Pill and Breast Cancer

Is the Pill Linked to Breast Cancer?

 By Deborah Sturm, RN

On September 21, 1957, journalist Mike Wallace interviewed Margaret Sanger, regarded then and today as the most prominent figure in the spread of the birth control movement in America.  In this interview, she identifies the Roman Catholic Church as society’s greatest opposition to the widespread acceptance of birth control methods, something she viewed as necessary in the alleviation of human suffering.

Ironically, Wallace not only puffed away on filterless Philip Morris cigarettes during the entire interview, he spent quite a bit of time actively promoting them during the broadcast.  Today, over half a century later, the promotion of smoking is regarded as highly unacceptable due to its established link to lung cancer.  And although smoking is still legal, it has been banned in many public access facilities.   No doubt, many class-action lawsuits against “Big Tobacco” have had a role in its stigmatization and, finally, its widespread banishment.

However, “The Pill,” a common form of birth control—approved by the FDA in 1960—is generally held in high regard today, owing to its alleged safety. Yet synthetic estrogens—a component of oral contraceptives—have come under scrutiny in the last decade or so because of their link to breast cancer.  Chris Kahlenborn, M.D., of the Polycarp Research Institute, believes that the dangers of “the Pill”   to women are minimized by contraceptive advocates.

Kahlenborn, co-author of the October 2006 Mayo Clinic Proceedings article entitled, “Oral Contraceptive Use as a Risk Factor for Premenopausal Breast Cancer: A Meta-analysis,” recently spoke to healthcare providers of the Pittsburgh Guild of the Catholic Medical Association at UPMC Mercy Hospital.  The researchers found that “21 out of 23 retrospective studies done since 1980 showed that women who took oral contraceptives prior to the birth of their first child sustained a 44% average increased risk of developing pre-menopausal breast cancer.”  The study indicates the risk rises to “52% for women who took “the Pill” for at least four years prior to the birth of their first child.”

According to the American Cancer Society, 212,920 women in the United States developed breast cancer in the year 2006, of which 40,970 women died.  One in eight women will develop breast cancer some time during her life.  (American Cancer Society, 2006)   Factors that have been implicated in an increased risk of developing breast cancer include positive family history, history of other cancers, radiation exposure, post-menopausal obesity, and alcohol consumption, to name a few.  Early menarche, late menopause, postmenopausal hormone use, and women having fewer children—factors related to hormonal activity and/or exposure—have also shown a link to its development.

A recent clinical trial by the World Health Organization reported that a woman’s risk of developing breast cancer is increased by prolonged exposure to exogenous estrogens and progestins.   Furthermore, the International Agency for Research on Cancer (IARC) recently classified postmenopausal hormone replacement and oral contraceptives as group 1 carcinogens, placing them in the same category as x- and gamma radiation, radionuclides, and asbestos.  It’s not difficult to find an article linking breast cancer and post-menopausal hormone replacement.  Many older women have used hormone replacement because of estrogen’s protective function against heart disease and osteoporosis.  However, despite the WHO’s report, the link between the use of oral contraceptives and breast cancer has gotten very little press.

The increased risk is believed to be attributed to the lack of normal glandular tissue differentiation that is associated with pregnancy.  The cellular differentiation that occurs during a full term pregnancy inhibits carcinogenic, or cancerous, changes in the cells.   Estrogen causes accelerated growth of breast tissue, and progesterone helps finish the glandular maturation process. The other pregnancy hormones—more specifically,post-pregnancy hormones—prolactin and oxytocin – play a protective (and underappreciated) role as well.

Similarly, induced abortion has been linked to an increased risk of breast cancer owing to mammary cells being left in a less differentiated, or less mature state, rendering them more vulnerable to exposure to carcinogens.

The lack of press regarding the oral contraceptive-breast cancer link, Kahlenborn says, is “probably money and pride.”  The oral contraceptive industry,” he says, “makes billions [from] OC’s each year.”  Furthermore, if the courts were to validate Kahlenborn’s study, the FDA would look pretty bad, “since they have been saying that OC’s are okay for the last fifty years.”

Perhaps light could be shed on this issue if a few rich donors took out full page ads in the New York Times or Wall Street Journal, Kahlenborn says.  But he believes that nothing less than a high-profile class-action lawsuit would be effective in exposing the pre-menopausal carcinogenic dangers of “the Pill”.

At least two articles have been written in an attempt to minimize or refute the Polycarp Research Institute’s findings.  These responses, Kahlenborn says, are merely “willful suppression.”

Suggested Reading: 

Kahlenborn, C., Moudugno, F., Potter, D., Severs, W.B.  Oral Contraceptive Use as a Risk Factor for Premenopausal Breast Cancer:  A Meta-analysis.  http://www.ncbi.nlm.nih.gov/pubmed/17036554