25 October 2015

The American Cancer Society has issued new guidelines for screening mammography, and they are sparking a lot of discussion. Previous guidelines, which have been in place since 2003, have recommended:

  • Annual mammography beginning at age 40 and continuing for as long as a woman is in good health
  • Clinical breast exam (CBE) [exam by a physician] about every 3 years for women in their 20’s and 30’s, and every year for women 40 and over
  • Women should know how their breasts normally look and feel and report any breast changes to a health care provider right away. Breast self-exam (BSE) is an option for women starting in their 20’s.

The current guidelines recommend:

  • Women should undergo regular screening mammography starting at age 45
  • Women 45 to 54 years of age should be screened annually
  • Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually
  • Women should have the opportunity to begin annual screening between the ages of 40 and 44 years
  • Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer
  • Clinical breast exam is not recommended for breast cancer screening among average risk women of any age

The full study was published in the Journal of the American Medical Association. These guidelines seem to be a drastic change, but they are based on careful evaluation of the available literature. They are also more in line with the US Preventative Services Task Force recommendations for breast cancer screening (which are in the process of being updated). Mammograms certainly are of benefit in terms of early detection. However, as we have gained a better understanding of the importance of tumor biology, the mantra “early detection saves lives” does not hold true for all.

As stated on the American Cancer Society website, “The goal of screening mammograms is to find breast cancer early, when treatment is more likely to be successful. But mammograms aren’t perfect, and they do have risks. Sometimes mammograms find something suspicious that turns out to be harmless, but must be checked out through more tests that also carry risks including pain, anxiety, and other side effects.” I disagree with using anxiety as a reason to limit screening recommendations. While some women do experience significant anxiety related to mammography callbacks, proper pre-mammogram counseling should help alleviate some of the worry. As Dr. Elaine Schattner noted in her piece published in Forbes, “concern about fear or anxiety should not form the basis of any screening recommendations”.

These guidelines apply to “average risk” women. But given that ANY woman (and any man) may develop breast cancer, what does “average risk” mean? The first part of risk assessment should be a careful history, including a careful and detailed family history. While most realize that a having a family history of breast cancer increases their risk, fewer understand that family history of other cancers, including ovarian, colon and pancreatic cancers may be “hereditary red flags”, and genetic counseling and testing might be indicated. There are several risk assessment models which can and should be used by physicians on a routine basis. Newer forms of risk assessment which include evaluations of small variations in an individual’s DNA may provide a more personalized risk assessment. The contribution of breast density as well as lifestyle factors such as weight, level of activity, and alcohol intake need to be considered. The North Shore – LIH Health System and Bright Pink both have helpful risk assessment tools.

Mammography has never been a perfect screening test. It has significant limitations in young women and those with dense breast tissue, and in older women it may find more than it needs to. We have a “one size fits all” test, and women and their breasts are most certainly NOT “one size fits all”. The decision when to begin screening and how often to be screened is now a shared decision, between a patient and her physician. Decision support tools, such as Weill Cornell Medical College’s Breast Screening Decisions program, can help women sort through the conflicting information and make a decision that is right for them.

While guidelines can be helpful in making recommendations for populations, the ideal screening method for the individual remains to be seen. For screening mammography to truly be of benefit, we need to determine who is at risk and then decide what imaging modality is most appropriate for that individual woman. We also need to know which lesions, once detected, can safely be ignored. We know where we need to be. Now the science and technology needs to catch up.

Additional information:
New Guidelines for Breast Cancer Screening in US Women – JAMA Editorial
Science Won’t Settle the Mammogram Debate
Stat News: New Guidelines Urge Later, Less Frequent Mammograms
Mammography Guidelines Revisited – Lori Marx Rubiner

 

24 September 2015

It is not uncommon that after a breast cancer diagnosis, a breast MRI is recommended. We know that there are limitations to mammography – it might not show everything of concern, especially in women with dense breast tissue. The idea behind preoperative MRI is that if there are other lesions, better to know about them and determine if they are cancerous or not, before going to surgery. This should lead to better surgical outcomes. Makes sense.

