By Alexia Fernandez
Updated September 15, 2016 at 05:04 PM EDT
Credit: Ilya S. Savenok/Getty Images for Tribeca Film Festival

Once a Charmed sister, always a Charmed sister.

Rose McGowan, who starred as Paige Matthews in the popular series after Shannen Doherty left the show in 2001, took to Instagram on Tuesday to support the cancer-stricken actress and dispel any rumors of rivalry between them.

Doherty revealed she’d been diagnosed with breast cancer last year and recently attended a Stand Up to Cancer event looking healthy, with her doctor sayingthat her chemotherapy was “nearly finished.”

Appearing to show support, McGowan shared an illustration on Instagram showing two women side-by-side, one with no hair and the other with a headscarf.

“We have a funny history. As young women we were pitted against each other for society’s pleasure. The rules of Hollywood engagement brainwashed into us were truly vile. The men & brainwashed women in our business made it so we couldn’t be friends, I regret that,” McGowan wrote.

McGowan was cast in 2001 and stayed on as one of the leading actresses until 2006, when the show came to an end. She replaced Doherty (Prue Halliwell) after rumors of on-set and off-set tensions between Doherty and co-star Alyssa Milano.

The series centered on the story three sisters who discovered they were descendants of a line of female witches. Each sister had a special ability and could combine their powers into the “Power of Three” to fight demons and other evils.

Doherty portrayed the eldest of the three but her departure resulted in her character’s death at the end of the third season. McGowan’s character was introduced in season four as the half-sister of the Halliwell sisters, completing the three sister storyline.

The two actresses have been rumored to be rivals in the past, which McGowan denies in her letter.

Meanwhile, Doherty recently revealed that she hasn’t let cancer get the best of her.

“I’ve been given a really interesting opportunity and one that in a way, I kind of feel blessed,” Doherty told ET in an interview. “Cancer has, in a strange way, done some amazing things for me. It’s allowed me to be more me, like much more in touch with who I am, and much more vulnerable and the person that I always was, but I think it got hidden behind a lot of other stuff.”