Dec 21, 2009, 1:20 PM
Causes, Symptoms and Treatments
Ovarian cancer continues to have one of the highest mortality rates of any cancer, and it is a leading cause of cancer deaths among women in the United States. This month, we remember the mothers, sisters, and daughters we have lost to ovarian cancer, and we extend our support to those living with this disease. We also reaffirm our commitment to raising awareness about ovarian cancer, and to advancing our screening and treatment capabilities for the thousands of American women who will be diagnosed this year.
Ovarian cancer touches women of all backgrounds and ages. Because of a lack of early symptoms and effective screening tests, ovarian cancer is often not detected in time for successful interventions. It is crucial that women know how to recognize the warning signs of gynaecological cancers and can detect the disease as early as possible. I encourage all women to learn about risk factors, including family history, and to discuss possible symptoms, including abdominal pain, with their doctor. Now, because of the Affordable Care Act, a wide range of preventive screenings is available to women without any copayments, deductibles, or coinsurance.
Ovarian cancer is a type of cancer that begins in the ovaries. Women have two ovaries, one on each side of the uterus. The ovaries — each about the size of an almond — produce eggs (ova) as well as the hormones estrogens and progesterone.
Ovarian cancer often goes undetected until it has spread within the pelvis and abdomen. At this late stage, ovarian cancer is more difficult to treat and is frequently fatal. Early-stage ovarian cancer, in which the disease is confined to the ovary, is more likely to be treated successfully.
Surgery and chemotherapy are generally used to treat ovarian cancer.
What is ovarian cancer
Ovarian cancer happens when cells that are not normal grow in one or both of your ovaries. The ovaries are two small glands, located on either side of your uterus. They produce female sex hormones and store and release eggs (ova).
Treatments for ovarian cancer are more successful when the cancer is found early. But most of the time, cancer has already spread by the time it is found.
This topic is about epithelial ovarian cancer. This is cancer that grows in the tissue covering the ovaries. It is the most common type of ovarian cancer and usually occurs in women who are past menopause.
Experts don’t know exactly what causes ovarian cancer. But they do know that DNA changes play a role in many cancers.
Symptoms of ovarian cancer may include:
· Recent, frequent bloating.
· Pain in the belly or pelvis.
· Trouble eating, or feeling full quickly.
· Urinary problems, such as an urgent need to urinate or urinating more often than usual.
These symptoms may be common in women who don’t have ovarian cancer. But if these symptoms are new for you, and they happen almost daily for 2 to 3 weeks, you should see a doctor.
Sometimes the doctor may feel a lump in or on an ovary during a routine pelvic exam. Often a lump may be seen during an ultrasound. Most lumps aren’t cancer.
If your doctor thinks you may have ovarian cancer, you may have a blood test called CA-125 (cancer antigen 125). Too much CA-125 in your blood can be a sign of ovarian cancer. But too much CA-125 in the blood can be caused by many things, such as the menstrual cycle, endometriosis, and uterine fibroids.
The only way to know for sure that a woman has ovarian cancer is with biopsies taken during surgery. Tissue samples will be sent to a lab to see if they contain cancer.
Surgery is the main treatment. The doctor will remove any tumours that he or she can see. This usually means taking out one or both ovaries. It may also mean taking out the fallopian tubes and uterus. Chemotherapy is often part of treatment. It may be given before and after surgery.
When you find out that you have cancer, you may feel many emotions and may need some help coping. Talking with other women who are going through the same thing may help. Your doctor or your local branch of the American Cancer Society can help you find a support group.
Ovarian cancer is any cancerous growth that may occur in different parts of the ovary. The majority of ovarian cancers arise from the epithelium (outer lining) of the ovary. According to the American Cancer Society it is the 8th most common cancer among women in the USA (excluding non-melanoma skin cancers). In the UK ovarian cancer is the fifth most common cancer among females, after breast cancer, bowel cancer, lung cancer and uterine cancer (cancer of the uterus).
Approximately 21,000 women in the USA and 5,500 women in the UK are diagnosed with ovarian cancer each year. Worldwide, around 140,000 women die of ovarian cancer every year.
Tragically, the overall five year survival rate is only 46 per cent in most developed countries (it is lower for more advanced stages). However, according to the National Cancer Institute, if diagnosis is made early, before the tumorhas spread, the five year survival rate is nearer 93 per cent. In 2009 scientists in the US said that current tests for diagnosing ovarian cancer are not good enough .
What are the ovaries?
The ovary is the female gonad, while the testis is the male gonad. A gonad is a reproductive gland that produces germ cells (gametes). A male sperm is a gamete, and a female egg is also a gamete. Each human gamete has 23 chromosomes, half the number of chromosomes contained in most types of human body cells.
