Components of the Risk Assessment Process
For consultands with a history of cancer, additional information collected includes the following:
- Site of primary tumor.
- Age at diagnosis.
- Tumor pathology.
- Treatment (surgery, chemotherapy, radiation therapy).
- Bilaterality of disease, if applicable.
- Current surveillance plan.
In some cases, a physical exam is conducted by a qualified medical professional to determine whether the individual has physical findings suggestive of a hereditary cancer predisposition syndrome or to rule out evidence of an existing malignancy. For example, a medical professional may look for the sebaceous adenomas seen in Muir-Torre syndrome, measure the head circumference, or perform a skin exam to rule out benign cutaneous features associated with Cowden syndrome, or perform a clinical breast and axillary lymph node exam on a woman undergoing a breast cancer risk assessment.
Documenting the family history
The family history is an essential tool for cancer risk assessment. The family history can be obtained via interview or written self-report; both have been found to result in equivalent information in a study that utilized a sample (n = 104) that varied widely in educational attainment. One study suggests that the use of paper-based family history questionnaires prior to the appointment provides accurate family history information. Details of the family health history are best summarized in the form of a family tree, or pedigree. The pedigree, a standardized graphic representation of family relationships, facilitates identification of patterns of disease transmission, recognition of the clinical characteristics associated with specific hereditary cancer syndromes, and determination of the best strategies and tools for risk assessment.[29,30]Factors suggesting inherited cancer risk were previously discussed.
Both multimedia-based (e.g., Internet) and print-based (e.g., family history questionnaires) tools are currently available to gather information about family history. In the United States, many are written at reading grade levels above 8th grade, which may reduce their effectiveness in gathering accurate family history information. On average, print-based tools have been found to be written at lower reading grade levels than multimedia-based tools.
Standards of pedigree nomenclature have been established.[29,30] Refer to Figure 1 for common pedigree symbols.
Figure 1. Standard pedigree nomenclature. Common symbols are used to draw a pedigree (family tree). A pedigree shows relationships between family members and patterns of inheritance for certain traits and diseases.
Documentation of a family cancer history typically includes the following:
- A minimum of three generations of relatives on both the maternal and paternal sides of the family. Information on multiple generations helps to demonstrate inheritance patterns. Hereditary cancer can be inherited from either the maternal or paternal side of the family, and is often an adult-onset disease.
- Race, ancestry, and ethnicity of all grandparents. This may influence decisions about genetic testing because specific mutations in some genes are known to occur with increased frequency in some populations (founder effect).
- Information about seemingly unrelated conditions, such as birth defects, atypical skin bumps, or other nonmalignant conditions of children and adults that may aid in the diagnosis of a cancer susceptibility syndrome.
- Notation of adoption, nonpaternity (the biologic father should be included in the pedigree), consanguinity, and use of assisted reproductive technology (e.g., donor egg or sperm), when available.