The one-time foreign affairs minister - nicknamed the "minister for fashion" by some - donned a crisp white shirt on Wednesday to help raise funds and awareness for ovarian cancer as part of Witchery's White Shirt Campaign.

Now in its 11th year, the womenswear label has raised more than $12 million towards ovarian cancer research.

"I'm obviously keen to be involved in fashion but today's event is something quite different," Ms Bishop told reporters.

"It's a statement way beyond fashion when we're talking about raising funds for ovarian cancer research."

The retiring Liberal MP said the campaign hit close to home - her two older sisters were previously diagnosed with ovarian cysts.

"We didn't know whether they were malignant or not," she said on Wednesday.

"So when I was asked to be an ambassador, I readily agreed because not much is known about ovarian cancer and we need more funds to be able to develop an early detection test to save lives."

Ms Bishop's sisters were lucky with the cysts proving to be benign.

Ovarian Cancer Research Foundation chief executive Lucinda Nolan says with no symptoms, no early detection test and a low survival rate it's difficult to raise awareness of the gynaecological cancer.

"People that get it don't survive," Ms Nolan told AAP.

"So this campaign provides a little bit of fun in such a very tragic and sometimes sad area of work.

"It's a time for people to dress up, show their support, support women not only by looking fashionable but by actually raising money."

Ovarian cancer has the lowest survival rate of any women's cancer and only 44 per cent of women diagnosed with ovarian cancer will be alive five years after diagnosis.

Witchery's White Shirt Campaign runs until World Ovarian Cancer Day on May 8.

Australian Associated Press