Breast Imaging

There is probably more written about the subject of breast imaging than almost any other breast topic.

What imaging modalities are available?

Mammograms.

-Mammograms are Xrays of the breast.  They involve exposure to small amounts of radiation and are the most studied mode of imaging used for breast screening.

Ultrasound.

-Uses sound waves to image the breast

MRI

-Should be used in exceptional circumstances

The many other imaging modalities have not been shown to be effective and will not be discussed here.

 

Imaging of the breast should be utilised for two purposes:

Diagnosis

Screening

Diagnosis.  Any woman over 40 with a lump in her breast should have a mammogram and ultrasound to determine the nature of the lump.  Most women under the age of 40 should have an US first and a mammogram if advised.  The purpose of the imaging is to diagnose the lump and to look at the remained of the breast and the other breast.

Screening: this is controversial.  The purpose of screening for any disease is to pick up the disease at an earlier stage than it would be detected naturally and so increase survival.  Appropriate imaging can diagnose cancer at an earlier stage and may be able to pick up pre cancer.  Adequate treatment of pre cancer may result in cancer being prevented.

Different countries have different policies as to when screening should start and how often it should occur.  There are several principles that should be adhered to:

  1. Any woman who has a screening mammogram must also have a breast examination. Cancers may not show up on a mammogram.  They are more likely to be missed in younger women (<50) and if the cancer is a lobular cancer.
  2. Generally screening should start at 50. In some countries, it is advised that screening should start at 40.
  3. Mammograms should occur at regular intervals. Exactly how often one should go for mammograms is unknown.  The US recommends every year.  The UK recommends every 3 years
  4. Women with a strong family history should start screening at a younger age and should go more regularly.

Written by Dr Jenny Edge

 

 

 

Understanding breast cancer screening

mammogram-breast-cancer-screeningIn order to understand breast cancer screening, it is important to explain some general principles of screening:

The disease screened for must be common. With 1 of 8 women suffering breast cancer during their life-time, this is clearly the case. While there are no accurate, recent statistics available for South Africa, our own cancer pick up rates indicate that contrary to official statements, breast cancer is as common in our population as in countries with established screening programs.

The disease must be sufficiently severe to warrant the screening effort. Nobody will dispute this for breast cancer.

A screening test must be available, that reliably picks up the signs of the disease. At the same time, a screening test must not generate too much “harms”. Mammography will pick up early signs of breast cancer in about 90 – 95% of cases, fulfilling the first condition. “Harms” mean that the test must not pick up signs of the disease in too many patients that with further work-up turn out to be false alarms. For mammography it is accepted, that less than 10% of women should be called back for further examinations. In our centre, about 4 – 5% of women are called back. It is also important, that while false alarms are inevitable, these can be sorted out with a minimum of cost and further harms done to the patient. Generally, less than 5% of women should have a biopsy to sort out findings. In our centre, it is about 2%. The vast majority of biopsies should be done as office procedures under mammographic or ultrasound guidance; only very rarely should a woman have to go to theatre to make a diagnosis. In our centre, only 2 in 100 biopsies are done as a theatre procedure. If a biopsy is performed, it must yield a diagnosis of cancer in 2 – 5 of 10 cases. In our centre, about 1 in 3 biopsies result in a diagnosis of cancer.

As new cases of the disease arise continuously, the screening test must be repeated at regular intervals. For mammographic screening, most cancer organizations recommend annual screening from age 40 onwards. In most governmental screening programs, the screening interval is 2 years for mainly financial reasons. Concerns about the radiation exposure are unfounded, as there is stringent supervision of mammography units by the Radiation Control Board in South Africa.

The screening test must pick up the disease so early, that it changes the course of the disease. In a well-run screening unit, about 1 in 5 cancers will be detected at a pre-invasive stage. This means, that the cancer is curable by surgery alone and does not require intensive treatment such as chemotherapy or radiotherapy. In our centre, one in 3 cancers is detected at the pre-invasive stage. More than half of the invasive cancers must be less than 2 cm in diameter. In our centre, about half of invasive cancers are less than 1 cm in size. The pre-invasive and these small invasive cancers can be cured in more than 90% of patients. It is well documented, that in regularly screened patients, the mortality of breast cancer is up to 50% lower than in those who do not undergo mammographic screening. Here, many misunderstandings arise. Breast cancer is a slowly growing cancer and effective therapy is available. This means, that the benefit of screening in the form of a reduced mortality becomes apparent only after about 10 years in those who underwent screening.

All the above shows that mammographic screening can change the course of breast cancer. It is unclear, however whether this is a given in South Africa. The effectiveness of screening is well documented in overseas screening programs, where stringent quality controls from regulatory authorities are applied. This is not the case in South Africa. Only a single unit in South Africa has ever published in peer-reviewed scientific journals its screening results and shown that it can provide screening at the quality of the best overseas units.

By Professor Justus Apffelstaedt, Associate Professor: University of Stellenbosch and Head of the Breast Clinic: Tygerberg Hospital

Does Breast Cancer Run in Families?

In yesterday’s blog we told you about the genetics of breast cancer, but: DID YOU KNOW: breast cancer can run in families, even when there is no evidence of the BCRA gene?

Genetics & a Family History of Cancer

A family history of certain types of cancer can increase your risk of breast cancer. This increased risk may be due to genetic factors (known and unknown), shared lifestyle factors or other family traits.

Only about 13 percent of women diagnosed with breast cancer have a first-degree female relative (mother, sister or daughter) who also have breast cancer.

A woman whose mother or sister has breast cancer is almost twice as likely to develop breast cancer as someone who has no family history of the disease. If more than one first-degree female relative has been diagnosed with, the risk is about three to four times higher.

Interestingly, the younger your relative was when she was diagnosed, the greater your chance of getting breast cancer. For example, if your mother was diagnosed with breast cancer before she turned 40 you have about twice the risk of a woman without a family history.

If you are wondering about your breast cancer risk, you also need to look at the medical history of your male relatives. Breast cancer in a close male relative, such as a brother, father or uncle, increases your risk of breast cancer.

Other hormone-related cancers such as prostate cancer are also relevant. If your father or brother has prostate cancer, especially if it was diagnosed at a young age, then your risk for breast cancer increases.

Find out more here }

Why do we give you this information? It is certainly not to scare you! We believe that if you know about your risks, you will be aware of the need for the regular screening which could save your life. #knowledgeispower 

–> If you would like to read an academic paper on familial risks, we can recommend this one.