I am a 67 year old widow with 2 children aged 43 and 45. Their father died from stomach cancer in 2018, he was 62 years old. His mother died at age 57 of stomach cancer in 1976 and now his sister is dying from stomach cancer at the moment, she is 76 years old. My children are very worried about the link and is this rare for 3 members of the same family to have Stomach cancer?