New Study: Breast Cancer Can Disappear Without Treatment

by PJ Hamel Patient Expert

If you were diagnosed with breast cancer, and knew it might disappear on its own, would you forego treatment surgery, radiation, chemo, hormone drugs and take that chance?

That's a choice women might possibly face in the future, if the surprising results of a recently completed Norwegian study prove true.

As lay people, we used to think that cancer, if left untreated, was a death sentence. Advances in research, primarily over the past 40 years, have made many kinds of cancer very treatable; and some even curable. But "the big C" is still something we fear deeply.

Now it appears that some breast cancers, if left untreated, can disappear on their own. Results of a joint study, carried out by a team of researchers from Norway and the Dartmouth Medical School, were published last week in the Archives of Internal Medicine. The study involved about 129,000 Norwegian women, aged 50-64, in two groups; one group was followed from 1992-1997, the second from 1996-2001.

Regular screening mammograms were introduced in Norway in 1996, so the women in the first group received only one mammogram, at the end of their study period. Meanwhile, women in the second group received regular screening mammograms between 1996-2001.

When breast cancer diagnoses for the two groups were compared, they were 22% higher in the second group, the group that had regular screening mammograms.

Why the huge discrepancy? As many as 66% of both invasive and non-invasive breast cancers may be termed "pseudo-cancers:" cancers which, if left on their own, would grow, then shrink, then disappear over the course of a couple of years, concludes Jan Maehlen, M.D., Ph.D., the study's co-author. Maehlen adds that he expects the study's results to be controversial.

Dr. Robert Kaplan of the School of Public Health at UCLA says the implications of the study are "potentially enormous." Kaplan, interviewed last week in The New York Times, said that his first reaction to the study was "This is pretty weird."

"But the more we looked at it, the more we were persuaded," he added. Kaplan, in an editorial accompanying the study's release, writes, "If the spontaneous remission hypothesis is credible, it should cause a major re-evaluation in the approach to breast cancer research and treatment."

So, as women facing a 1-8 lifetime chance of breast cancer, what do we do with this information?

On the one hand, there's fear from the American Cancer Society that women may use this as another excuse to skip their annual mammogram. Robert A. Smith, director of breast cancer screening at the ACS, said, "Their simplification of a complicated issue is both overreaching and alarming."

On the other hand, an array of medical professionals, from Dr. Suzanne Fletcher (Harvard Medical School) to Dr. Gilbert Welch (Dartmouth Medical School, the study's co-author) to biostatistician Donald A. Berry (M.D. Anderson Cancer Center, Houston) took the news as an opportunity to express concern that the medical community may currently be over-treating breast cancer.

"It's possible that we all have cells that are cancerous and that grow a bit before being dumped by the body," said Berry. ""early detection will lead to finding some of them. What will be the consequence? Prophylactic removal of organs in the masses? It's really scary."

Obviously, more data is needed to corroborate or disprove the Norwegian data. Kaplan said that a possible site for another study might be Mexico, where regular screening mammograms are just now being introduced.

Still, even if it eventually turns out that 67% of breast cancers will disappear without treatment, where does that leave us?

With yet another life-or-death decision. Right now, we have trouble deciding between a lumpectomy, a mastectomy, and a prophylactic double mastectomy. What if that tough choice also includes "no treatment at all," with "watchful waiting" replacing surgery and chemo and radiation, and a greater than 50-50 chance that the cancer could disappear on its own?

Would you take that chance?

PJ Hamel
Meet Our Writer
PJ Hamel

PJ Hamel is senior digital content editor and food writer at King Arthur Flour, and a James Beard award-winning author. A 16-year breast cancer survivor, her passion is helping women through this devastating disease. She manages a large and active online survivor support network based at her local hospital and shares her wisdom and experience with the greater community via