"I could decide to do nothing, but that's certainly not my personality," Lunden, 64, tells PEOPLE in its latest issue, on newsstands Friday. "I was handed an opportunity to learn everything that I can about this and try to help others."
Her first move? Going public with her battle. She announced the devastating news of her diagnosis to fellow cancer survivor Robin Roberts on the ABC morning show, where Lunden left with some valuable advice.
"Robin told me waiting for your hair to fall out is excruciating," she says. "So I didn't want to wait."
Just one week after finishing her first chemo treatment, the mother of seven decided it was time to say goodbye to her trademark blonde locks. "You know it's going to happen one of these days and you are wondering how and when, so I just owned it," Lunden explains.
But her decision to be photographed for PEOPLE's cover without the wig she currently wears took a bit more thought.
"I'm almost reluctant to say it because it sounds superficial," says Lunden. "But when you lose your hair, it just affects the way that you look at yourself in the mirror. You feel less feminine, pretty or desirable, and it's not an easy thing to go through."
But after much consideration, the long-term health advocate – who has been sharing her experience with breast cancer on her blog on JoanLunden.com and will appear during a weeklong series of segments on the Today show – knew what she needed to do.
"I had to make this big decision about whether or not to do the cover with no hair. It certainly isn't the comfortable way to go, but I decided I was going to try and help others and show women that this isn't the end of the world," Lunden says. "You can go on – and that was hugely empowering."
For much more from Lunden, including more images from our photo shoot, pick up the latest issue of PEOPLE, on newsstands Friday