Tag Archives: Orac

Can’t See the Metastatic Forest for the Breast Cancer Screening Trees

Others can speak far more knowledgeably and eloquently about the recent pink ribbon funding controversy. My concern is that we are missing the forest for the trees. Setting aside the funding issue, let’s consider the truth worth of these exams. Screening and self exams can be helpful. But let’s not kid ourselves. These tests are frankly not that great.

“Women are regularly told that screening mammograms save lives,” says the National Breast Cancer Coalition. “Evidence of actual mortality reduction is, in fact, conflicting and continues to be questioned by scientists, policy makers and members of the public. Since evidence does not currently significantly support, nor disprove the effectiveness of this test, receiving a screening mammogram should be a personal choice, not a medical mandate.”*

Essentially, we have better imaging technologies. The  average size lump found by first mammogram is about the size of a dime (~1.5 cm) but even tumors as small as pencil erasers can be seen.

The real problem is we don’t know WHAT we are looking at.

We don’t know  WHY some tumors spread beyond the breast.

We don’t know HOW to stop metastatic growth.

We are seeing more and more breast cancers earlier and earlier. In some cases, people are overtreated: It’s the oncological equivalent of using a shotgun to kill an ant. Many women may be diagnosed and treated for a cancer growing so slowly it might never have caused any symptoms or threatened their lives.

As surgeon/scientist/blogger David Gorski, explains, “… for mammographically-detected small tumors, almost always those detected by screening mammography, it’s not so clear whether all of these need to be treated. Overdiagnosis is being increasingly appreciated as a significant problem, and, indeed, may account for as many as 1 in 3 breast cancers detected by screening mammography (although more common estimates are on the order of 20%). There is even evidence–not bulletproof by any means, but intriguing evidence–that as many as 20% of mammographically detected tumors may actually spontaneously regress.”

Screening is just one tool. We need to look at the bigger picture. Unfortunately, the under treated are always with us:

“If we did what we already know, at least 37% of cancer deaths in people between the ages of 27 and 64 could be avoided right now,” writes ACS’s Dr. Len Lichtenfeld. “Where is the national conversation about the fact that poverty is a carcinogen? Are you talking about it? Is the media talking about it? If the silence is deafening, then perhaps you have your answer. “

Finally, as much as I have a vested interest in breast cancer research, it shouldn’t come at the expense of addressing other diseases. I concur with ACS’s Dr. Otis Brawley:  “The wisest advocacy for cancer science is support for more money for cancer research in general and support for funding the best science and encouraging scientific investigators to maintain an open mind,” says Brawley.  “Scientists must look for additional applications of findings beyond just their cancer of interest.”

You’ve probably heard of the chemotherapy drug Herceptin, which is used to treat about 25% of breast cancer patients. It was developed to treat neuroblastomas and gliomas, both cancers of the nervous system, but it didn’t work for those cancers.
Another example, cisplatin, was first developed as a treatment for testicular cancer.  It is now the most commonly used chemotherapy in the treatment of lung cancer and ovarian cancer. It is also used in some breast cancer treatments. The drug oxalaplatin used in colon cancer therapy was developed from cisplatin.  So testicular cancer research benefited a number of other cancers.
Similarly, the drug leuprolide was developed in the mid-1980s as a hormonal treatment for metastatic prostate cancer. This drug has since been FDA-approved for not only treatment of metastatic prostate cancer, but also premenopausal breast cancer, endometriosis, and precocious puberty.

The number of drugs that were developed for one disease but ended up being useful in others  is legendary and goes beyond cancer.

*Women age 40 and older should have mammograms every 1 to 2 years. Women who are at higher than average risk of breast cancer should talk with their health care providers about whether to have mammograms before age 40 and how often to have them.

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