Ovarian Cancer

Ovarian cancer begins in the ovaries, the female reproductive glands that produce eggs and the hormones oestrogen and progesterone.

Ovarian cancer is the fifth leading cause of cancer death in women. The American Cancer Society estimated that in 2020 about 21,750 women in the United States would be diagnosed with ovarian cancer and about 13,940 would die from it.

Types of ovarian cancer

The ovary is made up of three main types of cell, and the type of ovarian cancer depends on the cell it starts in.

• Epithelial tumours start in the cells on the outer surface of the ovary (epithelial cells). Malignant epithelial tumours are known as carcinomas and are the most common type of ovarian cancer. Their subtypes include serous carcinomas, clear cell carcinoma, mucinous carcinoma and endometrioid carcinoma.
• Stromal tumours start in the connective-tissue cells that produce oestrogen and progesterone (stromal cells). Malignant subtypes include granulosa cell tumours, granulosa-theca tumours and Sertoli-Leydig cell tumours.
• Germ cell tumours start in the cells that produce eggs (germ cells). Malignant subtypes include teratomas, dysgerminomas, endodermal sinus tumours and choriocarcinomas.

Risk factors

Several factors can increase the risk of developing ovarian cancer:

• Age: the risk increases with age, and ovarian cancer most commonly develops after the menopause.
• Inherited genetic mutations: mutations in the BRCA1 and BRCA2 genes increase the risk of developing ovarian cancer.
• Family history: women with a family history of ovarian, breast or colon cancer are at higher risk.
• Reproductive history: early menstruation and late menopause increase the risk. Women who have children after the age of 35, or who have never carried a full-term pregnancy, are also at higher risk.
• Taking hormones: women who use oestrogen hormone replacement therapy after the menopause have a higher risk than women who have never used hormones.

Signs and symptoms

Ovarian cancer often causes vague symptoms that can be mistaken for other conditions, and it is frequently not found until it is more advanced.

The most common signs and symptoms include:

• abdominal bloating
• pelvic or abdominal pain or discomfort
• a feeling of fullness
• needing to pass urine more frequently or urgently

Other, less common signs and symptoms may include:

• fatigue
• weight loss
• constipation
• changes in menstruation
• back pain
• pain during sexual intercourse
• abdominal swelling caused by fluid in the abdomen (ascites)

How ovarian cancer is diagnosed

Diagnosis usually begins with a review of your medical history and a physical examination, including a pelvic examination, followed by further tests and investigations such as:

• Imaging tests: ultrasound, CT and MRI scans. A PET/CT scan may also be used to find out whether the cancer has spread (metastasised) to other parts of the body.
• Biopsy: taking a sample of tissue for examination.
• Blood tests: including the tumour marker CA-125, alongside other blood tests.

Treatment options

After diagnosis, your doctor will establish the stage of the disease. Taking into account your current health, medical history and the results of staging, they will discuss the most suitable treatment options with you. Regular follow-up and periodic monitoring with tests and investigations are strongly recommended. Treatment is more likely to succeed when ovarian cancer is found early, before it has spread.

Treatment options include:

• Surgery is used to treat most ovarian cancers, and the type depends on the person's health and the stage of the cancer. Procedures may include removing the reproductive organs and, where needed, nearby tissue and affected areas:
• total hysterectomy (TAH): removing the uterus and cervix.
• bilateral salpingo-oophorectomy (BSO): removing both ovaries and fallopian tubes.
• unilateral salpingo-oophorectomy: removing one ovary and fallopian tube.
• debulking: removing as much of the tumour as possible.
• omentectomy: removing the omentum, a fold of fatty tissue in the abdomen.
• lymphadenectomy (lymph node dissection): removing affected lymph nodes.
• colectomy: removing the bowel.
• removing other organs to which the cancer has spread.
• Chemotherapy uses drugs, given intravenously or orally, to kill cancer cells throughout the body. Chemotherapy for ovarian cancer usually combines two different drugs and may be given before surgery to shrink the tumour, or after surgery to kill any remaining cancer cells. In some cases, intraperitoneal (IP) chemotherapy is given by injecting the drugs into the abdominal cavity.
• Hormonal therapy uses hormones or drugs to block oestrogen, such as luteinising-hormone-releasing hormone (LHRH) agonists, tamoxifen and aromatase inhibitors.
• Targeted therapy uses drugs that act on specific abnormalities within cancer cells.
• Radiotherapy uses high-powered energy beams to kill cancer cells. The most common form for ovarian cancer is external beam radiation therapy (EBRT); another is brachytherapy.
• Alternative treatments use other science-based approaches to attack cancer cells.

Reducing your risk

Taking oral contraceptives (the birth control pill) may reduce the risk of ovarian cancer, including for women who are at higher risk and those with an inherited BRCA mutation.