The ovary, also known as the egg sac, is one of a pair of reproductive glands in women. The ovaries are located at either side of the uterus (womb), in the pelvis. Each ovary is about the size and shape of an almond. The ovaries produce ova (eggs) and female hormones, such asestrogen and progesterone. These hormones regulate the menstrual cycle, pregnancy, and control the development of female characteristics, such as body shape, body hair, breasts, etc.
During the female menstrual cycle, which lasts about one month, one egg is released from one of the two ovaries - the egg travels through the fallopian tube and into the uterus. This is known as ovulation.
Cancer of the ovary can spread to other parts of the reproductive system as well as surrounding areas, such as the stomach, vagina and uterus. Ovarian cancer more commonly occurs in women aged 65 or over, but can affect women of any age.
What is cancer?
Cancer is a class of diseases characterized by out-of-control cell growth. There are over 100 different types of cancer that occur in various parts of the body - each is classified by the type of cell that is initially affected.
Usually our cells divide (multiply, form new ones) only when old and dying ones need to be replaced. However, the controls that regulate when a cell divides as well as when a cell should die sometimes become faulty. This may result in cells not dying when they should, while additional cells are still being added - an uncontrolled accumulation of cells. Eventually a mass of cells is formed - a tumor.
What are the symptoms of ovarian cancer?
In the early stages, ovarian cancer usually has vague symptoms which are not easy to recognize. In fact, doctors used to think that ovarian cancer had no symptoms (unfortunately, many still do). Even though healthcare professionals are much better at identifying ovarian cancer symptoms these days, patients often attribute their symptoms to other conditions, such as pre-menstrual syndrome, irritable bowel syndrome, or a temporary bladder problem.
The main difference between ovarian cancer and other possible disorders is the persistence and gradual worsening of symptoms. While most digestive disorders have fluctuating symptoms, those of ovarian cancer are more constant and steadily advancing.
The following are examples of possible early symptoms of ovarian cancer:
- Pain in the pelvis
- Pain on the lower side of the body
- Pain in the lower stomach
- Back pain
- Indigestion or heartburn
- Feeling full rapidly when eating
- More frequent and urgent urination
- Pain during sexual intercourse
- Changes in bowel habits, such as constipation
As ovarian cancer progresses these symptoms are also possible:
- Weight loss
- Fatigue (tiredness)
- Loss of appetite
Ovarian cancer is not a silent killer. A study by the National Breast and Ovarian Cancer Centre, Australia, found that 83% of women experience at least one symptom of ovarian cancer in the year prior to their diagnosis. The researchers also found that 17% of women waited more than three months after the onset of their symptoms before visiting their doctor, with 8% waiting more than six months. The most common symptoms, experienced by half of the study participants, were abdominal symptoms such as fullness and pain. Bloating, bowel or urinary symptoms were reported by approximately one third of participants.
If you experience bloating, pressure or pain in the abdomen or pelvis that persists for more than a few weeks you should see your doctor immediately. If you have already been to the doctor and ovarian cancer was not diagnosed, but treatment is not relieving symptoms, either see your doctor again or get a second opinion. It is important that the evaluation includes a pelvic examination.
People with close family members who have/had ovarian or breast cancer should see a doctor who is trained to detect ovarian cancer.
What are the causes of ovarian cancer?
Although we know that ovarian cancer, like many other cancers, is caused by cells dividing and multiplying in an unordered way, nobody completely understands why cancer of the ovary occurs. We know that the following risk factors are linked to a higher chance of developing the disease:
Most women who develop ovarian cancer do not have an inherited gene mutation. Women with close relatives who have/had ovarian cancer, as well as breast cancer, have a higher risk of developing ovarian cancer compared to other women. There are two genes - BRCA1 and BRCA2 - which significantly raise the risk. The BRCA1 and BRCA2 genes also raise the risk of breast cancer. Those genes are inherited. The BRCA1 gene is estimated to increase ovarian cancer risk by 35% to 70%, and the BRCA2 by 10% to 30%. People of Ashkenazi Jewish descent are at particularly high risk of carrying these types of gene mutations.
Women with close relatives who have/had colon cancer, prostate cancer or uterine cancer are also at higher risk of ovarian cancer.
Genetic screening can determine whether somebody carries the BRCA1 and/or BRCA2 genes. Although a test for gene mutations known to significantly increase the risk of hereditary breast or ovarian cancer has been available for more than a decade, a study by researchers from Massachusetts General Hospital found that few women with family histories of these cancers are even discussing genetic testing with their physicians or other health care providers.
