Abortion and Breast Cancer

During pregnancy, a woman's body undergoes a miraculous transformation.  A pregnant woman's hormone levels increase rapidly during this time by producing very high levels of estrogen and progesterone.  This surge in hormones induces the breast cells to divide and start a maturing process (differentiation) whereby they are changed into mammary (milk-producing) glands.  When a woman has an induced abortion, however, she cuts off this natural process of differentiation, leaving the breast cells in a state of transition and thus more vulnerable to carcinogens.  Once a woman has completed her pregnancy and given birth to her child, her breast cells will have finished the maturation process and will become stable again.  This is why girls and women who had an induced abortion before are at a much higher risk for breast cancer. 

Lack of Advocacy 

It would seem that advocates for women's issues would embrace the discovery of a major cause of breast cancer and spread the word to reduce the risk of the disease.  However, since breast cancer research could negatively affect the abortion industry, groups such as NOW and Planned Parenthood dismiss the research. 

Planned Parenthood makes over $40 million a year on abortion, and apparently the windfall cuts into concern for women's health.  In fact, abortion rights activists exiled Dr.  Janet Daling, who is pro-choice, after she found a connection between breast cancer and abortion. 

Breast cancer strikes at least 180,000 women each year.1 Advocacy for women demands that we put this issue at the forefront.  If a procedure can double a woman's chances of having breast cancer, she has the right to know. 

Recent Developments 

To this date, 37 studies have been conducted worldwide on the abortion/breast cancer link, and over 75 percent of them (28 studies) have shown that abortion is a risk factor for breast cancer.  Many of these studies were at least partially funded by the National Cancer Institute (which still denies evidence of a positive association).  Janet Daling at the Fred Hutchinson Cancer Research Institute in Seattle says in her 1994 study that, “[a]mong women who had been pregnant at least once, the breast cancer rate in those who had experienced an induced abortion was 50 percent higher than among other women.  Highest risks were observed when the abortion was done at ages younger than 18 years…or at least 30 years of age or older.” The 12 women who had a family history of breast cancer and had obtained abortions when they were teenagers all developed breast cancer! 2 

Despite years of studies affirming a link between abortion and breast cancer, a recent Danish study has caused pro-abortion sources to claim that the link is false.  The study, conducted by Dr. Mads Melbye, contains a very basic flaw.  For the duration of 20 years, Dr. Melbye studied a group of women who carried pregnancies to term.  In contrast, he studied a group of women who had abortions for less than 10 years.  3 This flaw corrupts the study in a very obvious way.  Breast cancer generally does not afflict women until they reach their midlife years.  Before age 30, the incidence rate for breast cancer is 1 in 2,525.  By age 45, the rate is 1 in 93. 4 

If a woman's progress is not charted during her midlife years, of course an encounter with significant occurrences of breast cancer will not be evident! Dr. Melbye did this with the half of his study which included women who had abortions, showing these women to have a low prevalence of risk.  However, he continued to chart the women who carried pregnancies to term as they entered the years of greatest risk for breast cancer, which artificially raises the prevalence of breast cancer. 

Oddly, just a decade ago, a previous Danish study (with some of the same women) found a 191 percent increased risk of breast cancer among women who had an induced abortion.5 

Studies that Found a Link

  • Three months before Melbye found “no relationship” between abortion and breast cancer, the British Medical Association had concluded just the opposite, basing its conclusion on 23 different studies. 6
  • In November 1994, Dr. Janet Dalin of the Fred Hutchinson Cancer Research Center found a 50% increased risk of cancer in subjects who had undergone abortion. 7
  • Joel Brind, Professor of Biology and Endocrinology at Baruch College of the City, University of New York, compiled almost every cancer-risk study taken since 1957.  His conclusion: breast cancer risk is 30 percent higher for women who have had induced abortions.
  • The Journal of the National Cancer Institute published a study in its December 4, 1996 issue by two Danish researchers involving 918 Dutch women which concluded the following: “A history of induced abortion was associated with a 90 percent increased risk for breast cancer.” The researchers found no such association among women who had given birth. 




  1. American Cancer Society. Cancer facts and figures. Atlanta: American Cancer Society, 1999:36. 
  2. Dr. Janet Daling, Risk of Breast Cancer Among Young Women, J. Nat. Ca. Inst., Vol. 86, No. 21, 11/2/94, pp. 1584-1592. 
  3. Brind J, et al. Induced abortion and the risk of breast cancer. N Engl J Med. 1997; 336: 1834.
  4. Feuer EJ, Wun L-M, Bering CC, et al: J Natl Cancer Inst 1993; 85:892
  5. Brind J, First Things 73 (May 1997): 12-15.
  6. Brind J, First Things 73 (May 1997): 12-15.
  7. Dr. Janet Daling, Risk of Breast Cancer Among Young Women, J. Nat. Ca. Inst., Vol. 86, No. 21, 11/2/94, pp. 1584-1592.