Prognosis
Ovarian cancer ranks behind lung, breast, and colorectal cancer as the fourth most common cause of female cancer death in this country. About 16,090 American women are expected to die from ovarian cancer in 2004.
In general, overall five-year survival rates (all stages combined) increased from 37% in 1974 to greater than 50% currently. Survival rates vary depending on different factors, including age and the stage at which it is detected.
The survival rate also varies according to the cancer stage:
- Five-year survival rates are over 90% if the cancer is still confined to the ovary at diagnosis.
- If it has spread to nearby regions in the pelvis, the survival rate drops to between 60% and 80%.
- If it has spread to sites outside the pelvis, the five-year survival rates are only 10% to 30%.
Unfortunately, most patients with ovarian cancer are not diagnosed until the disease is advanced, which typically involves spread to the upper abdomen. In order to establish a prognosis and determine treatment, the physician needs to know the cell type, stage, and grade of the disease.
Prognosis by Cell Type
About 90% of ovarian epithelial cancers fall into one of four major subtypes based on their origin and shape as viewed under a microscope:
- Serous. (This is the most common type.)
- Endometrioid. (This is sometimes associated with endometriosis and tends to have a more favorable outlook.)
- Mucinous. (The presence of malignant mucinous cells indicates a poorer outlook if the disease is advanced.)
- Clear cell. (Clear cell carcinomas are the most difficult to treat even when the malignancy is still confined to the ovary.)
The remaining 10% of common epithelial cancers are referred to as undifferentiated, because their exact cell of origin cannot be determined microscopically. These epithelial ovarian carcinomas tend to grow and spread quickly.
Prognosis by Stage
Cancers are staged (I through IV) according to whether they are still localized (remaining in the ovary) or have spread beyond the original site.
Prognosis by Grade
Tumors are also graded according to how well or poorly organized they are (their differentiation). Ovarian tumors are graded on a scale of 1, 2, or 3. Grade 1 tends to closely resemble normal tissue and has a better prognosis than grade 3, which indicates very abnormal, poorly defined tissue.
Other Prognostic Factors
Age. It is commonly thought that younger women have a better prognosis than older women, although a 1996 study indicated that the stage and grade of the tumor were the main factors in prognosis, while age itself played no role.