The ovaries are small, almond-shaped organs located on either side of the uterus. They are where eggs are produced. Ovarian cancer can occur in several different parts of the ovary.
Ovarian cancer can start in the ovary’s germ, stromal, or epithelial cells. Germ cells are the cells which become eggs. Stromal cells function like connective tissue. They make up most of the ovary. Epithelial cells are the outer layer of the ovary.
Incidence of Ovarian Cancer
The National Cancer Institute (NCI) estimates that 22,280 American women will be diagnosed with ovarian cancer in 2012. There will also be an estimated 15,500 deaths from this cancer in 2012.
Epithelial Carcinoma of the Ovary
Epithelial cell carcinoma is the most common type of ovarian cancer. It is also the fifth most common cause of cancer death in women. Fifty percent of cases occur in women over the age of 65.
Most patients have advanced disease at the time of diagnosis. The five year survival rate for this cancer is less than 10 percent.
Genetic Component of Epithelial Carcinoma of the Ovary
This type of ovarian cancer can run in families. According to the NCI, up to 10 percent of cases occur in women with a family history of:
- ovarian and breast cancer
- ovarian cancer without breast cancer
- ovarian and colon cancer
Women who have two or more first degree relatives with ovarian cancer are at the highest risk. However, even one first-degree relative increases risk. The “breast cancer genes” BRCA1 and BRCA2 are also associated with ovarian cancer risk.
Prognosis of Epithelial Carcinoma of the Ovary
Several factors are linked to increased survival in women who have this type of cancer:
- lower stage at diagnosis
- lack of fluid accumulation (ascites) in the abdomen
- younger age
- well-differentiated tumor
- smaller size of tumor at time of removal
Germ Cell Cancer of the Ovary
Germ cell cancers account for five to seven percent of ovarian cancers. These cancers develop from the cells that create eggs. They usually occur in young women and adolescents.
The average age at the time of diagnosis is 18. These cancers can be large. They tend to grow quickly. Sometimes tumors produce human chorionic gonadotropin (HCG). This can cause a falsely positive pregnancy test.
Germ cell cancers are very curable. They can be treated with surgery and chemotherapy.
Stromal Cell Cancer of the Ovary
Stromal cell cancers account for about five percent of ovarian cancers. They develop from the cells that hold the ovary together. These are also the cells that produce ovarian hormones including:
Stromal cell cancers grow slowly. They secrete estrogen and testosterone. Excess testosterone can cause acne and facial hair growth. Too much estrogen can cause uterine bleeding. These symptoms can be quite noticeable. This makes stromal cell cancer more likely to be diagnosed at an early stage. Because of this, these cancers have a favorable prognosis.
The average age of women with stromal cell cancer of the ovary is 45. However, it can occur at any age.
Symptoms of Ovarian Cancer
Early stage ovarian cancer may not have any symptoms. However, some symptoms women may have include:
- frequent bloating
- quickly feeling full when eating
- difficulty eating
- frequent, urgent need to urinate
- pain or discomfort in the abdomen or pelvis
With ovarian cancer, these symptoms have a sudden onset. They feel different from normal digestion or menstrual discomforts. They also don’t go away. If you have these symptoms for longer than two weeks, you should seek medical attention.
Other symptoms of ovarian cancer can include:
- lower back pain
- pain during intercourse
- change in menstrual cycle
- weight gain or weight loss
- vaginal bleeding
- back pain that worsens
Diagnosing Ovarian Cancer
Diagnosing ovarian cancer starts with a medical history and physical exam. The physical exam should include a pelvic and rectal examination. One or more blood tests may also be used to diagnose this condition.
- CBC (complete blood count) checks your overall health.
- CA125 (cancer antigen 125) levels may be elevated in ovarian cancer. They can also be elevated in other conditions such as endometriosis.
- HCG levels may be elevated if you have a germ cell tumor. This is normally a pregnancy protein.
- Alpha fetoprotein (AFP) may be produced by germ cell tumors. Elevated levels of AFP are also seen in other diseases.
- LDH (lactate dehydrogenase) levels can be elevated by germ cell tumors.
- Inhibin, estrogen, and testosterone levels may be elevated by stromal cell tumors.
- Liver function tests can be abnormal if cancer has spread to the liver.
- Kidney function tests help determine if cancer has obstructed urine flow or spread to the bladder and kidneys.
Other diagnostic studies can also be used to check for signs of ovarian cancer.
Biopsy is essential for determining if cancer is present. A small sample is taken from the ovaries to look for cancer cells. This can be done with a needle, guided by a CAT scan or ultrasound. It can also be done through a laparoscope. If fluid (ascites) is present, a sample can be examined for cancer cells.
Ultrasound of the abdomen and pelvis is used to look for changes in the ovaries and other organs caused by cancer.
CT scan and MRI can also be used to view the abdomen and pelvis.
PET scan can detect small cancers that are otherwise hard to see.
Laparoscopy examines abdominal organs to see if the cancer has spread. Biopsies can be obtained during this procedure.
Urinalysis looks for signs of infection or blood in the urine. These can occur ifcancer spreads to the bladder and kidneys
Chest X-ray can detect when tumors have spread to the lungs.
Barium enema looks for tumor spread to the colon or rectum.
Stages of Ovarian Cancer
Cancer of the ovary is staged according to the following criteria:
- Stage I cancer is confined to one or both ovaries – five year survival rate is 90 percent
- Stage II cancer is confined to the pelvis – five year survival rate is 70 percent
- Stage III cancer has spread into the abdomen – five year survival rate is 15 to 20 percent
- Stage IV cancer has spread outside of the abdomen – five year survival rate is one to five percent
Treatment for Ovarian Cancer
Treatment of ovarian cancer depends upon the type, stage, and whether you want to have children. Surgery is performed to:
- confirm the diagnosis
- determine the stage of the cancer
- remove the cancer
During surgery, an effort is made to remove all cancerous tissue. Biopsies may also be taken to see if the cancer has spread.
If you want to have children, and have stage I cancer, surgery would include:
- removal of the cancerous ovary and a biopsy of the other ovary
- removal of the fatty tissue (omentum) attached to some of the abdominal organs
- removal of abdominal and pelvic lymph nodes
- biopsies of other tissues and collection of fluid inside the abdomen
Surgery is more extensive if you don’t want to have children. You also need more surgery if you have stage II, III, or IV cancer. This includes:
- removal of the uterus
- removal of both ovaries and fallopian tubes
- removal of the omentum
- removal of as much cancerous tissue as possible
- biopsies of any tissue that might be cancerous
Surgery is usually followed by chemotherapy. Medications can be given intravenously or through the abdomen. This is called intraperitoneal treatment. Side effects of chemotherapy can be very unpleasant. They include:
- hair loss
- problems sleeping.
Carboplatin, cisplatin, and paclitaxel (Taxol) are common drugs used to treat ovarian cancer.