Ovarian cancer is a disease which causes cells in the ovaries to grow uncontrollably and in an abnormal manner causing the formation of a tumor. The ovaries are found in the female reproductive system on opposite sides of the uterus and are responsible for holding and releasing the egg during ovulation. There are three different types of ovarian tumors which are classified by where the cancer firsts starts growing
The three main types are:
Epithelial Ovarian Cancer- This form of cancer begins growing in the epithelium, which is the thin layer of tissue covering the ovary surface. It is the most common type of ovarian cancer, accounting for 90% of cases, and most frequently affecting women after menopause.
Germ Cell Ovarian Cancer- These cancers develop in the cells that become eggs. It is a rare type of ovarian cancer usually found in women under the age of 30.
Sex-chord Stromal Cell Ovarian Cancer- This cancer occurs in the ovary cells responsible for releasing female hormones such as estrogen and progesterone and is also a rare type affecting around 5% of all aged women with ovarian cancer.
Ovarian Cancer is also classified in stages of cancer development which are indicative of how far the cancer has advanced and whether it has spread to other organs. These stages are from one to four, with the earlier the stage of cancer when detected, having the greatest chance of recovery. Most commonly ovarian cancer is detected at stage three.
These stages are identified by the following descriptions:
Stage I– the cancer is found only in one or both ovaries.
Stage II- cancer has spread to other areas in the pelvic region including the uterus and fallopian tubes.
Stage III- the cancer has spread further throughout the abdominal region and may be found in the lining of the abdomen, or in the lymph nodes located within the abdomen.
Stage IV– cancer has spread further than the abdominal region to other organs.
It is estimated that around 750 women in Australia and 15000 women in the USA die from ovarian cancer each year and is the fifth highest in causing cancer-related deaths in women in the USA. The cancer affects around 1 in 70 Australian woman and is the most deadly of gynecological cancers, as its most commonly picked up in the later stages of the cancer when it is advanced, and as such, difficult to treat. Currently there are no reliable screening tests for ovarian cancer and the location of the ovaries makes them difficult to examine. Early detection is further complicated by ambiguity surrounding the early signs and symptoms of ovarian cancer and the tendency of these symptoms to overlap with other medical complications.
Signs and Symptoms
The signs and symptoms of ovarian cancer are often similar to those of a number of gastrointestinal disorders making identification of early stage ovarian cancer difficult. A pap smear cannot detect ovarian cancer, but the commonly associated pelvic examination may allow for detection of possible cancerous growths or ovarian cysts. The symptoms of ovarian cancer are usually fairly mild but are often persistent and may get worse over time, rather than being intermittent, which is often the case if the symptoms are due to digestive disorders. Many women are unaware of the symptoms associated with ovarian cancer and will often ignore the mild disturbances in their early stages. It is particularly important that women, especially post-menopausal women are vigilant in identifying early warning symptoms and seeing their doctor.
Some of symptoms of ovarian cancer include:
Lower Abdominal Pain and Back Pain – discomfort and pain in the lower tummy and pelvic region and/or unusual back pain that increases over time
Gastrointestinal Abnormalities- Persistent and often mild digestive upsets which may gradually worsen, including; flatulence, nausea, indigestion, bloating, swelling, feeling full and unusual changes in bowel habits such as constipation.
Change in Urinary Habits- increased frequency and urgency of urination
Unexplained Appetite and Weight Changes- sudden weight gain or loss, increased abdominal size and a loss of appetite
Ongoing Tiredness- feeling drowsy, tired and lacking energy
Vaginal and Menstrual Complications- unusual vaginal bleeding, pain during sex and abnormal menstrual cycles
The cause or causes of ovarian cancer are largely unknown and although risk factors have been identified, more research is required in this area.
Some of the risk factors that increase a woman’s chance of developing ovarian cancer include;
Older women are in the highest risk group as about 90% of ovarian cancers are found in post-menopausal women, with around two-thirds of ovarian cancer associated deaths occurring in women over the age of 55.
Individuals of Ashkenazi Jewish descent are at high risk of ovarian cancer and women in western civilizations have a higher incidence than those of other ethnic populations.
Women who have more children at a younger age seem to have a lower incidence of ovarian cancer. Also, women who have been pregnant, even if only once, have a lower risk of developing ovarian cancer than those who have not.
