Landmark study confirms chemotherapy benefit in breast cancer patients

December 11, 2009

Chemotherapy generally improves survival in postmenopausal breast cancer patients, according to a landmark study led by Dr. Kathy Albain of Loyola University Health System.

However a second study, also headed by Albain, found that a multigene test on a can identify a subset of women who may not benefit from .

The related studies were published simultaneously online, ahead of print, Dec. 10 in the journals Lancet and Lancet Oncology.

"With the right chemotherapy regimen, we can favorably impact survival," Albain said. "But it also is important to avoid the toxicity and medical costs of chemotherapy when it may not be needed."

Tamoxifen has long been a standard drug treatment for postmenopausal women with the most common type of , known as estrogen-receptor positive. Tamoxifen blocks estrogen's linkage with cancer cells, thus preventing the hormone from promoting cancer cells' growth.

There has been much debate over whether women with tumors that are fueled by estrogen would benefit from receiving in addition to standard antihormonal treatments such as tamoxifen. Previous studies found little or no benefit from adding chemotherapy in postmenopausal patients.

The new study is considered groundbreaking because it is more definitive than past studies and because it has set the current standard of care. The study was conducted by the Southwest Oncology Group, one of the largest federally funded clinical trial networks, and was funded by the National Cancer Institute.

The study followed a homogenous population of 1,477 women from multiple centers for 10 years. Unlike earlier studies, it included a regimen of anthracycline chemotherapy and a tamoxifen-alone control group.

The women were postmenopausal, and had hormone receptor-positive cancer that had spread to at least one lymph node in the armpit area. Women who received chemotherapy were 24 percent less likely to see their cancer come back. They also were 17 percent less likely to die during the time period they were followed, but this finding fell just short of being statistically significant.

All women in the study took a tamoxifen pill every day for five years. Researchers randomly assigned 361 patients to receive tamoxifen alone and 1,116 patients to receive tamoxifen plus a three-drug chemotherapy regimen for six months.

The chemotherapy regimen is known as CAF (cyclophosphamide, Adriamycin® and 5-fluorouracil). Women who underwent chemotherapy were more likely to experience a drop in infection-fighting white blood cells, soreness and painful ulcers in the mouth, blood clots, congestive heart failure and leukemia than those who received tamoxifen alone.

The study established the standard of care regarding when to give tamoxifen in relation to chemotherapy. The chemotherapy group was divided into women who began taking tamoxifen during chemotherapy and those who waited until they were done with chemotherapy before taking tamoxifen. Women who took after chemotherapy had better disease-free survival and overall survival.

Over the past several years, Albain and colleagues have presented ongoing data from this study, and their findings already have influenced how doctors around the world are treating breast cancer.

In the second study, published in Lancet Oncology, Albain and colleagues did a retrospective analysis to determine whether a 21-gene test can predict which women would benefit from chemotherapy.

The test, Oncotype DX®, is performed by Genomic Health Inc. The test examines 21 genes from a tumor sample to determine how active they are. A score is reported, which is then correlated with benefit to chemotherapy. The analysis found there appeared to be no benefit to who had a low score on the gene test, while those with higher scores did benefit.

More than 100,000 breast cancer patients have undergone the test since it became commercially available in 2004 for patients with estrogen-receptor positive breast cancer that has not spread to the lymph nodes. The new study indicates the test also could be useful in predicting whether chemotherapy -- the current standard -- could be avoided in a subgroup of patients whose cancer has spread to lymph nodes, Albain said.

"This study, along with other studies involving different gene tests, suggests that certain biologic subtypes of breast cancer may inherently be either susceptible to chemotherapy or resistant to chemotherapy," Albain said. "Prospective studies with larger sample sizes are needed to determine who will optimally benefit from chemotherapy."

Source: Loyola University Health System (news : web)

Related Stories

Recommended for you

One in five young colon cancer patients have genetic link

December 13, 2017
As doctors grapple with increasing rates of colorectal cancers in young people, new research from the University of Michigan may offer some insight into how the disease developed and how to prevent further cancers. Researchers ...

New strategy for unleashing cancer-fighting power of p53 gene

December 13, 2017
Tumor protein p53 is one of the most critical determinants of the fate of cancer cells, as it can determine whether a cell lives or dies in response to stress. In a new study published today in the journal Nature Communications, ...

Researchers develop test that can diagnose two cancer types

December 12, 2017
A blood test using infrared spectroscopy can be used to diagnose two types of cancer, lymphoma and melanoma, according to a study led by Georgia State University.

Cancer-causing mutation suppresses immune system around tumours

December 12, 2017
Mutations in 'Ras' genes, which drive 25% of human cancers by causing tumour cells to grow, multiply and spread, can also protect cancer cells from the immune system, finds a new study from the Francis Crick Institute and ...

Atoh1, a potential Achilles' heel of Sonic Hedgehog medulloblastoma

December 12, 2017
Medulloblastoma is the most common type of solid brain tumor in children. Current treatments offer limited success and may leave patients with severe neurological side effects, including psychiatric disorders, growth retardation ...

MRI scans predict patients' ability to fight the spread of cancer

December 12, 2017
A simple, non-invasive procedure that can indicate how long patients with cancer that has spread to the brain might survive and whether they are likely to respond to immunotherapy has been developed by researchers in Liverpool.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.