Every three weeks, Daisy Carlson visits her doctor and receives a drug infusion that keeps her breast cancer in remission. 

She's been doing it for 18 years. 

"It's been quite the journey," Carlson said. 

It started in 1999. Carlson was in her late 50s, and while checking herself — something she did on a regular basis — she found a lump. Days later she was sitting with her oncologist, Patrick Cobb, who confirmed the cancer.

"Seemed like things went from bad to worse," Carlson said. 

The cancer in her breast had spread and was discovered in 16 lymph nodes and in her bones. She had a number of tumors. 

"It's an aggressive cancer," Cobb said. 

Specifically, it's known as HER2 breast cancer. HER2 is a type of protein produced in the breast and when cancer attacks it the cancer grows faster and farther than other types of breast cancer. 

Within days Carlson underwent a mastectomy and started chemotherapy. Almost immediately she was placed on a new drug called Herceptin, which specifically targets the HER2 protein.  

It saved her life. 

The chemo along with the infusion sent her cancer into remission, eradicated her tumors and left her with a clean bill of health. Two years after the diagnosis, Carlson, an avid golfer, won the Pryor Creek Golf Club women's championship. She said she feels no ill effects from her regular drug treatments. 

These days, Carlson talks about how naive she was at the time of her diagnosis. Had the cancer struck two or three years earlier than it did, she likely wouldn't have survived. 

"Women with HER2 had a terrible prognosis," Cobb said. 

Herceptin came on the market in 1998, the year before Carlson's diagnosis, and now as a result, she's is still around playing golf every Tuesday. 

Before researchers had found a way to treat it, women with HER2 breast cancer had a 16 percent chance for survival in the first five years of their diagnosis. Treated with Herceptin, the rate increased to 36 percent. 

Part of that is because only a quarter of the women who are diagnosed with HER2 breast cancer are a biological match for the Herceptin treatment. Carlson, fortunately, was a match. 

Cobb said to Carlson they've been on this road together for a while. 

"You were a pioneer," he said. 

"When we started, your hair was still brown," she told Cobb, who's full head of hair is a snowy white.

Cobb operates out of the St. Vincent Healthcare Frontier Cancer Center on the West End. Carlson calls him her hero and will freely tell everyone in earshot that he's the best doctor there is.

"He's a great, great doctor," she said. 

The Herceptin infusion she receives every three weeks doesn't slow her down. They take about 15 minutes and at most leave her arm feeling very cold. She usually has to wear a heating pad. 

That wasn't always the case. 

"It was a bearcat in the beginning," she said. It was painful and the process took over an hour. 

The diagnosis has helped Carlson focus more on her health. She says she eats better than she probably would have and she stays as active as she can. Along with the golf, she's a regular bowler. 

She's also wiser. She's keen to tell people, women in particular, that's it's important they listen to their bodies. 

"Know your body," she said. "If there's something wrong, be aggressive about getting answers."