COLUMBUS, Ohio – Recent research is changing the way oncologists view and treat breast cancer, says Ohio State University breast-cancer expert Dr. Charles Shapiro.
Oncologists once assumed that breast cancer was one disease best treated with chemotherapy.
But studies done over the past few years indicate that there are at least five distinct molecular subtypes of breast cancer, each with varying outcomes based on specific gene profiles, said Shapiro, director of breast medical oncology at the Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James).
“The recognition of these subsets is important because it will shape and define the way we think of breast cancer,” Shapiro said. “This is an example of personalized medicine, in which doctors can predict how a particular breast cancer will respond to different treatments based on molecular subtypes.”
A better understanding of the molecular subtypes of breast cancer should improve doctors’ ability to predict patient outcomes, help identify the most effective treatments for individuals and lead to new drug targets, he said.
“Breast-cancer cells may look the same under a microscope, but they have very different behaviors and very different responses to treatment,” Shapiro said.
OSUCCC – James researchers continue testing novel agents, trying to improve breast cancer treatment. Shapiro oversees the Stefanie Spielman Breast Cancer Tissue Archive, which holds tissue samples from more than 2,000 breast-cancer patients from central Ohio. The samples will be used to evaluate genetic and molecular changes of potential importance to breast cancer.
“In the past, chemotherapy was considered a ‘one-size-fits-all’ treatment for breast cancer. And while chemotherapy is useful in breast cancer, it is often not selective enough. Research tells us that certain types of breast cancer, based on their level of gene expression, are more or less responsive to chemotherapy,” Shapiro said.
Certain molecules that are present on the breast-cancer cell help define the subsets and can be useful in guiding therapy, he said. Each subset responds to treatment differently, based on distinct gene profiles, Shapiro said.
“The more we can target therapies to the individual characteristics of the cancer cells, the more effective our therapies will be,” Shapiro said. “And these targeted therapies have the potential of minimizing side effects for normal tissues.”
For example, estrogen-receptor-positive breast cancer relies on estrogen for its growth and well-being, he said. At least two different forms of estrogen-receptor-positive breast cancer have different prognoses, based on their gene-expression level.
“The Herceptin story is a major advance in treating women with a specific type of protein on the breast-cancer cell,” Shapiro said. “Herceptin works incredibly well, but it works only in the subset that over-expresses the HER2 protein.”
But Herceptin is only the beginning, he said.
“The recognition of these subsets will guide the development of future therapies based on an understanding of what drives the breast-cancer engine in each subset to grow, proliferate and avoid death,” Shapiro said.
Such advances are seriously needed. A woman’s risk of developing breast cancer during her lifetime is one in eight. Each year, about 200,000 women are diagnosed with breast cancer, and about 40,000 die of the disease.
The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute is one of the nation’s leading centers for research on the prevention, detection, diagnosis and treatment of cancer. The OSUCCC – James encompasses six interdisciplinary research programs and includes more than 250 investigators who generate over $100 million annually in external funding. It is a founding member of the National Comprehensive Cancer Network, and OSU’s James Cancer Hospital is consistently ranked by U.S. News & World Report as one of America’s best hospitals for cancer care.# # #
Medical Center Communications