What is Ovarian Cancer?
Ovarian cancer is not a single disease. First there are “non-epithelial” and “epithelial” forms of this disease. “Non-epithelial” malignancies of the ovary, which are classified as either germ cell or sex cord tumorstypes are divided into either germ cell or sex cord tumors, account for ∼10% of all ovarian cancers. It should be noted that even within these two categories there are dozens of different types of tumors. Germ cell tumors are diagnosed primarily in young women whereas sex cord stromal tumors are more common in adult women. Germ cell tumors represent around 5% of all ovarian neoplasms and 80% of preadolescent malignant ovarian tumors. Sex cord stromal tumors are less common and account for around 3 to 5% of all ovarian malignancies.
The more lethal forms of ovarian cancer are termed “epithelial” and account for approximately 90% of all ovarian cancers. Importantly, a growing number of molecular-based studies have suggested these epithelial ovarian cancers can develop from cells not directly related to the ovary, including the fallopian tube, gastrointestinal tract, cervix and endometriosis. Epithelial ovarian cancer encompasses several histologically and molecularly distinct malignancies in the ovaries, including serous, mucinous, endometrioid, and clear cell carcinomas. Each of these distinct subtypes has been traced back to independent cell origins. In the case of serious ovarian cancer an increasing number of studies support the hypothesis that epithelial cells within the fallopian tube are the the origin of many of these tumors. Other scientists still believe that cells on the surface of the ovary can also give rise to this type of ovarian cancer . The origins of mucinous ovarian tumors are thought to be metastatic tumors from the gastrointestinal tract or cervix. For clear cell and endometrioid ovarian cancers, they are considered to originate from endometriosis.
The burning question that remains for many scientists to answer is if these epithelial tumors arise outside of the ovary and how and why they ultimately find a home in the ovary. The answer may lie in the unique functional characteristics of the ovary. During ovulation, the ovary releases one egg through the rupture of an ovarian follicle. The rupture and repair process during menstrual cycles repeatedly creates a local inflammatory microenvironment in which signals are produced at the ovulatory wound site of the ovary than can recruit these extra-ovarian pre-malignant and malignant cells to the ovary. This may also explain why increased ovulation is a risk factor of ovarian cancer and why the inhibitory factors of ovulation such as multiple pregnancies, breastfeeding, late menarche, and the use of oral contraceptives, reduce ovarian cancer risk according to epidemiological studies.
As with all cancers, it is extremely important to have open communication with your health care team during your treatment.
- Ovarian cancer will occur in 1 in 75 women.
- Each year in the U.S. more than 22,000 women will be diagnosed with ovarian cancer, and more than 14,000 will die from it.
- Symptoms are subtle, persistent and usually increase over time, so it is difficult to detect in early stages. Only 15% are found at an early stage.
- Detected early and treated properly, rates of survival increase to 93% at 5 years.
- Research shows that a referral to a gynecologic oncologist remains one of the top factors in increasing ovarian cancer survival rates and decreasing rates of recurrence.
Common Myths Regarding Ovarian Cancer
Myth: I get an annual PAP smear so I don’t have to worry about ovarian cancer.
Fact: A PAP smear detects cervical cancer, not ovarian cancer.
Myth: I’ve had a hysterectomy so I can’t get ovarian cancer.
Fact: Partial total hysterectomy procedures leave your ovaries and fallopian tubes intact. A total hysterectomy with a bilateral salpingo-oophorectomy removes your uterus and cervix, as well as both ovaries and fallopian tubes. This makes ovarian cancer less likely to occur, but it does not remove all risk.
Myth: The CA 125 blood test is a screening test for ovarian cancer.
Fact: The CA 125 level can be elevated by other conditions, and not always increased in ovarian cancer patients; therefore, it is not an adequate early detection tool when used alone.