Major stress possibly sparked by a bereavement, a job loss or divorce can cause breast cancer, researchers have proved. Risks of developing breast cancer increase by almost 12 times if a woman has suffered stress in the previous five years.

Surprisingly, women who confront problems and try and work them out are three times as likely to suffer breast cancer as those who have an emotional response to their troubles.

Other risk factors, but ones considered of lesser importance by the researchers, included smoking and being postmenopausal. They found no evidence to suggest that environmental factors had any significant part to play.

This is a landmark piece of research because it is the first time researchers have been able to scientifically prove what has been "known" for a long time.

A team of English and Chinese psychiatrists, radiologists, surgeons and cancer specialists, led by Dr C Chen from the National Cheng Kung University Medical School in Taiwan, questioned 119 women, aged between 20 and 70, who had been referred to King's College Hospital in London with a suspicious breast lump.

By questioning them, and assessing stress levels and other factors, they were able to show that women were more than three times as likely to develop breast cancer five years or less since suffering stress. This figure leapt to 11.6 times when adjustments were made for other factors such as age and the menopause (BMJ, December 9, 1995).

l Women with early breast cancer have as good a survival rate if they have a lumpectomy, followed by radiation therapy, as women who have a radical mastectomy. A recent review of research papers has confirmed the important finding made in 1989 which began to alter the way breast cancer is treated. The original research was questioned, however, because some of the data was later found to have been falsified (BMJ, December 2, 1995).