Despite the pain of stomach cancer treatment, Mr Koh Ming Hao, who died on June 8, never stopped helping others throughout his four years of battling the disease.

His family said about a quarter of the hundreds of mourners who turned up each day at a four-day wake held in Pasir Ris were strangers who knew about him through his social media accounts.

Flowers and tributes sent to the wake came from as far away as Australia, surprising the family.

His wife Daphnie Chong, 34, told The Straits Times: "These people had never met him before but they still came for the wake. It was very heartening to see. It shows how big-hearted he was to others."

When news of Mr Koh's death was reported earlier this week, many Facebook users saluted him for his bravery, and his family, including his wife, for their unconditional support during his battle against cancer.

Mr Koh, who worked as a manager at Microsoft, was diagnosed with Stage 4 stomach cancer in June 2013. Doctors gave him only a year to live. But he lived for four years and died a day after his 34th birthday on June 7, barely a year after marrying his long-time sweetheart.

While he was alive, he shared details of his fight against cancer on Instagram using the hashtag #watchmingbeatcancer. Initially set up to provide his friends with updates on his health and cancer treatment, the hashtag eventually took on a life of its own. Mr Koh had about 1,000 followers on his Instagram page before his death. There are now 2,000 followers for his account.

A Facebook page was also set up by Mr Koh, drawing at least 700 users from countries including the United States and Australia. The page is no longer available online. His wife said he had hoped to help other cancer patients in sourcing for effective treatment options and share his experience fighting the disease.

Mr Koh set up a small support group on messaging platform WhatsApp with five other cancer patients. He would often encourage the others, said Mr Simon Yong, 36, the fifth patient to join the group.

Mr Yong was diagnosed with oesophageal cancer in 2015 and has since recovered. "We never really met very often, but he played a very important role in my life," he said. "Although he was younger than me, I looked up to him as my role model because he was always so positive."

Mr Koh underwent more than 60 chemotherapy sessions, including radiotherapy and immunotherapy.

But over time, the treatment led to various side effects, including loss of hair and loss of function of his left leg, migraines and vomiting.

As a result, he lost about 20kg.

"He had to change his entire wardrobe and even started buying skinny jeans. But he tried to make the best of it by saying things like he's always wanted to try those clothes anyway," said Ms Chong.

Despite the pain, Mr Koh continued working and maintained an active life as much as possible, said his family and friends.

Mr Koh's family and friends believe he did not lose his battle against cancer. By surviving for four years, he had beaten the odds and demonstrated the power of an indomitable will.

He was cremated on June 11.

By sharing his story, Mr Koh's family hopes other cancer patients will be inspired by his positivity in overcoming the illness.

His cousin Jovina Foong, 31, said: "That's what he would want. For his story to help others."