Tailored treatments
In breast cancer, distinctions make the difference
For more than a century, solid tumors have been named after their home organ: lung cancer, kidney cancer, breast cancer. But, as scientists have come to discover, tumors with the same place of origin may be as diverse as members of a single neighborhood street gang — different in appearance and behavior, aggressiveness, and vulnerability.
Increasingly, what matters is not so much where a tumor cell begins, but how it's built: what genetic programming it carries, what markers appear on its surface, how its growth circuits are wired. Over the last 10 years, scientists have become more adept at identifying and sorting out different types and subtypes of tumors, as technological advances have made it possible to classify cancers by their genetic fingerprints, or individual patterns of gene activity in their cells. Scientists can now measure the activity of thousands of genes in a cell at once, thanks to the field of genomics (studying a complete set of genes in a cell) and its powerful tool, the "gene chip" that identifies the genetic fingerprints. The result is not only an ability to make more precise diagnoses, but to devise therapies geared to specific tumor types, targeting their idiosyncrasies and weaknesses.
The evolution from "one-size-fits-all" therapy to a more selective approach is nowhere more evident than in breast cancer. Doctors now categorize breast tumors by several criteria and treat them according to the answers of the following questions: Do they harbor inherited flaws in the genes BRCA1 or BRCA2? Do they depend on the hormone estrogen to fuel their growth? Do they proliferate by overproducing a protein called HER-2/neu?
"As research advances, breast tumors' genetic fingerprints may come to play an important role in how patients are treated," says Eric Winer, MD, director of the Breast Oncology Center in the Gillette Center for Women's Cancers at Dana-Farber. "If that approach proves successful, it may be applied to other cancers as well."
- Next: Signature differences
- Page: 1 | 2 | 3 | 4
