The combination of genetic and environmental factors that may lead to the development of cancer. By browsing, we can emphasize the importance of scientifically established factors, or those who are the subject of considerable controversy.

Age, genetic factors and family history

Breast cancer can occur at any age, her risk of occurrence increases with age. It doubles roughly every 10 years until menopause. In addition, it continues to increase.

If multiple cases of breast cancer are already known in your family, it can increase your own chance of developing the disease. In developed countries, between 5 and 10% of cases are linked to genetic predisposition. This is equivalent annually in world in 1 700 to 3 400 cases.

Specifically, the risk of cancer is twice as high among women whose close relatives (sisters, mothers or daughters) have developed breast cancer before age 50. The younger age of onset, the greater the danger is great. Thus, a woman whose sister developed cancer at the age of 30-39 years has a cumulative risk of 10% of itself be affected before 65 years, but this risk falls to 5% if her sister was aged 50-54 years at diagnosis. The risk also increases when more relatives are affected. A woman with two relatives with breast cancer including one aged under 50 at diagnosis is 25% risk of developing cancer before 65 years.

The origin of this danger, we found some genes, the best known are the BRCA1 and BRCA2 (for Breast Cancer which means breast cancer). These forms are alone responsible for 95% of familial forms of hereditary breast and ovarian cancer, and 65% of familial breast cancer alone. But other predisposing genes for breast cancer were identified.

Specifically, if multiple cases of breast cancer in your family you are afraid of a genetic predisposition, talk to your doctor or your gynecologist. This may if necessary refer you to one consultations oncogenetic (genetics applied to oncology).

Puberty, pregnancy, lactation and menopause

Precocious puberty and late menopause increase the susceptibility to be affected by cancer sein3. A woman whose menopause happens naturally after age 55 are twice as likely as women affected by menopause before age 45.

The absence of pregnancy or a late age for first child can increase the chances of being affected by this tumor. Having your first child after age 30 doubles the risk of breast cancer compared to women become mothers before age 20. The increased risk is greater for women over 35 years during their first pregnancy, it is even higher than women without children. A young age at the second child also reduces the likelihood of getting sick. Breastfeeding also has a protective role vis-à-vis the onset of breast cancer before menopause.