Preventive oncology

Demand for cancer risk assessment based upon the estimation of the genetic
component of cancer risk to a given individual is increasing rapidly. This is both
because of increased public awareness of the genetic aspects of cancer susceptibility and as a result of requests from clinicians for evaluation of their patients so that
appropriate surveillance protocols can be developed. Risk prediction in common
cancers is based upon careful assessment of family history of cancer and cancer related syndromes, and a personal history and examination (where appropriate).
The genetic risk assessment requires confirmation of the diagnosis in affected relatives whenever possible. Close links with oncologists and clinicians involved in
organizing surveillance are essential. Joint or multidisciplinary clinics may be
appropriate in this context and, ideally, a cancer family clinic network should be
developed throughout each region, province or state. Education for primary care
physicians should be provided, with guidelines for appropriate referrals.

There are a number of questions that can help when trying to assess an individual’s risk.
Ask about:
(a) Age of onset in the family member
(b) Site of primary tumour
(c) Number of affected members in the family
(d) Multiple primary tumours
Possible indications for referrals
Personal history
• Early onset of cancer (e.g. breast cancer diagnosed 40 years, colorectal cancer
diagnosed 45 years, etc.)
• Multiple primary cancers
Family history
• Three close relatives (same side of family) with cancer of the same or syndromically
related type (e.g. breast and ovarian or colorectal and uterine)
• Two close relatives (same side of family) with cancer, or the same or related type, with at
least one affected under 50 years
• One first-degree relative (mother or sister) with early onset cancer (e.g. breast cancer)
diagnosed 40 years, or 45 years if colorectal cancer
• One first-degree relative with multiple primary cancers
• Two or more relatives with uncommon cancers (e.g. sarcomas, gliomas, pancreatic
cancer, glioma haemangioblastomas, etc.)