• Mammogram screening and overdiagnosis: tumor size an issue?

    Hologic Imaging MachineDOTmed.com – Health Care Business Daily News
    Written by: Thomas Dworetzky , Contributing Reporter

    A just-published study of breast cancer data has raised the issue of overdiagnosis from mammography screening – and puts tumor size squarely in the middle of the debate.

    That’s because many “small breast cancers have an excellent prognosis because they are inherently slow-growing,” according to Yale Cancer Center experts in a June 8th New England Journal of Medicine report, which weighed in on the benefits of breast cancer early detection.

    Frequently these smaller tumors come from slow-growing cancers that may not become an issue during a patient’s lifetime, they noted. [Read More…]

  • Annual screening does not reduce risk of death from breast cancer

    Wednesday 12 February 2014 – 12am PST

    Written by David McNamee

    Copyright: Medical News Today

     

    According to a study conducted by researchers in Canada and published in the BMJ, annual screening for breast cancer does not reduce likelihood of dying from cancer any more than physical examination or usual care do in women aged 40-59.

    Cancers of the breast detected in screening (or “mammography”) are, on average, smaller than breast cancers that can be detected through physical examination. And experts know that women with small breast cancers have a better chance of long-term survival than women with large breast cancers.

    But experts cannot be sure that this better chance of survival is because of screening, or if this increased survival is influenced by other factors.

    These include factors called “lead time bias” and “over-diagnosis.” Lead time bias is when testing increases perceived survival time without affecting the course of the disease. Over-diagnosis is the clinical term for the detection of harmless cancers that will not result in symptoms during a patient’s lifetime or cause them to die.

    As breast cancer screening occurs annually for some women as part of an effort to lower breast cancer mortality rates, the researchers behind this new study wanted to measure how effective annual screening is in preventing death from breast cancer.

    “It is true that if you find cancer early it could be at a more treatable stage,” study author Prof. Anthony B. Miller told Medical News Today. “But there is no evidence that early detection affects the inherent biology of the cancer. Indeed it is possible that finding the cancer at an earlier stage will result in undertreatment. There is some evidence that is so.”

    “In our study, and in some other screening studies, those whose cancers were detected by mammography seemed to have more rapidly progressive disease. In addition, the mere fact that a cancer is detected by screening does not guarantee a benefit from detecting that cancer.”

    This was a large, long-term study across six Canadian provinces that followed 89,835 women between the ages of 40 and 59 over a period of 25 years. These women were randomly divided into two groups. The mammography group received one screening every year for 5 years, whereas women in the control group were screened only once.

    Over the entire 25-year study period, a total of 3,250 women in the mammography group and 3,133 in the control group were diagnosed with cancer. In the mammography group, 500 women died, compared with 505 women in the control group. So the mortality rates in both groups were similar.

    The authors say that an excess of 142 cancers were recorded in the mammography group during the 5 years of the screening period, with 106 excess cancers recorded after a period of 15 years. From this, the authors deduce that 22% of the cancers in the mammography group were over-diagnosed.

    “These cancers – comprising half of those found by mammography alone – could not have affected the woman’s lifetime,” said Prof. Miller, “instead there were adverse consequences that she had to endure, living with the knowledge that she had had breast cancer, though in fact that detection did not benefit her at all.”

    “So stopping mammography screening will not result in lives lost, but lives lived with greater quality of that life,” he added.

    What did other studies find?

    In 2013, Medical News Today reported on a UK-based study that also found breast cancer screening does not reduce deaths from the disease.

    But the findings of this study do contradict findings from some other similar studies. A Swedish study attributed a 31% reduction in mortality to mammography. But the authors of the Canadian study think that the Swedish trial was flawed and the difference is down to “an initial imbalance of the compared groups, not a benefit of screening mammography.”

    A large systematic review of data from 1976 to 2008 also had different findings to the Canadian study, estimating that 31% of all breast cancers were over-diagnosed. The Canadian researchers think this difference was due to that review taking a wider age range into account than their study, which looked at women between the ages of 40 and 59 only. They think that over-diagnosis is more common in people older than this, as there are more potential causes of death as individuals age.

    The researchers also admit that the result of the Canadian study may not be generalizable to all countries.

    Rationale for mammography should be ‘reassessed’

    Although Prof. Miller and his team assert that education, early diagnosis and clinical care remain priorities in treating breast cancer, they say that mammography does not result in a reduction in breast cancer-specific mortality for women aged 40-59 beyond that of physical examination alone or usual care in the community.

    The authors say that annual breast cancer screening should be urgently reassessed by policy makers, but they anticipate resistance from medical groups with “vested interests.”

    Prof. Miller told Medical News Today:

    “The greatest resistance will come from radiologists, who are convinced that finding cancers results in benefit, and who also benefit financially from that belief. We have demonstrated that is not so. Others whose advice resulted in the establishment of breast screening programs will also feel threatened.

    It is unfortunate that although we maintain we should practice evidence-based medicine, when that evidence is produced, there will be many who will seek the means to discredit that evidence because it is against their vested interests.”

    Rather than annual breast screenings, the authors of the study would like to see funding diverted into better public education programs to convince women to seek skilled advice if they detect an abnormality in their breast, and professional education programs that ensure doctors are familiar with the latest advances in research.

