The cancerous growth commonly arises from the outer lining of the ovaries (referred to as epithelial ovarian cancer) and rarely from the cells that form the eggs (known as germ cell tumours).
Ovarian cancer is considered as the fifth most common cancer in women and also as the leading cause of death from cancer in women. It was estimated that in 2008, ovarian cancer would result in 21,650 new cases among which about 15,520 women would face an increased risk of death due to the ovarian cancer in United States.
The lifetime prevalence of ovarian cancer has been predicted to be about 1.5%. Older women are most commonly affected wherein about two-thirds of the ovarian cancer associated deaths are noted in women aged 55 years and above.
Commonly referred to as the “silent killer”, ovarian cancer rarely results in any symptoms during the initial stages. Even if symptoms are noted, they are of a general type which makes it difficult to diagnose ovarian cancer in the earlier stages. Signs and symptoms such as pain in the abdomen, back pain, urinary urgency, and tiredness are commonly noted in various conditions of the reproductive tract. More specific symptoms such as pain in the pelvic region, abnormal vaginal bleeding and abnormal weight loss may point to ovarian cancer. The prognosis is good when the ovarian cancer is diagnosed at earlier stages and prompt treatment is carried out.
The definitive cause of ovarian cancer is not known. However, several risk factors that are associated with an increased incidence of ovarian cancer have been identified. Overall, it has been estimated that every woman has 1.5% chance of developing ovarian cancer during her life time. Various other factors that increase the risk have been discussed below.
Ovarian cancer tends to run in families wherein a woman whose mother, sister or daughter has suffered or is suffering from ovarian cancer is at a risk of developing ovarian cancer herself. The presence of other cancers such as the cancer of the breast, uterus, colon or the rectum in the family also tends to increase the risk of ovarian cancer. Researchers have suggested that a family history of ovarian cancer (wherein two or more members of the same family are affected) increases the risk by about 50%.
The risk of ovarian cancer increases in women who have other types of cancers such as breast cancer, and uterus, colon, or rectal cancers. The presence of some genes known as breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2) have been known to increase the risk of developing cancer by 35-70% and 10-30% respectively. Although these genes are associated with breast cancer, they are also known to be associated with cancer of the ovaries.
Women over 55 years of age are at an increased risk of ovarian cancer when compared to others. Most of the ovarian cancers are noted in postmenopausal women while it may also be observed in some women before menopause. About 25% of the deaths associated with ovarian cancer have been observed in women between the age group of 35 and 54 years.
Women who have never had a child have a higher risk of developing ovarian cancer when compared to women who have had at least one child. The risk of ovarian cancer is decreased in women who have given birth to two or more children. Some studies have pointed out that women suffering from infertility are at an increased risk of developing ovarian cancers.
Consumption of oral contraceptive pills is associated with about 40-50% decrease in the risk of ovarian cancers. Hormone replacement therapy (usually advised in post menopausal women) on the other hand is associated with an increased risk. Some evidence suggests that consumption of drugs to enhance fertility also increase the risk of ovarian cancer to a certain extent.
While some studies have reported increased incidence of ovarian cancer in women who are obese or who apply talcum powder in the genital regions, a definite relation between these factors and ovarian cancer has not yet been established.
The treatment option for ovarian cancer is decided based on factors such as: the extent of the cancer growth within the ovary; its spread to adjacent structures; age of the affected individual; childbearing status; and other associated risk factors.
While surgery and chemotherapy remain the mainstay for treating ovarian cancers, radiotherapy is also advised in certain rare instances.
Ovarian cancers that are diagnosed early have better prognosis wherein only the affected regions of the ovary are removed. However, in advanced stages, both the ovaries and other associated organs of the female reproductive tract may also have to be removed. The ovaries and other affected structures are removed by placing an incision over the abdomen region. In some cases, chemotherapy may be advised prior to surgery to reduce the size of the cancer tissues.
Chemotherapy involves the administration of certain drugs such as carboplatin and paclitaxel to kill the cancer cells. These drugs may either be injected through a vein or may have to taken as tablets. Chemotherapy may be advised before surgery or following surgical treatment for ovarian cancer. The main aim of chemotherapy in ovarian cancer is to clear the residual cancerous cells that may be left behind during surgery. It is also advised in cases where cancerous growth recurs following surgical therapy.
This mode of treatment is used to treat ovarian cancer cases in certain rare instances. The radiotherapy procedure involves controlled exposure of the affected region to X-rays for a short period of time at regular intervals.
Other treatment modalities that are being tested for its efficacy in treatment of ovarian cancers include:
- Gene therapy
These methods are aimed at preventing the occurrence of ovarian cancer by modifying the genes that are responsible for ovarian cancers or alter the body’s defence system so as to suppress the growth of cancer cells. Further research and development are required before these options become available on a widespread scale.
Complementary therapeutic options such as acupuncture, massage therapy, herbal supplements, vitamin supplements, special diets, and meditation/relaxation therapy are at times advised along with the conventional treatment to provide symptomatic relief and also counter the adverse effects of conventional therapies.