Transcript

Lee Tetreault:

Welcome to Frequently Asked Questions from the session: Breast cancer screening updates. We are joined by Dr. Marcus. Before we begin with these questions, Doctor, would you be able to reiterate a few key pointers from today's session to our audience?

Dr. Marcus:  

My pleasure. So some of the take-home points from my talk are, number one, it's important for all patients, with all patients, to assess patient risk prior to embarking on a discussion about breast cancer screening options. Some patients will be at high risk and will not be subject to the routine screening, they would not be people who would come under that. They might need more aggressive screening. Also, there are, for people who are not at markedly increased risk, there are risk score calculators that you can use, that are free and available online. One is from the National Cancer Institute, it's the NCI Breast Cancer Risk Assessment Tool, and you can plug age, race, familial risk factors, reproductive risk factors, and breast biopsy information, if known. Another is a free tool from the Breast Cancer Surveillance Consortium. And these are useful calculators for assessing a patient's personal risk.

If you have an older patient and you're trying to decide whether or not it's worth it to continue screening or stop screening, there are life expectancy calculators that you can use. One is called ePrognosis, it's from the University of California, San Francisco. And that's a useful calculator for when you're trying to figure out whether you should continue screening or whether it's not worth it to screening, say, perhaps the patient has a lot of comorbid conditions that are a much bigger threat to her life and health, than breast cancer would be. For average risk women, starting screening at age 50, and performing it on a biannual basis is associated with less radiation exposure, although it does find fewer cancers. And we also discuss the fact that supplemental ultrasound finds additional cancers, but national guidelines don't recommend it at this point for average risk women with dense breasts. Finally for women with an increased risk, supplemental ultrasound and MRI do find additional cancers, but also increase the likelihood of biopsy for lesions that are otherwise negative.

Lee Tetreault:

Thank you, Doctor. Now we're going to go into some of those frequently asked questions. First, how do you decide when to stop routine mammogram screening?

Dr. Marcus:  

Well, this is always a difficult area. Number one, there just wasn't enough data on older women in the major trials looking at mammography, to assess overall benefits and harms for this population. So as with all screening decisions, you really need to think about the patient's preferences and also about her comorbidities. On the one hand, older women are the highest risk group, as a group, for developing breast cancer, age is a big risk factor for developing breast cancer. But on the other hand, this is also a population that has more comorbidities and maybe, may pose more of a health risk to the patient.

Lee Tetreault:

What does the term breast density mean and what are its implications?

Dr. Marcus:  

Breast density is a radiologic term. It is not something that can be detected on physical exam. It basically... A woman with dense breasts has more fiber glandular tissue related to fatty tissue in the breast, and this affects the sensitivity and the specificity of mammography in detecting breast cancer. You should know that breast density decreases with age, and it also decreases with body mass index. It actually increases with hormone replacement therapy use. There are four classifications for breast density ranging from almost entirely fatty to extremely dense. Most women are in an in-between group with mostly fatty or heterogeneously dense breasts. One issue with breast density is that women with extremely dense breasts, compared with women who have almost entirely fatty, replaced breasts do seem to be at increased risk of developing breast cancer. However, the clinical implications of that in terms of mortality are not clear. We have not, at this point, found an association between death from breast cancer and having extremely dense breasts.

Lee Tetreault:

What is the role of the clinical breast exam, and self-breast exam in screening for breast cancer?

Dr. Marcus:  

So, at the current time, there really is a lack of evidence for doctors to do the clinical breast exam on a routine basis. It's actually recommended that we spend time talking about the risks of breast cancer with the patient, and that this actually might be a better use of our time than actually doing the breast exam. There is concern about an increased risk of false positives, you may feel something that then leads to additional diagnostic imaging, say with ultrasound and perhaps even to a biopsy, if you routinely do the clinical breast exam. Many societies however, say that it is important for women to be aware of changes in their breasts, and that actually the clinical breast exam may be a good opportunity, if you have a patient who says that she plans to do self-breast exam, to show her what would feel normal and what would be normal, and what would be a lesion of concern.

In terms of self-breast exam, where women routinely check their breasts every month themselves, most guidelines do not recommend this. It's been found in two large trials, that this leads to more biopsies and does not seem to make a difference in terms of mortality. However, again, some society, some groups such as American College of OBGYN do recommend that women have breast awareness. So that if they sense something abnormal that they go to their doctor to have that evaluated, since we all know patients who present with breast cancer where the first finding was a palpable lump.

Lee Tetreault:

And lastly, does adding ultrasound to mammography improve breast screening?

Dr. Marcus:  

In general, adding ultrasound to routine mammography will detect more cancers, but it also leads to a significant number of additional biopsies. There have been several studies looking at this. One, for example, looked at average risk women with dense breasts in Connecticut, and found that adding a mammogram led to a significant increase in biopsy. About 5% of the women in that particular study who underwent supplemental ultrasound, were then recommended to have a biopsy as a result of having had that ultrasound. These biopsies did find a small number of additional cancers that would not have been found, had the woman not undergone ultrasound. Very small, it was actually 0.3% of the women who underwent both were found to have additional cancers, as a result of having undergone that supplemental ultrasound. And actually there was a false negative result picked up at 12 months. Among high-risk women, women at high risk for developing breast cancer, who also have dense breasts, it seems that supplemental ultrasound is a little bit more effective.

The Akron study, which was a study looking at combined screening with ultrasound and mammography versus mammography alone, in women at elevated risk of breast cancer, did find that adding ultrasound picked up additional cancers, about 0.4% as opposed to 0.7% in sort of a snapshot of screening at one time, over a period of two years. But it also picked up, it also resulted in a significantly higher number of women being recommended for biopsy based on the ultrasound alone. So ultrasound certainly does detect a small number of additional cancers, but it leads to a lot more biopsies, a significantly higher number of biopsies. And insurance may not cover additional testing in such circumstances. That being said, it does seem to be more effective as a modality in high-risk women, rather than in the overall population. So again, you really need to think about your patient's personal risk for breast cancer and concern about developing the disease, versus willingness to possibly have to undergo biopsy.

Lee Tetreault:

This is great information, Doctor. Thank you so much for your time.

Dr. Marcus:  

Thank you.




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