Why does anyone get cancer?
March 28, 2024: Holy Thursday
A good friend believes that almost every cancer patient asks, “Why me?” That’s the wrong question. It would be just as fair to ask, “Why not me?” The right question is, “Why does anyone get cancer?” Further, “What do we think of a world in which anyone can get cancer?”
Cancer is a horror.
Tumours are parasites, eating the body from within, pseudo-organs that compete with the rest of the body for resources. Cancer wastes the body; during radiation, I lost 18 kg (40 pounds) between the disease and treatments. Tumours that press on your nerves cause agony, and those that erupt through your skin are hideously disfiguring.
Cancers kill you. When I was diagnosed, cancer had already metastasized to my lymph nodes. These nodes are junctions in a network of tubes circulating lymphatic fluid throughout the body. Tumour cells in lymph nodes can travel to other organs and establish colonies of daughter cells. New tumours grow from those colonies and destroy those organs, so your body systems fail, and you die. In my case, the primary risk is that there will be a metastasis from a lymph node in my neck to my lungs and from there to my brain. My primary tumour has survived all treatments to date. However, the treatments have so far—gratias Deo!—killed the metastases in my lymph nodes.
Cancer also induces patients to kill themselves. Cancer patients die by suicide twice as often as members of the general population (and four times as often for cancers like mine).
These deaths are utterly pointless. The parasitical plasmodium microorganisms that cause malaria kill many people, but at least the microorganisms themselves benefit from the slaughter. But unlike the malarial parasites, my tumour will not survive my death, nor will it produce offspring that might infect and kill you. Nothing benefits from cancer. Cancer is just mindless evil.
This raises a dark question: “Why is this evil—cancer—so common?” My body is a consortium of 30 trillion cells, each a living organism, many of which could live independently in the right environment. These cells have been reproducing throughout my life, replacing dead cells and adapting my body to changing environments. The body controls the reproduction of cells tightly to maintain its structural integrity. We do not want our livers to double in size or the walls of our aortas to thicken and restrict blood flow.
We generate 300 billion new cells daily. DNA replication from parent to daughter cell is highly reliable, but there is a tiny error rate. If the daughter cell with the error survives, that cell’s daughter cells will inherit this mutation, as will their daughters, and so on.
Occasionally, damage to a daughter cell will permit it to reproduce faster than it should. My tumour cells descend from a cell in the tissue that lines my throat. Am I to blame for the damage to that cell? You can reduce the chance that you will get throat cancer by not smoking, not drinking, and never having oral sex with someone infected with the human papillomavirus (HPV). (Or we could all get vaccinated for HPV, but that is another discussion.) However, you could do all those things and a cell in your throat could be damaged by something in your food or a cosmic ray. Everyone is at risk for cancer; you can and should reduce your risk, but you can never drive it to zero.
Cancer is built into the heart of multicellular life. Single-celled organisms evolved into multicellular organisms about 1.5 billion years ago. Every complex organism—including sentient life—derives from this foundational event. Think of multicellular organisms as societies, vast cooperatives of interdependent creatures. The cooperative works if every cell reproduces as much as it should and no more. Cancer occurs when that order breaks down.
So, why didn’t evolution make cellular reproduction perfect? I expect that perfect reproduction is mechanically impossible. But if cellular reproduction were perfect, we wouldn’t evolve. Evolution is about adaptation: species evolve because offspring do not perfectly replicate their parents, and mutations that increase fitness proliferate, adapting the species to the environment. To make evolution work, you want cellular reproduction that is nearly, but not quite, perfect.
Why does anyone get cancer? Because cancer is the price of multicellularity. It’s what we pay in return for our rich, sentient life.
At first glance, it may seem that I am trying to reconcile myself to the prevalence of cancer. On the contrary, the existence of natural evils like cancer is a profound problem for theists like me. The following argument lays out the problem of evil:
1. If God exists, God is omnipotent, omniscient, and morally perfect.
2. If God is morally perfect, God desires to eliminate all evil.
3. If God is omnipotent, God has the power to eliminate all evil.
4. If God is omniscient, then God knows when evil exists.
5. Evil exists.
6. If evil exists and God exists, then either God doesn’t have the power to eliminate all evil, or doesn’t know when evil exists, or doesn’t have the desire to eliminate all evil.
7. Therefore, God doesn’t exist.
I’ve just argued that mindless evil is built into the foundation of multicellular life; if so, premise 5 is true. If premises 1-4 are also valid, this argument proves that (7) God doesn’t exist.
The problem of evil is ancient. Many supposedly serious Christian writers lazily wave their hand at it and mumble something about how God’s ways are mysterious. This won’t do. We are committed to the truth. Having some answer to this powerful argument is critical.
We need to look carefully at premises 2 and 3.
Consider argument 2. God may have the desire to eliminate all evil. However, God also wanted to create a universe with free, sentient creatures. What are the constraints on the possible universes that have creatures with these properties? If God created a universe with no evil, it would be changeless in a moral sense; we would have no morally significant choices to make; time and history would not matter. If we were creatures who could not do evil, we would not be free.
Concerning 3, I do not think that God can do anything God might want. God cannot create a universe in which the circumference of a circle divided by its radius equals 6; this ratio must be 2p. Likewise, God cannot create a universe with an even prime number > 2; these examples can be multiplied indefinitely. How much do these constraints limit what God can do? They constrain the possible laws of physics in essential ways and, likewise, the possible cosmologies. My guess—this is above my paygrade—is that a universe that could include creatures with the freedom to make moral choices must be constructed over time through evolutionary processes. Evolutionary processes entail many natural evils, including cancer.
By the way, I believe entirely in premise 4: God knows everything. God experiences the suffering of all of God’s creatures. This is one meaning of Good Friday, but that is for another post.
In Judaism, there is a concept of "tsimtsum," meaning (roughly) that God withdraws or contracts Godself to make room for creation to exist. So I've long thought along similar lines to what you write about a "morally significant" universe. However, I interpret this as a (self-imposed) limitation on God's omnipotence, not as impinging on God's omnibeneficence.
I struggle, though, with keeping tsimtsum from slipping into deism. Certainly it is in tension with the active, interventionist God that I try to believe in...
The probability of each life existing at all is difficult to comprehend. Each life is the result of one sperm out of hundreds millions reaching an egg. And there have been approximately 22,000 generations of homo sapiens. And so on . . .