Ovarian cancer is a major health concern for women. As with any common and potentially serious disease, it is important to know what your risks are, and how to minimize them. The earlier it is detected, the better chance you have of a cure.
The two most important things you need to know about ovarian cancer are your risk factors and which screening procedures you should have. A risk factor is anything that increases the chance of getting cancer.
There are two types of risk factors: genetic and nongenetic. A genetic factor is inherited from your parents and cannot be changed. A nongenetic, or environmental, factor is something in your environment, which often can be changed. Nongenetic factors may include diet, exercise, or exposure to various substances.
A few risk factors for ovarian cancer have been identified, and others are suspected.
Heredity and Genetic Factors
Research has determined that 5 percent to 10 percent of all women with ovarian cancer have a genetic predisposition to the disease. This means that women with a family history (mother or sister) of ovarian cancer are at an increased risk of developing the disease.
The majority of hereditary ovarian cancers occur in women with one of two specific genetic abnormalities. These are referred to as the BRCA1 and BRCA2 genes, which are located on chromosomes 17 and 13, respectively. Women with the BRCA1 gene have an 85 percent risk of developing breast cancer, a 60 percent risk of developing ovarian cancer by age 70, and an increased risk of colon cancer. Individuals with the BRCA2 gene are also at an increased risk, although their risk is lower than that of those with the BRCA1 gene.
Environmental or Nongenetic Factors
Clinical research has suggested that increasing age, the prolonged use of hormone replacement therapy after menopause, and the use of fertility drugs may increase the risk of developing ovarian cancer.
Prevention
Cancer is a preventable illness. Two-thirds of cancer deaths in the United States are linked with tobacco use, poor diet, obesity, and lack of exercise. All of these factors are modifiable. Nevertheless, there is a low awareness of how to prevent cancer by making changes in lifestyle.
Some studies have indicated that women may reduce their risk of developing ovarian cancer by using oral contraceptives, giving birth to at least one child, breast-feeding, and having a hysterectomy or tubal ligation.
Removal of the ovaries: In women who have a strong family history of ovarian cancer or have the BRCA1 or BRCA2 gene, removal of the ovaries may be effective prevention of ovarian cancer. However, this procedure has not been proven to prevent cancer in all cases.
Researchers also lack sufficient documentation that this is the optimal approach for young women. Women with the BRCA1 or BRCA2 gene need to consider the potential for complications and side effects before committing to this procedure. Once the ovaries are removed, women no longer produce estrogen and may need long-term hormone replacement. In addition, there are other risks associated with early menopause.
Oral contraceptives: The use of oral contraceptives in women with the BRCA1 or BRCA2 gene may reduce the risk of ovarian cancer by 40 percent to 50 percent. This is currently the most frequent treatment recommended in younger women with these genetic abnormalities.
Diet: There is an enormous amount of information available about diet. Unfortunately, much of it is confusing and contradictory. However, some common behaviors related to diet are clearly and strongly linked to cancer risk.
Excess body fat increases the risk for many types of cancer. A high-calorie diet usually results in a high body mass index. It makes no difference whether the calories come from fats or carbohydrates. The best way to prevent excess body fat is to reduce the number of calories you consume. Regular exercise can help you to maintain your weight once you have reduced it.
Diets that are high in fat, red meat, or dairy products have shown increased cancer risk in some studies. One way to reduce this risk is to replace red meat with chicken, fish, nuts, and legumes.
There is strong evidence that moderate to high alcohol consumption also increases the risk of certain cancers. One reason for this relationship may be that alcohol interferes with the availability of folic acid. Alcohol in combination with tobacco creates an even greater risk of certain types of cancer.
Exercise: Higher levels of physical activity may reduce the incidence of some cancers. The association between exercise and ovarian cancer is not known.
Screening and Early Detection of Ovarian Cancer
"Screening" means the regular use of examinations or tests in people who are at high risk for cancer, but do not have any cancer symptoms. If you have certain risk factors, then you may be at high risk for a particular type of cancer. Screening will help to ensure that you discover any cancer at the earliest possible time. In most cases, this will greatly increase your chances of a cure.
It is not yet known whether screening can improve early detection and survival among women who are at high risk for ovarian cancer. Research is in progress to find effective screening methods.
Annual pelvic examination: Currently, the most widely used way to detect ovarian cancer is a complete gynecologic examination at least once a year. Because ovarian cancer begins deep in the pelvis, it often does not cause any symptoms until it is at an advanced stage. To improve outcomes for women with ovarian cancer, the disease has to be diagnosed early, before it spreads.
Strategies to Improve Screening and Early Detection
Unfortunately, due to a lack of definitive symptoms, the majority of women with ovarian cancer are not diagnosed until their cancer has reached an advanced stage. For this reason, ovarian cancer has been referred to as the "silent killer."
However, some recent studies have indicated that the majority of women with ovarian cancer actually do experience symptoms before their diagnosis. Because symptoms may be subtle and vary from person to person, women and/or their physicians may not associate the symptoms with ovarian cancer.
The symptoms include abdominal abnormalities, such as increased abdominal size, abdominal bloating, and abdominal pain. Other frequently experienced symptoms are indigestion, abnormal vaginal bleeding, constipation, pelvic pain, urinary frequency or incontinence, pain with intercourse, nausea, fatigue, back pain, and diarrhea.
Several new methods of screening have been tried, but no method has been uniformly successful. The screening methods include transvaginal ultrasound, the measurement of serum CA-125, and genetic testing for BRCA1 and BRCA2. Although these options have yet to become standard procedure, they may play a role in the early detection of ovarian cancer in selected patients in the future.
Transvaginal ultrasound: Two recent clinical studies have suggested that transvaginal ultrasound may be an effective screening technique for detecting ovarian cancer. During a transvaginal ultrasound, a receiver is inserted into the vagina. The receiver transmits sound waves to create a picture of internal structures. Because cancerous tumors are a different density than normal tissue, the sound waves create a different pattern when they bounce off of the cancer.
Transvaginal ultrasound has been used to detect stage I and stage II ovarian cancer in some women. These early-stage cancers probably would not have been detected by a normal pelvic examination.
CA-125: Elevated levels of the protein CA-125 in the blood have been associated with ovarian cancer. However, elevated CA-125 levels do not necessarily suggest ovarian cancer because CA-125 levels can be elevated in a number of other cancers and benign conditions, and during the first trimester of pregnancy. In general, the higher the level of CA-125 found, the greater the chance of having ovarian cancer, especially for women past menopause.
Predictive genetic testing: The identification of cancer susceptibility genes has led to predictive genetic testing. The breast cancer susceptibility genes—BRCA1 and BRCA2—have also been associated with an increased risk of ovarian cancer. Since most ovarian cancers are not the result of known inherited mutations, not all women would benefit from genetic testing.
However, women who appear to be at a high risk may benefit from undergoing a test to determine if they do carry the BRCA1 or BRCA2 gene. An accurate genetic test can reveal a genetic mutation, but cannot guarantee that cancer will or will not develop. At this point, genetic tests are used to identify individuals who are at an increased risk of developing cancer, so that these individuals may have the option of taking preventive measures, such as increased surveillance, or consider prophylactic surgery. For more information about genetic screening, please go to Genetic Testing.