The problem is, studies have not been able to show a benefit to preoperative MRI. This was addressed in a recent issue of JAMA Oncology. Dr. Angel Arnaout and colleagues reported on the Use of Preoperative Magnetic Resonance Imaging for Breast Cancer: A Canadian Population-Based Study. In this retrospective population-based study, 53,015 patients with operable (early-stage) breast cancer were identified between 2003-2012.

Overall, close to 15% of patients underwent an MRI, and the use increased from 3% to 24% during the 10 year period.

Screen Shot 2015-10-15 at 2.08.59 PM

Patients undergoing a preoperative MRI were more likely to be younger, of higher socioeconomic status, cared for in teaching hospitals, being cared for surgeons with a high volume of breast cancer cases, and cared for by younger surgeons. Preoperative MRI was associated with a higher likelihood of additional imaging and biopsies, greater than 30 day wait time to surgery, and higher rates of mastectomy as well as contralateral prophylactic mastectomy.

These findings were discussed by Drs. Habib Rahbar and Constance Lehman in an accompanying editorial. They pointed out several limitations in the study, such as not knowing the MRI results, and not having the genetic mutations status (such as BRCA 1/2) of the patients. However, they noted that “this study adds to the growing body of evidence that the use of MRI in the preoperative setting is associated with more aggressive surgery of the affected breast”. They also noted that given concerns of breast cancer overtreatment, we need to modify our approach. They pointed out that MRI might be useful in developing individualized treatment approaches, such as multiple lumpectomies if more than one cancer is found (instead of mastectomy). They appropriately called for more research to determine how preoperative breast MRI should best be utilized.

20 July 2015

This is not a new question, and I promise there will be many parts to this story. The latest: Breast Cancer Screening, Incidence and Mortality Across US Counties, published in the July 2015 issue of JAMA Internal Medicine. The authors of the study noted that rates of early breast cancer detection have increased with the widespread use of screening mammography, but death rates from breast cancer have not decreased, leading to the conclusion that many breast cancers are “overdiagnosed”.

One would expect that if there were an increase in the number of early breast cancers detected due to screening mammography, fewer women would subsequently die from breast cancer. Isn’t early detection the key to survival? A reasonable question that is raised from this study is “What is the value of screening mammography?”. First, several points:

  1. The authors noted that the rates of early breast cancer, especially DCIS, have increased significantly with the widespread use of screening mammography.
  2. It is well known that some breast cancers have such an indolent biologic behavior that they will never become a threat to a breast or to a life.
  3. The more we screen, the more we find. Not everything needs to be found.
  4. Finding indolent lesions is considered “overdiagnosis”. Treating these lesions with traditional surgery, radiation and other treatments is considered “overtreatment”.
  5. Early detection does not always equal cure. Some breast cancers have a very aggressive behavior, and may prove to be fatal even when diagnosed in early stages.

Before you cancel your upcoming mammogram, appointment, some limitations of the study were pointed out in an accompanying editorial: Effect of Screening Mammography on Cancer Incidence and Mortality. One of the biggest criticisms is how the study was actually conducted, using the “ecological method”, which studies large groups, not individuals. It is not possible to tell if the women who were diagnosed with breast cancer are the same ones that subsequently died due to the disease. Other limitations of this of study are that no information is available on tumor subtypes or adjuvant therapy (chemotherapy, hormonal therapy and radiation). Another limitation of the study is that it evaluated data over a 10 year period, which might not be long enough to have an impact on survival rates. Finally, it was discussed that there was the potential for “confounding bias” – factors associated with an increased risk of breast cancer might also be associated with an increased rate of obtaining screening mammograms. [For a good discussion of the types of bias that may be present in research studies, review this article from HealthKnowledge.]

There is no question that we are finding more early stage breast cancers, including DCIS. There is much debate on whether or not DCIS even represents “cancer”. But the reality is that while we recognize that not all cancers will progress, we do not yet have the ability to predict the behavior of a cancer with certainty for an individual woman. We do not yet have that crystal ball.

