The journal Nature recently published results of a 5-year study examining the genetic makeup of breast cancer tumors. Researchers’ findings were stunning: six new types of breast cancer, beyond the previously known four, have been discovered. In the future, oncologists may be able to fine-tune treatment to match the genetics of a survivor’s particular cancer type.
Think of breast cancer treatment as baking brownies. Try following this recipe: “Mix sugar, butter, cocoa, eggs, salt, and flour. Bake.”
Now try this one: “Melt 1 cup butter with 2 cups sugar. Add 4 large eggs, 2/3 cup cocoa powder, ½ teaspoon salt, and 1 cup flour. Pour into a 9” x 13” pan, and bake at 350°F for 28 minutes.”
Success lies not just in the ingredients but in the details, right?
Same with cancer treatment. The more “details” your oncologist knows about your particular cancer diagnosis, the more able s/he is to identify the exact tools needed to successfully treat it.
Now, a large international study, undertaken by researchers in Canada, Great Britain, the U.S., and Norway, has taken the first steps in providing doctors with the information they need to better treat their breast cancer patients.
Researchers examined, at the genetic level, more than 2,000 breast cancer tumor specimens going back 10 years. They then matched the tumors back to their “donors” – the women who’d had them removed as part of their breast cancer treatment. Researchers determined the age and treatment protocol for each woman, and the outcome – did she recover, or have a recurrence, or die?
Based on this information, the study was able to identify 10 specific types of tumors, each responding to treatment in a different way – some very well, some not at all.
Let’s take a hypothetical case. Mary and Diane have seemingly identical diagnoses – stage II invasive ductal carcinoma, hormone-receptive, two lymph nodes involved. They receive the same treatment – surgery and chemo.
10 years later, Mary is healthy. Diane has a recurrence after 6 years, and passes away.
Now, no one knows for sure. But if those women’s oncologists could take their initial diagnosis to the next level – the genetic level – they might see that Mary’s hormone-receptive cancer is a type that’s very vulnerable to her own immune system: cancer cells are under constant attack, and losing the battle.
On the other hand, examining Diane’s cancer cells at the genetic level might show they’re a type that’s impervious to her immune system; nothing is able to stop them.
Given that knowledge, perhaps Mary’s doctors would advise her to skip chemo as an unnecessary evil; while Diane’s would ramp up her treatment, maybe adding radiation to the tumor site.
Mary might enjoy life without chemo’s harsh lasting effects; Diane might be alive.
Today, doctors have only a few biological “signposts” to help them make cancer treatment decisions. Is the cancer invasive? Is it hormone-receptive? Is it HER2-neu positive?
Five years from now, the decision tree may have more branches. If the cancer is hormone-receptive, will it respond better to Arimidex, or to tamoxifen? If it has XYZ genetic footprint and chemo is indicated, will Adriamycin be effective? How about Taxol?
Not only might doctors be able to prescribe more specific, effective treatments; they also might avoid those that show little chance of working.
While today’s Oncotype-DX test is a fairly effective predictor of chemo’s effectiveness, it’s still generalized. In future, your doctor may be able to look at your personal cancer, and determine for sure not only that chemo will be effective, but that a particular combination of drugs will be best.
Or, even better, s/he’ll be able to see that your cancer will respond very well to hormone therapy; chemo would be overkill, and do nothing but make you miserable.
It’s all in the details, right? And it’s details like these that could introduce a brave new world of breast cancer treatment.
Sifferlin, A. (2012, April 19). Breast cancer: Not one disease but 10, researchers say. Retrieved from http://healthland.time.com/2012/04/19/breast-cancer-not-one-disease-but-10-researchers-say/
Branswell, H. (2012, April 19). Study extends breast cancer subtypes from 4 to 10. Retrieved from http://www.globaltvedmonton.com/health/study+extends+breast+cancer+subtypes+from+4+to+10/6442624261/story.html
Curtis, C. E. et. al. (2012, April 18). The genomic and transcriptomic architecture of 2,000 breast tumours reveals novel subgroups. Retrieved from http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10983.html
Published On: April 21, 2012