Breast Screening
NHS Breast Screening Programme Introduced in 1988 Invites women from age group for screening every 3 yrs. Age extension roll-out in progress includes ages Due for completion Women over 70 can request screening every 3 yrs at their local unit.
Why every 3 years? –Higher number of false positives with annual screening leading to unnecessary investigations. Why the lower age limit? –Only 15% breast cancers occur before age 45. Mammography more difficult to interpret in younger age group due to density of breast tissue. Why upper age limit? –May pick up latent cancers which would not have presented clinically within the woman’s lifetime. Leading to unnecessary intervention.
Screening does not prevent cancer developing (unlike Ca cervix) But may detect cancers earlier- giving a better prognosis. For more info on statistics and cancer detection rates see: Breast Screening Programme Report : link available from NHS Breast Screening website.
Breast Cancer Population risk is about 1:12 5% genetic predisposition Genes that predispose can be inherited by both sexes but not expressed to same degree. High penetrance. BRACA1 & BRACA2, TP53 gene mutations. May get clusters of cancers which are not explained by identifiable genetics.
How do we assess genetic risk? Family hx is most reliable way of assessing. Important to identify those at risk as may require increased frequency of screening. Prophylactic mastectomy decreases risk of ca breast by up to 90%.
What to ask the patient: Who in the family was affected? Need to look over 3 degrees of relatives What type of cancer was it? The more detail the better: breast, ovary, endometrium, prostate At what age? don’t forget males in a family who may be carriers but not express the gene- male with a mother and sister affected counts as an affected relative.
Genetic Clues in the FH Two or more closely related people (1 st, 2 nd degree) with same type cancer. Unusual combinations of cancers in a family. Or more than one in an individual eg: breast & ovary, colorectal & endometrial Same cancer in successive generations Cancer at unusual young age- breast/colorectal <40.
NICE Guidelines Who should be referred to secondary or tertiary care? Tertiary Care: –If a faulty gene has been identified within the family: should refer straight to tertiary care for specialist genetic counselling services –May include surveillance: mammography/ MRI (in younger women), genetic testing, prophylactic surgery.
What is raised risk? Is there one of the following present in the family history? Applies to female breast cancers only: One 1st degree relative diagnosed before age 40. One 1st degree relative and one 2nd degree relative diagnosed after average age 50. Two 1st degree relatives diagnosed after average age 50.
What is more than raised risk? Is there at least one of the following present in the family history? A 'yes' to any indicates a positive referral. Female breast cancers only One 1st degree relative and one 2nd degree relative diagnosed before average age 50. Two 1st degree relatives diagnosed before average age 50. Three or more 1st or 2nd degree relatives diagnosed at any age. Male breast cancer One 1st degree male relative diagnosed at any age. Bilateral breast cancer One 1st degree relative where 1st primary diagnosed before age 50. For bilateral breast cancer, each breast has the same count value as one relative. Breast and ovarian cancer One 1st or 2nd degree relative with ovarian cancer at any age and one 1st or 2nd degree relative with breast cancer at any age (one should be a 1st degree relative).
NICE guidelines cont.. So what NICE is saying is that women aged who are at ‘raised’ or ‘more than raised’ (ie: high) risk should be offered annual screening. However: –Women aged under 40 at increased risk would usually only be offered increased screening as part of a national research programme or audit –Women aged 50+ at increased risk would usually not be offered any additional screening ie: they would cont with the normal 3 yearly screening programme as per the rest of the population.
Summary Genetic predisposition to Ca breast is actually small – 5%, but important to identify FH most important in assessing genetic risk Gather information from patient- usually over more than one consultation. If unsure use NICE pathway to decide whether to manage in primary care or to refer. Find out what your local services are so you know what you can offer the patient!