Headlines across the country today announce, "Exercise Can Ease Pain from Breast Cancer Drugs" (USA Today), "Exercise Helps Women Tolerate Breast Cancer Drugs (Boston Globe), "Exercise Eases Common Breast Cancer Treatment Side Effect" (Huffington Post). Dr. Jennifer Ligibel, at the Susan F. Smith for Women's Cancers at Dana-Farber, just presented her findings on exercise at a major breast cancer symposium. The study is good news for women with breast cancer or at high risk of cancer--and for Dr. Joel Brind, who has a double interest in the results.
The study explored whether regular, supervised exercise might help reduce the aches and pains that tempt so many breast cancer patients to stop taking the estrogen-blocking drugs they need to fight tumors. Women who exercised regularly claimed 20% less joint pain, while a control group that followed normal daily activities claimed 3% less pain. Less pain equals more gain for women whose lives may depend on their ability to gag down a drug that makes them ache all over.
The science behind these cancer drugs is simple--estrogen is the "gasoline" of female physiology. On the one hand, it's what keeps the human race alive--but it has its dangers. In particular, estrogen causes certain types of breast tissue to reproduce rapidly. Women with estrogen-sensitive tumors (as well as women who have no tumors yet but are at high risk of developing them) can be helped with drugs which the body from using estrogen (such as Tamoxifen) or that keep estrogen from being produced in the first place ("aromatase inhibitors" like Letrozole).
That is no surprise to Dr. Brind, who made headlines of his own in 1993 when he claimed that women who choose abortion are more likely to develop breast cancer. Abortion leaves women awash in the estrogen of early pregnancy without the protective effects of third-trimester hormones. (If estrogen is like gasoline, third-trimester hormones are like rain that puts out the fires.) Brind (a professor of human biology and endocrinology at Baruch College of the City University of New York) thought he was just doing science when he connected the dots between research on rats, research on humans, and increasing breast cancer rates around the world. To his dismay, the vast majority of endocrinologists, breast cancer researchers, and women's health advocates rejected his reasoning, even though study after study shows a modest increase in breast cancer risk after induced abortion.
Dr. Brind found himself back in the news recently when Chinese researchers reported a statistically significant 44% increase in breast cancer risk after one or more abortions. Dr.Yubei Huang's "meta-analysis" aggregated data from 37 different studies in China, and found a consistent "dose-response relationship" that greatly strengthens the importance of the findings. Pro-life groups spread the word to their audiences, but the report got little play in big media.
What mainstream coverage that there was downplayed the link, insisting that the Chinese team used a "notoriously misleading method" that depended on women's personal accounts of their abortion history instead of official abortion records. The "recall bias" argument claims that women with cancer are more likely to tell the truth about something as personal as abortion, whereas healthy women might be tempted to conceal their past. This hypothetical bias has been put to the test by Dr. Janet Daling, of Fred Hutchinson Cancer Research Center in Seattle, who included a "control group" of women with cervical cancer to find out whether they showed a link to abortion. If "recall bias" created a false association between abortion and breast cancer, it should create the same mirage with cervical cancer. Dr. Daling found no relationship between abortion and cervical cancer (proving that in her study, at least, healthy women were not lying about their abortions), and a 50% increase in breast cancer risk among young women who chose abortion.
That should have put the so-called "recall bias" argument to rest--but when it comes to abortion, science takes a back seat to politics. Brind was mocked, attacked, and eventually outvoted at a 2003 conference at the National Institute of Health. The abortion/breast cancer link was dead. The science was settled. Those who argue that abortion increases the risk of breast cancer are now in the same category as those who deny that humans cause global warming.
So--what does a professional endocrinologist do after the National Institute of Health tells him to sit down, shut up, and stop talking about the effect of estrogen on breast tissue? In Brind's case, he keeps on researching. Dr. Brind started studying amino acid metabolism and discovered that a single amino acid--glycine--has a big effect on aches and pains. As it turns out, chicken soup is good for more than the soul--the proteins in chicken broth are rich in glycine, and they really do relieve the symptoms of the common cold. Brind encourages people with chronic pain to eat more jello, drink more soup, or use "Sweetamine," his own glycine-based supplement.
Which brings us back to today's news. Several hours of exercise each week may help women take their cancer drugs because it reduces joint pain by 20%. What if a daily dose of sweetamine reduces joint pain even more? Exercise is good in its own right, but if it is only a means to the end of helping women tolerate their medication, sweetamine might be far better. It's easy to make sure women take their sweetamine each day. It's hard to crack the whip to make them exercise!
It should be obvious what the next research project ought to be. Somebody needs to compare three groups of women: some taking sweetamine, some who exercise, and a "control group" of women who do neither. If sweetamine reduces joint pain more than exercise does, it may well be prescribed along with the estrogen-blockers it enables women to take.
This world is a funny place. We might yet see the very experts who mocked Brind's claim that estrogen raises the risk of cancer prescribe his remedy for the aches caused by estrogen-blockers!