Each year, approximately 20,000 American women are diagnosed with ovarian cancer and about 15,000 women die of the disease. But how is ovarian cancer connected with ovarian cysts? And what types of ovarian cancer do doctors diagnose?
Women have two ovaries, one on each side of the uterus in the pelvis. The ovaries produce eggs (ova) which can be fertilized and develop into a fetus. The ovaries also create the female hormones estrogen and progesterone. The ovaries contain 3 kinds of tissue:
Epithelial cells - Most ovarian cancers start in these cells, which make up a layer that covers the ovary.
Germ cells – Germ cells create eggs (ova) inside the ovary.
Stromal cells- Stromal cells are the connective cells that hold the ovaries together and create the female hormones estrogen and progesterone.
What is an ovarian cyst?
An ovarian cyst is a collection of fluid or solid tissue that is found inside or on the surface of an ovary. Most ovarian cysts disappear after a few months. Most ovarian cysts are benign (not cancer) but a small number of ovarian cysts are or become malignant (cancer). But sometimes a doctor will find a cyst that does not go away or that gets larger. The doctor may order tests to make sure that the cyst is not cancer.
What is ovarian cancer?
Ovarian cancer is cancer that begins in the cells of the ovaries. Normal cells grow and divide to form new cells as the body needs them. During cancer, this process goes wrong. As new cells form when the body does not need them, and old cells do not die when they should. Extra cells can then form a mass of tissue called a “growth” or “tumor”. Tumors can be malignant (cancerous) or benign (non-cancerous).
Ovarian cancer can invade, shed, or spread to other organs. Cancer that spreads is said to “metastasize”. Note here that when cancer spreads from the ovaries to another part of the body, new tumor(s) contain the same kind of abnormal cells. Cancer cells that break off from the main ovarian tumor can form new tumors on nearby organs and tissues. Or a malignant ovarian tumor can grow and invade organs next to the ovaries (the fallopian tubes and uterus). Cells from an ovarian tumor can also enter the bloodstream or spread through the lymphatic system. Doctors call the new tumor "distant" or a metastatic disease.
Types of ovarian cancer
There are more than 30 types and subtypes of ovarian cancers (also known as malignancies), each with unique properties, different appearances and behaviors. Most oncologists (cancer specialists) group ovarian cancers within three major categories, according to the kind of cells from which they were formed:
Most ovarian cancers are either ovarian epithelial carcinomas (cancer that begins in the cells on the surface of the ovary) or malignant germ cell tumors (cancer that begins in egg cells). Additionally, some tumors that are located next to ovarian tissues are considered ovarian cancer. For example, doctors treat extra-ovarian peritoneal carcinoma (technically cancer of the membrane lining the walls of the pelvic cavity) as if it were advanced ovarian cancer.
But do doctors know what causes cancer of the ovaries? Does diet or having children affect your risk of the condition? And which women in particular are more at risk of developing ovarian cancer? More on risk factors and causes of ovarian cancer here.