Testing for Ovarian Cancer
Early diagnosis of ovarian cancer is rare because of the absence of symptoms in the early stages and the lack of reliable screening methods to detect ovarian cancer specifically. A Pap smear has no role to play in the detection of ovarian cancer unless it has metastasized to the cervix or vagina. Surgical diagnosis and staging should be done as soon as possible, with minimum pre-operative tests, when a pelvic mass is suspected to be ovarian cancer.
While a clinical history of vague gastrointestinal symptoms or abnormal vaginal bleeding may be correlated with ovarian cancer after it is diagnosed, it is rare where these symptoms immediately raise the concern ovarian cancer. High risk women should be monitored and the presence of these symptoms should prompt immediate investigation. Read more on ovarian cancer risks.
Methods to Diagnose Cancer
Women with a personal or family history of breast, uterine or colon cancer, or those with a close family member (mother, daughter, or sister) affected with ovarian cancer may be at increased risk of contracting the disease. These women may be advised to go for genetic testing. Women with mutations in BRCA1 and BRCA2 genes need close monitoring as these are high-risk groups for ovarian cancer. Prophylactic oophorectomy may be done as a preventive measure against ovarian cancer in selected cases.
An abdominal mass, swelling, or presence of fluid in the abdomen (ascites) detected during a physical examination may be suggestive of ovarian cancer. A pelvic examination may reveal a unilateral or bilateral fixed mass or growth in the ovary. A mass may sometimes be felt in the abdomen.
- A complete blood count (CBC) and serum electrolyte tests are essential when ovarian cancer is suspected.
- Liver function tests (LFT) may be done to assess involvement of the liver.
- An elevated CA-125 in a postmenopausal woman may be suggestive of ovarian cancer. The levels of tumor marker or cancer associated antigen CA-125 in the blood may be used to detect ovarian cancer but the results are not always sufficiently sensitive or specific for ovarian cancer to be of much use as a screening method. Colon, pancreas, breast, stomach, or uterine cancers may also be associated with an elevated CA-125 value. A normal CA-125 level does not exclude the diagnosis of cancer either.
- A serum hCG level should be obtained in all women in whom pregnancy is a possibility.
- A serum alpha fetoprotein (AFP) and lactate dehydrogenase (LDH) measurement is advisable in young girls with a pelvic mass because of the likelihood of a cancerous germ cell tumor.
Imaging studies can help to detect a mass in the pelvis but they will not be able to confirm the diagnosis of ovarian cancer.
- Ultrasound may be helpful in detecting a pelvic mass. Transvaginal ultrasound (done by placing a probe in the vagina) provides better images than abdominal ultrasound.
- CT scan can help to show in more detail the size of the growth, lymph node enlargements, and metastasis to other organs.
- MRI (magnetic resonance imaging), in addition to being more expensive, may not have any advantages over a CT scan except in evaluation of pregnant patients by avoiding radiation exposure of the fetus.
- Chest x-ray may show spread of cancer to the lungs.
- PET (positron emission tomography) scans are sometimes done to detect spread of ovarian cancer. In this method a type of radioactive glucose is used for cancer detection.
- Mammography may be done as a screening procedure to exclude breast cancer, keeping in mind the link between ovarian cancer and breast cancer.
- A barium enema may be advised in patients to exclude colon cancer.
- Colonoscopy is preferred to barium enema to exclude metastasis to the colon.
Tissue samples for biopsy may be taken by means of laparoscopic surgery (through a tiny incision in the abdomen) when the tumor is small, or by a laparotomy (a larger incision is made to open the abdomen) in case of larger tumors.
Surgical staging is done at the time of surgery by sending the removed organs and tissues for microscopic examination.
A sample of tissue may be taken from the tumor and sent for analysis. Cancer cells found in the sample will confirm the diagnosis of ovarian cancer as well as determine the type of cancer. The stage and grade of the cancer can be determined by taking biopsies from various sites. Read more on ovarian cancer stages.
