Colorectal Cancer Isn’t Just an Older Person’s Disease Anymore in Singapore

SINGAPORE – Mr Ambrose Lee was 36 when he was diagnosed with colorectal cancer – a disease that usually strikes those in their 50s and older.

In July 2022, he experienced heart palpitations and shortness of breath. He would feel unusually winded after walking short distances, something he attributed to the lingering effects of a Covid-19 infection. 

Concerned about his health, he saw a general practitioner (GP), who found nothing abnormal, but referred him to Ng Teng Fong General Hospital for further tests.

At the hospital, doctors conducted a series of blood tests and found that Mr Lee’s red blood cell count was alarmingly low. 

Initially, the doctors suspected thalassemia, an inherited blood disorder that affects the body’s ability to produce haemoglobin and healthy red blood cells. They administered iron infusions, but his iron levels remained critically low. 

“This raised concerns of internal bleeding, prompting doctors to conduct further investigations,” says Mr Lee, who is single and works as a freelancer in the psychology field.

Over several days, he underwent multiple scans. These showed no visible signs of internal bleeding. As a last step, doctors performed a colonoscopy and an upper endoscopy to check for abnormalities in his digestive tract and colon. 

It was during this procedure that they discovered a tumour in his colon. Mr Lee was then told he had Stage 2 colon cancer.

Unlike typical colorectal cancer patients – who experience symptoms such as changes in bowel habits, blood in the stool or abdominal discomfort – Mr Lee had none of these clear warning signs.

“The only indication was a persistent feeling of incomplete bowel evacuation, which I had been experiencing for at least six months before my diagnosis. Despite having regular and normal bowel movements, I often felt that my bowels were not fully emptied,” says the 39-year-old.  

During the surgery, doctors discovered that the cancer had already spread beyond the colon to his lymph nodes. This led to a revised diagnosis of Stage 3 colorectal cancer, requiring the removal of half his colon.

After the surgery, he underwent eight cycles of chemotherapy over six months.

Increasing trend of early-onset disease

Mr Lee is part of a growing number of younger adults being diagnosed with early-onset colorectal cancer. 

Also known as young-onset colorectal cancer, it refers to colon or rectal cancer diagnosed in people under the age of 50.

Colorectal cancer usually starts with growths of tissue, called polyps, on the inner lining of the colon or rectum, which may develop into cancer over time.

A recent study by the Singapore General Hospital (SGH) and National Cancer Centre Singapore (NCCS) has shed light on shifting trends in colorectal cancer in Singapore, particularly among adults below the age of 50. 

The study, published in JMIR Public Health and Surveillance journal in February, analysed 53,044 colorectal cancer cases identified from the Singapore Cancer Registry between 1968 and 2019.

Among these, 6,183 cases involved individuals aged 20 to 49 who were diagnosed with early-onset colorectal cancer.

The study found that the age-specific incidence rate of early-onset colorectal cancer increased from 5 per 100,000 population in 1968 to 9 per 100,000 in 1996, rising at an annual rate of 2.1 per cent.

This was followed by a slower increase to 10 per 100,000 in 2019, rising at 0.64 per cent annually.

The data also revealed demographic differences. 

Malays experienced a rapid and persistent rise in colorectal cancer incidence across all age groups. Among Chinese aged 20 to 49, however, only rectal cancer cases showed an upward trend.

Colorectal cancer is the most common cancer among men and the second most common cancer among women in Singapore, after breast cancer.

Dr Lionel Chen, consultant at SGH’s department of colorectal surgery, says early-onset colorectal cancer makes up 10 to 12 per cent of all colorectal cancer cases diagnosed every year, and about one in 10 patients may be younger than 50 years old.

Assistant professor Dawn Chong, senior consultant at NCCS’ division of medical oncology, says younger people who are diagnosed with colorectal cancer may have hereditary conditions.

These include familial adenomatous polyposis (characterised by the development of numerous polyps in the colon and rectum) or hereditary non-polyposis colorectal cancer.

Both Dr Chen and Prof Chong were involved in the study. 

Family history plays a part

Dr Chen says a family history of colorectal cancer, particularly in close relatives like parents or siblings diagnosed at a young age, significantly increases an individual’s risk of developing early-onset colorectal cancer.

Dr Chen adds that people with such a family history are often advised to start screening at 40 years old, or 10 years younger than the age of the youngest family member diagnosed with colorectal cancer, whichever comes first.

It was not until Mr Lee spoke with his family that he discovered a significant family history of colorectal cancer on his father’s side. His grandmother, aunt, cousin and uncle had all been diagnosed with the disease.

Receiving a cancer diagnosis was shocking for Mr Lee, who was working in sales and doing a part-time degree in psychology and criminology.

