The 58-year-old, who had half a lung removed during surgery last year, paused midway through her 5km run on Sunday (July 22) to take her cancer medication before pressing on.
Madam Lim, who works in the healthcare sector and underwent chemotherapy after she was first diagnosed, recalled the painful ordeal.
"I thought it would be the end of me," she said. "But if other people can make it, I am sure that I can make it."
She was one of 8,000 people who took part in this year's Singtel-Singapore Cancer Society Race Against Cancer, which raised more than $1.1 million for charity.
The money will go towards the society's programmes to support cancer patients and their families, including funding the treatment of needy patients, which amounts to about $2 million a year.
The run, which took place at East Coast Park on Sunday morning, was flagged off by Minister of Trade and Industry Chan Chun Sing.
Singapore Cancer Society chief executive Albert Ching said he was deeply encouraged to see so many people show support for this year's event, which is the 10th time the race has been held.
"Many runners here today ran because they are cancer survivors, or because they are now battling cancer," he added.
Other participants included a group of 22 chief executives from organisations such as Singtel and AXA Insurance, as well as a team of doctors celebrating their 10th year since graduating from medical school.
Mr Marcus Daniel Lim, who was diagnosed with tongue cancer in 2016 and underwent surgery, also ran on Sunday to show his support for others who are fighting the same battle.
"When I went for my (medical) appointments, I saw so many patients who were fighting, and many were so much older and more frail than me," said Mr Lim, who works as a planning director in the home furnishing industry.
"I realised that staying positive is so important," added Mr Lim, who hopes to inspire other cancer patients to press on.
This year's edition also features a 10km "virtual run" for people who want to show their support but were unable to take part in the race.
Those who sign up, complete the run by the end of this month and send proof to Singapore Cancer Society will get a finisher's medal.
People who wish to sign up for the virtual run can do so at connect.justrunlah.com/rac2018virtual]]>