Anti-choice Claims About Abortion and Breast Cancer
Undaunted by the absence of compelling evidence associating induced abortion with a woman’s risk of developing breast cancer, anti-choice extremists insist on making the connection anyway. Once more they are using misinformation as a weapon in their campaign against safe, legal abortion. In the guise of an ostensible concern for women's health, these ideologues point to inconclusive, and at times flawed, studies for alleged evidence of a possible association, while ignoring or dismissing overwhelming evidence that induced abortion does not place women at greater risk of breast cancer. Neither the National Cancer Institute nor the American Cancer Society recognizes the reliability of such an association (ACS, 1999; NCI, 1999). Yet anti-choice zealots have drawn highly questionable conclusions to develop "public education" campaigns such as the advertisements sponsored by Christ’s Bride Ministries that appeared on public transportation vehicles in Philadelphia warning that "women who choose abortion suffer more and deadlier breast cancer" (Slobodzian, 1999). Anti-abortion foes are also lobbying for legislation that would require telling women who are considering abortion that having one would place them at in increased risk for breast cancer (Querido, 1999).
While researchers do not know what causes breast cancer, reproductive factors have been associated with risk for the disease since the 17th century, when breast cancer was noted to be more prevalent among nuns. It is known that having a full-term pregnancy early in a woman's childbearing years is protective against breast cancer, and some studies have also indicated that breastfeeding, especially in women who are young when they give birth, may reduce a woman's risk of developing the disease. A woman's age at menarche and menopause also influence her risk for breast cancer, with earlier onset of regular menstrual cycles and later age at menopause associated with higher risk (Kelsey & Gammon, 1991). However, the best available evidence — from large population-based cohort studies — shows no net effect that induced abortion places women at increased risk for developing breast cancer (Bartholomew & Grimes, 1998).
Hypothesis: Hormones Lead to Breast Cell Differentiation
The theory linking pregnancy termination and breast cancer is based on the hormonal disruption that occurs when a woman's pregnancy is interrupted. Pregnancy initiates a surge of sex hormones (estrogen, progesterone, and prolactin), which leads to differentiation of the cells in the breast glands in preparation for lactation. The changing concentrations of hormones during the second and third trimesters of pregnancy lead to increased differentiation. In a first pregnancy, the results of these hormonal changes permanently alter the structure of the breast. Adherents of this theory claim that interruption of the first trimester of a first pregnancy causes a cessation of cell differentiation that may result in a subsequent increase in the risk of cancerous growth in these tissues (Brumsted & Riddick, 1990; Westhoff, 1997). Attempts to prove this theory, however, have failed.
Many Factors Contribute to Inconclusive Study Results
At least 75 research studies worldwide have collected data about breast cancer and reproductive factors such as childbirth, menstrual cycles, birth control pills, and abortion. Approximately 25 studies have examined the risk of developing breast cancer for women who have had abortions. Cancer researchers at the National Cancer Institute, the American Cancer Society, and major universities say that the most reliable studies show no increased risk, and they consider the entire body of research inconclusive (ACS, 1999; NCI, 1999; Rosenfield, 1994?).
A number of factors may render a study unreliable:
Miscarriages and induced abortion affect a woman’s body differently but many studies have not distinguished between them.
Many women do not report miscarriages because they are unaware they have had them.
Abortions are often unreported because of the privacy of the decision to terminate a pregnancy.
Some studies have not examined the possibly different effects of abortion after or before a full-term pregnancy.
Other studies have not been careful to examine the impact of age at the time of abortion and age at the time of first childbirth.
Many studies have been too small to be statistically significant. |
