SINGAPORE - More women over the age of 50 in Singapore are going for their first breast cancer screening, but most still do not get a second check-up done two years later.

From 2014 to 2016, the number of women who went for their first mammogram rose by around 1,000 each year - from 6,550 in 2014 to 8,598 in 2016, the latest statistics from the Health Promotion Board show.

But from 2016 to 2018, more than four-fifths of them did not go for a second mammogram, despite this age group being at risk of breast cancer.

The rates for women getting a second mammogram were 13.6 per cent in 2016, and rose to around 18 per cent in 2017 and last year.

These numbers are a cause for worry as breast cancer remains the most common cancer among Singaporean women, with one in 14 suffering from the condition before the age of 75.

Breast cancer is also the most lethal cancer among women, accounting for 17.3 per cent or 2,105 of deaths from cancer from 2011 to 2015, according to the Singapore Cancer Registry Annual Registry Report 2015.

Last year, 991 women died from the condition.

Doctors caution that an absence of abnormality in the first mammogram does not mean this will be the case in subsequent mammograms.

"For any health screening to be effective, it cannot be a one-off event," said Dr Chan Ching Wan, a senior consultant in the Division of Surgical Oncology at the National University Cancer Institute, Singapore (NCIS).

"Regular breast screening in particular is important because it allows for early detection of most breast cancers, and we know that treatment of early stage breast cancer has far better outcomes."

She added that patients often did not go for screening because of misconceptions and fears about mammograms and breast cancer.

There is usually no pain or symptom in the early stages of breast cancer.

Risk factors for breast cancer include being 40 and older, a family history of breast cancer, early onset of menstruation and late menopause, as well as having no children or having the first child at a late age, especially above 30.

Dr Samuel Ow, a consultant in the NCIS' Department of Haematology-Oncology, said that around 20 per cent and 10 per cent of breast cancer patients were diagnosed at stage 3 and 4 respectively because of poor screening uptake.

In these cases, the cancer was not picked up during a mammogram but through complaints to doctors about issues such as breast lumps or other breast abnormalities.

Dr Ow said a mammogram is by far the most reliable screening tool for breast cancer.

"Women aged 40 to 49 should discuss the option of screening mammograms once a year with their doctor, and those who fall outside of the screening guidelines should be reviewed by their doctor if they have risk factors such as a family history of breast or ovarian cancer," he added.