Zheng G et al. – Based on the current study, breast cancer (BC) was shown to share susceptibility with a number of other cancers.

Methods

• Relative risks (RRs) were calculated for BC in families with increasing numbers of patients with discordant cancers, and conversely, familial RRs for cancers in families with increasing numbers of BC patients.

Results

• The total number of familial BCs was 12,266.
• 14.9% families had one first-degree relative with BC and 1.2% of families had at least 2 affected relatives.
• Ovarian and prostate cancers showed the strongest associations with BC.
• Pancreatic, thyroid, endometrial, and testicular cancers, uveal melanoma, nervous system and endocrine tumors and non-Hodgkin lymphoma had an association with familial BC.
• The RR for BC increased by increasing numbers of patients with any cancer in family members, especially when three or more family members were affected.