  • The Other Side of Angelina Jolie’s Double Mastectomy

    By Christiane Northrup, MD

    Many women became familiar with the breast cancer type 1 gene (BRCA1) when actress Angelina Jolie announced that she had undergone a double mastectomy as a preventative measure. The reasoning that Jolie shared with the media was focused on her risk—according to her medical professionals, Jolie’s variation on the BRCA1 gene gave her an 87 percent chance of developing breast cancer. So even though she did not have breast cancer, Jolie felt HER risk was too high to ignore this genetic predisposition and had the double mastectomy.

    I’m not writing to judge Angelina Jolie or the decision she made, which seems to have been the “right” choice for her. I’m writing because I know that having a preventative double mastectomy will not be the first choice for many women. And these women need to understand all sides of this issue before making a choice that’s right for them.

    First, it’s important for you to know that only about two percent (2%) of all breast cancers involve an inherited gene, either the BRCA1 or the BRCA2! The first has a higher risk than the second, and both genes are also associated with ovarian cancer. (BRCA1 is more common in Hispanic, African American, and Jewish women of Ashkenazi descent.) That said, if you have a strong history of breast or ovarian cancer, but test negative for either gene, your family history may be a bigger indicator of your breast cancer risk than the gene is.1 Jolie’s mother died in her fifties of ovarian cancer, and Jolie has a significant family history of breast and ovarian cancer—including an aunt who died from breast cancer shortly after her announcement.

    One aspect of the story that really got people’s attention was the statistic “87 percent risk.” That number sounds frightening, because it’s so specific! Jolie’s medical professionals didn’t cite an 85 or a 90 percent chance, or a range—they gave Jolie an 87 percent risk of developing cancer. Let’s look more closely at this, because it’s a great example of our misunderstanding of the genetic connection to disease.

    Jolie’s “number” is based on older estimates, which have been disputed by the National Institutes of Health. In fact, a 1997 study showed the risk of Jolie’s particular mutation to be closer to 56 percent. There are many factors that affect a woman’s chance of developing breast cancer—regardless of whether she has the BRCA1 or BRCA2 gene.

    •    In an blog called “What Doctors Didn’t Tell Angelina Jolie”2 journalist Lynn McTaggart points out, “New evidence shows that even a faulty BCRA1 gene, as Jolie has, may require epigenetic modification, or ‘silencing,’ before cancer progresses.”3 In layman’s terms, this means that a physiological change is required to activate the gene.

    •    Vitamin D levels play a huge role in protecting women from cancers of all kinds. We now know that the risk of breast cancer is cut in half in women with adequate levels of vitamin D. 4

    •    The nutrition a girl gets at critical times in her life, particularly as a fetus and during puberty, greatly influence the expression of genes like BRCA1.5

    •    Daily intake of fruits and vegetables also lowers your risk of breast cancer. Karolyn Gazella writes, “Specific to BRCA1 and BRCA2, a 2009 study featured in the journal Breast Cancer Research and Treatment demonstrated that women with the inherited mutation who ate more fruits and vegetables significantly reduced their risk of developing cancer compared to the women with the mutation who ate fewer fruits and vegetables.”6

    •    In a 2006 study also featured in Breast Cancer Research and Treatment, women who carried the mutation and had normal weight, and prevented weight gain as they aged, also had a much lower risk of developing cancer than women with the mutation who were overweight.

    •    Our families’ emotional legacies play a large role in all our health issues, and are hard to quantify in studies—although they absolutely are a factor.

    If you look at your family history and wonder whether you should have genetic testing, think hard about why you want to do so. The recent Supreme Court decision that denied a patent to the company that developed the breast cancer gene test has resulted in a flurry of other parties offering the test at a much lower cost. This is a double-edged sword for at-risk women unless they are fully informed about their true risks. Click here to read these risks.

    Before you have the testing, ask yourself the following: What would I do with the information? Would you be swayed by your doctor to get a preventative double mastectomy? Would you stop looking for ways to mitigate your risk? Would you let medical test results override your inner guidance?

    Whether the results are negative or positive, there are no guarantees. Regardless of what your choices are, or what your results may be, the most powerful thing you can do for your breast health is to cultivate a loving relationship with them, making breast-healthy lifestyle choices, and, if you are concerned, monitor their health with an attitude of self-love and self-care—not a “search and destroy mentality.” Acknowledge that your breasts—like every other part of your body—have the ability to become and stay healthy throughout your life.

    [1] American College of Obstetrics & Gynecology, Committee on Genetics, 1996, Breast-Ovarian Cancer Screening, Committee decision no. 96, Washington, D.C.
    [2] McTaggart, L. What Doctors Didn’t Tell Angelina Jolie, May 31, 2013,
    [3] Birgisdottir, V. Epigenetic silencing and deletion of the BRCA1 gene in sporadic breast cancer, Breast Cancer Res, 2006, 8: R38.
    [4] National Human Genome Research Institute, Three Breast Cancer Gene Alterations in Jewish Community Carry Increased Cancer Risk, but Lower Than in Previous Studies, 1997.
    [5] De Assis S, Hilakivi-Clarke L. Timing of dietary estrogenic exposures and breast cancer risk, Ann N Y Acad Sci, 2006; 1089: 14–35.
    [6] Gazella, K. Angelina Jolie Missed an Important Opportunity, Psychology Today: The Healing Factor, May 16, 2013.