Passing a laparoscope (a thin tube with a light source, tiny camera and a magnifying device at the end) through a tiny incision in the abdomen allows for proper visualization of the ovary and other structures within the pelvis and abdomen. Tissue samples for biopsy may also be taken during a laparoscopic procedure.
A laparotomy may show obvious cancer in the ovaries or other structures in the abdomen. If cancer is suspected, surgery may be done for treatment of ovarian cancer. Samples for biopsy may be taken and staging of the cancer done at the time of surgery.
Removal of ascitic fluid from the abdomen as a means of testing for cancer cells is not routinely advised. Even with widespread intra-abdominal dissemination, false negative results are possible in a large number of cases. Also, there are more chances of cancer cell dissemination during the procedure.
Removal of fluid around the lungs in a pleural effusion for the purpose of testing for cancer cells may be recommended prior to surgery. If cancerous cells are found in the fluid, the patient is diagnosed with stage 4 cancer and the surgical procedure re-evaluated, keeping in mind the poor prognosis in these cases.
Ovarian Cancer Treatment
The mainstay of treatment of ovarian cancer is surgery, combined with chemotherapy. The role of radiation therapy in the treatment of ovarian cancer is limited. The specific type of treatment to be undertaken for ovarian cancer will depend upon :
- Age of the patient
- General health of the patient
- Type of ovarian cancer
- Stage and grade of ovarian cancer
- Degree of spread and metastasis of the cancer
- Desire to have children
- Recurrence of cancer
- Side effects of treatment vs benefits
The aim of surgery is to detect, confirm, stage, and finally treat the disease. Surgery should ideally be done at the time of an exploratory laparotomy for the diagnosis of ovarian cancer. As much of the cancer tissue should be removed as possible for the best results. This may reduce the possibility of persistence or recurrence of cancer.
The type of surgery to be performed will depend upon the stage of cancer and the desire to have children.
In women with early stage cancer, (stage 1, where the tumor is confined to the ovary), and in patients who also desire to have children, the uterus and the unaffected ovary are left intact. However, a biopsy is taken from this healthy ovary to rule out the possibility of any cancerous changes in it. Usually, only the cancerous ovary and the fallopian tube of that side are removed (salpingo-oophorectomy). Early stage 1 cancer may be cured by surgery alone.
In women with more advanced cancer (stage 2, 3, and 4), and those with stage 1 cancer who do not want any more children, or if both the ovaries are involved, the surgery will be more extensive than a salpingo-oophorectomy. The surgery will involve removal of the :
- uterus with the fallopian tubes and ovaries of both sides (total hysterectomy with bilateral salpingo-oophorectomy).
- omentum (the fold of peritoneum attached to the stomach and other abdominal organs, containing mainly fatty tissue, blood vessels and lymphatics).
- regional lymph nodes
- any other cancerous issue
Chemotherapy is prescribed following surgery in most ovarian cancers except in stage 1 cancers.
Cytoreductive or Debulking Surgery
A cytoreductive or debulking surgery is done primarily when the cancer has spread extensively, or in those patients in whom debulking was not done at the time of initial surgery. This involves removal of as much of the tumor as possible. The goal in debulking surgery, which is likely to give the best prognosis, is to leave behind tumors no larger than 1 cm (centimeter).
Sometimes, a second-look surgery is performed after completion of chemotherapy to check for residual cancer in the remaining pelvic and abdominal structures. Any remaining cancer may be removed during the second-look surgery. In some cases, chemotherapy may shrink the tumor, thus making surgery possible the second time where it was not so in the first instance. Fluid and tissue samples may be taken at the time of surgery and examined for cancer cells.
