Ovarian cancer is a relatively rare disease. The American Cancer Society estimates that only 21,000 new cases of are diagnosed every year. Despite this, ovarian cancer is the fifth leading cause of cancer death among women. It begins in the ova, where female eggs are produced, along with estrogen and progesterone.
Approximately 20 percent of ovarian cancers are detected at an early stage, offering patients improved treatment prospects. The five-year survival rate for women with stage I or stage II ovarian cancer is over 90 percent. Early detection drastically improves the chances of survival, so all women should be familiar with the signs and symptoms of ovarian cancer.
Ovarian Cancer Symptoms
Ovarian cancer is a “silent killer.” Many of its early symptoms are nonspecific and easy to dismiss, which is why it is normally not diagnosed until it reaches an advanced stage. The most common early symptoms of ovarian cancer are:
- Frequent urination
- Constipation, diarrhea, or other changes in bowel habits
- Pelvic and abdominal pain
Symptoms become more pronounced when the cancer begins to spread beyond the ovaries. Common ovarian cancer signs during this stage include:
- Abdominal bloating
- Pain during intercourse
- Persistent fatigue
- Unexplained weight gain or weight loss
- Deeper voice, growth of male pattern hair, or the development of other masculine traits
Patients who experience any of these symptoms for more than 2-3 weeks should see their doctor immediately. Early detection not only increases the odds of survival, it also increases a woman’s options during treatment.
Ovarian Cancer Types
Most types of ovarian tumors are benign. They grow slowly and are unlikely to spread to other organs. Malignant tumors are divided into three categories, based on the type of cell where they originate.
Epithelial Ovarian Tumors
Epithelial ovarian tumors begin on the surface of the ovary and are the most common type of ovarian cancer. Approximately 85-90 percent of patients are diagnosed with it. Because they grow on the surface of the ovaries, they frequently spread to surrounding organs and tissues. Epithelial ovarian tumors are most common in women over 50.
Germ Cell Tumors
Germ cell tumors begin in the cells that produce eggs and account for less than 2 percent of ovarian cancers. The prognosis for a woman with germ cell tumors is generally positive. Around 90 percent survive for at least 5 years following their diagnosis. Germ cell tumors are most common in women aged 10-30.
Ovarian Stromal Tumors
Ovarian stromal tumors begin in the ovary’s connective tissue and in the cells that produce estrogen and progesterone. They are extremely rare, accounting for approximately 2-4 percent of all ovarian cancers. Ovarian stromal tumors are low-grade cancers and the survival rate for women with ovarian stromal tumors is very high. Though ovarian stromal tumors affect women of all ages, certain sub-types are more common in adolescents than in adults.
Ovarian Cancer Screening
Since there is currently no single test or exam that can effectively screen for ovarian cancer, it is difficult to detect at an early stage. To give themselves the best possible chance, women should receive routine physical exams, report symptoms when they arise, and be aware of their own personal risk factors, such as age, gene mutations, or family history. Doctors screen women for ovarian cancer using three methods:
Routine Physical Exam
During a physical exam, doctors use their fingers to check the size, shape, and consistency of a woman’s ovaries and uterus. If they discover a pelvic mass, it could be a symptom. Unfortunately, pelvic exams are not an ideal screening method. Detecting pelvic masses is difficult and many early stage cancers are overlooked. However, pelvic exams are inexpensive, easy to perform, and provide patients with an extra layer of protection. Women should receive a physical exam at least once a year.
During a transvaginal ultrasound (TVUS), a doctor inserts an ultrasound wand into the vagina in order to inspect the uterus, fallopian tubes, and ovaries. The wand generates sound waves that bounce off the reproductive organs and are picked up by the wand’s receiver. The receiver transmits its date to a computer that transforms it into images. Once a TVUS has identified an ovarian mass, the radiologist will evaluate its characteristics and assign it a score based on the risk of malignancy index. The higher the score, the more likely the tumor is to be cancerous.
CA-125 Blood Test
CA-125 is a protein found throughout your body. Its exact purpose is unknown, but it’s found in much higher concentrations in ovarian cancer cells. Unfortunately, CA-125 is an inexact biomarker. Elevated CA-125 levels are also a symptom of several other diseases, such as uterine fibroids (noncancerous uterine growths), pelvis inflammatory disease, and cirrhosis of the liver. Elevated CA-125 levels can also be caused by pregnancy, which why doctors only recommend CA-125 blood tests for high-risk patients.
