What Is Cancer and How Does Cancer Develop?
We’re all familiar with the idea that our bodies can fight off infection, but what you may not realize is: we have defense systems against diseases like cancer as well. We went looking for answers to the questions “What is Cancer?” and “How does cancer develop?”
In this post, Dr. Trutt explores two theories of how our cells’ defense systems break down– so we can look at what we might do to optimize them.
What is cancer?
Cancer is a collection of cells that don’t respond to the normal signals that control growth. So, if the adjacent cells are telling the cancer cell to stop multiplying, it doesn’t listen– it keeps multiplying, growing into a tumor.
How does cancer develop? That’s where it gets interesting. There are two schools of thought:
The most popular theory is the “somatic mutation theory,” which means that cancer is caused by mutations in your DNA. Since the 1950s, almost all research on cancer has been focused on that theory, and that’s what I was taught in medical school.
But back in the 1920s, a guy named Otto Warburg proposed another theory: the Metabolic theory of cancer. Warburg discovered that cancer cells gobble up sugar 50 times faster than normal cells. According to his theory, cancer is caused by a defect in the part of our cells that generates energy– the “engines” of our cells, which are called mitochondria. He believed that if the mitochondria are damaged, sometimes a cell manages to reprogram its metabolism, allowing it to generate energy outside the mitochondria– and much faster than normal cells. That gives it enough energy to keep multiplying, even at the expense of the cells around it.
Warburg was a genius, and he won the Nobel Prize. But his theory disappeared.
Watson and Crick make a splash
In 1953, Watson and Crick discovered the structure of DNA. Everyone got excited about genetics, and Warburg’s metabolic theory got swept under the rug. A few scientists and doctors remained interested in it, but the mainstream medical (and pharmaceutical) community ignored it entirely. Which is ironic, because oncologists use Warburg’s insights every day when they order PET scans on their patients. A PET scan uses radioactive sugar to look for tumors; since tumors consume so much sugar, they light up intensely on PET scans. But despite that obvious clue that Warburg was on to something, his theory about cell metabolism being at the root of cancer was ignored: everyone was focused on genetic mutations instead.
In the past decade though, the Metabolic theory has been making a comeback .
It’s certainly true that cancer cells have a variety of genetic mutations. But we also know that most cancer cells have defective mitochondria, and generate energy outside the mitochondria– using a tremendous amount of sugar in the process. So, it may be that mitochondrial damage occurs, and the cells start having trouble producing energy. That compromises your cells’ defense systems– and once your defenses are down, toxins or viruses or some other insult creates DNA mutations in your cells. In other words, the DNA mutations are there– but they may be the result of the disease, rather than the cause of it. The actual cause may be a defect in the mitochondria. In any event, I’m glad that Warburg’s metabolic theory is back in the game, because it’s giving everyone– doctors and patients– more tools to work with.
Should you care which theory is correct?
I do, because the somatic mutation theory is quite depressing.
If the somatic mutation theory (SMT) is correct, cancer is essentially inevitable. It’s also a nearly impossible puzzle to crack: despite twenty years of effort, during which tens of thousands of tumors have been genetically sequenced, we are no closer to finding any sort of reliable genetic pattern that can be used to “cure” or prevent cancer. So, the SMT essentially says that we are all doomed to get this disease, the treatment for which is incredibly toxic and costs about $10,000/ month. (And a “cure” is perpetually ten years in the future– just as soon as we sequence another ten thousand tumors… or so we’re told.)
On the other hand, if the metabolic theory is correct—or even partly correct– most cancers are preventable, and the treatment of cancer becomes a lot cheaper and a lot less toxic. So, the optimists among you will definitely want to root for the metabolic theory.
A Tale of Two Theories
The full story of the rise of the somatic mutation theory, and how the Metabolic Theory was almost lost to history, is equal parts intriguing, frustrating, and inspiring. That story has been told exceedingly well by Travis Christofferson in his book Tripping Over the Truth, which I encourage you to read for the full picture.
But for those who want an abridged version:
Every time a new cell is created in your body, you make a copy of your DNA for the new cell. Each copy of your genome (your DNA) has three billion building blocks of DNA– called “base pairs.” A group of three base pairs is called a “codon,” and each codon is a code that represents one of the twenty-one amino acids that are used to form proteins. (This page shows which codons code for which amino acid, if you’re into that sort of detail.) If you line up enough amino acids, you get a protein. So, think of a codon like a railroad car. Codons line up to form a train, and each train can be a different length or have the railroad cars in a different order. Those trains are your genes. Genes are like sentences, the instructions that tell your cells which proteins to make to keep you running in peak form.
Our bodies create around 200 billion brand new cells every day. That’s a lot of DNA to copy. If any of those base pairs is copied incorrectly, that’s called a mutation. The problem with mutations is that the affected gene might start giving faulty instructions.
So, we need a repair team in place to fix DNA mutations– and we have a very effective one. We’re able to repair about 99% of the mutations that happen during DNA replication. DNA repair is one layer of our defense against disease.
But we still miss 1% of mutations…
…and the problem is, it’s 1% of a HUGE number. We make 200 billion new cells every day. With three billion DNA base pairs per cell, that’s 600 quintillion chances to make a mistake every day, just from normal cell division. Our cells make a mistake about every 100 millionth base pair or so. That means one mistake slips through for every few new cells. If we make 200 billion new cells every day, that’s a lot of mistakes.
