If Kristin Johnson St. Goddard's 18-year battle with Stage 4 breast cancer taught her anything, it's not to take life for granted.
She was 28 when she was first diagnosed with Stage 2 breast cancer in September 1986.
By October of the following year, she finished her treatment and thought she had gotten rid of it for good.
Fast forward to 1997. She was having a lot of pain in her chest and thought she was having a heart attack.
What she was feeling was the breast cancer, only this time it was Stage 4.
Her doctor told her she only had 18 months to two years to live.
RELATED: An 8-year-old girl is battling breast cancer, but a 'flood of angels' has her back
"When I heard the news, my heart sank," St. Goddard, 58, told TODAY.com. "I didn't believe it."
Little did she know she had a long road ahead of her — 18 years and 17 different treatments later, she's still fighting a good fight.
Some of the treatments have worked and others have not, but she claims that she's experienced nearly every side effect possible, including losing her hair and eyelashes.
"Although her situation is unusual, it's not unheard of," Dr. Len Lichtenfeld, Deputy Chief Medical Officer for American Cancer Society, told TODAY.com. "When we look at cancer in general, there are always circumstances where we see patients that do much better than we would've anticipated."
She doesn't let her cancer slow her down though.
When TODAY.com spoke to her, she was attending the Wrangler National Finals Rodeo in Las Vegas and planned to spend the holidays in St. Mary, Missouri, where her son, Nathan Goddard, 34, resides with his two children.
It's also where she lived before moving to Seattle, her current hometown, in 1999 for treatment. Her story was first reported by local KING5-TV.
Since getting her prognosis in 1997, she's traveled to Italy, France, Belgium and England.
At home, she keeps busy by volunteering, going out to lunch with friends and spending time with her other son, Kyle Goddard, 32, who checks on her regularly.
She also volunteers for Gilda's Club, a community organization for people living with cancer and their families founded in memory of late "Saturday Night Life" star Gilda Radner.
"She makes me tired," Anna Gottlieb, Founder of Gilda's Club Seattle, told TODAY.com.
RELATED: 'Joey is at peace': Singer enters hospice, spends last days showering baby with love
Although she's grateful to be able to travel around the world — oral chemotherapy treatment makes traveling easier — the disease still prevents her from doing simple things that once gave her pleasure.
"I know it may sound small to others, but I used to take a bath every day. I love taking baths. It was my time to relax and be by myself, but I can't take baths anymore because of my draining tubes," St. Goddard said.
She also used to walk five miles a day, but doesn't have the stamina to do so anymore.
"I've been in limbo for 18 years and that's not a place you want to be in," St. Goddard said.
"I'm not going to sit here and act like I don't cry every day, but you go ahead the best you can and all I can be is grateful to be alive."