In today's world, humans are at the top of the food chain. We have almost no natural predators as there are few animals that rely on humans as prey. Pathogens are the only exception. Viruses, bacteria, parasites and other classes of infectious agents are left as natural checks upon the human race, and remain our only foreign predator (humans excluded).

Each class of pathogen is different and requires different approaches for treatment, another approach to defeat our natural enemies. We have antibiotics for bacteria, vaccines and our own immune systems for viruses, and more toxic drugs to battle parasites. But this leaves out a very large class of predator: cancer.
Cancer is a maverick. It answers to no one and responds to only the most extreme treatments. The problem with cancer is that it is us. Mutated, perverted and lethal, cancer is still essentially made from us. Thus, we will always have cancer. It is frustrating to hear people say things like:

"Why isn't there a vaccine for cancer?"

"There is so much research for cancer, why haven't they come up with a cure yet?" 

These statements assume fundamentals about cancer that are inherently problematic. No vaccine exists for cancer, because we cannot alert our immune systems to rogue cells more than they already check for. Our immune systems have already in place, from the day we were born, a complex mechanism to check proper cell function by the types of proteins being expressed on the surface of the cells. If agents of the immune system see that a cell is "rogue" than it will induce apoptosis (cell death) to prevent proliferation of this cell which could grow into cancer. There are billions upon billions of cells in our body, and only a fraction of cells in our immune systems, rogue cells slip past our immune system and cancer grows. No vaccine can prepare our immune systems for every possible cell abnormality, and therefore cancer is beyond this approach.  There are a few cancers which have viral origins (such as the HPV virus to cervical cancer) and research has generated a vaccine to prevent against infection of this virus which can cause this type of cancer. But this distinction is that the vaccine is to prevent infection of the virus, not against the cancer itself.

Secondly, there is a lot of research dedicated studying cancer. But they might as well be studying hundreds of different diseases. Each cell in our body is capable of developing cancer and thus, there are almost an infinite number of possibilities for how cancer will develop. Breast cancer, lung cancer, skin cancer, liver cancer, colon cancer, each have different symptoms, growth patterns, and different deadly implications.

Because cancer is made from our own cells, it is very hard to distinguish the good cells from cancer cells. This is why we have to resort to such toxic means to destroy them. Chemotherapy and radiation therapy are both inherently toxic and dangerous treatments to undergo. Radiation therapy localizes radiation to where the mass of cancer cells lie, in a tumor. The radiation destroys the DNA of the cells as well as causing damage to other structures of the cells. This is effective, but if cancer cells (even one) breaks off from the main tumor and spreads (via the lymph system or bloodstream) to another organ, it can create a completely new and more dangerous tumor quite easily. This is when we introduce the big guns: chemotherapy. Chemotherapy is the introduction of toxic chemicals into our bodies which target quickly dividing cells. This is the only factor that we can use to distinguish our own cells from cancer cells, and we pay a hefty price. Not only are rapidly dividing cancer cells get targeted, but also our own cells which have to be replaced by quick growing cells. Nails, hair, stomach lining, skin and blood cells all suffer as a result. Our hope is that enough of our good cells is left after the cancer is gone. If we are lucky, we can endure the toxicity and torture of chemotherapy longer than our cancer can, and that our good cells can recover after we do.

But this does not always happen, and often we succumb to cancer. Our own cells turn on us, overtake us and eventually destroy us. Because the origins of cancer are so nebulous and triggers are almost infinite, there will always be cancer in our futures. I DO believe strongly in our own abilities as well. Out of need, we will strive to develop new, better, more efficient and more effective forms of cancer treatment. We might look to simple methods (cyroablation) or more complex (gene therapy).  Cancer will not defeat us, but will urge us to develop better treatments and will push us to study our own  cells, systems  and tissues to better understand ourselves.

Our battle with cancer is an age old biological arms race. Like the cheetah and the gazelle, when one develops claws and sharp teeth for catching, the other develops lightning speed to outrun them. As soon as one advantage is given, there is a new defense to counter it. The same is true for us. We will always develop an upper hand and be driven forward by our need to maintain it. Although we may never be rid of cancer, we will develop better and better treatments and through our need, will gain an invaluable understanding of ourselves that will not only allow us to battle our own cancers, but also fight our other natural predators and counter other diseases.