The patient generally undergoes a pelvic ultrasound or pelvic CT scan to confirm that the mass is a tumor (rather than something benign, such as a cyst), and then undergoes surgical resection.
A fine needle aspiration (FNA) biopsy is usually not done, as surgery is the cornerstone of treatment for all stages of ovarian cancer. The exception is in patients who are not initially surgical candidates. These patients will undergo an FNA to confirm the cancer diagnosis prior to initiation of systemic or supportive treatments.
The diagnosis and subtype of ovarian cancer are confirmed by pathologist review of a tumor specimen obtained from surgical resection or biopsy. The most common subtype of ovarian cancer is epithelial carcinoma, which accounts for two-thirds of cases.
Epithelial ovarian carcinomas may be of the serous, mucinous, or clear cell type, with the latter two carrying a poorer prognosis. Other subtypes of ovarian cancer include germ cell cancers, stromal ovarian tumors, and mixed malignant Mullerian tumors. These types represent only about 5% each of ovarian cancers and are often diagnosed confined to a single ovary.
Testing for Ovarian Cancer
Once the diagnosis of ovarian cancer (with subtype) is confirmed, the patient undergoes a wide variety of tests to evaluate the extent of disease, the prognosis for survival, and to establish baseline organ function prior to treatment.
The extent of ovarian cancer is determined by:
- Pelvic physical exam
- Abdominal/pelvic ultrasound and/or CT scan
- (These two tests are most often done prior to surgical resection.)
- Surgical resection of the pelvic mass (This is done both as a therapeutic modality and to adequately stage the patient.)
- Chest x-ray or chest CT scan
- GI evaluation, if symptoms are present
Note that the use of PET scans in monitoring ovarian cancer patients for recurrence is increasing. PET stands for positron emission tomography, with the imaging provided by cellular uptake of fluorine-18-fluorodeoxyglucose. Viable cancer cells are able to take up this sugar, while dead or fibrotic cells will not. This helps clinicians to assess for recurrence without performing another surgical procedure. PET scans are not currently recommended for initial diagnosis of ovarian cancer.
Patient prognosis is determined by:
- Evaluation of performance status
- Pathologic subtype
- Tumor grade of I, II, or III (I is the best prognosis.)
- CA-125 level in the blood (This is a tumor marker indicative of tumor burden.)
- Amount of residual tumor after surgery (Less than 1 cm is optimal.)
- Determination of performance status based upon age and other comorbid disease states is critical because (1) Many of the treatments for ovarian cancer can be very toxic, and (2) 50% of all cases occur in women over the age of 65 years.
Baselines are established for the following:
- Complete blood count (Almost all chemotherapy causes bone marrow suppression.)
- Serum electrolytes
- Renal and liver function tests
Staging Ovarian Cancer
Ovarian cancer is staged with the typical I, II, III, and IV designations. In addition, the tumor is given a histologic grade of I, II, or III. Grade I describes a well differentiated cancer and a good prognosis, whereas grade III is an undifferentiated cancer and a poor prognosis. Both stage and grade are critical in assessing for the risk of recurrence.
Stages of Ovarian Cancer
The stage I through IV definitions for ovarian cancer are listed below. Note that stages I through III are also divided into three substages, designated A, B, and C, based upon the extent of disease and organs involved.
- Stage I: Cancer is limited to the ovaries (70 to 95% survive 5 years)
- IA: Only one ovary involved.
- IB: Both ovaries involved.
- IC: One or both ovaries involved, as well as a ruptured ovarian capsule, tumor on the ovary surface, or cancer cells in washings of the pelvic cavity.
- Stage II: Cancer extends into the pelvic cavity (50 to 80% survive 5 years)
- IIA: Extension to the uterus and/or fallopian tubes.
- IIB: Extension to other pelvic tissues.
- IIC: Extension to any pelvic organ with cancer cells in washings of the pelvic cavity.
- Stage III: Cancer involves the pelvic lymph nodes or other organs outside the pelvic cavity (20% survive 5 years)
- IIIA: Microscopic spread outside the pelvic cavity.
- IIIB: Visible spread of 2 cm or less outside the pelvic cavity.
- IIIC: Visible spread greater than 2 cm outside the pelvic cavity or involvement of pelvic lymph nodes.
- Stage IV: Cancer has spread to distant sites (5 to 10% survive 5 years). Distant metastases present, often the liver or lung.
65 to 75% of patients diagnosed with ovarian cancer have advanced disease (stage II, III, or IV). Patients with stage I ovarian cancers have over a 95% chance of long-term survival with surgery alone. All other patients are at significant risk of recurrent disease and should consider participation in a clinical trial.