Do Birth Control Pills Increase Your Risk Of Breast Cancer?
A study published in the prestigious Journal of the American Medical Association (10/11/00) evaluated whether there was any increased risk of breast cancer in women who have a strong family history of breast cancer already.† They found that there was a significantly increased risk of breast cancer in these women IF they had taken birth control
pills BEFORE 1975 when the hormone dosages were generally much higher than
they were after 1975 (which were much higher even than they are now).
The study found that among sisters and daughters of women with breast cancer,
users of the pill before 1975 were three times more likely than non-Pill users
to get the disease.† If at least five family members had breast or ovarian cancer,
pill users faced an 11-fold risk compared to non-users.
It is important to note, however, that granddaughters of women with breast cancer did not appear
to be at increased risk for breast cancer.† The researchers suggested the risks
were probably only associated with older forms of the pill made before 1975.
†Another reason for this finding may be because the granddaughters' average
age was 43 and therefore many of them may not have developed breast cancer yet.†
The size and duration of this study is too small to determine this.
Birth control pills have long been thought to increase women's risk of breast
cancer only slightly, by about one additional cancer in 20,000 women. †Recent
research has suggested the risk "disappears" after women stop taking them. †In
addition, physicians have long suspected that the "increased risk" of breast
cancer in women taking birth control pills may actually be attributed to what
we call a "surveillance bias".† That means that women taking birth control pills
are more likely than women not taking the Pill to have their annual physical
exam including a clinical breast exam and thus more likely to be referred earlier
for mammography if they have a suspicious lump. †The authors' of this study
were careful to comment that women with a strong family history of breast cancer
are also much more likely to be very vigilant in doing breast self-exam and
having regular screening mammography.
The details of this study:
The study was primarily conducted by epidemiologists from the University of
Minnesota and the Mayo Clinic Cancer Center. ††It included 3,396 blood relatives
of 426 women diagnosed with breast cancer between 1944 and 1952.† It is the
first multigenerational study of its type.
After 50 years of identifying the original 426 women, their living relatives
were questioned and their medical records were reviewed between 1991 and 1996.
The findings suggest that the pill-linked risks are in women with the
BRCA genetic mutations associated with breast and ovarian cancer, although it
is very important to note that genetic testing was not actually performed
in the study.