Archive for December, 2011
31 December 2011
The end of the year is a time for reflection and for refining our goals. For 2011 I made a goal to start a cancer Q&A blog, with an original charter to pen one article per week.
Although I love writing about cancer, and science in general, I am hereby putting my blog on hold to devote more time to research experiments in 2012. Perhaps my future path could encompass science education or science communication, but for the time being this graduate student must focus on the hurdles at hand. After all, I am a a graduate student in a research-heavy PhD program. Unfortunately this blog does not help me graduate any faster.
I am still available to research questions per request, and love to help people in endeavors scientific, be it researching questions, giving lectures, or even the occasional lab tour.
While I can only hope I have helped make a dent in the lack of science education with my ask-a-scientist blog, I have most certainly learned a lot from the process expanded my repertoire of knowledge. Good journalism and good science have a lot in common, and both require an extraordinary amount of effort to perform even the smallest task well.
Thank you for being a part of this experiment in science communication, dear reader. I wish you the best for 2012.
17 December 2011
This week’s article comes from Randal Hollis in San Diego, CA:
What kinds of cancer existed in ancient times?
I seriously love this question. It very nicely addresses a common misconception about cancer: that it is a contemporary disease.
For this I will delve into my favorite book of 2010, which happened to win the Pullitzer Prize in Nonfiction and is officially endorsed by the Cancer for Dummies blog: The Emperor of all Maladies: A Biography of Cancer by Siddhartha Mukherjee
(A book review by Yours Truly can be found here: http://ryongraf.com/2011/01/book-review-the-emperor-of-all-maladies-by-siddhartha-mukherjee/)
In 1930 an ancient papyrus scroll dated from the Old Kingdom in Egypt was translated, believed originally be the work of Imhotep, around 2625 BCE. The Edwin Smith Papyrus was an ancient combination of case-study and surgical instruction manual, and outlined two cases of a growing, spreading mass that was largely inoperable. Scientific historians believe these cases to be the first written record of cancer, over 4700 years ago! (pg. 40)
Image: The Edwin Smith Papyrus
The word “Cancer” is analogous with “Crab”, and the term was first used to describe the condition by Hippocrates around 400 BCE. “The tumor, with its clutch of swollen blood vessels around it, reminded Hippocrates of a crab dug in the sand with its legs spread in a circle.” Although few tumors actually resemble crabs, medical writers in the coming centuries added embellishments. (pg. 47)
The likelihood of ancient specimens of cancer is very small. This is in part due to the fact that most tissues where cancers arise are epithelial and soft tissues that typically decompose. Tumors of hard tissue, like osteosarcomas of the bone, are comparatively rare. In 1990 paleopathologist Arthur Aufderheide of the University of Minnesota at Duluth had the opportunity to perform necropsies on a “treasure trove” of naturally mummified bodies from a grave in the Atacama Desert (southern Peru) dating back to the Chiribaya people (AD 850-1470). In one of the specimens he discovered an osteosarcoma (bone tumor) on the upper arm of a woman that died in her mid-thirties! (pg. 43)
Mukherjee goes on to describe several cases of Egyptian mummies that do not contain tumors per se, but contain hollowed out regions of bone that were likely burrowed out by ancient tumor metastases!
These examples are by no means exhaustive, and I do not want to plagerise Mukerjee’s footwork, so I will stop there. These examples all date from before the Industrial Revolution, electricity, modern chemistry, and the nuclear age. Cancer is an old disease that has been around for a long time.
As to what kinds of cancer existed in ancient times, the records are not robust enough to make assessments of cancer incidence rates compared to today, but the records that do exist indicate that ancient people developed breast cancer, lymphomas, osteosarcomas (bone cancer), liver cancer, and other types.
It is not until our civilization that it has been remotely possible to treat cancer, much less cure any patient. That itself should be a point of pride for us modern day-ers!
3 December 2011
How will we treat the cancer of the future? Sequence a patient’s genome, and the cancer’s!
If you just let out a gasp of incredulity, that’s perfectly natural and healthy. If you don’t know what a genome is, no worries. A genome is the sum of all genes in an organism. You have about 28,000 genes in your genome. Every gene is a sequence of DNA made up of the base pairs A, T, C, and G, so a strong of DNA might read: ATGTTCGAA. If you were to store your genetic sequence in a simple text file, it would take up about 1.5 gigabytes of space!
The New York Times reports that in July of 2007 the cost of sequencing an individual’s genome was about $8.9 million. On Wednesday The Times reported that the cost of sequencing is approaching $1000.
So what’s the big deal? Your genome contains just about everything about you that can and will be determined by your genes. That includes what types of cancer you could likely develop in your lifetime. But that’s not where it stops. In a scenario only five years ago that seemed like science fiction, it might be possible in the next decade to sequence both a patient’s genome, and the genome of their cancer!
As I’ve echoed in this blog many times, cancer is not one disease, but a collection of many different diseases with overlapping etiology, outcomes, and genetic underpinnings. This makes it frustratingly hard to treat, because two cancers that appear identical under the microscope might actually respond to very different therapies.
If treating cancer is a game of oncological chess, having the cancer genome would be like knowing the next five moves of your opponent. It would be like seeing not only the boxer’s next punches, but knowing in advance where he will let his guard down. It would be like building the ship outside of the bottle.
However, the next technological caveat, as Andrew Pollack discusses in his NY Times article, is not our ability to sequence genomes, but process and analyze them. And, even if you knew where the next five punches were going to come from, would you have the tools to exploit it? Cancer genome sequencing will not be the cure by itself. But, it is a tool so powerful that we cannot yet fully comprehend its scope.
Just five years ago this scenario was distinctly in the realm of science fiction, something I might consider in 10-20 years. I never dreamt that we’d be on the cusp in 2011!