Thoughts On Breast Cancer and HRT

By now you have undoubtedly heard the news, announced in mid-December, that breast cancer incidence in the US plummeted by a surprising 7 percent, or 14,000 cases, between the years 2002 and 2003. If someone had devised a drug that could lead to such a rapid decline in this dreaded disease there would be statues of that person in every town square. But while no one yet knows for sure what caused this dramatic decline, most experts believe it was due to the fact that women in their thousands decided to shun hormone replacement therapy (HRT).

The research that uncovered the sudden drop in breast cancer incidence was carried out by Dr. Peter Ravdin, a research professor in the Department of Biostatistics at M.D. Anderson Cancer Center. Ravdin and his colleagues looked at the records of nine US regions that supply data to the National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) database. According to their analysis, which was presented at the San Antonio Breast Cancer Symposium in December 2006, the age-adjusted breast cancer incidence decreased by 7 percent by the end of 2003, when compared with the previous year. Put another way, there were 124 breast cancer cases per 100,000 US women in 2003, compared with 134 cases in 2002. Looking more closely at the figures, the researchers found that breast cancer incidence decreased by 6 percent in the first half of 2003 and then by a whopping 9 percent in the second half of the year (Marchione, AP/Forbes, 12/15). The study concluded that approximately 14,000 fewer women were diagnosed with breast cancer in 2003 than in the previous year. That’s a lot of misery avoided.

The study also found that the rate of decline in breast cancer incidence was greatest among post-menopausal women. In the 50 years and older age group, breast cancer rates dropped by 15 percent.

In the past, small declines in breast cancer incidence have been noted from time to time, and have generally been attributed by the medical profession, in a self-congratulatory way, to earlier detection through mammography and to the use of chemopreventive drugs such as tamoxifen and raloxifene. However, in this case the drop could not be attributed to any medical intervention. Instead, the decrease coincided with a precipitous decline in the use of hormone replacement therapy (HRT) by menopausal and post-menopausal women.

In particular, suspicion fell on the drug Prempro, which contains two agents, Premarin (a form of estrogen derived from pregnant mares’ urine) and Provera (a synthetic form of the hormone progesterone). According to an article in the Wall Street Journal, the use of HRT declined about 30 percent in 2002, after a large prospective study called the Women’s Health Initiative announced that breast cancer risk had increased for women who used HRT to control menopausal symptoms over a prolonged period of time. This study also showed that, contrary to widely touted assertions, the use of HRT was not associated with a decrease the incidence of heart disease. In fact, the study demonstrated not only a 26 percent increase in breast cancer in women taking HRT, but also a 41 percent rise in strokes and a 29 percent increase in heart attacks for women on this drug!

It is noteworthy that many of the women who stopped using HRT did so on their own initiative, and sometimes over the vociferous objections of their doctors.

There is still no definitive proof that the drop-off in the use of HRT caused the decline in breast cancer incidence. But according to Rowan Chlebowski, MD, PhD, of Harbor-UCLA Medical Center, who was a co-author of the study, it is the most likely explanation. “To have this kind of drop in cancer rates you need something very big to explain it,” he told the Los Angeles Times, 12/15). As Dr. Ravdin, the lead author of the study, put it in his presentation at the San Antonio Breast Cancer Symposium, “We know that this decline is a real effect, not just a statistical anomaly.”

Another team of researchers, led by Christina A. Clarke, MD, from the Northern California Cancer Center in Fremont, CA, recently reported similar findings in the Journal of Clinical Oncology. “Hormone therapy use dropped 68 percent between 2001 and 2003, and shortly thereafter we saw breast cancer rates drop by 10 to 11 percent,” said Dr. Clarke. “This drop was sustained in 2004, which tells us that the decline wasn’t just a fluke.”

There is a school of thought that suggests that while the hormones in HRT may have fueled a surge in breast cancer incidence, they did not directly cause the cancers but only made them appear sooner. Some doctors therefore fear that breast cancer incidence will again surge in coming years, as if it were making up for lost time. “It’s quite likely that some of these tumors have just been slowed and that we’re going to see a boost in incidence in the next few years,” said Dr. Donald Berry, head of the division of quantitative sciences at M.D. Anderson and a co-author of the first study.

Another scientist added: “There may be some tumors that actually stop growing because the only thing they were living on was the fuel of the hormones. The long-term impact [of the study] is going to be something that will take another five years to completely understand.”

Some media commentators have expressed surprise, and even doubt, that HRT could be associated with so many cases of breast cancer. But this association is not really news. Critics of HRT have been saying as much for years. Hormone replacement therapy was always based on dubious science - but great marketing. It all began in 1968, when, with financial backing of Ayerst Laboratories, Dr. Robert A. Wilson wrote the influential book Feminine Forever. He stated his basic philosophy as follows: “The unpalatable truth must be faced that all post menopausal women are castrates… From a practical point of view, a man remains a man until the very end.” What offensive nonsense! Yet a three billion dollar business was constructed around the flawed and condescending concept that menopause somehow “castrates” women.

By the mid-1970s it was clearly shown that unopposed estrogen (i.e., estrogen taken without the hormone progesterone to balance it) raised the risk of both endometrial and breast cancer. Sales of HRT started to plummet. The pharmaceutical industry’s response was to add progestin, a synthetic form of progesterone, to the mix. The result was the blockbuster drug, Prempro.

(Click here for conclusion to this two-part article)

Ralph W. Moss, Ph.D.www.CancerDecisions.com