How should contralateral breast cancer risk predictions be interpreted?

The BOADICEA model includes the following assumptions/limitations when it computes contralateral breast cancer risk:

1. Contralateral breast cancer risk is computed using only the following information for the index:

• Age at diagnosis of the first breast cancer

• Genetic and other risk factors (including family history)

No other information is considered in predicting contralateral breast cancer risk.

See What information do the breast and ovarian cancer models use to determine risks? and Antoniou et al. Br J Cancer 2008 for further details.

2. The model assumes that only one breast remains at risk.

3. Treatment of the first cancer (in particular hormonal therapy etc) and tumour pathology are important risk factors for contralateral breast cancer. However, these risk factors are not taken into account by the model. For example, systemic treatment is associated with a reduction in contralateral breast cancer risk. This is a limitation of the model which we aim to address in the future.