| It is not yet fully understood what the hormonal risk | | | | the first period and the first pregnancy. There is a lot |
| factors are, but there have been some interesting | | | | of speculation as to why this is so. One possible |
| clues. It is known that it has something to do with | | | | explanation is that between menarche and the first |
| age and the menstrual cycle: the younger the woman | | | | pregnancy the breast tissue is especially sensitive to |
| is at her first period and the older she is when she | | | | carcinogens (cancer promoting agents). This seems |
| goes to menopause, the more likely she is to get | | | | to be true. Several factors such as diet, alcohol |
| breast cancer. It seems that the longer a woman has | | | | consumption and radiation exposure all seem to have |
| reproductive levels of hormones, the more | | | | a greater effect on a woman's breasts between her |
| susceptible she is to breast cancer. If she | | | | first period and her first pregnancy than they do |
| menstruates at more than 40 years of age, she | | | | later. Thus, the developing breast is more susceptible |
| seems to have a particularly high risk. If the ovaries | | | | to carcinogens than the breast that has gone |
| are removed early and no hormone replacement is | | | | through its complete hormonal development. The |
| given, the risk of getting breast cancer is greatly | | | | increased vulnerability may relate to the cells' |
| reduced. It is not exactly an all-cure, sadly, since it | | | | capability of mutating up until the first pregnancy. |
| would also heighten the danger of osteoporosis. If a | | | | There seems to be something about the first |
| woman has had a hysterectomy (removal of the | | | | pregnancy of a woman that halts the cells from |
| ovaries), it may or may not influence her vulnerability | | | | being able to sustain a mutation, the greater the |
| to breast cancer, depending upon whether the | | | | chance that they'll mutate in response to a |
| ovaries, as well as the uterus, are removed. If a | | | | carcinogen and in a way that develops into breast |
| woman still has her ovaries, her body is still going | | | | cancer. |
| through hormonal cycles, even though there aren't | | | | A factor relating to the number of menstrual cycles |
| any more periods. | | | | is breast-feeding. Recent findings have shown that |
| Pregnancy also seems to affects breast cancer risk. | | | | women who breast-feed for a long period of time, |
| Women who have never been pregnant appear to | | | | more than 6 consecutive years, have a decreased |
| be more at risk than women who have had children | | | | risk of breast cancer. In addition, women who have |
| before the age of 30 and women who have their | | | | had early pregnancies and have breast-fed have a |
| first pregnancies after 30 have a greater risk than | | | | diminished risk of subsequent breast cancer. This is |
| women who have never been pregnant at all. The | | | | most likely related to fewer ovulatory cycles at a |
| hormones of pregnancy carried to term will mature | | | | crucial moment in the reproductive life. |
| the breast tissue in a young woman. The same | | | | It is now obvious that most studies on hormonal risk |
| hormones after 30 may actually stimulate breast | | | | factors of breast cancer are still very much at the |
| tissue that has already been mutated. Several studies | | | | theorizing stage: as yet, it is not known why there is |
| indicate that a pregnancy that ends in miscarriage or | | | | this vulnerable time in a woman's life and why or how |
| abortion slightly increases breast cancer risk. | | | | internal hormones affect breast cancer. |
| The key seems to be the amount of time between | | | | |