Wednesday, April 20, 2011

Emperor of All Maladies: Lesson Three [What is Disease?]

Mukherjee describes oncologists' difficulty "lumping the lumps."

He cites the massive differences between a condition like Hodgkin's lymphoma and pancreatic cancer- both are termed cancer, but they couldn't be much different from each other in presentation, course, and prognosis. Calling them both cancer seems naive. But, lumping them together galvanizes support to attack their common roots. (All cancers share at least one common trait- they derive from a single aberrant cell from among the many trillions that make up our bodies.)

So here we are, stuck on the horns of the dilemma between splitting conditions into separate disease classifications so they can be understood, and lumping them together so that we can summon our collective forces against common roots.

Both approaches have their merits and limitations. I propose a unification.

Let's imagine that all disease is like a mountain range with tall, jagged peaks. Let's further imagine that modern medicine approaches the mountain range of disease from above, first encountering the tips of the tallest peaks. Delving into history, these would mainly be infections, but also trauma, problems with pregnancy, and a few degenerative complaints like arthritis and gout.

In order to learn about diseases, the very first step had to be characterizing them so that, as I pointed out in an earlier post, the conditions could be measured, and then the progress of certain interventions could be assessed. Returning to Hodgkin's lymphoma- until Thomas Hodgkin classified it and gave it a name, absolutely no real progress could be made in treating the condition because medicine didn't even know it was a problem.

In my analogy, Thomas Hodgkin found the tip of the mountain peak that is Hodgkin's lymphoma.

Pancreatic cancer was characterized by many people, but one of the earliest was Giovanni Margagni.

Now let us imagine medical science learning more and more about these two conditions, uncovering ever more of their respective mountain sides. Mountain peaks get broader as one approaches their bases, and the peaks of a range merge at their bases. So too, eventually, will the peak that is Hodgkins lymphoma merge with the peak that is pancreatic cancer, and the different teams of researchers will both be exploring the inner workings and pathology of cell division. These teams would eventually be joined by the researchers of all cancers who have followed the different trajectories that unregulated cell growth can take in different tissues and from different causes.

And now, please indulge me as I sweepingly describe the history of medicine in stages:

1. Medicine has not yet found the mountain range. There is no classification of diseases, just attempts to propitiate forces deemed beyond our control.

2. The first peaks are systematically described, measured, and experimented with. With a common understanding, success in treatment can be built upon, and some conditions are improved and cured.

3. Research unearths ever deeper root causes of disease, to the point we are at today where there is significant overlap between conditions. In this way, our treatment of one condition aggravates the overlapping systems inherent in other conditions. (The first, discrete conditions that medicine tackled, like strep throat, were cured without side effects. Today, cox2 inhibitors for arthritis can cause heart disease because somewhere this far down, inflammation and heart disease overlap.)

4. The next stage of medicine will largely abandon the traditional classification for a modern conception: it will reclassify (and therefore refocus research) around the root mechanisms of cell and tissue damage. I believe this will center around the processes of organ manufacture and transplant. After all, it doesn't matter what mountain peak lead to heart disease- if you can get a brand new heart, you're cured.

I think this unifies the current debate by preserving the need to both split and lump. We just need to change what we're splitting, and reexamine how to lump.

For a glimpse at my favorite candidates for root causes of tissue damage, see Aubrey de Grey's plan for Strategically Engineered Negligible Senescence.

If you want to stare slack-jawed in mesmerized disbelief, watch Anthony Atala display a kidney that he printed with a 3-D printer.

1 comment:

Nadine Bekkouche said...

Yes!! Exactly! The organ systems that are treated as separate overlap at their bases! I would add that psychological manifestations of disease (some suggest that depression is a result of chronic inflammation) should be included in this mountain range.
But if diseases overlap, then why would the replacement of one organ system be the answer? It's like (to mess up your analogy) looking at a field that won't produce anymore and saying let's give up and get a new field as opposed to looking for different options of tilling or working with the land.
Also!! What about the natural history of peak formation? That is to say, if we get the geology right and the movement of the tectonic plates, then we should be able to affect the emerging land's topography. So instead to spiky peaks, we could have rolling hills. (The movement of tectonic plates here could reflect social planning and public health approaches that could impact the development of disease.)
Love this post! :)