Oncogenetics: The importance of genetic diagnosis in oncology

Approximately one in eight women (12.5%) will develop breast cancer in her lifetime. Ovarian cancer affects one in 72 women.

Between 5-10% of breast and ovarian cancers are hereditary and the associated mutations are found in the BRCA1, BRCA2, RAD51C, RAD51D, CHEK2, ATM, BRIP1, PALB2, TP53, CDH1 and BARD1 genes. These genes can be tested for in at-risk families.

The lifetime risk of colorectal cancer in the general population is approximately 1 in 23 (4.3%) for men and 1 in 25 (4.0%) for women. However, this risk can increase by a factor of 4 if there is a family history of colon or rectal cancer.

The two most common syndromes are familial adenomatous polyposis (FAP) and Lynch syndrome (also known as hereditary non-polyposis colon cancer, HNPCC). Other types of hereditary colorectal cancer include juvenile polyposis syndrome, serrated polyposis syndrome, Cowden syndrome, MUTYH-associated polyposis syndrome and Peutz-Jeghers syndrome.

Ataxia-telangiectasia, Beckwith-Wiedemann syndrome, Birt-Hogg-Dubé syndrome, Carney complex, Cowden syndrome, familial adenomatous polyposis, familial GIST, familial malignant melanoma, familial pancreatic cancer, hereditary breast and ovarian cancer, hereditary diffuse gastric cancer, hereditary leiomyomatosis and renal cell cancer, hereditary mixed polyposis syndrome, hereditary pancreatitis, hereditary papillary renal carcinoma, juvenile polyposis syndrome, Li-Fraumeni syndrome, Lynch syndrome, Multiple Endocrine Neoplasia Type 1, Multiple Endocrine Neoplasia Type 2, MUTYH-associated polyposis, neurofibromatosis type 1, neurofibromatosis type 2, nevoid basal cell carcinoma syndrome, Peutz-Jeghers syndrome, tuberous sclerosis syndrome, Von Hippel-Lindau syndrome, Werner syndrome and xeroderma pigmentosum.