The results of a new study support the theory of a direct correlation between breast cancer diagnoses and exposure to distressing life events, according to a Reuters report on the findings published in online BioMed Central journal BMC Cancer.

The research was carried out by Dr Ronit Peled and other researchers at the Ben-Gurion University of the Negev, Beer Sheva, in Israel, compared 255 women below the age of 45 diagnosed with breast cancer, with 367 women of similar age in good health.

The research team considered links between breast cancer and stressful life experiences, including bereavement or divorce of parents before the age of 20, as well as moderately stressful events such as job loss, serious illness in a close relative, or separation from a spouse.

In a telephone interview with Reuters Health, first author Dr Peled said, "Young women who are exposed to severe life events more than once should be considered as a risk group for breast cancer and treated accordingly."

Even taking into consideration other potentially influencing factors, researchers still identified a positive association between breast cancer and the experience of more than one severe life event, reports Reuters.

Such women were 62 per cent more likely to develop breast cancer than women who had not encountered an extremely stressful event in their life.

Researchers also found breast cancer sufferers to have higher scores of depression and lower scores of happiness and optimism than healthy women.

Peled said that happiness and optimism seemed to offer natural protection against breast cancer.

"The more you are happy and feel optimistic with your life, the less the probability of developing breast cancer," he was quoted as saying by Reuters.