The time it takes ovarian cancer to develop varies. Some types progress from early to advanced stages within a year.
The ovaries are two small, gland-like organs on either side of the uterus. They are connected to the uterus by ligaments.
Ovarian cancer occurs when cancer cells are present in, near (such as in the fallopian tubes), or on the ovaries. The small size of the ovaries means that there may be no symptoms of ovarian cancer until it grows or spreads.
This article discusses what ovarian cancer is, how it spreads, and how to detect it.
Cancer occurs when cells in the body grow uncontrollably. Doctors used to believe that ovarian cancer occurred only when this happened in the ovaries. They now think that ovarian cancer begins at the ends of the fallopian tubes.
According to the National Ovarian Cancer Coalition (NOCC), 1 in 78 females will receive a diagnosis of ovarian cancer during their lifetime.
There are many different types of ovarian cancer. Each type traces back to one of three cell types in the ovaries:
- Surface epithelium: These are cells on the outer lining of the ovaries.
- Germ cells: These are the cells that form eggs.
- Stromal cells: These are hormone-releasing cells that connect the different ovarian structures.
Epithelial ovarian tumors
Epithelial ovarian tumors are masses that form on the outer lining of the ovaries.
Having an epithelial ovarian tumor does not necessarily mean that a person has cancer. This type of tumor can be benign, borderline, or malignant.
Benign epithelial ovarian tumors do not spread or cause cancer. Different types of benign epithelial ovarian tumor include Brenner tumors, cystadenomas, and others.
According to a 2019 review of research, a borderline epithelial ovarian tumor is one that spreads through the epithelial cells without affecting the other tissues around the ovaries.
Borderline tumors generally grow slowly and have better outcomes than other ovarian cancers.
Carcinomas refer to malignant ovarian epithelial tumors. Most cases of malignant ovarian cancer are epithelial ovarian carcinomas, which can be any of the following:
- serous carcinomas
- clear cell carcinomas
- mucinous carcinomas
- endometrioid carcinomas
Ovarian germ cell tumors
Ovarian germ cell tumors are cancers that start in the egg cells. This type of cancer is rare, accounting for under 2% of all ovarian cancers.
It has a generally good outlook, with most people surviving for 5 years or longer after diagnosis.
Different types of ovarian germ cell tumor include:
- Teratomas: These are tumors that resemble a developing embryo. Doctors sometimes call them dermoid cysts.
- Dysgerminomas: These are slow-growing types of ovarian cancer that tend to affect females in their teenage years and 20s.
- Endodermal sinus tumor and choriocarcinoma: These tumors tend to affect younger females and may start in the placenta during pregnancy.
Ovarian stromal tumors
Ovarian stromal tumors account for approximately 1% of all ovarian cancer diagnoses. More than half of these cases are in females over the age of 50 years.
These tumors may cause vaginal bleeding and unusual facial and body hair growth. In some cases, they can start to bleed and cause sudden, severe abdominal pain.
Ovarian cancers grow and develop at different rates. Some types may grow very quickly.
According to the University of Kansas Cancer Center, ovarian cancer can progress quickly. It can go from early stages to advanced stages within a year.
Malignant epithelial carcinoma, which is the most common type of ovarian cancer, can spread within a matter of weeks to months.
Ovarian cancer symptoms can be unclear and difficult to detect before the cancer spreads. Early stage cancers may have no symptoms at all.
If they do occur, some ovarian cancer symptoms may include:
- Stage 1: The cancer has not spread outside the ovaries.
- Stage 1A: The cancer is limited to one ovary. There is no tumor on the external surfaces.
- Stage 1B: The cancer is limited to both ovaries. There is no tumor on the external surfaces.
- Stage 1C: The cancer is limited to one or both ovaries, but there is a tumor on the surface of one or both ovaries.
- Stage 2: The cancer has spread to the uterus or other nearby organs.
- Stage 2A: The cancer has extended, metastasized, or both to the uterus, fallopian tubes, or both.
- Stage 2B: The cancer has extended to other pelvic tissues.
- Stage 2C: The cancer is at either stage 2A or 2B, but there is a tumor on the surface of one or both ovaries.
- Stage 3: The cancer has spread to the lymph nodes or lining of the abdomen.
- Stage 3A: The cancer is confined to the true pelvis.
- Stage 3B: There is a tumor in the abdomen that is smaller than 2 centimeters (cm) in diameter.
- Stage 3C: There is a tumor in the abdomen that is larger than 2 cm in diameter.
- Stage 4: The cancer has spread to distant organs, such as the liver or lungs.
A person may be unaware that they have ovarian cancer for years. Doctors detect only 20% of ovarian cancers during the early stages.
As the ovaries are so small, there may be no symptoms of cancer until it grows or spreads.
Early detection of ovarian cancer can be a challenge because there are no reliable screening tests for it.
The American Cancer Society (ACS) recommends that people undergo regular gynecological exams and contact a doctor if they have any possible symptoms for longer than a few weeks.
A doctor will generally start by discussing the person’s medical history and checking for enlarged ovaries. They may order imaging tests, such as a CT scan or pelvic ultrasound, to look for ovarian cancer.
The doctor will also order blood tests, including a blood count, tests for liver and kidney function, and a CA-125 test. Having high CA-125 levels can indicate the presence of ovarian cancer.
However, it is important to note that CA-125 is only one tumor marker that doctors use in the diagnosis of ovarian cancers. CA-125 levels can be elevated for many reasons, including noncancerous causes.
The doctor may also completely excise the cancer for biopsy. According to the ACS, removing the tumor is a common form of ovarian cancer biopsy.
According to the NOCC, surgery to diagnose and remove the cancer is the most common treatment for ovarian cancer.
Depending on the type and stage of ovarian cancer a person has, a doctor may also recommend:
- radiation therapy
- certain lifestyle changes
- participation in clinical trials
A person’s treatment plan will depend on their overall health and the type and stage of ovarian cancer they have.
The outlook will vary depending on several factors, including the person’s age, their overall health, and the type and stage of ovarian cancer they have.
According to the ACS, average 5-year survival rates of the different types of ovarian cancer are as follows:
Invasive epithelial ovarian cancer:
- localized: 93%
- regional: 75%
- distant: 31%
Ovarian stromal tumors:
- localized: 98%
- regional: 89%
- distant: 60%
Germ cell tumors of the ovary:
- localized: 98%
- regional: 94%
- distant: 73%
Fallopian tube cancer:
- localized: 95%
- gegional: 53%
- distant: 45%
Ovarian cancer is a relatively common type of cancer that starts in the ovaries. The small size of the ovaries means that there may be no symptoms until the cancer grows or spreads.
If a person has any symptoms of ovarian cancer that last for longer than a few weeks, they should contact a doctor immediately. Ovarian cancer can spread quickly, and early diagnosis and treatment lead to better outcomes.