Breast cancer screening


Q. Why screen?
Answer. All women in the UK are invited to attend for screening by mammography every 3 years from age 50. This has been shown to detect many more "early" and small breast cancers than would be expected without screening. As a result it is possible to cure more women with breast cancers detected by screening than it is to cure women who present symptomatically with, for example, a breast lump. Screening does not, however, prevent breast cancer and some women will still die of breast cancer despite having regular mammography.

Q. Why does screening not normally start until age 50?
Answer. Breast cancer is more common as women get older and mammography is more sensitive at detecting cancer in older women. The success of screening largely depends on how common the disease is and the ease with which it can be detected. Young women are more likely than older women to have cancers that cannot be seen on a mammogram. As there are disadvantages to screening as well as advantages, it is currently thought that the disadvantages outweigh the advantages in women under age 50 but this is debated.

Q. What are the disadvantages of screening?
Answer. Mammography may detect a change in the breast that turns out to be non-cancerous. Tests, sometimes including surgery, may need to be performed before reassurance that all is well can be given. Each mammogram also gives you a small dose of radiation. Whilst we do not believe that this is a concern, it is theoretically possible that regular mammography in young women may actually cause a breast cancer to occur. Attending for mammography may also cause considerable anxiety.

Q. Why am I being offered screening by mammography before I am 50?
Answer. For young women at increased risk of breast cancer the advantages of screening by mammography outweigh the disadvantages, in my opinion. Whilst there are still limitations with mammography, this remains the best way we have of detecting breast cancer "early" while it is small.

Q. Are there alternatives to mammography?
Answer. One alternative to mammography is to be examined regularly by an expert in breast examination. There is little evidence to suggest that this is an effective method of screening but it might be of value in those at high risk of breast cancer. Another way is MRI screening. This may be more sensitive than mammography at detecting breast cancer. However, it is expensive, it may detect more changes that require investigation but turn out to be non-cancerous (about a 1 in 10 chance of this) and it has not been shown to improve overall survival in women who are screened. It is currently only considered for young women at very high risk.

Q. How often will I have a mammogram?
Answer. Mammography is currently recommended every year for young women at increased risk of breast cancer and every 3 years for women over age 50 (although this is currently being reduced to age 47). Young women have mammograms more frequently than for older women, because breast cancer in young women may appear more quickly than in older women. If you are aware of a breast problem before you are due for your routine appointment you can arrange to be seen at the clinic rather than seeing your GP.

Q. At what age does screening start for women at increased risk of breast cancer?
Answer. Screening women who are at increased risk of breast cancer usually starts at age 35 - 40 depending on degree of risk. MRI screening is offered to women at high risk and starts at age 30.

Q. At what age will screening stop?
Screening is by invitation every 3 years as part of the UK national breast screening programme up untill age 70 (currently being extended to age 73). Thereafter you will need to request that you are still screened if you wish to be.

Q. How do I get more information?
Answer. When you attend the clinic the benefits and limitations of screening will be explained to you. Any further questions you have will be addressed.