We are using the breast cancer definition used by the eMERGE program, with some slight modifications. Follow this document for implementation.
Modifications:
We will only include cis females in the analyses
The standard definition requires controls be age 18+. If the age distribution of cases within a study is much older (e.g. 30+), then studies may filter controls based on age >= the minimum age of identified cases
We recommend using age at the sample draw used for genotyping for cases and controls to adjust for age in analyses. If this is not available, age at enrollment or consent would suffice. Traditionally, age at case diagnosis is often used in conjunction with control current age or enrollment age; however, this does not properly account for true age differences between cases and controls and can lead to age-associated somatic variation (e.g., CHIP) differing between cases and controls).
We are not considering cancer subtypes
The only covariate to be collected is age.
Case definition:
All of the following:
Female
Age >= 18 years
At least one occurrence of the female breast cancer diagnostic codes (Table 1) or at least two occurrences (from distinct calendar days) of breast cancer history codes (Table 2) if the patient has no breast cancer diagnostic codes
Control definition:
All of the following:
Female
Age ≥18 years
However, if the age distribution of cases within a study is much older (e.g. 30+), then studies may filter controls based on age >= the minimum age of identified cases
None of the female breast cancer diagnostic codes (Table 1) or the breast cancer history codes (Table 2)
Covariate data to collect:
Age – please collect data (if available) on all ages listed below:
For cases:
Age at sample draw for genotyping (preferred)
Age at enrollment
Age at diagnosis
For controls:
Age at sample draw for genotyping (preferred)
Age at enrollment
Age at last contact/EHR record
