Women diagnosed with cancer in one breast often face a difficult decision of whether to surgically remove both, and a new study found double mastectomies may be performed too often.
The surgery does not increase survival in most women, and is typically recommended for about 10 per cent of those considered at high risk for breast cancer.
Some 69 per cent of women who underwent surgery to remove a healthy breast did not have major family or genetic risk factors, said the study published in the Journal of the American Medical Association.
Meanwhile, just a quarter of women who did face a higher risk of future cancer had the recommended surgery to remove both breasts.
Women with certain mutations in the BRCA1 and BRCA2 genes, or who have a strong family history of breast cancer, are usually advised to have both breasts removed after a diagnosis in one, to avoid a recurrence.
The procedure and recommendation received widespread publicity when actress Angelina Jolie revealed last year that she had the BRCA1 mutation and had undergone a double mastectomy.
However, some women instead "appear to be using worry over cancer recurrence to choose [the removal of both breasts]," said lead author Sarah Hawley, associate professor of internal medicine at the University of Michigan Medical School.
"This does not make sense, because having a non-affected breast removed will not reduce the risk of recurrence in the affected breast," Hawley said.
The research was based on a sample of 1,447 US women, average age 59, who were diagnosed with stage 1-3 cancer in one breast.
Nearly 8 per cent of the women had both breasts removed, 35 per cent had just the affected breast removed, and nearly 58 per cent had breast conservation surgery, in which only the lump is taken out.
Researchers found that women with higher education levels were more likely to choose to have both breasts removed, with concern about the disease surfacing in the healthy breast listed as a pressing factor.
These women could be driving a rise in double mastectomy operations over the past decade, even though the procedure carries an increased risk of surgical complications and a longer recovery time, researchers said.
An accompanying editorial by Shoshana Rosenberg and Ann Partridge of the Dana-Farber Cancer Institute in Boston pointed out the emotional complexities that women face after receiving a diagnosis of breast cancer.
"Anxiety and fear certainly hamper optimal decision-making," they wrote.
"While [double breast removal] might be considered overtreating women ... it might still be the right choice for some women for risk reduction, cosmetic, and/or emotional reasons."
They urged doctors to share the decision-making process with patients in order to find "balance around this issue".
Mexico City breast-feeding ad campaign comes under fire
Mexico City thought it had a racy but catchy advertising campaign for its effort to boost the low level of breast-feeding by Mexican mothers, going with a slogan that roughly translates as "give your breast to your child, don't turn your back on them".
But the adverts have drawn a storm of protest. Mothers and women's groups say the government is trying to make women feel guilty instead of addressing real-life barriers to breast-feeding. They say many women need proper nutrition, more information, more maternity leave and permission to breast-feed or pump milk at work.
The adverts "condemn mothers, rather than informing them about breast-feeding, and they reduce a social problem with multiple players - fathers as well as mothers, workplaces, health authorities, and public spaces and the community at large - to one person: the mother," a group of activists wrote in a complaint to the city's human rights commission.
City officials were seeking to address the fact that only one in seven mothers in Mexico breast-feeds exclusively in the first six months, the standard recommended by the World Health Organisation.
"It doesn't look like they did any diagnosis as to why women don't breast-feed," said Regina Tames, director of the Group for Informed Reproductive Choice. "They just lighted on a banal argument that women were selfish and don't want to mess up their bodies."
Adding insult to injury, the adverts also feature thin actresses and entertainers in topless poses, with a banner stretched strategically across their chests, exposing only suspiciously flat tummies.
An official at the city's health department, who was not authorised to be quoted by name, denied media reports that the print and internet adverts had been withdrawn, but acknowledged the campaign was being reworked. The official said that the slogan about "turning your back" will be changed and that the next phase of the campaign may include more average, everyday mothers.