SINGAPORE - In 2015, Ms Ong Li Hui was breastfeeding her son when she felt pain on the left side of her breast.

She thought it was due to a clogged milk duct, but it grew more intense as months passed. Finally, she went for a check-up after finding a lump in her left breast.

A biopsy in October that year found that the receptionist-cum-administrative assistant, who was then in her 30s, had stage 3 cancer. Though cancer cells were found only in her left breast, she decided to undergo a bilateral mastectomy - the removal of both breasts - to prevent the spread of the cancer to the right breast.

She thought that would put an end to her ordeal, but in December last year, a check-up showed that the cancer had spread to her hip bone. This meant she had advanced breast cancer, also referred to as metastatic or stage 4 breast cancer - that has spread to other parts of the body, such as the bones, lungs or brain.

Ms Ong, 41, who has two sons aged seven and 11, was "shocked" and "lost" following the diagnosis. "It was quite a blow to be told I had late-stage cancer."

In recent years, more women are being diagnosed with advanced breast cancer.

There were 910 such cases recorded from 2011 to 2015, up 697 cases from 2006 to 2010, according to the Singapore Cancer Registry's Annual Registry Report 2015, which was released in 2017.

There are also more younger women being diagnosed with breast cancer. From 2011 to 2015, 4,616 women below age 54 were diagnosed with breast cancer, up from 4,577 from 2006 to 2010.

In Singapore, it is the leading cancer among women, with 9,634 new cases recorded from 2011 to 2015. It is the top killer among all cancers diagnosed in women.

About four in five patients with stage 4 breast cancer do not live past five years, notes Dr Lee Guek Eng, a senior consultant at Icon Cancer Centre.

Dr Tira Tan, a consultant at the National Cancer Centre Singapore's division of medical oncology, says there is a need to raise awareness about the disease because its incidence is "rising exponentially".

"This includes breast cancer of all stages affecting women of all ages. Young women are not spared," she adds.

The rise in breast cancer cases among pre-menopausal women may be due to factors such as a delay in childbirth, alcohol consumption, smoking, and an unhealthy and sedentary lifestyle, says Dr Tan.

The main risk factors for breast cancer include age, race, family and personal history of cancer, early onset of menstruation and late menopause.

Symptoms of advanced breast cancer include a lump in the breast, neck or under the arms, nipple discharge, persistent bone pain, persistent cough, shortness of breath and headache.

Dr Lee says many young women do not associate a lump or other symptoms as a sign of cancer, as they think they are young and not at risk.

"This means that when they eventually visit a doctor, the cancer would usually be larger, more aggressive and diagnosed at an advanced stage," Dr Lee, a specialist in medical oncology, adds.

Dr Tan says that while advanced breast cancer is not curable, it can be treated and managed through treatments such as chemotherapy, immunotherapy and hormone therapy, depending on the sub-type of the cancer.

Both doctors stress the importance of seeking medical attention early if there are signs and symptoms of advanced breast cancer.

A communications executive, who wanted to be known only as Amanda, wasted no time in going for a check-up when she felt a lump in her right breast in 2016. She was diagnosed with advanced breast cancer, and last year, she found out it had spread to her lungs and brain.

The 35-year-old is now on oral targeted therapy and hormone therapy to treat the cancer.

She says: "The news of the disease spreading came as a shock, but I knew I had to face it without fear. I even asked one of my friends to make sure my funeral matters are taken care of, because I do not want my parents to worry."

The illness put a strain on her marriage and led to a divorce in December last year.

But she has nevertheless tried to remain positive. "My friends and family have supported me through the journey and encouraged me," she says.

Both Ms Ong and Ms Amanda have adopted a healthier lifestyle - cutting down on dessert and fast food and eating more fruit and vegetables. They also make it a point to exercise every week.

While there is no sure way to prevent cancer, the risk can be lowered through a healthy diet and regular exercise, says Dr Tan.

This includes doing 150 minutes of moderate-intensity aerobic activity a week, limiting alcohol consumption, not smoking and maintaining a healthy weight.

The Health Promotion Board also recommends women aged 40 to 49 to go for a mammogram once a year, and women aged 50 and above to go once every two years.

Says Dr Tan: "A mammogram is important as early stages of breast cancer may show no signs or symptoms. The earlier a cancer is found, the better the treatment options and the greater the chances of survival."

Five myths about advanced breast cancer

1. Myth: Young pre-menopausal and healthy women are spared from advanced breast cancer.

This is false. Younger women can develop advanced breast cancer.

2. Myth: There are limited options to treat advanced breast cancer.

This is false. There are different sub-types of breast cancers, broadly categorised by the expression of proteins such as the oestrogen receptor, progesterone receptor and human epidermal growth factor receptor on the tumour cells.

Treatment of advanced breast cancer is tailored to the different sub-types of breast cancer and may include surgery, radiation therapy, chemotherapy, targeted therapy, hormone therapy or immunotherapy.

3. Myth: Advanced breast cancer is a death sentence.

This is false. There has been significant improvement in diagnostics and treatment, and survival rates have gone up. While not curable, advanced breast cancer is treatable.

4. Myth: Advanced breast cancer requires more aggressive treatment than earlier-stage breast cancer.

This is not necessarily so. The goal of treatment for advanced breast cancer is to optimise tumour control while minimising symptoms related to the disease or treatment. Often, the treatment of advanced breast cancer is better tolerated than that of early breast cancers.

5. Myth: A bilateral mastectomy (surgically removing both breasts) prevents advanced breast cancer.

No. While a bilateral mastectomy may be considered a risk reduction strategy in women at high risk of breast cancer, it does not eliminate the risk of advanced breast cancer.

• Source: Dr Tira Tan, a consultant at National Cancer Centre Singapore's division of medical oncology