After eight years of searching, an international team of scientists found that a single nucleotide polymorphisms (SNP) on chromosome 9 that is uniquely linked to ovarian cancer. The scientists estimated that women carrying that particular version of the SNP on both copies of chromosome 9 have a 40 per cent higher lifetime risk of developing ovarian cancer than women who do not carry it on either copy of chromosome 9, while women with only one copy of the variant have a 20 per cent higher lifetime risk of developing ovarian cancer than women who have none.
In March 2013, scientists from the University of Cambridge and the Institute of Cancer research announced that they had identified over 80 genome regions that can increase a human’s risk of developing ovarian, breast and prostate cancers.
The majority of ovarian cancers occur in women over 65 years of age. A higher percentage of post-menopausal women develop ovarian cancer compared to pre-menopausal women.
High number of total lifetime ovulations
There is a link between the total number of ovulations during a woman’s life and the risk of ovarian cancer. Four principal factors influence the total:
- Never having been pregnant - women who have never become pregnant have a higher risk of developing ovarian cancer compared to women who have became pregnant. The more times a woman has become pregnant the lower her risk is.
- Never having taken the contraceptive pill - women who have never been on the contraceptive pill have a higher risk of developing ovarian cancer compared to women who have. Taking the Pill for 15 years halves the risk of ovarian cancer, a study by the Collaborative Group on Epidemiological Studies of Ovarian Cancer found.
- Early start of menstruation (early menarche) - women who started their periods at an early age have a higher risk of developing ovarian cancer.
- Late start of menopause - women whose menopause started at a later age than average have a higher risk of developing ovarian cancer.
Some gynaecologic surgeries may reduce the risk
Women who have had their fallopian tubes tied (tubal ligation) are estimated to have a 67% lower risk of ovarian cancer. A hysterectomy is said to reduce the risk by about one third.
Infertility or fertility treatment
Some studies have found a link between infertility treatment and a higher risk of ovarian cancer. Nobody is yet sure whether the risk is linked to infertility treatment, just infertility itself, or both. A Danish study published in the peer-reviewed British Medical Journal concluded that the use of fertility drugs does not increase a woman’s risk of developing ovarian cancer. The study involved 54,362 women with infertility problems referred to all Danish fertility clinics between 1963 and 1998.
Women who have been diagnosed with breast cancer have a higher risk of developing ovarian cancer.
Being obese or overweight increases the risk of developing many cancers. The more overweight you are, the higher the risk. Several studies have also shown that obese cancer patients are more likely to have faster advancing ones compared to cancer patients of normal weight. Obese older women who have never used hormone replacement therapy have nearly twice the risk of their normal weight peers of developing ovarian cancer, according to a study by the researchers at the National Cancer Institute.
New research suggests that women who are overweight or obese are more likely to develop ovarian cancer, compared with women of a healthy weight. Being overweight or obese ‘a risk factor’ for ovarian cancer. Investigators from the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research conducted the study as part of the WCRF’s Continuous Update Project.
Diagnosis of ovarian cancer
There is a tragic myth among many health care professionals and patients in too many countries about early stage ovarian cancer having no symptoms. A UK study, called The Target Ovarian Cancer Pathfinder study which surveyed 400 UK general practitioners and over 1,000 women, including 132 with ovarian cancer, found that 80% of GPs in the UK were wrongly of the view that women have no symptoms in the early stages of ovarian cancer. Studies in countries with top healthcare services have come up with similar findings.
The GP (general practitioner) will carry out a vaginal examination and check for any visible abnormalities in the uterus or ovaries. The doctor will also check the patient’s medical history and family history. Further tests will be ordered - these are usually done by a gynecologist - a doctor who specializes in treating diseases of the female reproductive organs.
If the woman is diagnosed with ovarian cancer the doctor will want to identify its stage and grade. The stage of a cancer refers to the cancer’s spread while the grade refers to how aggressively it is spreading. By identifying the stage and grade of the cancer the doctor will be able to decide on the best treatment. The stage and grade of ovarian cancer alone cannot predict how it is going to develop.
The following tests are used to diagnose ovarian cancer:
- Blood test
There is a cancer marker called CA125 (cancer antigen 125) which is made by certain cells in the body. A high blood level of CA125 may indicate the presence of cancer, but could also be due to something else, such as infections of the lining of the abdomen and chest, menstruation, pregnancy, endometriosis, or liver disease. This blood test is just one test among others, designed to help the doctor make a diagnosis. Normal blood levels of CA125 alone do not definitely mean there is no cancer either. They are just indications.
- This is a device that uses high frequency sound waves which create an image on a monitor of the ovaries and their surroundings. A transvaginal ultrasound device may be inserted into the vagina, while an external device may be placed next to the stomach. Ultrasound scans help doctors see the size and texture of the ovaries, as well as any cysts.
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Author Dr AZADEH Senior Lecturer at the University of The Gambia, Senior Consultant, Obstetrics & Gynaecology, Medical Director