Proteins do not predict outcome of herceptin treatment in HER2-positive breast cancer

December 9, 2011 in Cancer

Precisely quantifying the amount of three different HER growth proteins, along with several other proteins believed linked to breast cancer, did not predict a patient's outcome after treatment for HER2-Positive Breast Cancer with Herceptin, say Mayo Clinic researchers. HER2-positive breast cancer gets its name from a protein called human epidermal growth factor receptor 2 that promotes cancer cell growth.

The finding, presented at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium, represents a disappointment to oncologists who had hoped to find distinct biomarkers beyond standard HER2 testing that could help them gauge how well Herceptin will work for patients.

"This study debunks the hopeful notion, strongly felt in the community, that measuring levels of a number of different proteins in the HER2 family could help oncologists better tailor their use of Herceptin," says the study's senior investigator, Edith Perez, M.D., director of Mayo Clinic's Breast Program in Florida.

"Improving our ability to predict the benefit of Herceptin treatment beyond testing for HER2 protein and genes remains an important goal, but we are not there yet," she says.

Currently, patients are considered eligible for Herceptin if a pathologist estimates that at least 10 percent of their tumor samples test positive for HER2 growth proteins. However, the test is relatively subjective, based on a HER2 stain on a slide of tumor tissue. While the test can predict the outcome of Herceptin treatment, which shuts down the HER2 growth receptor for some patients, it cannot do so for all patients, Dr. Perez says.

Researchers used a tool that precisely measures the amount of a protein expressed in a cancer sample. According to Dr. Perez, this study was the first to meticulously measure , including HER2, HER3, HER4, EGFR (), ER (estrogen receptor), and PTEN (a ) in almost 1,400 .

Many researchers thought that analysis of the HER3 protein might be a good predictive marker because HER2 and HER3 interact together to promote cancer growth, Dr. Perez says.

"A biopsy could have 80 percent HER3 protein, and it wouldn't be any different in terms of a patient's outcome from Herceptin use than a tumor that had 5 percent HER3 protein," she says.

The next step to finding predictive biomarkers showing a benefit to use will be to look at multi-gene profiles, not single biomarkers, Dr. Perez says.

Provided by Mayo Clinic search and more info website

not rated yet  

Rank not rated yet
Relevant PhysicsForums posts

More news stories

American cancer society celebrates 100 years of progress

(HealthDay)—The American Cancer Society, which is celebrating on Wednesday a century of fighting a disease once viewed as a death sentence, is making a pledge to put itself out of business.

Cancer created 3 hours ago | popularity not rated yet | comments 0

CT detects twice as many lung cancers as X-ray at initial screening exam

National Lung Screening Trial (NLST) investigators also conclude that the 20 percent reduction in lung cancer mortality with low-dose computed tomography (LDCT) versus chest X-ray (CXR) screening previously reported in the ...

Cancer created 3 hours ago | popularity not rated yet | comments 0

Research offers promising new approach to treatment of lung cancer

Researchers have developed a new drug delivery system that allows inhalation of chemotherapeutic drugs to help treat lung cancer, and in laboratory and animal tests it appears to reduce the systemic damage ...

Cancer created 6 hours ago | popularity not rated yet | comments 0 | with audio podcast

Study details genes that control whether tumors adapt or die when faced with p53 activating drugs

When turned on, the gene p53 turns off cancer. However, when existing drugs boost p53, only a few tumors die – the rest resist the challenge. A study published in the journal Cell Reports shows how: tumors that live even i ...

Cancer created 7 hours ago | popularity not rated yet | comments 0 | with audio podcast

Small increase in cancer risk following CT scans in childhood and adolescence

Study leader, Professor John Mathews from the University of Melbourne said this small increase in cancer risk must be weighed against the undoubted benefits from CT scans in diagnosing and monitoring disease.

Cancer created 11 hours ago | popularity not rated yet | comments 0


Slowing the aging process—only with antibiotics

Swiss scientists reveal the mechanism responsible for aging hidden deep within mitochondria—and dramatically slow it down in worms by administering antibiotics to the young.

Having both migraines, depression may mean smaller brain

(HealthDay)—Migraines and depression can each cause a great deal of suffering, but new research indicates the combination of the two may be linked to something else entirely—a smaller brain.

Brain can be trained in compassion, study shows

Until now, little was scientifically known about the human potential to cultivate compassion—the emotional state of caring for people who are suffering in a way that motivates altruistic behavior.

Researchers complete largest genetic sequencing study of human disease

Researchers from Queen Mary, University of London have led the largest sequencing study of human disease to date, investigating the genetic basis of six autoimmune diseases.

Novel approach for influenza vaccination shows promise in early animal testing

A new approach for immunizing against influenza elicited a more potent immune response and broader protection than the currently licensed seasonal influenza vaccines when tested in mice and ferrets. The vaccine ...

Calorie information in fast food restaurants used by 40 percent of 9-18 year olds when making food choices

A new study published online today (Thursday) in the Journal of Public Health has found that of young people who visited fast food or chain restaurants in the U.S. in 2010, girls and youth who were obese were more likely ...