Why haven't we cured it yet?

Dec 05 2010 Published by under Medicine

I was watching one of the 24-hour news stations last night (no, not that one) and saw a breast cancer activist wondering why we don't devote  resources to an all-out fight to cure breast cancer as we did with polio, leading to its eradication in the US.  I often hear questions like this: if we can (send a man to the moon, wipe out polio, etc) then why can't we cure cancer?

It's a good question, in context.  When one of the diseases you care most about is still out there, while others are on the wane, it can add to fear and to frustration.  I don't wish to minimize the political choices behind research funding, but there are good biological explanations for why some diseases are "wiped out" while others still plague us.

Illnesses are caused by a variety of problems, some internal, some external, some unknown.   In the history of medicine and public health, we've only been able to eradicate a single human disease.  Smallpox was ideal in this sense.  Humans are the only natural host, and transmission was usually from person to person---there was no reservoir for the disease other than people.  In theory, then, all it would take is immunization of most humans to eradicate the disease in nature, and that's what was done.  Near the end of the pandemic, teams would travel to outbreaks vaccinating the people within the outbreak area, and in surrounding areas to contain the spread.  This way there was less need to re-vaccinate entire populations.

Polio is a little more difficult.   It only infects humans but the virus is transmitted though fecal contamination of water and sometimes from person to person via oral secretions.   One infected person and a poor water treatment system can lead to continued spread.  This meant that to eradicate polio in the US, a massive vaccination program was needed, one which began with the development of polio vaccines after WWII and essentially ended in the late 1970s when polio was no longer transmitted in the US.  As Maryn McKenna documents in Beating Back the Devil, the eradication campaign had a rocky start, with an early batch problem leading to transmission of polio in some areas.  The fact that millions still clamored for the vaccine shows how much polio was (rightly) feared.  The eventual success of vaccination saved millions from paralysis, illness, and fear.   In parts of the world where natural, economic, and military disasters are most prevalent, polio is still a problem.

Polio is a simple disease---one virus, one host, an effective vaccine---and still it's out there (although not in the US).  Cancer is so much more.  The term "breast cancer" refers to many different diseases, all of which cause abnormal growth of breast cells.  The fight against breast cancer requires improved prevention, early detection, and treatment of the disease at all stages.  And we have been improving, with death rates from many cancers decreasing.   But the disease(s) have many causes, some of which are not amenable to change.  You cannot change a family history of breast cancer.   Unlike lung cancer, there aren't a lot of strong environmental risks (such as cigarette smoking) that can be modified.  We are largely stuck with early detection and good treatment.   Breast cancers caught early can often lead to surgical cure, but our screening methods are imperfect and likely always will be.  There is no perfect test that finds all breast cancers but also avoids erroneous diagnoses that lead to unnecessary tests and treatments.  And there is no guarantee that a cancer found early will be cured---only probabilities.

Perhaps thinking of the "fight against cancer" as a win-lose battle is not all that productive.  Human health and disease is complex and there are rarely simple answers.  The simplest answers---improving economic and social justice---are often the hardest to achieve.  But that doesn't mean we can't try.

8 responses so far

  • Zuska says:

    This post hits home hard with me, as I have a close relative fighting breast cancer right now. A clean bill of health just six months or so before the discovery of widespread stage IV disease. Thank you for writing this. It needs to be said and heard, many times over.

  • Very nice post, bro. Diseases caused by microorganisms we have the chance to eradicate, because we can target therapies to unique features of the microorganism physiology that don't exist for the human host. Diseases that are derangements of normal human physiology, such as cancer, heart disease, lung disease, autoimmune disorders, and on and on and on, are infinitely more difficult to treat. This is because we need therapies that that interfere with the deranged aspects of human physiology without disturbing normal human physiology. Very, very, difficult issue, and in some cases likely intractable.

    • daedalus2u says:

      CPP, most of those are not intractable, they do get better with more nitric oxide ;). But you are right, you have to administer the NO without disturbing the rest of physiology which is quite tricky unless you know how to do it. Then it is easy ;).

  • daedalus2u says:

    The problem is that for many diseases a “war fighting” paradigm is not appropriate and won't work. It worked against smallpox for the reasons you mention, it is a single disease, with a single host, with a treatment that is extremely effective (vaccination) and which provides near life-long protection.

    Wars are fought at the bottom by soldiers following orders from the top. If those at the top don't know what to order those at the bottom to do, a war fighting control paradigm won't work and can't work.

    There are problems that a war-type solution could work for, for example hunger. We know how to solve the problem of hunger, give hungry people food to eat. The problem is that people at the top don't derive enough profit/power/kudos from feeding people at the bottom. Education is another problem that could be fixed by a war-type solution, but again, those at the top don't gain enough profit/power/kudos from educating those at the bottom.

    So instead of applying war-type solutions to problems that could be fixed by war-type solutions, war-type solutions are applied to problems that wars will never fix, the war on drugs for example. The reason a war-type solution is being applied to the problem of drugs is because the leaders do get enough profit/power/kudos from having the people at the bottom fight the war on drugs, even if the war on drugs will never be successful.

    It is the same with all wars. They are fought to bring profit/power/kudos to those at the top. It is the war profiteers who drive war-type solutions to problems. It is the process of fighting the war that brings the profit/power/kudos to the war profiteers, so fighting wars that can be won and the war-type approach can be abandoned will always be rare.

  • Dianne says:

    We didn't cure polio. We just know how to prevent it. If someone actually gets polio, the treatment is supportive. And thanks to the anti-vaccination movement, we could be seeing more and more cases...

    But back to the original question: Curing cancer isn't like curing polio (even if we had). It's more like curing infectious disease. Curing breast cancer isn't like curing polio. It's more like curing viral illness. Curing hormone receptor positive breast cancer isn't like curing polio. It's like curing all DNA viruses...You get where I'm going with this, right? Cancer isn't a single disease. It's more like a final common pathway and lots of thinks can go wrong to push a cell down that pathway. Details like which cell went wrong and how exactly it went wrong are important to knowing what the best approach is. A single common treatment is fantasy and may always be.

    Finally, we can, under some circumstances, cure breast cancer. In 2002, the five year survival was 90%. Some patients with stage I-III disease will recur. But most won't. There is no Cure for Cancer, but there are cures for some cancers and, with continued work, that number will expand.

  • Dianne says:

    Something went wrong with the link that was supposed to be in the above post. Here it is:

  • JJM says:

    I believe polio also affects chimpanzees (I don't know about other primates).

  • dmonfan says:

    Great and current article on this subject by Malcolm Gladwell