What are ovaries, and what do they do?
A woman has two ovaries attached to the top of the uterus or womb. After puberty the role of the ovaries is to produce an egg each month and to produce female hormones. Each month when the egg is produced a cyst on the ovary is formed, which is quite normal. This usually occurs in the middle of the cycle. The egg is usually sucked up by the fallopian tube and, if intercourse has occurred recently, will meet the sperm in the tube. The meeting of the egg and sperm is termed fertilization, and once this occurs the fertilized egg, or ovum, moves down the tube and sticks, or implants, in the uterus to eventually form a baby. If fertilization does not occur, the egg is usually absorbed by the body.
What is ovarian cancer?
Ovarian cancer usually forms on the outside or skin lining of the ovary. This skin, or epithelium, also lines the inner surface of the abdominal cavity. Rarely, cancer can start in this skin beside the ovary, so some patients can have ovarian cancer with normal appearing ovaries. Cysts that form on the ovary can be normal or ovulation cysts, benign cysts or cancer cysts.
Am I at risk for ovarian cancer?
Each year in New South Wales approximately 364 women develop ovarian cancer, and 235 of these women will eventually die from this cancer. Most ovarian cancers develop sporadically, which means we don’t know why it happens. A hereditary or family component is only involved for 5-10% of women who develop ovarian cancer. There are various things that can increase or decrease your risk of ovarian cancer. However, these risk factors cannot tell you whether you definitely will or won’t get ovarian cancer. Your risk of developing ovarian cancer may be higher:
- as you get older
- if you have a family history of ovarian cancer
- if you have an abnormal (mutated) gene
- if you have had many ovulations in your life (e.g. if you started puberty early, went through menopause late, haven’t had children or breastfed, or used a fertility treatment where drugs stimulated ovulation)
- if you have a fatty diet your risk of developing ovarian cancer may be lower:
- if you have used the oral contraceptive pill
- if you have had your fallopian tubes clipped to prevent pregnancy
These risk factors are explained in more detail below. Ovarian cancer is more common as women get older, particularly over the age of 50 and those who have gone through menopause (change of life). Other than age, the next most important risk factor for ovarian cancer is a family history, especially if your family members were affected at an early age. If your mother, sister, or daughters have had ovarian cancer, then you have an increased risk of developing ovarian cancer. Some women who have a hereditary risk of cancer may also be at risk of developing bowel, breast and uterine cancer. Some of the abnormal (mutated) genes that cause hereditary cancer can be identified, so some women may choose to undergo genetic testing. Remember that just because you have a gene mutation doesn’t mean you are definitely going to get ovarian cancer, and likewise just because you test negative for the mutated or abnormal gene, doesn’t mean you are 100% protected. If you are at an increased risk, our team can discuss the option of chemoprevention (taking medication to reduce your risk), increased surveillance with blood tests and ultrasound, or even removing your ovaries (prophylactic surgery) to prevent cancer developing. Women who have had lots of ovulations throughout their life are also at an increased risk of developing ovarian cancer. Starting puberty early, going through menopause (change of life) late, not having children or breast feeding, and not having used the oral contraceptive pill will increase a woman’s risk. There may be a slight increase in risk for women who have had fertility treatment where drugs were used to stimulate ovulation. For reasons that we cannot fully explain, women who have had a tubal ligation or clipping of the tubes to prevent pregnancy have a lower risk of developing ovarian cancer. A fatty diet may also increase your risk of ovarian cancer.
How can I prevent ovarian cancer?
Generally speaking, cancer cannot be prevented. We can screen for pre-cancerous changes, and we are reasonably good at that with the mammogram for breast cancer and the Pap test for cervical cancer. Unfortunately, screening for ovarian cancer is very difficult. The ovaries are deep inside the pelvis, so feeling them on a routine pelvic examination is not accurate. The only way you can change your risk of ovarian cancer is to modify the risk factors you have. For instance, having a fatty diet increases your risk of developing ovarian cancer, but changing to a healthier diet can reduce your risk again. The situation is a little more complex for those women who have an abnormality in the genes that causes ovarian cancer. These genes are the breast cancer genes 1 and 2 (BRCA1 and BRCA2). It is important to discuss your individual case with our expert team at the High Risk Breast Ovarian Cancer Clinic.
What screening tests are available?
Most women with ovarian cancer are diagnosed with advanced stage disease. However, if early stage disease could be detected by using an accurate screening test, survival rates would be much higher. Although a lot of effort has been put into developing an accurate screening test for ovarian cancer, unfortunately there are none available. This makes it hard to detect early stage cancer. Currently we can only use a combination of identifiable risk factors, a cancer blood test to measure the level of CA125 (a substance in the blood), and ultrasound to detect early stage ovarian cancer. The problem with this approach is that many ultrasound abnormalities are detected that are not cancer, and the CA125 level can be high for many reasons that are not cancer. This means that many women would have to undergo unnecessary surgery based on inaccurate screening tests, before one case of early ovarian cancer could be found. For this reason, only women at high risk are advised to undergo screening for early detection of ovarian cancer. .
What are the signs of ovarian cancer?
Patients with ovarian cancer often do not develop symptoms until the ovary has become much bigger than normal or the cancer has spread. Even when symptoms develop, they are often vague and more commonly associated with other non-cancerous conditions. These symptoms include:
- bloating, gas, indigestion or cramping pain
- abdominal swelling
- a change in bowel habit or bladder habit
- loss of appetite
- feeling full very easily after a meal
How is ovarian cancer diagnosed and staged?
