Genetic testing rates for ovarian cancer low across Ontario

April 14, 2017
In a recent study, Dr. Jacob McGee, a professor in the Schulich School of Medicine & Dentistry and a gynecology oncologist at London Health Sciences Centre, found that, on average, less than seven per cent of Ontario women with the most common type of ovarian cancer were seen for genetics consultation within two years of diagnosis. McGee and his colleagues were able to demonstrate that, by changing the way women are referred for ovarian cancer genetic consultation, it is possible to increase genetic testing rates from less than 20 per cent to almost 80 per cent, potentially increasing diagnostic and treatment outcomes. Credit: Crystal Mackay//Special to Western News

Nearly 3,000 Canadian women will be diagnosed with ovarian cancer this year. Often undetected, until it progresses to late stages, the disease is the fifth most common – and the most serious – cancer in women.

Symptoms of generally appear after it has already spread within the pelvis and abdomen and, once it has spread, the is difficult to treat. In these later stages, it is often fatal. Early-stage ovarian cancer, in which the disease is confined to the ovary, is more likely to respond to treatment – an indication early detection and intervention could be key in increasing treatment and survival rates.

Genetic consultation in ovarian cancer testing – which has shown promising potential for life-saving benefits – isn't as common as it should be, according to Western researchers.

In a recent study, published in the March issue of the International Journal of Gynecological Cancer, Dr. Jacob McGee, a professor in the Schulich School of Medicine & Dentistry and a gynecology oncologist at London Health Sciences Centre (LHSC), found that, on average, less than seven per cent of Ontario women with the most common type of ovarian cancer were seen for genetics consultation within two years of diagnosis.

Women at the highest risk of developing high-grade serous ovarian cancer (HGSC) are those with a mutation in their BRCA (tumour suppression) genes, which can be identified through genetics consultation.

Given the results of the study, McGee and his colleagues were able to demonstrate that by changing the way women are referred for ovarian cancer genetic consultation, it is possible to increase genetic testing rates from less than 20 per cent to almost 80 per cent, potentially increasing diagnostic and treatment outcomes.

The identification of the BRCA mutation can mean the difference between life and death for family members of the affected individual. For women with the BRCA mutation, there is a 50 per cent chance they will pass that mutation on to their children and grandchildren. If the hereditary gene can be found in the affected individual, and then identified in their , it can be followed by life-saving interventions including surgically removing the ovaries and fallopian tubes, before there is a diagnosis of cancer. This preventative procedure has been shown to drastically reduce mortality rates, McGee explained.

Identification of the gene also allows for consideration of treatment with a PARP (poly-ADP-ribose polymerase) inhibitor, a new class of medication found to be beneficial only for women with this mutation.

McGee and his research team cite an intervention at LHSC's London Regional Cancer Centre (LRCP), which has increased the rate of consultation in London to well above the provincial average.

In London, the genetics referral process for patients with HGSC was altered from an 'opt-in' to an 'opt-out' process. This involves automatically forwarding the list of new HGSC ovarian cancer patients to the cancer genetics clinic through an advance directive. Seeing a genetic counsellor or geneticist becomes the default, with patients stepping outside of the referral process only if their physician cancels the consultation with genetics. In the first year of implementation, 77 per cent of patients at LRCP diagnosed with HGSC completed genetics consultation, well above the provincial average identified in McGee's study.

"This process has been surprisingly easy to implement, and we think it could be a good fit for other centres across the province," said McGee, a Lawson Health Research Institute scientist.

Despite the province's expanding genetic counselling eligibility in 2001 to all with HGSC ovarian cancer, consultation rates in Ontario remained low during the study period, between 1997 and 2011. The rates did rise, peaking at 13.3 per cent in 2011, however, the numbers remained well below where McGee believes they should be.

"These numbers show no matter what centre you are in, there have to be better interventions to help patients see a genetic counsellor," he said. "This is something absolutely worth doing because of the impact it has for both the patient's current treatment and in preventing ovarian cancer cases down the road."

Explore further: Drug combination boost PARP inhibitor response in resistant ovarian cancer

More information: Genetics Consultation Rates Following a Diagnosis of High-Grade Serous Ovarian Carcinoma in the Canadian Province of Ontario. International Journal of Gynecological Cancer. DOI: 10.1097/IGC.0000000000000907

Related Stories

Drug combination boost PARP inhibitor response in resistant ovarian cancer

April 3, 2017
About one-third of patients with ovarian cancer who wouldn't be expected to respond to a PARP inhibitor had partial shrinkage of their tumor when a kinase inhibitor was added to treatment, report scientists from Dana-Farber ...

Significant increase in number of women tested for BRCA gene, but many high-risk patients still missing out

March 22, 2017
Discovery of the BRCA genetic mutation in the mid-90s represented a breakthrough in breast and ovarian cancer prevention. About 5-10% of breast cancer cases and 10-18% of ovarian cancer cases can be attributed to two BRCA ...

Women's wellness: Early diagnosis for ovarian cancer

September 21, 2016
According to the Centers for Disease Control and Prevention, more than 20,000 women in the U.S. are diagnosed with ovarian cancer each year. September is Ovarian Cancer Awareness month and physicians want to raise awareness ...

Ovarian cancer: Genetic testing should be accessible to all women with the disease

April 15, 2015
The genes BRCA1 and BRCA2 play a significant role in hereditary breast and ovarian cancers. Recent media attention has focused on American actress Angelina Jolie's decision to have her ovaries and fallopian tubes surgically ...

Know your risk for ovarian cancer—and the symptoms

September 9, 2016
(HealthDay)—A major shift is needed in the prevention and treatment of ovarian cancer, according to a doctor who specializes in the disease.

Simplifying access to gene testing for women with ovarian cancer

July 13, 2016
A new streamlined approach to genetic testing for women with ovarian cancer provides testing rapidly and affordably, allowing many more patients to benefit from personalised cancer management and their relatives to benefit ...

Recommended for you

Clear link between heavy vitamin B intake and lung cancer

August 22, 2017
New research suggests long-term, high-dose supplementation with vitamins B6 and B12—long touted by the vitamin industry for increasing energy and improving metabolism—is associated with a two- to four-fold increased lung ...

Study provides insight into link between two rare tumor syndromes

August 22, 2017
UCLA researchers have discovered that timing is everything when it comes to preventing a specific gene mutation in mice from developing rare and fast-growing cancerous tumors, which also affects young children. This mutation ...

Retaining one normal BRCA gene in breast, ovarian cancers influences patient survival

August 22, 2017
Determining which cancer patients are likely to be resistant to initial treatment is a major research effort of oncologists and laboratory scientists. Now, ascertaining who might fall into that category may become a little ...

Study identifies miR122 target sites in liver cancer and links a gene to patient survival

August 22, 2017
A new study of a molecule that regulates liver-cell metabolism and suppresses liver-cancer development shows that the molecule interacts with thousands of genes in liver cells, and that when levels of the molecule go down, ...

Zebrafish larvae could be used as 'avatars' to optimize personalized treatment of cancer

August 21, 2017
Portuguese scientists have for the first time shown that the larvae of a tiny fish could one day become the preferred model for predicting, in advance, the response of human malignant tumors to the various therapeutic drugs ...

Scientists discover vitamin C regulates stem cell function, curbs leukemia development

August 21, 2017
Not much is known about stem cell metabolism, but a new study from the Children's Medical Center Research Institute at UT Southwestern (CRI) has found that stem cells take up unusually high levels of vitamin C, which then ...

0 comments

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.