An Undead City Under Siege
The fight for survival against cancer is an intense battle, one that is more exciting than any movie. This is what happens when your body is under siege:
The Elimination Phase It starts with a single corrupted cell that is unable to repair its genetic code and begins to rapidly multiply. Over a few weeks, the corrupted cell turns into dozens, hundreds, and thousands of mutated cells that form a tiny tumor. The tumor needs resources to survive, and a few cells unlock a mutation that allows them to order the growth of new blood vessels. This causes damage to the neighboring healthy cells, which attracts the attention of the immune system.
The Attack Phase The first responders of the immune system, macrophages and natural killer cells, go to work killing and eating tumor cells. Dendritic cells collect samples of dead tumor cells, and activate the heavy weapons of the immune system: helper and killer T cells. These specialized super weapons have a library listing every bad thing that could enter the body, and they know what to look for.
The Siege Phase The T cells block the growth of new blood vessels, which starves thousands of tumor cells and puts an end to their growth. With no way to hide from the carnage, the tumor collapses as hundreds of thousands of tumor cells are massacred. The macrophages then clean up and consume the carcasses, and order healthy tissue to regenerate.
In the end, your body has successfully crushed the illegal Tumor Town without mercy. You will never know about this fight or how many times this has happened inside your body. Except, in this case something did not go as planned. The Equilibrium Phase: Unfortunately, natural selection spoils your victory. By doing its best to destroy the tumor, your immune system accidentally selects the fittest tumor cells. Remember, the tumor consists of different lineages that keep growing and keep mutating. Most of these are eradicated, but just a few are more resilient. One cell survives - it comes from the fittest tumor lineage and was just a bit better at surviving the massacre than anyone else. It decides to do it all over again, but better this time. This tumor cell is much stronger than any of the thousands that were killed; maybe it is better at hiding, or fighting back. Maybe it grows faster or is better at stealing resources. Maybe it can survive with much less oxygen. And so it all begins again; it’s like the surviving rebels that started Tumor Town have learned their lessons. Now they know the law better and how to break it, what permits help them, how to avoid the police. And so the surviving tumor cell makes thousands of copies that mutate and form new lineages, until once again a tumor has grown, made up from more resilient cells. The immune system does not care though, and this time it even has experience - instead of starting with police, swat teams go right in to tear Tumor Town down, killing its inhabitants without mercy. But once again they don’t get everyone - one of them survives: a fitter tumor Cell from an already fitter lineage. This time it gets a cheap suit and studies the building code, pretending to be a lawyer to start Tumor Town all over again. This struggle now repeats a few times, each time the rebels learn a bit more about how to avoid the law. If at any point, the immune system gets all of the tumor cells, the story ends. But in this case, it doesn’t. Finally, a tumor cell changes in a way that makes it properly dangerous, cancer - the type that kills people. How? Immune cells have an off switch that deactivates them before they can attack - which in principle is a good idea. The immune system is extremely dangerous and in many cases it needs to be shut down, like around your central nervous system. But this off switch can be exploited. The mutated tumor cell finds a way to switch the immune system off by targeting inhibitor receptors on anti-cancer cells. Inhibitor receptors stop immune cells from, well, killing. This cell is the now powerful founder of a new lineage of cancer cells and mass produces thousands of new copies that once again change and mutate further, building yet another Tumor Town. The Escape Phase: The new cancer cells have become immune to the immune system and everything is different this time. Tumor Town has been rebuilt, even uglier and stranger than before, but now the cancer city council has forged all sorts of permits. As building inspectors come to shut down construction, they get confused. Stunned they wander off, unable to order the destruction of the sprawling buildings. Police try to enter the illegal city to arrest the builders and execute inhabitants - but this time Tumor Town has erected its own roadblocks that keep the law from entering. Confused officers stand around helplessly. As Tumor Town slowly envelops the former Brooklyn and more and more civilians die, T Cell swat teams arrive to end this travesty. But things got worse - new lineages of Tumor Town officials have started to forge court documents that order police to shoot at the Swat teams. What the cancer cells are doing at this point is actively shutting down immune defenses by sending corrupt signals. The now malignant tumor is no longer a pushover and has begun creating the Cancer Microenvironment; a sort of borderland that is hard to cross. All avenues of attack have been shut down and uncontrollable growth is the consequence. This is a dangerous tumor. Cells that are strong and able to fight, push the immune system back and expand further. If more mutations happen, then some of the cancer cells will begin to explore the world and expand into other tissues, to build new towns. And this is exactly what makes cancer so harmful: it is taking up space and stealing so many nutrients that the true self has no room to function anymore. If this goes on for too long, organs will shut down. But this tactic is a dead end. The more successful cancer gets, the more damage it does to its world. When the body dies, the cancer dies too. It truly is a game without winners.
Except, humanity is planning to win this game. At this moment hundreds of thousands of scientists are working on new and better ways of killing cancer, to destroy and burn down Tumor Towns for good. In recent years immunotherapy has made enormous progress – it is a relatively new therapy in which the individual’s own immune cells are modified to kill cancer better than any medicine can do. It’s like giving the building inspectors machine guns and flamethrowers.
But this is a story for another time – for now cancer is a battleground – but if human ingenuity is to be trusted, then one day, maybe in the not too distant future, we will eradicate it once and for all.
This video was made possible in part by direct viewer support and in part through a grant by Gates Ventures. Thanks a lot for their support! Please check out our source document for more background and in-depth information!