Although individuals with Li-Fraumeni Syndrome (LFS), due to mutations in the TP53 gene, have a very high lifetime risk of cancer, risks of initial and subsequent cancers are not well defined. Through a group of patients with the classic form of LFS, researchers at the National Cancer Institute estimated their cancer risks. They evaluated a total of 286 individuals with TP53 mutations from 107 families, and found of women 50% had developed cancer by age 31 and of men 50% had developed cancer by age 46. This suggests that on average women with LFS tend to develop cancer earlier than their male counterparts. For women, cancer risk was the contributing highest after age 20, mainly due to high risks of breast cancer. This differed in men, where the risk was highest in childhood and later adulthood. Among both sexes, almost 100% of individuals had developed cancer by age 70. Cancer risks outlined by type of cancer developed by age 70 among women and men with LFS are shown in the table below.
| Cancer Type |
Cancer Risks by Age 70 |
|
|
Women |
Men |
|
| Breast cancer |
54% |
~ |
| Soft tissue sarcoma |
15% |
22% |
| Brain cancer |
6% |
19% |
| Osteosarcoma |
5% |
11% |
Of individuals who developed cancer, about half went on to develop at least one more cancer after an average timeframe of 10 years. Furthermore, having been diagnosed with one cancer did not lower their risk of developing a subsequent cancer. The new information from this study helps to refine cancer risk estimates among those with LFS, which is needed to guide their cancer risk management strategies.
Mai et al. Cancer. 2016 Dec 1;122(23):3673-3681. PMID: 27496084.