The ovaries are two organs which are adjacent to the uterus. Their dual functions are the storage of eggs for reproduction and the production of female sex hormones.
The latter helps in the development of the breasts, vagina, uterus, fallopian tubes, and body shape during puberty; and regulates the menstrual cycle.
Tumours are non-cancerous (“benign”) or cancerous (“malignant”). Benign tumours do not spread and may require treatment but they are rarely life threatening. Malignant tumours, however, spread to other parts of the body and is life threatening; as such, it is important to detect them early.
According to the Malaysia National Cancer Registry 2012-2016, malignant ovarian tumours are the fourth most common cancer in women and the tenth most common overall.
The highest incidence was in the 65 to 69 age group. The overall lifetime risk was one in 167. It was one in 160 for Malays, one in 169 for Chinese, and one in 164 for Indians.
Two main factors increase the risk of ovarian cancer, i.e. age and family history.
Increasing age increases the risk of ovarian cancer — most cases occur above the age of 50. However, there are some instances of ovarian cancer in younger women.
The risk of ovarian cancer is increased if two or more relatives on the same side of the family have ovarian or breast cancer. This is because of the inheritance of the faulty gene mutation, BRCA1 or BRCA2.
The rare familial condition, hereditary nonpolyposis colorectal cancer (“HNPCC”), due to the inheritance of the faulty genes i.e. MLH1, MSH3 and MSH6, can increase slightly the risk of ovarian, uterus, stomach, colon, pancreatic, biliary and bladder cancer.
The following factors can increase slightly the risk of ovarian cancer i.e. a long menstrual history (periods starting before 12 years, menopause after 50 years, having first child after 30 years, not having children and not breastfeeding); endometriosis; and use of oestrogen-only hormone replacement therapy (“HRT”). Smoking may increase the risk of mucinous ovarian cancer.
There are three main types of ovarian tumours, depending on the part of the ovary it arises from, i.e. epithelial, germ cell, and sex cord stromal.
Malignant epithelial tumours develop from the outer surface of the ovary. They account for 90% of all ovarian cancers and have six types i.e. serous, mucinous, endometrioid, clear cell, transitional cell and undifferentiated.
Germ cell tumours develop from cells that produce eggs. Most occur in younger women and about 90% are curable with preservation of fertility.
Sex cord stromal tumours arise from the ovarian connective tissue. They are rare and usually considered low-grade cancers with about 70% presenting in Stage I.
Stages And Grades
There are four stages in ovarian cancer, i.e.:
- Stage I – Cancer is confined to one or both ovaries
- Stage 2 – Cancer is outside the ovary or ovaries, but has spread no further than the pelvis i.e. uterus, bladder, lower intestine
- Stage 3 – Cancer involves one or both ovaries with spread beyond the pelvis into the abdominal cavity (but not the liver) and/or to nearby lymph nodes
- Stage 4 – Cancer has spread to other parts of the body e.g. liver, lungs and brain.
As different cancers grow at different rates, they are graded according to their expected growth. The tumour grade is based on how much it resembles normal tissue. Low grade cancer grows slowly, whereas high grade ones grow and spread rapidly. The tumour grades are:
- Grade 0 – The tissue is borderline cancerous with low malignant potential i.e. unlikely to spread and are usually curable.
- Grade 1 – Well-differentiated with many healthy- looking cells
- Grade 2 – Moderately differentiated with more abnormal cells than healthy ones
- Grade 3 – Poorly differentiated or undifferentiated cells with lack of normal tissue
- Grade GX – The grade cannot be evaluated
Many women have no symptoms until they are at the advanced stages. This is because symptoms are often vague or may be that of other less serious conditions.
The four primary symptoms of ovarian cancer are:
- Persistent abdominal/pelvic pain
- Persistent bloating
- Eating difficulty or feeling full quickly
- Needing to pass urine frequently
Sometimes, there may be other symptoms that occur on their own or at the same time as those above. They include changes in bowel habits e.g. diarrhoea or constipation; fatigue and back pain.
Many of the above symptoms occur from time to time, and are often due to other, non-serious conditions.
Symptoms due to ovarian cancer, however, are different in that they are:
- Persistent (they do not go away)
- Frequent (they are present for more than 12 days a month)
- Get progressively worse
- New (they started in the last 12 months)
- Unusual (do not feel normal)
The above are well summarised in the Ovarian Cancer Awareness month infograph from the Malaysian International Representative Committee of the Royal College of Obstetricians and Gynaecologists, and the Malaysian Gynaecological Cancer Society, an appropriate project with International Women’s Day on 8 March 2022.
It is prudent for any woman with any of the above symptoms on most days of the month to seek medical attention from a general practitioner and/or gynaecologist.
This is especially so for anyone with increased risk of ovarian cancer. Although the symptoms may be due to some other condition, it is best to have a medical evaluation. Better safe than sorry!
There is no effective and reliable diagnostic test for ovarian cancer.
If there are signs and symptoms of ovarian cancer, the following tests are available especially for those at increased risk:
- Pelvic examination can detect an enlarged ovary or fluid in the abdominal cavity. The examination of the vagina, uterus, ovaries, and rectum can detect any unusual changes like a mass. However, some cancers are very small and cannot be detected on pelvic examination.
- Transvaginal ultrasound involves the insertion of a probe in the vagina to look at the ovaries and uterus. This examination is especially appropriate for those at increased risk for ovarian cancer or those with an abnormal pelvic examination.
- CA-125 blood estimation measures the level of a protein which is increased in ovarian/fallopian tube cancer. However, CA-125 is not a key marker of ovarian cancer because some benign tumours e.g. fibroids, endometriosis can also increase CA-125, and some ovarian cancers do not produce sufficient CA-125 for a positive test. Because of these reasons, CA-125 is not routinely used as a screening test for those at average risk, but rather as a baseline for monitoring those on treatment.
- Computed tomography (“CT”) scan is a detailed x-ray examination which inform on whether the ovarian cancer has spread to other organs. It does not detect small tumours well but may detect spread to adjoining organs.
- Magnetic resonance imaging (“MRI”) may be helpful in examination of the brain and spinal cord where the cancer could have spread.
- Positron emission tomography (“PET’) scan involves intake of radioactive glucose that is taken up by rapidly growing cancer cells which is detected by pictures of areas of radioactivity. This provides useful information on whether abnormal areas seen in other tests are likely to be cancerous.
The treatment modalities are surgery, chemotherapy, radiation and/or a combination of the treatment modalities.
The outcome of ovarian cancer depends on many factors like age, stage and type of cancer and overall health.
The majority of ovarian cases are diagnosed when they are at advanced stages i.e. 3-4 in which survival rates are low.
As such, early detection is critical.
Dr Milton Lum is a Past President of the Federation of Private Medical Associations, Malaysia and the Malaysian Medical Association. This article is not intended to replace, dictate or define evaluation by a qualified doctor. The views expressed do not represent that of any organisation the writer is associated with.
- This is the personal opinion of the writer or publication and does not necessarily represent the views of CodeBlue.