instructions for how much they should multiply and where. Sometimes there are mutations that make those instructions corrupt, so they’ll continue multiplying and create things like tumors. They also might do things that those cells don’t normally do. In worst case scenarios, they expand into different parts of your body making them especially resistant to treatment.
The really difficult thing for people to grasp is that random mutations happen all the time. There are so many cells, and so many replications, that just from the huge numbers you’ll get a few defects. The vast majority of defects just mean that the new cell dies, but some of those defects are still viable, like a new mole growing. The body’s immune system will also hunt out abnormalities and treat them as invaders, so there are actually a decent amount of cancers that people develop in their life that are just removed on their own.
But in those great amounts of numbers, sometimes there’s a mutation that still passes as normal, so the immune system doesn’t get rid of it, and it starts manipulating the resources around it.
Some of these we may be lucky enough to just cut off, like melanoma. But if there are any in vital organs, then they need more precise methods like chemicals and radiation.
And the cells are still very similar to your original body, so the radiation and chemical treatments will still do a lot of damage to your body, but hopefully it will do more damage to the cancer and eliminate it.
MSc. Biomed here. 🙂 Used to do some cancer research during my internships too.
You already got some explanations here but will toss in my own regardless:
Cancer is a mix of a few things going wrong in the same cell. It’s never one thing, hence why there are pre-cancerous cells and cancer genes that don’t indicate active cancer, but much higher cancer risk (less things need to go wrong next, so cancer is much more likely). Basically these things going wrong are:
* Uncontrolled growth. Usually this is an activating mutation for a signaling pathway in the cell.
* Diminished or blocked self-destruction. Cells that are damaged or irregular will either try to moderate and repair the damage, or if it is too severe, kill themselves to not endanger the body. Cancer cells need this last part to be turned off.
* Diminished or blocked self-regulation. Similar to the above point, cells generally have controls for their pathways. If something is extremely high, there’s usually something slowing it down to keep it in check. These also need to be disrupted, and some are so important/common to stopping uncontrolled growth they are literally known as tumor suppressor genes.
The specifics depend on the cancer, but there’s pretty common trends, and a lot of pathways or specific mutations that are commonly observed among different cancer forms.
So cancer are cells that don’t want to die.
Under normal circumstances cells die after a while. That’s how they work. However sometimes they arbitrary decide to stop hearing the body, and go amok. This causes them to multiple nonstop. The body normally can take care of it. It has multiple specialists for this job. In fact, this job is a common occurrence in your body. A healthy body neutralises multiple cancer cells throughout it’s life. The problem arises when their numbers increase a lot, or when they affect critical organs.
Cancer is difficult to treat because it’s made up of you. It’s not an different organism. Your cancer cells are essentially your cells. As such, developing a drug that kills cancer cells without hurting your good cells is difficult.
Due to their high respawn rate, even a single can wreck havoc on a weakened body. Thus the best way to kill cancer is by going full ala fever mode. Deal immense damage on your body HOPING the infection will die before the body does.
Ps a more, non eli5 reason as to why cancer cells forms, well when cells replicate, they essentially have their DNA copies. However, that is not perfect. Sometimes DNA is copied with some errors. These errors lead to cancer AND aging. Slightly off topic, but aging is probably caused by the shortening of telomeres. Telomeres are 2 small spots on the end of chromosomes. Like DNA, telomeres get reduced in every cell replication. Also fun fact, whales traditionally don’t get cancer. Due to their huge size, cancer needs to grow exceptionally large to cause significant damage. In fact they need to grow so big, that by that time, the cancer themselves have formed cancer on their own.
Sharks are also another species known for their, let’s say immunity to cancer. Crocodiles, although not known for their immunity to cancer, can’t really die of old age. Like, not the same we die of old age.
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