Women who have a genetic risk or personal or family history of breast cancer also have a greater risk of developing ovarian cancer. Another genetic risk factor for ovarian cancer is hereditary nonpolyposis colorectal cancer (HNPCC), which is associated with an increased risk of a number of cancers including the colon, stomach, small intestine and uterine lining.
Infertility and Hormone Replacement Therapy
Women who have infertility problems have a higher risk of developing ovarian cancer, as do women taking fertility drugs. Also women who have used hormone replacement therapy for five years or longer are at greater risk of developing ovarian cancer
The use of contraceptives appears to decrease a women’s risk of developing ovarian cancer.
A number of different lifestyle and environmental factors can increase a woman’s risk of developing ovarian cancer, including; the use of talcum powder in vaginal regions, exposure to asbestos, a diet high in fat and childhood obesity and having had childhood mumps. However many of these risk factors are controversial and may not necessarily be causal.
In many women cysts may form on the ovaries. This is a fairly normal occurrence during ovulation. Cyst formation in postmenopausal women however, places the woman at a higher risk of developing ovarian cancer have a greater chance of being cancerous. The likelihood of cancer increases with the size of the growth and with age.
There are a number of complications associated with ovarian cancer that are responsible for some of the symptoms experienced by women suffering from the disease. Cancerous growths can cause blockages in the intestines causing a range of gastrointestinal problems. Other health problems include excess fluid in the abdomen and loss of organ function. Due to ovarian cancer often going unnoticed, the cancer can metastasize spreading to other organs and causing more damage.
Ovarian cancer treatment and prevention for high risk women, often requires the removal of many reproductive organs. In most cases the cancer affects post menopausal women who are no longer able to conceive. Ten percent of ovarian cancers however, are found in younger women, who, if undertaking surgical removal of reproductive organs, will be unable to have children.
Possible treatment methods
Without a screening test for diagnosis, doctors must perform a number of tests in order to identify the presence of ovarian cancer. Tests can include a pelvic examination to feel for growths on the ovaries, an ultrasound, computerized tomography or magnetic resonance imaging to see any growths and a blood test that looks for the presence of the CA 125 protein. These tests however are unable to definitively determine whether the patient has ovarian cancer, but do provide the doctor with more information. If the prognosis is ovarian cancer the patient will undergo laparoscopy surgery, whereby small incisions are made in the abdomen in order to obtain ovary tissue samples to test for the presence of cancer. In the event of a diagnosis of ovarian cancer, a laparotomy, a more invasive form of surgery, will remove the ovaries and other cancer cells.
Surgery is the main treatment options for ovarian cancer. By removing the cancerous cells and also the remaining ovary cells that have the potential to become cancerous it is possible to eradicate ovarian cancer of it is caught in the early stages. In many of these surgical procedures the surgeon will remove both ovaries, fallopian tubes, the uterus and lymph nodes in the same area. Also excised is the omentum, which is the fatty tissue in the abdomen and in some instances, depending on the severity of the cancer, part of the intestines are removed.
To ensure the destruction of all cancer cells, chemotherapy is often undertaken after the surgery with the most common treatment for ovarian cancer being the intravenous administration of the two chemotherapy drugs; carboplatin and paclitaxel. If cancer is found elsewhere in the body (that is the cancer has spread in the later stages of ovarian cancer) or if the cancer returns, further chemotherapy may be undertaken to treat the patient. In some cases chemotherapy drugs may be injected directly into the abdominal area for a more intensive treatment, however there are severe side affects associated with this procedure. Recent advances in the field of ovarian cancer include drug candidates Telcyta, which increases the efficiency of current chemotherapy drugs and Catumaxomab that may prove to be a better treatment option.
Radiation therapy is another option but is very rarely recommended for cases or ovarian cancer. Other treatments are under investigation such as gene therapy, vaccines and immunotherapy.
Whilst there are no other treatment alternative that have proven to be successful in treating ovarian cancer, research has identified a number of preventative measures that can reduce the risk of women developing ovarian cancer. These include; the use of oral contraceptives, pregnancy and breastfeeding and having a hysterectomy. Another preventative measure for women in the high risk category is the removal of their ovaries prior to any cancerous growths. This procedure however can have a range of other health complications.