Most patients are referred to their Certified Gynaecological Oncologist (CGO) after evaluation of abnormal symptoms and the presence of a mass or lump within the pelvis. The evaluation usually involves a CA125 blood test and either an ultrasound or CT scan. Due to our inability to distinguish between benign and cancerous lumps in such testing, most patients undergo surgery to remove the lump. Sometimes a frozen section is performed – this is where a small amount of the lump is removed while the patient is still asleep on the operating table, and is snap frozen. The pathologist slices a very thin amount of the tissue and tries to determine whether the lump is benign or malignant using a microscope. A frozen section is not nearly as accurate as the final pathology results, but it will give the surgeon an indication of the likely outcome. If cancer is confirmed, further surgery is undertaken (outlined in detail below). The role of surgery in early cancer is to see if the cancer has spread to any other tissues, including the lymph nodes. In more advanced cancer, the role of surgery is to remove all or as much cancer as possible, so there is less cancer that needs to be eradicated through chemotherapy. After surgery, patients are assigned a clinical stage known as the FIGO stage (see below). This allows us to give our patients some idea about the likelihood that their treatment will be successful, and helps us to compare our treatments with other cancer groups around the world. Generally speaking, a higher stage means that the cancer has spread further and is more serious. Stage I: ovarian cancer confined to the ovary or ovaries Stage II: ovarian cancer that has spread beyond the ovaries, but is confined to the pelvis (can be in the uterus, bladder or rectum) Stage III: ovarian cancer that has spread to the peritoneum (the lining of the abdomen) and/or lymph nodes Stage IV: ovarian cancer that has distant spread (metastasis) to other organs.
What are the treatments for ovarian cancer?
Almost all women with ovarian cancer will have some type of surgery in the course of their treatment. The purpose of surgery is first to diagnose and stage the cancer as outlined above, and then to remove as much of the cancer as possible. In early stage cancers (stage I and II), surgeons can often remove all of the visible cancer. Generally, women with ovarian cancer will also have a hysterectomy (removal of the uterus) and bilateral salpingo-ooporectomy (removal of both ovaries and fallopian tubes) as part of their operation. This is because there is always a risk of microscopic cancer in both of the ovaries and the uterus. The only circumstance in which a woman may not have this entire operation is if she has a very early stage cancer (stage IA) that looks favorable under the microscope (grade 1). Women with more advanced cancer (stage III or IV) will often have debulking surgery, which means that their Gynaecological Oncologist will attempt to remove as much disease as possible. Often it is not possible to remove all the cancer, but patients who are left with a small amount of cancer tend to do better than those left with a large amount of cancer after surgery. Sometimes a patient will have their surgery after 3 cycles of chemotherapy. This is called interval debulking and is done if patients are not strong enough for aggressive surgery initially, or if we wish to shrink the tumour before surgery. Occasionally further surgery is performed at a later stage if the cancer returns – we call this secondary debulking. This is only done for selected patients, when it has taken a long time for their cancer to return and a CT scan has shown one or two lumps that seem easy to remove.
Even when all cancer is removed, there is always a risk that the cancer might return. To reduce this risk, most patients will be offered chemotherapy along with their surgery. There are many different chemotherapy drugs, and they are often given in combinations. Patients will usually have to go to a clinic to get the chemotherapy because many of the drugs have to be given through a vein. Different chemotherapy regimens are used for different purposes. The most common combination currently used for ovarian cancer is a drug called Paclitaxel plus either Cisplatin or Carboplatin (platinum containing drugs). There are also other drugs that can be used, like Gemcitabine, Doxorubicin, Doxil, Caelyx and Etoposide. Sometimes new combinations are tried if there is no response to the original combination. There are advantages and disadvantages to each of the different regimens, which your Medical Oncologist will discuss with you. Based on your own health, your personal values and wishes, and side effects you may wish to avoid, you can work with your doctors to come up with the best regimen for your situation. Our team will also talk to you about being involved in the latest cancer treatment research. This generally involves a clinical trial, where you are offered either:
- the best current treatment (known as the gold standard treatment), or
- another combination of drugs that we believe is as good or better.
The treatment you are offered is decided at random once you have read about the research and given consent to take part, so you have an equal chance of being offered either treatment. It is through such medical research that we have been able to advance cancer treatment. treatment.
Radiotherapy is not often used in the treatment of ovarian cancer, but it involves using high energy rays (similar to x-rays) to kill cancer cells. These rays come from an external source, which requires patients to come in to hospital 5 days a week for up to 6-8 weeks. The treatment takes just a few minutes, and is painless. Radiotherapy can also be used to ease pain caused by metastases (cancer spread to other organs) and stop tumors from bleeding. Generally, doctors try to limit the amount of radiation that your vital organs receive, and avoid treating large portions of the bowel and pelvis to reduce damage to healthy tissue. This makes radiation less useful in ovarian cancer, where disease is often spread throughout the abdomen and pelvis.
After treatment is completed, patients are monitored regularly to make sure the cancer has not returned. This involves 3 monthly visits to start with. Your doctor will ask you some questions and perform an examination, including a pelvic examination and a CA125 blood test. CT scanning is not a routine part of follow-up care, but may be done if the doctor is unsure about their examination findings or if the blood test shows rising CA125 levels.
A Certified Gynaecological Oncologist (CGO) is a specialist gynaecologist who is trained in women’s cancer surgery. Patients whose surgery is undertaken by a CGO are more likely to have optimal debulking surgery and adequate staging, resulting in a greater chance of longer survival.