Accurate assessment of family histories is necessary to estimate the level of risk to the patient, as it is the risk group that will guide the management strategy. The degree of risk to an individual depends upon the following factors:

• Type(s) of cancer(s) that occurred in the family
• Number of relatives who developed cancer
• Presence of associated cancers
• Ages at which the relative(s) developed cancer
• The age of the individual seeking advice

Family history assessment typically places the risk of an individual into one of three risk categories:

• near-population risk
• moderate risk
• high risk

Near-population risk

Patients who do not meet the minimum referral criteria have a risk of developing cancer at, or close to that of the general near-population. The term low risk is often used, although this term is misleading - it relates to the patients being at low genetic risk of developing cancer.

These patients fall outside the minimum threshold for surveillance, and thus are

not seen at the surveillance units or at clinical genetics. Patients assessed as having a near-population risk of breast cancer should still attend for surveillance under the National Breast Screening Programme when called.

Typically, patients at near-population risk receive a brief letter explaining that they do not require screening, plus an information sheet that explains how their family history was assessed.

Moderate risk

Patients who meet the minimum referral criteria have an increased risk of developing cancer

Patients at moderately increased risk (sometimes referred to as intermediate risk) are unlikely to carry the current known cancer predisposing genes, although epidemiological evidence suggests that their risk of developing cancer is higher than the general near-population. Several studies to identify new susceptibility genes are in progress.

Patients at moderate risk are usually referred for surveillance. DNA should be banked from living affected relatives where possible. MSI tumour studies may be undertaken on tissue previously removed from affected family members. An appointment with the clinical genetics team would not offer any additional management options at this time.

An example of a moderate risk colorectal cancer family can be seen here.

High risk

This term relates to patients who are at a high genetic risk of developing cancer because of their family history. Their family history is likely to show an autosomal dominant pattern of inheritance, with family members affected at a very early age (often below 40). Multiple primaries and bilateral tumours in individuals are common.

In addition to regular surveillance, the patients are offered an appointment in clinical genetics where the role and possibility of molecular genetic testing can be discussed. The patients' perception of their own cancer risk can be also be explored, and the patient can usually be given information on their own risk of being a gene carrier and their personal risk of developing cancer.