Could lifestyle factors and behaviours affect the chances that a breast cancer survivor would develop cancer in the other breast?
A study analyzed data on 1,091 women, 40 to 79 years old, who had been treated successfully for breast cancer, including 365 who subsequently developed a new cancer in their other breast.
Women who were considered obese (with a body mass index of 30 or higher) when first diagnosed were 40% more likely than non-obese women to develop a second cancer. Those who consumed one or more alcoholic drinks a day were 70% more likely than no-drinkers to have a second cancer. The likelihood was about doubled among women who smoked, compared with those who had never smoked. Those who smoked and also had one or more alcoholic drinks daily had a seven-fold greater risk for cancer in other breast than did women who smoked or drank less.
Who may be affected? Breast cancer survivors, who have a considerably greater chance of developing a tumor in their other breast than the average woman who does of getting an initial breast cancer diagnosis.
Some of the lifestyle data came from the women’s responses to questionnaires. The first breast cancer for all participants was oestrogen receptor-positive; whether the findings would apply to women with oestrogen receptor-negative tumors was not tested.
(Source: Journal of Clinical Oncology, September 8, 2009)
