Any cancer diagnosis is difficult, but a diagnosis of ovarian cancer may be especially troubling because it's often found late in the disease. Only about one in five women with ovarian cancer is diagnosed at an early stage.
Once ovarian cancer is found, doctors will do tests to figure out how far the cancer has spread and assign a stage to the cancer, according to the U.S. National Cancer Institute (NCI).
There are four stages of ovarian cancer. Generally, the lower the number, the less the cancer has spread, states the American Cancer Society (ACS). To determine the stage of ovarian cancer, doctors consider the size of a tumor and whether it has spread to lymph nodes or to more distant parts of the body, such as the liver and the bones. Doctors may refer to these factors by the letters T, N and M: T for tumor size, N for nearby lymph nodes and M for metastasis (the term for cancer that has spread past its original location).
Cancer can spread throughout the body via three ways:
- Through the body's tissues. The cancer develops in one area, such as in ovarian tissue, and might then spread to nearby tissues, such as the fallopian tubes.
- By way of the lymph system. This is the part of the immune system that carries lymph fluid throughout the body. If cancer gets into a nearby lymph node, it can then travel to lymph nodes in other parts of the body, according to the NCI.
- Via your blood.
Ovarian cancer stages
- Stage 1 (also called stage I). This stage of cancer means that the cancer is only in the ovary. It has not spread to nearby lymph nodes, and it has not traveled to distant sites. There are also subtypes of Stage 1. An ovarian cancer called Stage 1A means it affects only one ovary. A cancer called Stage 1B affects both ovaries, according to the ACS. With Stage 1C, the cancer is either in one or both ovaries but is considered to be of a higher risk for several possible reasons. The tumor capsule may have ruptured before surgery or broke during surgery, which could allow cancer cells to leak into the pelvis or abdomen. The cancer might also be on the outer surface of the ovary. It's also possible that cancer cells might be in the fluid surrounding the ovaries.
- Stage 2 (stage II). Cancers in this stage have spread past the ovaries, but have not invaded nearby lymph nodes. In Stage 2A, the cancer has spread to the uterus or fallopian tubes. Stage 2B cancers are in nearby pelvic organs, like the bladder, rectum or lower colon.
- Stage 3 (stage III). This stage of cancer is divided into three main types. Stage 3A is cancer that may have spread to nearby organs and possibly lymph nodes. There also may be cancer cells found in the lining of the abdomen (peritoneum) that aren't visible but are found if a sample of the abdomen is tested in a lab. Stage 3A cancers have not spread to more distant sites within the body, according to the NCI. Stage 3B cancers can be found in one or both ovaries and organs outside of the pelvis. The new cancer sites can be seen by a surgeon, but are smaller than ¾” or 2 centimeters, the ACS states. That’s about the size of a peanut. Cancer at this stage has not spread inside the liver or spleen or to more distant areas. When ovarian cancer reaches stage 3C, the new cancer deposits are larger than ¾”. The cancer may have spread to the outside of the liver or spleen, but it has not reached inside the liver or spleen or traveled to more distant sites.
- Stage 4 (stage IV). This is the stage for ovarian cancer that has spread to organs past the abdominal area, according to the American Society of Clinical Oncology. With Stage 4A ovarian cancer, it has spread to the fluid around the lungs. Stage 4B ovarian cancer is even more widespread, traveling to farther organs and to lymph nodes beyond the abdomen.
What are ovarian cancer survival rates?
The stage of ovarian cancer can dramatically affect ovarian cancer survival rates, as can the type of ovarian cancer. There are three main ovarian cancer types: epithelial, germ cell and stromal.
- For epithelial ovarian cancer. This is the most common type of ovarian cancer. It typically begins on the surface of the ovary (the epithelium), according to the Ovarian Cancer Research Alliance (OCRA). Overall, this type of ovarian cancer has a five-year relative survival rate of an average of 47 percent, according to the ACS. That means about half of people diagnosed with this cancer are still alive five years later. These survival rates are based on data from people who were diagnosed from 2009 to 2015. Where the cancer is located gives a more precise estimated survival rate. For example, if the cancer is localized, meaning it has not spread past the ovary, the five-year survival rate is actually 92 percent. If the cancer is regional, meaning it has spread only to other areas in the abdomen, the five-year survival is 76 percent. However, once the cancer has spread to distant areas, the five-year survival drops to 30 percent, states the ACS.
- For ovarian germ cell tumors. This rare type of cancer develops in the reproductive cells of the ovaries, OCRA says. The overall five-year survival for this type of cancer is 93 percent. But again, location influences that number. Cancers limited to the ovaries have a 98 percent five-year survival, according to the ACS. If the cancer has spread to other abdominal areas, five-year survival is 94 percent. If distant sites are involved, the five-year survival rate drops to 74 percent.
- For ovarian stromal tumors. This is another rare type of tumor. It develops in connective tissue in the ovary, according to the OCRA. Overall survival at five years is 88 percent, according to the ACS. If the cancer has stayed in the ovary, there’s a 98 percent five-year survival compared to 89 percent if the cancer has spread to the abdominal area. People with ovarian stromal tumors that have invaded distant sites have a 54 percent five-year survival rate.
It's important to keep in mind that survival rates are only estimates. They cannot be used to predict how long any individual with cancer might live. Your doctor can help you understand what these numbers mean for you.
There are three main categories of treatment for women diagnosed with ovarian cancer: surgery, chemotherapy and targeted therapies. Radiation therapy and immunotherapy are being studied in ovarian cancer, according to the NCI.
Surgery is the main treatment for early ovarian cancers. The goal is to remove as much of the tumor as possible. With chemotherapy, explains the NCI, drugs that are used are designed to kill cancer cells or stop them from growing. Targeted therapy is medication developed to specifically target the cancer cells while leaving normal cells unharmed.
When ovarian cancer is more advanced, treatments other than surgery are needed. After surgery, women with later-stage ovarian cancer will likely have either chemotherapy or targeted therapy added on to their treatment regimen. Your doctor might also suggest taking part in a clinical trial for access to the latest medications. But before doing so, you’ll want to thoroughly discuss all risks and benefits of treatment with your doctor.
- American Cancer Society, Can Ovarian Cancer Be Found Early? https://www.cancer.org/cancer/ovarian-cancer/detection-diagnosis-staging/detection.html
- U.S. National Cancer Institute, Ovarian Epithelial, Fallopian Tube and Primary Peritoneal Cancer Treatment (PDQ) - Patient Version https://www.cancer.gov/types/ovarian/patient/ovarian-epithelial-treatment-pdq#_156
- American Cancer Society, Ovarian Cancer Stages https://www.cancer.org/cancer/ovarian-cancer/detection-diagnosis-staging/staging.html
- American Society of Clinical Oncology, Ovarian, Fallopian Tube, and Peritoneal Cancer: Stages and Grades https://www.cancer.net/cancer-types/ovarian-fallopian-tube-and-peritoneal-cancer/stages-and-grades
- Ovarian Cancer Research Alliance, Types of Ovarian Cancer https://ocrahope.org/patients/about-ovarian-cancer/types-ovarian-cancer/
- American Cancer Society, Survival Rates for Ovarian Cancer https://www.cancer.org/cancer/ovarian-cancer/detection-diagnosis-staging/survival-rates.html