TP53 and breast cancer: The frequency of PVs in high-risk BC genes (BRCA1, BRCA2, CDH1, PALB2, PTEN, and TP53) was greater for patients with BC as the 1st cancer diagnosis, 8.7% (95% CI 7.7–9.8%) compared to BC as a 2nd or ≥ 3rd cancer diagnosis, 4.1% (95% CI 3.4–4.9%) and 3.7% (95% CI 2.1–7.9%), respectively (p for trend < 0.001).