Ovarian Cancer

What Causes Ovarian Cancer?

The cause of ovarian cancer is still not fully understood. Cancer begins when healthy cells acquire a genetic mutation that turns normal cells into abnormal cells. As these abnormal cells accumulate, they form a mass or tumour. Cancer cells invade nearby tissues and can break off and spread somewhere else in the body (metastasis).

Tumours that grow in the ovaries are usually benign (lacks the ability to spread), although some can be malignant (able to spread to non-adjacent cells). Ovarian tumours originate from ovary cells and undergo a transformation that enables them to grow continuously and in a disordered manner. These mutated cells then invade and destroy the tissues around them.

Types of Ovarian Cancer

There are four main types of ovarian cancer, named after the part of the ovary that is affected. Knowing exactly which type of cancer a patient has, helps doctors determine the best treatment plan.

Epithelial ovarian cancer

This is the most common type of ovarian cancer, and arises from the epithelium – the cells covering the ovary. More than nine out of 10 ovarian cancers are epithelial in nature.

Germ cell and sex-cord stromal cell ovarian cancers

These two types of ovarian cancer are rare. Germ cell cancers arise in the cells that mature into eggs, and usually only affect women under the age of 30. Sex-cord stromal cancers arise in the cells that release female hormones, and can occur at any age. They both usually respond very well to treatment and are often curable. In cases where the cancer affects only one ovary, it may still be possible for younger women to have children after treatment.

Borderline tumours

Borderline tumours are epithelial tumours that are not as aggressive as other forms of ovarian cancer. Sometimes the term ‘low malignant potential’ is used to describe borderline tumours.

The prognosis for women with borderline tumours is generally very good, whether the disease is diagnosed early or late.

Most ovarian cancers are either epithelial carcinomas or malignant germ cell tumours.

Ovarian Cancer Stages

Stage 1 – confined to one or both ovaries
Stage 2 – has spread to other locations in the pelvis, such as the uterus or fallopian tubes
Stage 3 – has spread beyond the pelvis or to the lymph nodes within the abdomen
Stage 4 – has spread to organs beyond the abdomen, such as the liver or the lungs


Symptoms of ovarian cancer are not specific and can be easily confused with other more common conditions, including digestive problems. It is important to see a doctor for any signs or symptoms that are a change from the norm. Some of these include:

  • Abdominal pressure, fullness, swelling or bloating
  • Pelvic discomfort or pain
  • Persistent indigestion, gas or nausea
  • Changes in normal bowel habits – diarrhea or constipation
  • Changes in bladder habits, frequent urination
  • Persistent back pain and tiredness
  • Clothes fitting tighter around your waist
  • Lower back pain
  • Feeling full quickly
  • Pain during sex

Risk Factors

Family History

A family history of breast or ovarian cancer is one of the strongest risk factors for ovarian cancer and regular check-ups are highly recommended.


A mutation in the BRCA1 and BRCA2 genes is known to increase the risk of ovarian cancer.



The risk increases with age. Ovarian cancer usually develops after menopause, though it can also occur earlier.

Menstrual & Reproductive History

Women are at a greater risk if they began menstruating before the age of 12, have never been pregnant, had their first child after age 30, or experienced menopause before age 50.


Many studies have shown an association between obesity and increased risk for ovarian cancer.

Hormone Replacement Therapy (HRT)

Long-term use (more than five years) of HRT may increase the risk of ovarian cancer.

Previous Cancer Diagnosis

If there has been a previous diagnosis of cancer of the breast, colon, rectum or uterus, the risk of ovarian cancer is increased.



Tests and procedures to diagnose ovarian cancer include:

Pre-operative evaluation
  • Pelvic Examination – using two fingers inserted into the vagina while simultaneously pressing on the abdomen, the doctor is able feel the uterus and ovaries. A speculum can also be inserted to visually check the vagina and cervix for abnormalities.
  • Ultrasound and MRI scanning – to check for signs such as an enlarged ovary or fluid in the abdomen.
  • CA 125 Tumour Marker – this blood test checks for the protein found on the surface of ovarian cancer cells. Many women with ovarian cancer have abnormally high levels of CA 125 in their blood.
Intra-operative evaluation
  • Laparoscopy
  • Frozen Section
  • Histopathology

While a frozen section procedure is still necessary to confirm the diagnosis if the cyst sample tests positive with OvaCis™, the advantage of obtaining quick and accurate results on-site in the operating theatre is invaluable. The number of medical personnel and resources needed for the cystectomy are also minimised, making the surgery more affordable for doctors and patients alike.

  1. IARC, GLOBOCAN 2002. Cancer Incidence, Mortality and Prevalence Worldwide (2002 estimates). 2004.
  2. Ovarian Cancer Statistics. Ovarian Cancer National Alliance. 2013.
  3. Testing Biopsy and Cytology Specimens for Cancer. American Cancer Society, 3 July 2013.