The stage of ovarian cancer means where the disease is at the time it is discovered. After surgery, your doctor may be able to see what stage your cancer is at. Laboratory reports will confirm exactly what stage and type of ovarian cancer you have.
New guidelines on the staging of ovarian cancer which include more detailed classifications are being introduced by the International Federation of Gynaecology and Obstetrics. The new system came into effect on January 1 2014, and will refine the familiar stages one to four, which dates from 1988, with new stage criteria and added classifications.
The guidelines also apply to fallopian tube and primary peritoneal cancers. Although the new system is unlikely to affect women’s treatments, clinicians may now use the new categories to describe their cancers. The system aims to make it easier to compare patients between cancer centres and to reflect increasing knowledge of the disease.
This is the earliest stage and means that the cancer affects only one or both of the ovaries.
At this stage the cancer causes few symptoms and most women are not aware that anything is wrong. Only a small number of women (15%) have their cancer found at this early stage. At surgery, even if a cancer appears to affect only the ovary, it is possible that it has spread. To be certain that a cancer is at stage one, samples from other areas are taken and examined under the microscope.
The stages of ovarian cancer are classified further using the letters a, b, and c and numbers 1,2 and 3. If cancer is confirmed as stage one, the outlook is good. This is particularly the case if the cancer is just inside one ovary (stage 1A) or both ovaries (stage 1B). In this case, surgery may be enough to treat the cancer. If the cancer involves the surface of the ovary or ovaries or there are cancer cells in the body fluid around the ovaries (stage 1C), you may also need chemotherapy.
1A The cancer is contained on one ovary/tube.
1B The cancer is contained in both ovaries/tubes.
1C The cancer is limited to one or both ovaries or fallopian tubes.
1C1 Limited to one of both ovaries/tubes, cells have leaked into the abdomen during investigative surgery.
1C2 Limited to one or both ovaries, but there has been a rupture before surgery, or a tumour on the ovary surface.
1C3 Cancer cells present in abdominal fluids (ascites) or washings.
If the ovarian cancer is at stage 2, the cancer has spread outside the ovary into the pelvis or has gone into the uterus (womb). Ovarian cancer at stage 2 is only found in about 10% of women with the disease. This is because the lining of the pelvis and abdomen are not separated, so the cancer usually spreads to the abdomen at the same time as the pelvis.
If you have stage 2 ovarian cancer, you are more likely to have chemotherapy as well as surgery.
2A The cancer has spread to the pelvis, uterus or fallopian tubes.
2B The cancer has spread to other pelvic tissues.
This is the most common stage and is found in approximately 65% of women with ovarian cancer. At this stage the cancer may have spread to the lining of the abdomen, the surface of the bowel, the omentum and the lymph nodes in the pelvis or around the aorta.
The tumour on the lining of the abdomen releases fluid which collects inside the abdomen. This collection of fluid is called ascites. If your ovarian cancer is at stage 3, your surgeon will try to remove as much of the tumour as possible. You will probably also need to have chemotherapy.
Sometimes, you may need more surgery if the tumour is not completely removed during the first operation or you may have chemotherapy before your operation.
3A1 Cancer has spread only to the peritoneal lymph glands.
3A1(i) Disease in the lymph glands measures up to 10mm in diameter.
3A1(ii) Cancer in the lymph glands measures more than 10mm.
3A2 Microscopic disease has spread beyond the pelvis and measures more than two centimetres, without affecting the peritoneal nodes.
3B Visible cancer has spread beyond the pelvis and measures less than 2cms.
3C Visible cancer has spread beyond the pelvis by more than 2cms, including the surface of the liver and spleen.
Approximately 10% of women with ovarian cancer will have stage 4 cancer.
Stage 4 means the cancer has spread beyond the abdomen to the liver or lungs. Sometimes the cancer spreading to your lungs may be the first symptom of the cancer, if it causes you to feel short of breath or cough. An x-ray will show whether the cancer has spread to your lungs.
If you have stage 4 ovarian cancer, you may have surgery and chemotherapy, or just chemotherapy.
4A. The cancer causes fluid between the lung lining and chest wall, a pleural effusion.
4B. Cancer has spread to more distant organs including lymph nodes outside the abdomen.
Grading or differentiation is about how the cancer cells look under the microscope compared with normal cells.
Knowing the grade helps your doctor decide whether you need further treatment after surgery. Grading is divided into three groups: one (low), two (moderate) and three (high). It is a prediction of how your tumour may behave.
This is how ovarian cancers are graded:
Low-grade or well differentiated (grade 1) - the cancer cells look similar to normal cells and usually grow slowly and are less likely to spread.
Intermediate or moderately differentiated (grade 2) - the cancer cells look more abnormal and are slightly faster-growing.
High-grade or poorly differentiated (grade 3) - the cancer cells look very different from normal cells and may grow more quickly.