This lesson seeks to tell you about how cancer impacts the body in a wide variety of ways both directly and indirectly.
We’ll discuss things like pressure atrophy, paraneoplastic syndromes, peritonitis, and many other things.
How Cancer Impacts the Body
Everyone has heard of cancer. When I say the word ‘tumor,’ be it malignant or otherwise, people immediately think of a lump or bump. That’s the generalization of cancer: lumps and bumps. But it’s oh so much more – unfortunately, much more! How cancer affects the body goes way beyond clusters of cells growing in large masses, as this lesson will explore and point out with some examples.
Physical Forces of Cancer
The lumps and bumps that may grow as a result of cancer aren’t there for looks. They can, due to their size, cause some serious physical damage. For instance, as a tumor grows larger and larger, it can cause something known as pressure atrophy, or the wasting away and destruction of tissues as a result of compressive forces.
One notable example of this is a meningioma. This is a benign tumor. You’d think the word ‘benign’ means it’s innocent. The problem is that, as it gets larger and larger, it begins to compress the brain and compress important structures and eventually leads to seizures and the death of the individual it affects.You can simulate pressure atrophy yourself by taking some Play-Doh and rolling it up into a ball.
Thereafter, begin by taking a marble and slowly increasing the downward pressure onto the ball of Play-Doh. You’ll begin to mush the dough as you do so; that’s kind of what happens in pressure atrophy.Another problem with lumps and bumps will have nothing to do with mushing of organs or tissues. A lump or bump may obstruct important things.
One easy-to-picture example is of a big mass growing inside of the intestines. This mass will block the passage of food down the GI tract, leading to a potentially life-threatening back-up of food. In severe cases, it may cause the intestines to rupture and lead to a very painful death by way of infected peritonitis, or the inflammation of the membrane that lines the abdominal cavity and many of its organs.
There are plenty of other physical problems cancer can cause, such as pressure upon bone causing pain, interfering with the range of motion of a person, and so forth. There are too many to list, and we need to move on to something known as a paraneoplastic syndrome in order to appreciate the many different types of problems cancers can cause besides anatomical or physical problems. A paraneoplastic syndrome is an often systemic, or body-wide, clinical problem resulting directly from the presence of cancer cells that is not directly associated with their actual location or their metastasis.If that sounds confusing, don’t worry, I’m here to help.
A cancer cell may cause the obstruction of the gastrointestinal tract if it’s growing inside of it, just like I mentioned before. That is not a paraneoplastic syndrome because the effect that tumor’s growth has on the body is limited to only the local area of the body where it is causing an obstruction. If the cancer spreads to another part of the GI tract and causes a new obstruction there, it’s also not a paraneoplastic syndrome because, by definition, paraneoplastic syndromes aren’t a result of cancer metastasis.However, if the tumor growing in the GI tract secretes some kind of compound, like a hormone, that spreads around the body and causes your body’s tissues, organs, immune system, or metabolism to go crazy, that is a paraneoplastic manifestation of that cancer.
Because the spread of the molecule that causes this problem is not dependent on the actual location of the cancer cells themselves, only on the type of cancer that it is, as well as what it secretes or the body’s immune response to it, it’s therefore a paraneoplastic syndrome.One real-world example of this is when a tumor known as a thymoma may release substances that mimic a compound in our body called ACTH. If there’s too much ACTH in the body, it can lead to a disease called Cushing’s syndrome.
As a further important note, ACTH is produced by the pituitary gland. If a tumor is growing in the pituitary gland itself and therefore causes oversecretion of ACTH that leads to Cushing’s disease, that is no longer considered a paraneoplastic syndrome since this disease is a direct consequence of local cancer growth in the pituitary gland itself as opposed to a cancer unrelated and far removed from this endocrine gland secreting things that cause the body to think there is a large presence of ACTH. This is important to note because many different types of local cancers can cause hormonal imbalances, such as those of the thyroid gland, adrenal glands, and so forth.So, to summarize, you can picture a paraneoplastic syndrome as follows. If you take a bag of flour and drop it on your foot, it will cause your foot a lot of pain. You can think of the lumpy bag of flour as one single tumor. The pain is a local effect on your leg and is not a paraneoplastic syndrome.
However, if that tumor, the bag of flour, starts to spew out little molecules of flour all over the room, causing everyone to choke, that is a paraneoplastic syndrome. That’s because what spread around the room was not the tumor itself, the bag of flour, but the stuff the tumor secreted, the molecules of flour out of the flour bag.
Other Effects of Cancer
Besides hormonal effects on the body and physical changes, cancers can cause many more problems in the body.
For instance, they can cause immune suppression by growing in and destroying the immune cell-producing bone marrow. This same process can also lead to anemia. Cancer can rupture important blood vessels and cause someone to bleed internally. As you can tell, the different ways by which cancer can kill are extremely varied, and we’ve only just scratched the surface. If you can imagine it, cancer can probably do that to your body from within.
Let’s hope, however, you don’t have to go through any of it. Cancer can damage your body through pressure atrophy, or the wasting away and destruction of tissues as a result of compressive forces. It can also obstruct luminal, or hollow, structures within your body. If that happens in your intestinal tract, it can lead to peritonitis, or the inflammation of the membrane that lines the abdominal cavity and many of its organs.Finally, cancer doesn’t have to exert only local or direct effects; it can use the body’s immune system or its own molecules to wreak havoc upon the entire body or far away from its own location by way of something we collectively term a paraneoplastic syndrome, which is an often systemic, or body-wide, clinical problem resulting directly from the presence of cancer cells that is not directly associated with their actual location or their metastasis.
Following this lesson, you should be able to:
- Describe how cancer can cause damage by pressure atrophy
- Define peritonitis and how it can be caused by cancer
- Explain what paraneoplastic syndrome is