Why aggressive breast cancer in young women? Think hormones!

Breast cancer used to be a disease of older women. Screening with mammograms is not recommended under age 40. But now the Feb 27 issue of the Journal of the American Medical Association (JAMA) reports a near doubling in the rate of metastatic breast cancer in women age 25–39 between 1976 and 2009. The rate has been increasing slowly but steadily, and shows no sign of leveling off.

These days, young mothers of small children are facing mutilating surgery, debilitating chemotherapy, and even death. Yet there has been no corresponding increase in older women.

The American Council on Science and Health calls the increase “slight” (from 1.53 per 100,000 to 2.9 per 100,000), and suggests it could be explained by better diagnostic tests and staging. But these are not early cases, and they are occurring before the age of first mammography.

As possible causes, an article in MedPage Today suggested rising obesity rates, changes in alcohol and tobacco use, and genetics, though tobacco use has not been increasing, nor is there any rationale for an increase in cancer genes.

The obvious but unmentioned cause is hormones. Breast cancer is generally hormone sensitive, and is often treated with anti-estrogens. After the Women’s Health Initiative, many women stopped taking hormone replacement therapy out of fear of invasive breast cancer.

But since the Sexual Revolution, young women in huge numbers have taken higher doses of hormones than their menopausal sisters—in birth control pills. In 2005, the World Health Organization classified oral contraceptives as class-1 carcinogens, one of only about 100 substances found to be “carcinogenic in humans.”

The most important cause of a high estrogen level is pregnancy. By the end of the first trimester, estrogen increases by 2,000 percent, stimulating proliferation of cancer-vulnerable Type 1 and Type 2 lobules. However, by the end of pregnancy, 85 percent of breast tissue has matured into cancer-resistant Type 4 lobules because of hormones made by the fetal-placenta unit. This is why a completed pregnancy has an undisputed protective effect against breast cancer, explains breast surgeon Angela Lanfranchi. This protective effect is lost when a pregnancy is aborted, leaving the breasts in a more vulnerable state than before.

At least 29 epidemiological studies have shown a significant increase in breast cancer in women who have had an abortion. In one study, women who had abortions before age 18 and after 8 weeks gestation had a 9 times higher risk—if they had a negative family history for breast cancer. Women in this group who had a positive family history all had breast cancer before age 45.

Not all studies have shown a positive association, and the National Cancer Institute announced, in a 2003 consensus workshop, that “induced abortion is not associated with an increase in breast cancer risk.”

In 2001, however, the observed increase in breast cancer since the 1980s was found to be as predicted in a 1996 meta-analysis of studies of an abortion-breast cancer link by Joel Brind of Baruch College.

Women in the Roe v Wade generation at the very least lose the protective effect of the first full-term pregnancy if they abort their first baby. According to many studies, abortion may have an independent effect of increasing risk of breast cancer by an average of 30 percent. With a disease as common as breast cancer, that is many thousands of extra cases of heartbreak.

Shouldn’t women contemplating an abortion be informed of this possibility? They may still decide to have the abortion, but could be extra vigilant and opt for early screening. And they could avoid hitting their vulnerable breasts with a class-1 carcinogen just afterward.

Let us not forget that the AMA and other influential organizations denied the evidence of a tobacco-lung cancer link for decades. Are we having déjà vu all over again? This time with young women who had one elective surgical procedure, instead of old men who had heavily smoked what my grandfather (without aid of the Surgeon General) called “cancer sticks” for decades?

About the author: Jane M. Orient, M.D., Executive Director of Association of American Physicians and Surgeons, has been in solo practice of general internal medicine since 1981 and is a clinical lecturer in medicine at the University Of Arizona College Of Medicine. She received her undergraduate degrees in chemistry and mathematics from the University of Arizona, and her M.D. from Columbia University College of Physicians and Surgeons. She is the author of Sapira’s Art and Science of Bedside Diagnosis; the fourth edition has just been published by Lippincott, Williams & Wilkins. She also authored YOUR Doctor Is Not In: Healthy Skepticism about National Health Care, published by Crown. She is the executive director of the Association of American Physicians and Surgeons, a voice for patients’ and physicians’ independence since 1943. For additional information on health-related issues, click here for AAPS Online or click here for www.takebackmedicine.com.