If a test uncovers signs of ovarian cancer, doctors need to perform a laparotomy. During this procedure, a surgeon makes a small incision in the abdomen in order to inspect the ovaries or remove a tissue sample for biopsy. In some cases, a less invasive procedure called laparoscopic surgery may used instead. During laparoscopic surgery, doctors examine the ovaries using a thin, fiber optic rod with a camera, which requires a much smaller incision than a laparotomy.
Ovarian Cancer Stages
Ovarian cancer is divided into four stages. Each stage tracks how far the cancer has progressed. Early stage ovarian cancers are confined to the ovaries and fallopian tubes, while late stage cancers have spread to the lymphatic system and other major organs.
The cancer is only present in the ovaries. It may be in one ovary or both. The cancer may also be present in one or both of the fallopian tubes. If the cancer is on the outside of the ovaries, the tumors may have split open, makes it possible for cancer cells to spread out into the abdomen.
The cancer is in both ovaries and fallopian tubes and it has spread to other organs in the pelvis, such as the uterus, colon, rectum, or bladder.
The cancer has spread beyond the pelvis to the lymph nodes and the lining of the abdomen. Tumors are larger than 2 centimeters and are visible to the naked eye.
The cancer has metastasized and spread to lymph nodes and organs outside the pelvis, such as the bones, liver, lungs, and spleen.
Once doctors know the cancer’s stage, they can determine the best course of treatment. Treatment for ovarian cancer is complicated and patients should discuss their options thoroughly with their doctor before making a final decision.
Ovarian Cancer Treatment
The primary treatments for ovarian cancer are surgery, chemotherapy, hormone therapy, targeted therapy, and radiation therapy. When deciding on the appropriate course of treatment, doctors consider the patient’s age, cancer type, cancer stage, and their overall health.
Most women with ovarian cancer require surgery. Standard surgery for germ cell and ovarian stromal tumors is a hysterectomy (removal of the uterus) and a salpingo-oophorectomy (removal of ovaries and fallopian tubes). If the cancer is caught early, the surgeon may be able to treat it by only removing one ovary, leaving the other intact. Surgery for epithelial ovarian cancer is more complicated. First, the surgeon has to stage the cancer by opening up the patient to see how far the cancer has spread. Normally, this requires the surgeon to remove the uterus, ovaries, and fallopian tubes. They may remove a small number of lymph nodes as well, for biopsy. Once the surgeon has seen how far the cancer has spread, he or she moves onto the second phase: debulking, also known as cytoreduction. During this phase, the surgeon removes the cancer from the abdomen and any organs it has spread to, such as the bladder, colon, stomach, and spleen.
For ovarian cancer, a typical course includes three to six cycles of chemotherapy, with rest periods in between. It’s normally administered through an IV that delivers chemo drugs directly into the bloodstream (systemic chemotherapy). However, for some types of ovarian cancer, chemotherapy drugs are injected directly into the abdominal cavity, saturating the tumors with cancer-killing drugs (intraperitoneal chemotherapy). Combining systemic and intraperitoneal chemotherapy has proven very effective and many patients receive both. Chemotherapy may be given before surgery, to shrink tumors, or afterwards, to eliminate lingering cancer cells.
Hormones, such as estrogen and progesterone, stimulate certain types of cancer, causing them to grow and multiply quickly. Hormone therapy prevents these hormones from interacting with cancer cells, either by blocking the cells’ hormone receptors or by inhibiting hormone production. Without access to estrogen or progesterone, the cancer shrivels up until it disappears or a surgeon removes it. Ovarian stromal tumors respond very well to hormone therapy, while epithelial ovarian tumors do not. Doctors may also prescribe hormone therapy after the cancer has gone into remission, to keep it from recurring.
Targeted therapy eliminates cancer cells without affecting healthy cells. It does so by attacking cancer on a genetic level, targeting the genetic marker that separate cancer cells from normal cells. The two most popular targeted therapy drugs for ovarian cancer are bevacizumab and olaparib. Bevacizumab prevents tumors from forming new blood vessels; without a steady supply of blood, the tumor withers and dies. Olaparib prevents cancer cells from repairing damaged DNA, which leads to cellular breakdown and death. Targeted therapy is only effective against a small number of ovarian cancers, but that number may expand as researchers investigate new cures.
Radiation was a common treatment for ovarian cancer until the 1990s, when it was overtaken by advancements in chemotherapy and gradually phased out. Physicians occasionally use radiation therapy to eliminate small, localized tumors, but because surgery and chemotherapy have proven far more successful, these instances are very rare.
Patients interested in exploring the latest ovarian cancer treatments should consider volunteering for a clinical trial. Clinical trials test the effects of new medications on a group of volunteers in order to evaluate their effectiveness and, hopefully, create a breakthrough.