HNPCC vs Lynch Syndrome

Q: What’s the difference between Lynch syndrome and HNPCC?

A: Lynch syndrome used to be known as HNPCC, which stands for hereditary non-polyposis colorectal cancer. Dr. Henry Lynch studied families with multiple cancers. At the time, the most commonly known hereditary colon cancer was Familial Adenomatous Polyposis (FAP). In FAP people have 100s of colon polyps with cancer occurring in the 20s and 30s. It can be inherited if only 1 parent has the disease.  However, in the families Dr. Lynch was studying these families only had a few polyps, although they still had cancer at a young age and could also be inherited by only 1 affected parent.  That is why it was known as “non-polyposis”. When these people were also found to have other cancers, besides colon cancer, it did not make sense to call someone with uterine cancer “hereditary non-polyposis colorectal cancer” if they did not also have colorectal cancer. Since Dr. Lynch published extensively on this problem, it became known as Lynch syndrome.