Types of Ovarian Cancer

According to MD Anderson Cancer Center, there are more than 30 different types of ovarian tumours which are categorized according to cell types.  Some are non-cancerous and do not spread beyond the ovary, others are malignant and can spread to other parts of the body.

The three most common types of ovarian cancer are:

1. Epithelial tumours which originate in the cells that cover the outside of the ovary.  This is the most frequent type of ovarian cancer accounting for approximately 90% of the cases.  It is most common in women over the age of 60 but can develop at any age.
2. Germ cell tumours which originate in the egg-producing cells and are found within the ovary.  This type of cancer is most common in adolescents and women under the age of 30.  It accounts for about 5% of all ovarian cancers.
3. Sex cord stromal tumours develop in the connective tissue that holds the ovary together and produces the female hormones estrogen and progesterone.  It is relatively rare accounting for 5% of ovarian tumours.

Within these broad categories are two sub-categories - hereditary or sporadic cancer.  Hereditary ovarian cancer usually means that the person carries the defective BRCA1 or BRCA2 genes.  About 10% of ovarian cancers are inherited from a blood relative.  Sporadic cancer is cancer of unknown origins.

People who inherit the defective BRCA1 or BRCA2 genes are at a significantly higher lifetime risk of developing breast and/or ovarian cancer.  Therefore screening for these genetic defects becomes an important tool for the ovarian cancer patient themselves and her family.  Please refer to Genetic Testing under the Hope and Healing tab on the website for more details.

Prevention of inherited breast cancer usually involves heightened breast screening, possible use of drugs such as Tamoxifen, possible removal of the breasts.  Prevention of inherited ovarian cancer usually involves prophylactic removal of the fallopian tubes and ovaries.