TORONTO -- In sharing the gut-wrenching journey of her diagnosis and treatment for metastatic breast cancer at age 37, Teva Harrison let her images speak first -- and then the words followed.

Her comic book-style illustrations inspired the short essays featured in her graphic memoir "In-Between Days."

"When I was starting to make sense in my own head of what was going on with me, when I was trying to clarify and sort it out, drawing about it really was the best way for me to get the thoughts and the feelings out," Harrison said in an interview at her Toronto home.

"To me, the things that are the scariest are the things in the dark, the things we don't talk about, the things we're trying not to look at. And so, by putting them in the light, giving them form was almost like taking some power back for myself."

In the opening essay titled "What's Wrong With Me?" Harrison recalls the lingering, excruciating pain radiating in her hips and back, which made everything from carrying groceries to running a challenge. Harrison's concerns over her discomfort are reflected in her illustrations, depicting meetings with doctors in search of answers.

Harrison eventually discovered a lump in her breast. Following a mammogram, she learned she had cancer. A subsequent scan found the disease had spread to her bones and was incurable.

"In-Between Days" documents the struggles Harrison faces in confronting the disease, from managing pain and side effects, to re-examining long-term goals and dreams.

Throughout it all, Harrison found catharsis through art.

"Putting ideas into pictures and drawing them, I get into this sort of flow where I'm not necessarily ruminating, I'm not thinking about the hard things," said Harrison, 39. "I'm thinking about how to make a mark and how to make a shape and: 'Am I happy with the composition?'

"Even if I'm drawing about cancer, it sort of takes me out of the experience of dwelling on the fact that I have cancer."

Harrison also provides perspective on how metastatic breast cancer differs in its absence of obvious signs of illness, especially to outsiders.

"Pain isn't visible, discomfort generally isn't visible. And so, people see a pretty healthy-looking young woman just going about their day," she said.

"Sometimes, I think that's a gift in that you can be a little anonymous in a crowd. But sometimes it could create awkward situations, like when I'm really tired because of say, radiation, or some other kind of treatment, and man, do I want to sit down. But knowing how I look, I'm more likely to give my seat to a woman with a cane.

"I think the default is to be kind, and if people could see it on me, if they could identify that I'm a sick person, I'm certain they would always be offering me a seat. But there's no way they could tell."

Harrison devotes a portion of the book to speaking about her family, a point she felt was important because of the hereditary nature of her disease.

Among the most poignant essays is devoted to her whirlwind courtship and marriage to her husband, David, who is a central figure throughout the memoir in his enduring support of Harrison.

"When we got married 14 years ago, there was this promise of forever. And to me, forever meant having kids and getting old and helping each other down the streets with our walkers and shaking our sticks at the kids on our lawn," she said with a laugh.

"And even though we still have forever, our love story is likely going to be cut a little short because of this disease. And I thought without that story, we don't have as much of an idea of what's being lost."