Hereditary Colon Cancer
Dear OncoLink "Ask the Experts,"
I am looking for a clinical study on hereditary connections for Colon Cancer.
I have an intensive family history of colon cancer. My paternal Grandfather died from it in his 50's. My father has had 7 colon polyps removed and his two sisters have had colon cancer recently. I also have had 3 colon polyps removed and have on going abdominal pain and bloating at times. I am currently seeing my physician for this.
I would appreciate any information I can get on hereditary colon cancer.
Anil Rustgi, MD, OncoLink's Editorial Advisor on Gastrointestinal Cancers, responds:
It appears that based upon your description your family may have a form of familial colon cancer called hereditary nonpolyposis colorectal cancer HNPCC. It is defined by clinical and genetic criteria. The clinical criteria include three or more family members with colon cancer; one should be first-degree relative of the other two, spanning two generations and one case before age of 50. These criteria have been modified recently to take into account variants of HNPCC and genetic understanding.
Often it is recommended for HNPCC associated families that the siblings, father, and paternal aunts (and their children) get periodic colonoscopy (every 1-2 years).
Endometrial and ovarian cancer can be associated with HNPCC and therefore, women at risk or affected would benefit from annual pelvic Ultrasound and possibly, periodic endometrial biopsies.
Genetically, it is very helpful to obtain tissue blocks from parental aunts for immunohistochemical staining of MSH2, MLH1 and PCR analysis for microsatellite instability. Tissue blocks are wax embedded pieces of tissue that are typically removed during surgery or autopsy. They are saved by the pathology laboratory that first examined them. Often they save them for years and may be obtained at your request.
Based upon these results, it may be recommended to see a genetic counselor and have MSH2/MLH1 gene testing initially of aunts, and then family members based upon the gene testing.