Removing healthy breast: More S'pore women opting for questionable move

SINGAPORE - When Ms Karen Chia, 38, found out last year that she had cancer in her left breast, she decided her right breast had to go as well.

It was the same decision Ms Tan Poh Hoon, 44, made when a lump in her right breast turned out to be cancerous.

They are among an increasing number of women here, with early-stage cancer in one breast, who are choosing to have their cancer-free breast surgically removed as well.

It mirrors a trend in the Western population that has existed for the last 15 years.

But would such a drastic step benefit women with breast cancer?

Removing the healthy breast effectively reduces the risk of cancer in that breast by 91 per cent to 96 per cent in high-risk patients, which includes women with hereditary breast cancers and those who have had extended radiation treatment covering the chest, neck and armpits.

Its benefits for those who do not have such risks, however, are much fewer, according to research.

Still, this strategy is increasingly being adopted in the United States, although the number of patients with BRCA gene mutations, which predispose them to cancer, is not on the rise, said Dr Ong Kong Wee, a senior consultant in surgical oncology at the National Cancer Centre Singapore (NCCS).

Curious about the use of preventive mastectomy in an Asian population,

Dr Ong and his surgical resident, Dr Sim Yi Rong, conducted a retrospective review of all patients who had breast cancer surgery from 2001 to 2010 at the cancer centre.

They found a three-fold increase in the number of women, over the time period, who chose to have their healthy breasts surgically removed.

The study, which was published last October in an Elsevier journal, The Breast, is the first Asian report on such rates and trends in Singapore, which has the highest incidence of breast cancer in Asia, said Dr Ong.

There has been a near-three-fold increase in the incidence of breast cancer, or an annual increment of almost 4 per cent, from 1968 to 2002.

The reasons are most likely lifestyle factors, such as obesity and not having children, and the move towards a Western diet, experts say, but also better and early diagnoses and treatment.

Fear a driving factor

For the last 30 years, breast cancer has been the most common malignancy among Singaporean women, accounting for almost three in 10 of all female cancers.

Dr Ong's study showed that between 2001 and 2010, 30 women chose to have their healthy breast removed out of the 5,130 who had surgery for breast cancer.

While the overall rate of this type of surgery was low, there was a three-fold increase over the time period, from 0.46 per cent in 2001 to 1.26 per cent in 2010, said Dr Ong.

The patients were Singaporean women known to have primary cancer in one breast and no evidence of cancer in the other breast.

The most commonly cited reason for choosing to remove the healthy breast was the fear of developing a tumour in that breast, the study showed.

One patient expressed surveillance fatigue, both financial and emotional, meaning the regular check-ups were taking their toll.

Only one of these 30 patients had genetic screening done and was found to carry the BRCA gene, which increases the risk of getting breast cancer.

Five women had their healthy breasts removed at a later date when they developed either a clinically benign-looking breast lump on the remaining breast or a nipple discharge, triggering their fear of cancer.

The women who chose to remove their healthy breasts were also in the younger age group, said Dr Ong.

Many studies confirm that it tends to be younger women who choose to remove the other breast, contrary to the assumption that preserving the breast may be more important for them, he said.

The study also looked at whether the preventive mastectomy was justified.

It found that three, or 10 per cent, of the women had cancer in the breast which was removed, which they did not know about before they had it removed.

And two women, or 7 per cent, had high-risk lesions (abnormalities) in the removed breast.

This sounds like a high percentage, but the truth is more complicated, said Dr Ong.

First, the small sample size of 30 women could have falsely elevated the percentage, said Dr Ong.

Second, there may be an element of "over-diagnosis" as current statistics show that the incidence of women having cancer clinically detected in the other breast at the same time or in the next five years is only about 4 per cent.

This means that some very small tumours may be present but never become life-threatening, said Dr Ong.

So for the vast majority of women with cancer in one breast, having the other breast removed may bring peace of mind, but the move may well be unnecessary.

Limited benefits

Limited benefits

New research findings presented last October at the 2013 Clinical Congress of the American College of Surgeons suggested that women without the BRCA gene mutation who underwent such preventive surgery when they had early-stage breast cancer did not live significantly longer than women who did not have such surgery.

Researchers compared the two groups of women and estimated that women in the first group may live a maximum of six months longer.

The data was culled by researchers from the Early Breast Cancer Trialists' Collaborative Group and the Surveillance, Epidemiology and End Results programme, which included information on the treatment and survival of more than 100,000 women with early-stage breast cancer and who had participated in randomised trials over the last 30 years in the US.

Associate Professor Philip Iau, senior consultant and leader of the breast oncology tumour group at the National University Cancer Institute (NCIS), Singapore, said other studies show women who have preventive surgery when they are not considered high-risk patients derive just 2 per cent more benefit in surviving five years.

The NCIS has not done its own study, but doctors there have not noticed a trend in breast cancer patients seeking to have their healthy breasts removed, said Prof Iau.

However, there is a small subset of patients for whom such surgery is certainly beneficial.

These are patients who carry a mutation in the BRCA1 and BRCA2 genes, said Prof Iau. Over half of these patients can be expected to develop cancer in the other breast within the next five to seven years, he said.

Potential carriers with these mutations can usually be identified by examining their family histories of breast or ovarian cancer.

They also tend to get the disease at a relatively early age, usually below the age of 40, said Prof Iau.

At NCCS, women who do not have a BRCA1 or BRCA2 mutation but who request to have their healthy breasts removed, may do so only after much counselling by breast surgeons and specialist breast-care nurses, said Dr Ong.

They would talk to the patient about the chances of cancer occurring in the other breast or spreading elsewhere and the benefits of surgery.

This is to help her decide whether removing a healthy breast would improve her odds of being alive 10 to 20 years from now.

For women who are planning reconstructive surgery at the same time, there will be a need to manage the expectations of just what a reconstructed breast looks and feels like, and the cost and possible complications of the procedure, said Prof Iau.

Dr Ong added that such preventive surgery is clearly indicated only in women carrying the BRCA gene mutation and is not encouraged in all other cases.

"For the vast majority of cases, what is more important is close surveillance and early detection of breast cancer," he said.

wanching@sph.com.sg

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