About one in three patients with FMEN1 has gastrin-releasing tumors, called gastrinomas.
The gastrinomas associated with FMEN1 are difficult to cure by surgery, because it is difficult to find the multiple small gastrinomas in the pancreas and small intestine.
The pituitary gland becomes overactive in about one of four persons with FMEN1.
Occasionally, a person who has FMEN1 develops islet tumors of the pancreas that secrete high levels of pancreatic hormones other than gastrin.
The overactive endocrine glands associated with FMEN1 may contain benign tumors, but usually they do not have any signs of cancer.
Another type of benign tumor often seen in people with FMEN1 is a plum-sized, fatty tumor called a lipoma, which grows under the skin.
Occasionally, a person who has FMEN1 develops tumors of the pancreas that secrete high levels of pancreatic hormones other than gastrin.
An example of a benign tumor that may become quite large in people with FMEN1 is the pituitary tumor called prolactinoma.
Another school advocates early surgery to try to remove pancreatic cancers in FMEN1 before they spread outside the pancreas.
Doctors agree that excessive release of certain hormones (such as gastrin) from pancreatic cancer in FMEN1 needs to be treated, and medications are often effective in blocking the effects of these hormones.
Although FMEN1 tends to follow certain patterns as described earlier, there is considerable variation in the ways FMEN1 can affect a person's health.
In the next few years, scientists hope to develop a simple test that will identify the abnormal FMEN1 gene.