Call it the faceoff to "F--k Cancer."

Vancouver's Susan Fiedler is headed to B.C. Supreme Court in a bid to stop a pair of celebrity activists from allegedly infringing on her trademark of the controversial slogan.

In a notice of civil claim, Fiedler says she started fundraising with F--k Cancer emblazoned bracelets in 2008 — before Yael Cohen or Julie Greenbaum began using the term to raise money for charity.

"A big part of what I'm doing is really protecting my intellectual property," said Fiedler.

"It's that or run the risk of losing my rights entirely. I was there first. This is important to me. I've put a lot of time and effort and life energy into this. I'm a cancer survivor; it just doesn't seem right to give up."

Celebrity activists

Fiedler wants a judge to declare that she has enforceable rights over the trademark, which has already been the subject of a series of bitter legal disputes.

Yael Cohen applied to have this design trademarked. It has appeared on T-shirts sold through letsfcancer.com. (http://www.letsfcancer.com/)

The battle pits Fiedler against two women who have earned considerable celebrity through their philanthropy.

Cohen started her awareness-raising charity in 2009 after making a F--k Cancer T-shirt for her mother, who was battling breast cancer at the time.

She has since made numerous television appearances, and last July, Cohen married Justin Bieber's manager, Scooter Braun.

Greenbaum lost her mother to cancer in 2010. Shortly after, she started holding large-scale F--k Cancer events and parties to raise money for research.

Last October, she and Cohen announced plans to work together.

In her notice of claim, Fiedler says she started selling F--k Cancer bracelets to raise money for charity in 2008.

Fiedler claims she was inspired by her own battle with non-Hodgkins lymphoma, and signed up "celebrity ambassadors" for her cause, including the Barenaked Ladies, Sarah McLachlan and Brett Wilson.

Fiedler says McLachlan first told her about Cohen's F--k Cancer organization.

Causing confusion

In 2010, Cohen filed an application with the Canadian Intellectual Property Office to register the term as a trademark. Fiedler opposed the move.

That process ultimately led to a Federal Court decision last year in which Cohen attempted unsuccessfully to make a last-ditch argument that no one should be able to trademark the phrase, because of the obscenity.

A judge ordered her to pay Fiedler $5,000.

In her B.C. Supreme Court claim, Fiedler says the situation is causing confusion.

Sarah McLachlan is a celebrity ambassador for Susan Fiedler's F--k Cancer initiative. (sarahmclachlan.com)

"That confusion has been caused by the deliberate deception of the public by the defendants," the claim says.

"As a result of the confusion and the deliberate deception and misrepresentations made by the defendants … the plaintiffs have suffered damages."

Fiedler says she has heard nothing from the rival F--k Cancer organizations since the Federal Court ruling, and now has no choice but to enforce her trademark in court.

"It's been extremely stressful. It's been demoralizing," she said.

"I still don't want to give up, but it's not an easy situation to be in considering what I set out to do."

Fiedler says she would still like to come to some kind of settlement in the future.

None of the claims have been proven in court.