Preventive (Prophylactic) Surgery
This type of surgery is not really a treatment for ovarian cancer but rather a preventive measure. Women at high risk of developing ovarian cancer, such as those with mutations in BRCA1 and BRCA2 genes, may be advised on undergoing bilateral salpingo-oophorectomy for the prevention of ovarian cancer. This surgical option has to be carefully assessed keeping in mind that future pregnancy will not be possible (unless donor eggs are used) following removal of both ovaries. It will also bring on menopause.
The use of drugs to destroy cancer cells is known as chemotherapy. Drugs commonly used are paclitaxel, carboplatin, and cisplatin, which may be used singly or in combination. In ovarian cancer, chemotherapy is commonly used as an adjuvant therapy meaning it is most effectively used after surgery, to destroy any remaining cancer cells. In some cases, chemotherapy is given prior to surgery to reduce the size of the tumor, thus making surgery easier. Chemotherapy may also be used in case of recurrent cancer and also in palliative therapy.
Chemotherapy for ovarian cancer may be administered by the intravenous (IV) or the intraperitoneal (IP) route – into the vein (IV) or into the abdominal or pelvic peritoneal cavity (IP). Although IP treatment may offer better results in terms of survival, the side effects may be more intolerable than IV treatment.
The side effects of chemotherapy may include :
- Nausea and vomiting
- Loss of appetite
- Severe weakness
- Extreme fatigue
- Abdominal pain
- Weakened immune system
- Hair loss
With radiation therapy, high-energy rays are usually focused on specific points to kill cancer cells. Radiation therapy is not usually considered for ovarian cancer because of widespread dissemination of the cancer in the abdominal cavity by the time it is diagnosed. The amount of radiation that would be necessary for treatment would cause more harm than good in most cases. Radiation therapy is used more often in palliative therapy to provide symptomatic relief in advanced cases.
When the cancer does not improve or seems to get worse even after treatment, palliative therapy may be considered. This will not make the cancer go away but may help to prolong the life of a patient, reduce symptoms such as pain, and help the patient cope with the disease. Chemotherapy or radiation therapy may be considered such cases.
Prevention of Ovarian Cancer
Prevention and early detection of ovarian cancer is hindered by the fact that there are no accurate screening methods specifically for ovarian cancer.
- Regular pelvic examinations may help in early detection in some cases, but is not an extremely accurate screening method for ovarian cancer.
- Women with strong family history of breast or ovarian cancer should undergo genetic testing to detect the presence of mutant genes that are risk factors for ovarian cancer.
- Preventive surgery, involving removal of the ovaries (prophylactic oophorectomy), in women with mutations in BRCA1 and BRCA2 can protect against ovarian cancer.
- Pregnancy, breastfeeding, and prolonged use of contraceptive pills may protect against ovarian cancer. There are risks associated with long term use of contraceptive pills, such as increased risk of breast cancer, which need to be considered, though.
- Lifestyle changes which include a balanced diet with less fat consumption and losing weight if obese may help to lower the risk.
Prognosis for Ovarian Cancer
As with all cancers, the prognosis or likely outcome for patients with ovarian cancer is primarily related to the stage and grade of disease at the time of diagnosis. Since most ovarian cancers are detected after the cancer has disseminated within the abdominal cavity or has metastasized to remote sites, the prognosis is often poor. The outcome is significantly improved when the cancer is detected while still confined to the ovary.
Prognosis of a cancer is often described in terms of the 5-year survival rate. This indicates the percentage of patients who survive or live 5 years or more after diagnosis of the cancer. The type of ovarian cancer also determines its prognosis. On the whole, the 5-year survival rate of germ cell carcinomas are better than that of epithelial carcinomas of the ovary.
Ovarian cancer detected in stage 1 of the disease, when it is limited to the ovary, may have a 5-year survival rate of over 90%. However, the survival rate drops drastically to less than 20% when detection is in the late stages with metastasis to distant organs.
The other factors that may be related to prognosis of ovarian cancer are the age of the patient, general health status, the type of treatment undertaken and the individual response to it. The prognosis of recurrent ovarian cancer is usually poor.