Breast cancer: Reducing the risk of unnecessary chemo

November 08, 2010

A fundamental principle of medicine is: "first, do no harm." However, for doctors who treat breast cancer, this is easier said than done. Every year, almost 22,000 Canadian women are diagnosed with breast cancer -- their treatment usually involves surgery to remove a tumour and then chemotherapy to reduce the risk of cancer returning. But studies show that for most patients with early stage breast cancer, chemotherapy following surgery is totally unnecessary and therefore does more harm than good.

Identifying whether a patient's cancer is at low or high risk of recurring would help doctors reduce unnecessary treatments for low risk patients. This could have a huge impact on a patient's quality of life and also significantly reduce the cost of health care.

Did you know?

Chemotherapy can be devastating both physically and emotionally. Side effects of breast cancer chemotherapy range from nausea, vomiting and hair loss to mouth sores, menopause, infertility, numbness and aching of the joints, hands and feet.

Currently, most doctors assess a patient's prognosis using their age and "tumour grade," but this approach doesn't work very well. Now, NRC researchers have developed a tool to determine which breast cancer patients have little risk of their disease recurring. The tool -- an algorithm that identifies "gene expression signatures" or biomarkers that can predict low risk tumours with 87-100 percent accuracy in different groups of patients -- has the potential to virtually eliminate unnecessary chemotherapy.

To conduct their study, which appeared in a recent issue of Nature Communications, Dr. Edwin Wang and his colleagues at the NRC Biotechnology Research Institute in Montreal (NRC-BRI) used published data on gene expression profiles from more than 1000 breast cancer samples. "Every tumour has a gene expression profile, which indicates how the patient's genes have changed," he explains. "We combined this data with information on the patient's outcome -- such as whether the original tumour spread and how long the person survived -- to develop our algorithm."

The NRC team now hopes to see its algorithm applied in a clinical setting. "We have a provisional patent on the intellectual property and we would like to get a Canadian company to license it and turn it into a kit format," says Dr. Maureen O'Connor of NRC-BRI, who co-authored the study. "We've had interest expressed from more than one company so far."

Dr. O'Connor adds that the NRC algorithm could be adapted to other types of cancer where over-treatment is common, such as prostate cancer. "Prostate cancer in particular is usually not an aggressive disease, but the treatment can be extreme," she says. "We would like to develop a test that can predict with 99 percent accuracy whether a patient's cancer is not aggressive, so they can make the best decision about whether to proceed with treatment right away."

In future, the algorithm may also help pave the way toward personalized therapy for cancer patients. "On average, every cancer patient has 14-16 mutated genes," says Dr. Wang. "Based on their unique genetic signature, we hope to figure out which mutations to target to block the cancer process in each patient."
-end-


National Research Council of Canada

Related Breast Cancer Articles from Brightsurf:

Oncotarget: IGF2 expression in breast cancer tumors and in breast cancer cells
The Oncotarget authors propose that methylation of DVDMR represents a novel epigenetic biomarker that determines the levels of IGF2 protein expression in breast cancer.

Breast cancer: AI predicts which pre-malignant breast lesions will progress to advanced cancer
New research at Case Western Reserve University in Cleveland, Ohio, could help better determine which patients diagnosed with the pre-malignant breast cancer commonly as stage 0 are likely to progress to invasive breast cancer and therefore might benefit from additional therapy over and above surgery alone.

Partial breast irradiation effective treatment option for low-risk breast cancer
Partial breast irradiation produces similar long-term survival rates and risk for recurrence compared with whole breast irradiation for many women with low-risk, early stage breast cancer, according to new clinical data from a national clinical trial involving researchers from The Ohio State University Comprehensive Cancer Center - Arthur G.

Breast screening linked to 60 per cent lower risk of breast cancer death in first 10 years
Women who take part in breast screening have a significantly greater benefit from treatments than those who are not screened, according to a study of more than 50,000 women.

More clues revealed in link between normal breast changes and invasive breast cancer
A research team, led by investigators from Georgetown Lombardi Comprehensive Cancer Center, details how a natural and dramatic process -- changes in mammary glands to accommodate breastfeeding -- uses a molecular process believed to contribute to survival of pre-malignant breast cells.

Breast tissue tumor suppressor PTEN: A potential Achilles heel for breast cancer cells
A highly collaborative team of researchers at the Medical University of South Carolina and Ohio State University report in Nature Communications that they have identified a novel pathway for connective tissue PTEN in breast cancer cell response to radiotherapy.

Computers equal radiologists in assessing breast density and associated breast cancer risk
Automated breast-density evaluation was just as accurate in predicting women's risk of breast cancer, found and not found by mammography, as subjective evaluation done by radiologists, in a study led by researchers at UC San Francisco and Mayo Clinic.

Blood test can effectively rule out breast cancer, regardless of breast density
A new study published in PLOS ONE demonstrates that Videssa® Breast, a multi-protein biomarker blood test for breast cancer, is unaffected by breast density and can reliably rule out breast cancer in women with both dense and non-dense breast tissue.

Study shows influence of surgeons on likelihood of removal of healthy breast after breast cancer dia
Attending surgeons can have a strong influence on whether a patient undergoes contralateral prophylactic mastectomy after a diagnosis of breast cancer, according to a study published by JAMA Surgery.

Young breast cancer patients undergoing breast conserving surgery see improved prognosis
A new analysis indicates that breast cancer prognoses have improved over time in young women treated with breast conserving surgery.

Read More: Breast Cancer News and Breast Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.