He grappled with questions like, “Why me?” and “What’s next?”. The fear of the unknown and uncertainty about his future led him to experience anxiety.

After seeing a psychologist, he learnt to accept his condition, focus on treatment and take life one step at a time.

The effects of chemotherapy took a toll on Mr Lee. His fingers and feet would constantly feel numb, and he lost most of his sense of taste. 

“The most serious symptom was fatigue. Some days, I could barely get out of bed or do anything because I felt completely drained. It was like experiencing a hangover, but three times worse,” he says.

Processed meat, lack of exercise can raise risk

Early-onset colorectal cancer can also develop without a family history, often due to lifestyle and environmental factors, says Prof Chong. 

A diet high in processed and red meat, which has become more common in Asia due to urbanisation and Western influences, increases the risk, she says.

Other contributing factors include a lack of physical activity, smoking, high alcohol consumption, a low-fibre diet and obesity.

Experts say a mix of such factors, including genetics and how proactive people are in seeking medical help or going for screening, has likely led to higher colorectal cancer rates among the Chinese and Malay populations.

However, there are also people who have been diagnosed with colorectal cancer even though they have no risk factors.

Dr Chen had a patient in her 20s who had intermittent abdominal cramps for a few months and was thought to have irritable bowel syndrome. 

She developed worsening abdominal pain, had bloatedness and vomiting, and was diagnosed with colon cancer, which required surgery and chemotherapy.

She maintained a healthy lifestyle, exercised regularly, did not smoke and had no family history of the condition.

Pay attention to symptoms

Most individuals diagnosed with early-onset colorectal cancer have symptoms, with the most common being blood in the stools, abdominal pain and change in bowel habits, notes Dr Chen.

Prof Chong adds that younger patients are more commonly diagnosed at an advanced stage compared with older patients. This means they are more likely to experience symptoms, as the early stages of colorectal cancer may have no noticeable signs.

In 2022, IT business analyst W.T. Tan was diagnosed with Stage 2 rectal cancer at the age of 42. 

He had noticed blood in his stools, but dismissed it as a symptom of haemorrhoids as he had a history of the condition. 

He waited two to three months before seeing a GP, who prescribed haemorrhoid medication. The treatment appeared to work initially, but the bleeding returned after a week.

After multiple visits to the GP and no improvement, Mr Tan, now 45, saw a specialist at a private clinic.

A colonoscopy revealed a tumour in his rectum. To treat the cancer, he underwent surgery to remove the tumour.

Mr Tan, who is married and has a son, advises people to listen to their bodies. Reflecting on his own experience, he says: “I ignored the symptoms of blood in the stools.” 

He encourages those hesitant to discuss health concerns with family or friends to turn to reliable sources like HealthHub for information, and consult a doctor.

Mr Lee, who has been in remission since May 2023, continues to go for follow-up checks at Ng Teng Fong General Hospital every six months. 

Even though he has recovered, he decided to join the SemiColon support group at Singapore Cancer Society in 2024. 

Says Mr Lee: “I know how it feels to be diagnosed with cancer, so I wanted to provide support to people who are going through a similar journey.”

With close to 300 members, the SemiColon support group provides a space for colorectal cancer patients to connect, share experiences and receive guidance from peers and healthcare professionals.

The rising incidence of colorectal cancer among younger adults, Dr Chen says, may suggest a need to re-evaluate the recommended screening age and consider extending it to those from the age of 45.

This would be similar to the guidelines on colorectal cancer screening published by the American Cancer Society and United States Preventive Services Taskforce. 

In Singapore, the current recommended age for colorectal cancer screening for people at average risk is 50.

Average risk refers to those who do not have a family history of colorectal cancer or other significant risk factors, such as inherited genetic conditions or a personal history of certain types of polyps.

However, Dr Chen adds: “The incidence of colorectal cancer in Singapore among young adults is not as high as those above 50 years of age, and the cost-effectiveness of lowering the age of colorectal screening must be considered as it may add substantial costs to the healthcare system.”

Tips to lower risk

To reduce the risk of colorectal cancer, experts recommend adopting a healthy lifestyle, which includes eating a balanced diet rich in fruit, vegetables and whole grains, as well as exercising regularly.

In addition, limit the intake of red and processed meat, avoid excessive alcohol consumption, do not smoke and maintain a healthy weight. 

“If you have a family history of colorectal cancer, consider discussing earlier screening options with your doctor,” advises Dr Chen.

Until April 30, you can register for the #My1stColonoscopy free colorectal screening organised by 365 Cancer Prevention Society and Icon Cancer Centre. Find out more about the eligibility criteria and register at str.sg/sV3Z

Article repurposed from The Straits Times, by Amrita Kaur is a journalist at The Straits Times, where she covers the evolving healthcare landscape in Singapore, including mental health and wellness.