What she didn't expect was to be diagnosed with an aggressive form of colon cancer only a month later.
The tumour has since spread to her liver and her lungs, and Arnot has had three surgeries to remove parts of the tumour to keep the disease at bay.
But when she was recently denied access to the pricey drug Avastin, Arnot began wondering why some colon cancer patients are given the chance to live longer while others aren't.
"I strongly believe in equal access to treatment," she said. "Not only does it extend life, it gives (patients) a better quality of life."
Avastin is a drug used in combination with chemotherapy that has been clinically proven to extend survival for aggressive colon and lung cancer. It costs $50,000 for a course of treatment, and blocks tumour growth and spread by cutting off the tumour's blood and oxygen supply.
Manitoba Health gives funding to CancerCare Manitoba, which then administers cancer treatment to patients and decides which drugs to fund -- including pricey new treatments like Avastin.
CancerCare CEO Dr. Dhali Dhaliwal said since aggressive colon cancer is always fatal, oncologists have prescribed Avastin for few patients.
On average, patients with aggressive colon cancer will die within two years if they continue chemotherapy or nine months if they discontinue all treatment.
Avastin will extend life by about four months for the average patient, but Dhaliwal said cancer agencies can't afford to spend $50,000 for terminal patients. He said CancerCare has to weigh how to best spend its limited funds, and developing screening programs to detect the disease before it spreads will help save more lives.
Giving every colon cancer patient Avastin would cost about $7 million a year, compared to the $3-million cost of a provincial colon cancer screening program.
If caught early, colon cancer is treatable.
Each year in Manitoba, about 780 people are diagnosed with colon cancer and half will die.
Nearly four years after her initial diagnosis, Arnot is still battling cancer. Although she had a brief remission for six months, the tumour continued to grow and she had part of a lung removed last year.
Arnot now has chemotherapy every three weeks.
While she still doesn't understand why she can't have Avastin, Arnot said she wants everyone over 50 to know to get tested for the disease.
This spring, CancerCare is mailing 20,000 colon cancer screening kits to Manitobans age 50 to 74. They expect it could reduce the number of people who die from the disease by as much as 20 per cent.
"We need to educate people so that they don't end up with the same problems as I have," Arnot said.