Every year, government-run agencies issue hundreds of millions of dollars in funding for cancer-related research. Scientists who’ve applied for funding and gotten their requests approved reach out and grab a hold of this money, which they use to pursue their goal of solving the riddle that is cancer. They investigate tumor-generating processes in animal models, look into how various environmental factors shape the evolution of cancer, and try to map out the many genes, receptors, and hormones that play a role in the pathogenesis of melanoma, hepatocellular carcinoma, and other cancers. Their ultimate objective is to find an effective treatment or cure for the terrible disease that is cancer.
At first glance, it may seem that these researchers have all bases covered. Upon closer inspection, however, it becomes clear that this may not be the case. Few cancer researchers look at cancer from an evolutionary perspective and ask themselves whether cancer afflicts humans who live in a natural environment.
Many recognize that cancer evolves via Darwinian selection, but few have broadened their evolutionary thinking beyond that. This arguably represents a gaping hole in modern cancer research. I don’t claim to be an expert on the molecular mechanisms of cancer; however, I do know a thing or two about evolution that I think could come in handy when it comes to elucidating why and how cancer develops, as well as what we can do to prevent and treat this disease.
The endless quest for a cure
Given that hundreds of billions of dollars and countless work hours have been put into deciphering and finding an effective treatment for cancer over the most recent decades, it’s logical to assume that we’re today a lot closer to finding a cure for breast cancer, hepatocellular carcinoma, and other cancers than we were 40 or 50 years ago. This assumption is today fairly widespread, in part because news reporters have a habit of putting out articles with titles such as: New research could revolutionize cancer care, A cure for cancer is on the horizon, and Soon, cancer may be history.
Unfortunately, such articles have little to no basis in reality. The harsh truth is that we haven’t really made that much progress towards effectively “curing” cancer. We’ve changed our screening methods and the way we manage the disorder; however, we certainly haven’t been able to annihilate it. Actually, in many parts of the world, cancer rates (as well as the rates of many other major diseases) have been on the rise (1), despite the fact that researchers have been working tirelessly to find an effective remedy for the “cancer situation”.
The average Joe probably finds it surprising that we haven’t made more progress in this area. The average Darwinian thinker, however, is probably not surprised. Darwinian science illuminates the fact that natural selection has equipped organisms such as ourselves with cancer-suppressing apparatus. These apparatus are very complex, in the sense that they involve the coordinated efforts of a variety of microbes, receptors, and immune cells. They are also very powerful; however, they are not incorruptible or immune to evolutionary mismatch.
The fact that these apparatus are extremely complex highlights the fact that they can’t be controlled with a single drug or some type of conventional medical device. A smoker who’s damaged the DNA of his lung cells and compromised his body’s ability to ward off cancerous lung cells can’t simply take a drug and expect things to work themselves out. He can certainly undergo chemotherapy, which kills cancer cells, but that won’t bring his body’s built-in defense systems up to full speed. In other words, from a Darwinian perspective, it’s not surprising that we haven’t found “a magic pill” that effectively counteracts or cures cancer.
How Darwinian science could change the trajectory of modern cancer research
Darwinian insights can help guide modern cancer research. They provide a basis for generating hypotheses and ideas and can help slim down the field of modern cancer research, which is, at present, arguably inflated. At present, a lot of money and resources are invested into cancer research projects that have no evolutionary basis and that are based on a premise that doesn’t conform to Darwinian science. By incorporating more evolutionary science into the paradigm that currently guides the workings of modern cancer research, that could change.
Not only can Darwinian theories help illuminate what happens inside of the body as cancer develops; they can help us determine what the ultimate causes of cancer are. The recognition that a human body that is matched with an environment that fits well with the human genetic make-up is much less likely to develop cancerous lesions than a body that is matched with an environment that matches poorly with the human genetic makeup is extremely powerful, in the sense that it can help us determine why cancer develops, and by implication, what we can do to prevent and treat cancer. By comparing the two bodies, we can potentially make some significant headway towards solving the riddle that is cancer.
Obviously, different types of cancers differ with respects to their etiology and distribution; however, they can all conform to the “rules of evolution”. Many evolutionary scientists have focused on antagonistic pleiotropy, reduced selection pressure, and life history theory as it relates to the development of cancer. That’s obviously something that’s important to consider up in all of this; however, I’d argue that mismatch theory is even more important. I think it’s a mistake to start by focusing on the aforementioned things without first looking into the distribution of cancer in nature and throughout evolution.
The evolution of cancer
In some ways, the evolution of cancer resembles the evolution of problematic bacteria that cause human illness. Let’s take C.diff for example, which has thousands of human deaths on its conscience. This bacterium is not able to proliferate inside the gut of someone who harbors a diverse, resilient colonic microbiota rich in acid-producing friendly bacteria. It only causes problems when it’s inside the body of someone who doesn’t possess a healthy microbiota, and hence, doesn’t possess a fully functional defense system against pathogens.
This is somewhat analogous to what happens in cancer. The fact that the incidence of cancer is very low among humans who live in a Paleolithic-type environment, in combination with the fact that a large body of evidence shows that immunocompromised individuals are more likely to develop cancer than healthy, immunocompetent folks (2, 3, 4, 5)., clearly suggests that cancer isn’t something that just happens out of the blue. It only develops and kills under certain conditions. This is not to say that all of the lives that cancer has claimed could have been prevented or that genetics don’t matter. All I’m saying is that it’s a lot more difficult for cancer cells to proliferate inside a healthy body than inside an unhealthy one.
I’d argue that we should shift some of the focus and efforts away from finding “a quick fix” or vaccine that’ll eliminate cancer and start devoting more attention to elucidating the evolutionary causes of cancer and finding ways to enhance the workings of the built-in cancer-suppressing apparatus that evolution has equipped the human body with. That won’t necessarily bring patients with late-stage cancers back to life; however, it can certainly aid our efforts to bring cancer rates down.
The bottom line
Despite searching long and hard, we have yet to find a cure for cancer. Perhaps it’s time we consider traveling into new, largely unexplored territories. Darwinian medicine won’t necessarily equip us with the tools we need to effectively cure mature cancers; however, it does provide us with a framework for understanding and preventing cancer, as well as developing better treatments for different cancers and enhancing the quality of life of cancer patients.