What is the Future of Sequencing a Patient's Genome for Precision Medical Care?

Quora
The best answer to any question.
July 19 2013 3:40 PM

What is the Future of Sequencing a Patient's Genome for Precision Medical Care?

154389947
Back in 2003, Nobel Prize laureate James D. Watson announced that a six-country consortium has successfully drawn up a complete map of the human genome, completing one of the most ambitious scientific projects ever and offering a major opportunity for medical advances.

Photo by Robyn Beck/AFP/Getty Images

This question originally appeared on Quora.

Answer by Jae Won Joh, M.D.:

Genome sequencing will help us create narrower subcategories of disease.

Advertisement

Please note that I do not use the word "individualized" to describe this process, as I think its use essentially creates a misconception. I'll explain by taking you through a simplified look at the progression of medicine through the lens of cancer.

Many years ago: We first encounter cancer; we have no idea what on earth it is. We may see growths or maybe even cut into a few, but it is an astonishingly foreign disease entity because we don't understand the science behind it—all we know is that this "tumor" is often incompatible with life, and therefore needs to be treated somehow.

jae1

With advances in microscopic technology and cell biology, we eventually arrive at the notion of classifying tumors as malignant vs. benign. Boom. First data point. Patients are now sorted into one of these two categories, allowing treatment to be focused onto the malignant lesions.

jae2

We then analyze retrospective data and pathologists come up with tumor grading and tumor staging to help calculate the risk index of future patients' tumors. Boom. Second and third data points help us significantly refine, as we realize that malignant vs. benign isn't as cut-and-dry as we'd thought. Patients are now sorted into one of over a dozen categories depending on their tumor's grade and stage, allowing the aggressiveness of treatment to be scaled to the severity of the lesion.

jae3

And so it has gone on. If we look at breast cancer, discovery that some tumors overexpress HER2+/neu added a data point, allowing patients to be categorized further into those who may benefit from treatment with Trastuzumab. Other cancers have their specific markers and/or drugs as well.

What we can conclude from this march of progress, then, is that sequencing a patient's genome (if it can be made cost-effective, widespread, and easily analyzable) may allow us to further refine our subcategories of disease, helping us put people into smaller and smaller "buckets", as it were.

However, we have already reached a point where it is simply not cost-efficient to thoroughly investigate a specialized "best" cure for every single subcategory of a given disease. This is why I eschew use of the word "individualized" when it comes to medicine--it's simply not possible.

Sometimes, it's a money issue, and this is where people's emotions and/or entitlement can clash with the practical constraints of statistical/capitalistic reality. Sure, we can all agree that it's tragic when a young child develops a subcategory of cancer that occurs in 1 in every 300,000 people, but demanding that companies divert R&D from developing drugs for subcategories that occur in 1 in 50,000 people to research the rarer form is simply not reasonable. In short, the bigger buckets capture more research funds.

Much of the time, though, it's just not necessary to do this; who cares what specific strain of rhinovirus gave you the common cold, if generic supportive care will get you better? If one treatment will work for a large bucket, why bother drilling down?

And for new discoveries, it's simply a time issue, and this is natural. In medicine, the ability to diagnose has usually come before the ability to treat as R&D plays catch-up to new discoveries.

So while genomic sequencing is really, really cool, and we will continue to use it in more and more ways, we have to remember that there are constraints on what this new data can practically achieve. Just because we can test for something does not automatically make the test useful or clinically worthwhile...

More questions on medicine and health care:

TODAY IN SLATE

Culturebox

The Ebola Story

How our minds build narratives out of disaster.

The Budget Disaster That Completely Sabotaged the WHO’s Response to Ebola

PowerPoint Is the Worst, and Now It’s the Latest Way to Hack Into Your Computer

The Shooting Tragedies That Forged Canada’s Gun Politics

A Highly Unscientific Ranking of Crazy-Old German Beers

Education

Welcome to 13th Grade!

Some high schools are offering a fifth year. That’s a great idea.

Culturebox

The Actual World

“Mount Thoreau” and the naming of things in the wilderness.

Want Kids to Delay Sex? Let Planned Parenthood Teach Them Sex Ed.

Would You Trust Walmart to Provide Your Health Care? (You Should.)

  News & Politics
Politics
Oct. 22 2014 9:42 PM Landslide Landrieu Can the Louisiana Democrat use the powers of incumbency to save herself one more time?
  Business
Continuously Operating
Oct. 22 2014 2:38 PM Crack Open an Old One A highly unscientific evaluation of Germany’s oldest breweries.
  Life
Dear Prudence
Oct. 23 2014 6:00 AM Monster Kids from poorer neighborhoods keep coming to trick-or-treat in mine. Do I have to give them candy?
  Double X
The XX Factor
Oct. 23 2014 8:51 AM The Male-Dominated Culture of Business in Tech Is Not Great for Women
  Slate Plus
Tv Club
Oct. 22 2014 5:27 PM The Slate Walking Dead Podcast A spoiler-filled discussion of Episodes 1 and 2.
  Arts
Brow Beat
Oct. 23 2014 9:00 AM Exclusive Premiere: Key & Peele Imagines the Dark Side of the Make-A-Wish Program
  Technology
Future Tense
Oct. 22 2014 5:33 PM One More Reason Not to Use PowerPoint: It’s The Gateway for a Serious Windows Vulnerability
  Health & Science
Bad Astronomy
Oct. 23 2014 7:30 AM Our Solar System and Galaxy … Seen by an Astronaut
  Sports
Sports Nut
Oct. 20 2014 5:09 PM Keepaway, on Three. Ready—Break! On his record-breaking touchdown pass, Peyton Manning couldn’t even leave the celebration to chance.