So now what? The conclusion always seems to be “ask your doctor”. But physicians do not have all of the answers. What is clear is that the decision to begin or continue screening mammography is no longer automatic – discussion about the benefits of mammography, the potential harms, a woman’s own risk tolerance, and personal beliefs is necessary – this is the essence of shared decision making.

Various online tools have been developed to help women make more informed decisions. One is Weill Cornell Medical College’s Breast Screening Decisions, meant to be used by women in their 40’s. This is a start. We also need to develop that “cancer crystal ball”, which will allow us to more accurately predict who will develop cancer, and the behavior of a cancer that has developed. We’re just not there yet. Stay tuned as this is certainly not the last word on this issue.

17 February 2014

Spoiler alert – this will hardly be the last word on the screening mammography debate…

Last week, the British Medical Journal published a Canadian Study which concluded that mammograms are not effective in reducing breast cancer deaths. The study involved 90,000 women. However, there are some major flaws in the study, and “rapid response” letters to the editor were published within hours of the study release. So while the headlines scream “mammograms are not helpful”, the study is in question and it may not be possible to draw this conclusion.

While previous randomized trials have shown a reduction in breast cancer mortality due to screening mammography, there is no doubt that mammography is far from perfect. We have to screen a large number of women to diagnose one with breast cancer. In doing so, a percentage of women will require additional imaging and/or will undergo a needle biopsy for a benign finding. Mammography is not as helpful in younger women and in those with dense breast tissue. In addition, as technology has improved to allow us to see through the breast with more detail, we are diagnosing cancer (and precancerous conditions) that may never become a threat to a woman’s life.  We are trying to find the balance between early detection which often (but not always) leads to improved survival, versus over diagnosis and over treatment.

Part of the problem is our technology. The results of screening mammography are highly variable depending on the patient’s age, breast density, weight, use of hormone therapy, and other factors. We have a one-size-fits-all test, which as every one knows, is really one-size-fits-none. We are also limited in who we screen. Women younger than 40 without a family history of breast cancer have no routine screening recommendations, and mammography is not very helpful in this age group. Many will use this as an argument for the use of ultrasound or MRI examinations. While these modalities may be extremely helpful in a given patient, they have not been proven to be effective in reducing mortality from breast cancer when applied to a general screening population.

It is important to realize that we have an imperfect technology, and our application of that technology to the individual is also imperfect. More research is needed to determine who is actually at risk, and who will truly benefit from screening. In addition, screening needs to be more individualized – a mammogram is not the right screening tool for all. Dr. Peter Beitsch, Past-President of the American Society of Breast Surgeons, has said on many occasions that “female and 40 is no longer acceptable for screening mammography – we need to risk assess each woman individually and use appropriate breast imaging tailored to them.”

In addition to more individualized screening, research is needed into which cancers even need to be treated. Many breast cancers found on mammography may never become a threat to a woman’s life. However, a hallmark of cancer is cell mutation – the slow-growing cancer today may not behave that way in the future, so at this point we err on the side of over treatment, as we cannot reliably predict future biologic behavior. Dr. Robert Miller, a medical oncologist who the Senior Director, Quality and Guidelines and Medical Director, CancerLinQ, at the American Society of Clinical Oncology, stated that “we simply can’t tell if early breast cancer diagnosed by mammogram will be indolent or not. For the individual patient we can’t say it’s ‘over diagnosis’. ”

And that’s really the bottom line. For an individual patient, we do not always have the right answer – our science and technology are just not there yet. While this is frustrating for many patients as well as for physicians, it is exciting to be practicing in a time when we are making progress (albeit slow) towards more individualized screening and treatment recommendations.

16 October 2013

This is one of my most comprehensive interviews to date. It aired on Santa Clarita Valley TV and I had the opportunity to discuss a wide range of topics, including breast self-exams, male breast cancer, genetic testing for breast cancer, “pink washing” and more! Many thanks to SCVTV as well as Tami Edwards and Dave Caldwell, for spending so much time on such important topics.