Luckily, most of those mutations are harmless. There is a lot of redundancy in our genes, to allow for mistakes, and most cells are short-lived and are unlikely to pass along a harmful mutation. But stem cells are a different story.
Tell me about stem cells.
Stem cells are the cells that maintain the structure of each organ, so they have the ability to differentiate into multiple cell types. That’s fantastic in my medical practice, where I use stem cells to heal problems with the lungs, the joints, many different areas of the body. But if your stem cells develop mutations, that flexibility can work against you: in a stem cell, mutated DNA could result in that cell forming a tumor.
If you prefer an even-more-abridged version, the Somatic Mutation Theory (SMT) can be distilled down to this:
Stem cells accumulate about 40 new mutations every year. The longer we live, the more mutations our stem cells acquire. According to the SMT, at some point we will get unlucky– and one of those stem cell mutation will lead to cancer.
Our risk of cancer is increasing over time. If you were born after 1960, your lifetime risk of cancer is roughly 50%. The question is, why?
If you believe in the genetic (“somatic mutation”) theory,it’s happening mainly because we are living longer. The longer you live, the more DNA mutations accumulate in your stem cells. So, if you quit smoking, you will decrease your risk of lung cancer and emphysema; your clothes will smell better, and you won’t harm the people you live with — all very good reasons to quit smoking! But there’s a catch: although anti-smoking campaigns have sharply lowered the incidence of lung cancer, they haven’t lowered the overall cancer incidence. People just get different cancers.
Think about this: according to the somatic mutation theory,
- 63% of pancreatic cancer cases,
- 73% of breast cancer cases,
- 99% of brain cancer cases, and
- 100% of prostate cancer cases
…have nothing to do with lifestyle factors. That means they are not considered preventable. They’re more or less considered to be due to “bad luck.” They’re caused either by genetic mutations, or by DNA damage that occurs as a normal part of cellular metabolism, similar to wear and tear on your car.
The Metabolic Theory doesn’t agree that cancer is essentially inevitable. According to the metabolic theory, those genetic mutations that we see in tumors are not causing cancer. Rather, they are a “side effect” of damage to the mitochondria: once the mitochondria are damaged, your cellular defenses get messed up and it becomes easier for DNA damage to occur. So, you will see a wide variety of mutations… which explains why it has been impossible for researchers to find a specific pattern to the mutations in cancerous tumors, despite having spent billions of dollars trying. According to the metabolic theory, cancer is not inevitable: if we protect the mitochondria, we can significantly lower the risk of cancer.
So besides obvious advice like “don’t smoke,” how can we proactively lower our cancer risk?
We should look at both theories to optimize our plan of action:
According to the somatic mutation theory, yes you’d want to quit smoking, but you’ll also have to find a way to address the unavoidable DNA damage and DNA mutations that arise from normal cellular processes. You have to optimize your body’s ability to deal with those, and support all of your natural, layered defense systems against disease. We’ll talk about ways you can do that in just a moment. You might also want to take a look at your particular genetic predispositions, so that you can decide if there are any interventions that might be specific to you.
What do you mean when you say “genetic predisposition?”
People like Angelina Jolie have really raised public awareness of the BRCA gene, which causes a 500% increase in your risk of breast and ovarian cancer. So, that’s often what people think about when they hear “genetic risk.” But that’s not what I’m referring to. I’m talking about dozens of mutations that are less dangerous than BRCA, but could still double or triple your risk of getting a specific cancer. Prostate cancer, as I mentioned, has no known environmental component at all. It’s caused by DNA damage and mutations that occur due to normal metabolic processes over the course of your life. However, there are still some “minor” mutations that you may be born with, which would predispose you to getting prostate cancer earlier than most men. We now have the ability to test for those mutations, so that you can decide if you want to be more vigilant, or look into ways of boosting your defenses.
The Metabolic theory has a different point of view. The Metabolic theory says that it’s all about mitochondrial function: that lifestyle choices and carcinogens can lead to altered mitochondrial function, and that some cells with damaged mitochondria figure out how to generate energy outside the mitochondria, bypassing all the normal checks-and-balances against uncontrolled growth. So you’d want to focus on protecting and optimizing mitochondrial function.
It is possible to protect mitochondrial function with diet, certain supplements, and lifestyle changes. It’s also possible to exploit the metabolic weakness of tumors: namely, that they use an inefficient metabolic pathway to make energy, and that pathway requires a LOT of sugar. This is why it’s exciting to see the Metabolic theory of cancer making a comeback: the Metabolic theory gives us more tools to fight back, and most of those tools are much less toxic.
Ok, so give us the details: what’s our plan?
Here’s where there is a certain elegance to the whole story:
Many natural interventions have been found over the years that seem to defend against the Somatic Mutation pathways, whether by supporting apoptosis, or cell-cycle arrest, or by beneficially affecting cancer stem cells. But interestingly, when we go back and look at those same interventions through the prism of the Metabolic theory, we find that they are also supporting healthy mitochondrial function. So, no matter which theory is correct, many of the same naturopathic remedies can be applied– which is comforting, because it gives us tools that we can apply right now without worrying that they will be declared “obsolete” as the pendulum swings between those two theories.