Ovarian cancer is one of the frequently diagnosed cancers affecting all ages. It is ranked as the eighth most dangerous cancer.² Usually, the risk is after menopause. In this article, you will explore more about ovarian cancer, its causes, and risk factors.

What is ovarian cancer?

Ovarian cancer is a group of diseases that originates in the ovaries, or the nearby areas of the fallopian tubes and the peritoneum.¹ There are two ovaries, which are located in the pelvis and on each side of the uterus. These ovaries make hormones and produce eggs for reproduction. On each side of the uterus, there are two thin fallopian tubes. Eggs from the ovaries pass through the fallopian tubes to the uterus.¹

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What are the types of ovarian cancer?

The type of ovarian cancer you have is based on the type of cell where the cancer starts developing. There are mainly three types of ovarian cancer: 

• Epithelial ovarian cancer: It is the most common type of ovarian cancer, developing from the epithelial cells that surround the ovaries 
• Stromal tumours are a form of ovarian cancer that begins in the cells surrounding the eggs inside the ovaries
• Germ cell tumours: These develop from the reproductive cells, which are also called germ cells. They can be cancerous or non-cancerous

Symptoms of ovarian cancer

The signs and symptoms of ovarian cancer include:

• Abnormal vaginal bleeding (post menopausal in particular)
• Pain or pressure in the pelvic area
• Abdominal or back pain
• Bloating
• Difficulty in eating (feeling full too fast)³
• Unexplained weight loss
• Urge to urinate frequently and/or constipation⁴
• Pain during intercourse⁵
• Fatigue 

How can ovarian cancer be diagnosed?

Ovarian cancer can be diagnosed as follows

• Medical history²
• Family health history (if someone among your relatives has or had ovarian cancer)
• Physical examination of the pelvic region
• Imaging tests- ultrasounds, MRI, CT scans of the abdomen and pelvic area
• Blood tests, such as the CA-125 blood test
• Surgery³
• PET scan (positron emission tomography) is a test that helps in finding abnormal tissues in the body²

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By Cancer Research UK - Original email from CRUK, CC BY-SA 4.0, Link

By Cancer Research UK - Original email from CRUK, CC BY-SA 4.0, Link

By Cancer Research UK - Original email from CRUK, CC BY-SA 4.0, Link

Causes and risk factors of ovarian cancer

Genetic factors

Ovarian cancers can be hereditary. The reason could be inheriting certain genes from either of your parents. Genes are made up of DNA, and 10 to 15% of ovarian cancers are genetic.

Inherited Gene Mutations

BRCA1 and BRCA2 are important genes that help breast and ovarian cells grow in a healthy, normal way. There are times when changes take place, and these genes undergo mutations. This causes a 10 percent risk of ovarian cancer and a 3% risk of breast cancer. There is a 50% chance of inheriting the mutation if either of our parents had the same mutation.

Research studies show that people with an inherited BRCA1 gene mutation have a 35% to 70% chance of developing ovarian cancer during their lifetime, while those with a BRCA2 gene mutation have a 10% to 30% lifetime risk. Genetic testing can be used to detect other genes that also cause ovarian and breast cancers.

Lynch syndrome 

Lynch syndrome is an inherited condition, also known as hereditary non-polyposis colorectal cancer (HNPCC). People with this syndrome are at increased risk of several types of cancer, one of which is ovarian cancer, which has a prevalence of 0.9-2.7%.⁹ It is caused by mutations in specific genes that are responsible for repairing DNA damage in cells.

The symptoms of Lynch syndrome depend on which organ it affects. If it leads to endometrial cancer, it can cause vaginal bleeding or pain in the lower belly (pelvic area). Continuous stomach pain and bloating are the reasons for ovarian cancer, as well as an urge to urinate more frequently, extreme tiredness, and weight loss without any reason.

Other tumours related to Lynch syndrome include colorectal, endometrial, gastric, ovarian, pancreatic, Ureteral, renal pelvis, biliary tract, brain tumours, sebaceous gland, and small Intestine cancer.⁶

Age

The risk of ovarian cancer increases with age. It usually affects people aged 45 and older, with the highest number of cases seen between 75 and 79 years old.

You are at risk of developing ovarian cancer at a younger age if you had breast cancer before age 40 or if you had a family history of breast, ovarian, uterine, or colorectal cancer before age 50 years. The percentage of ovarian cancer tends to be higher after age 40. It is around 90%.

You are also at increased risk if you belong to Ashkenazi or Eastern European Jewish ancestry.

Also, if you have had endometriosis or experienced early menstruation.

The early stages of pregnancy, not how long the pregnancy lasts, help protect against ovarian cancer.⁸

Women who have their menopause after 55 years are prone to having a higher risk of developing cancer. Deaths caused by ovarian cancers are highest among those aged 65-74.

Use of certain chemicals

Chemicals like poly and perfluoralkyl substances (PFAS), parabens, and bisphenol A (BPA) are linked to hormone-related cancers of the breast, ovary, skin, and uterus. Research is ongoing to understand these chemicals in a better way to prevent the risk of many types of cancer.¹³

Environmental toxins

Some harmful substances in the environment have been linked to a higher risk of developing ovarian cancer.

1. Asbestos exposure through products in occupational settings¹²
2. Using talcum powder in the genital area may cause it to enter the ovaries, where it can lead to inflammation
3. Pollution and toxins like pesticides, chemicals from industry, and endocrine-disrupting compounds have been known to interfere with hormone regulation, leading to changes in ovarian tissues at the cellular level
4. Smoking, consuming a high-fat diet, and improper lifestyle are considered causes for specific subtypes of ovarian cancers

How to lower the risk of ovarian cancer?

1. Carrying a pregnancy to full term
2. Breastfeeding for more than a year
3. Ligating the tubes.
4. Removal of ovaries and fallopian tubes
5. Removal of the Cervix or Uterus reduces the risk of ovarian cancer⁹
6. Taking birth control pills that contain estrogen and progesterone for more than 5 years

Lifestyle factors

• Follow a healthy diet with adequate exercise
• Do not smoke
• Maintain your weight¹⁰

What are the treatment options for ovarian cancer?

Available options for the treatment include:

1. Surgery 
2. Chemotherapy
3. Radiation therapy
4. Palliative care¹¹ 

FAQs

Which cancers are linked to inherited harmful changes in BRCA1 and BRCA2?

Pancreatic cancer, Prostate cancer, and other cancers like stomach and melanoma.

What genes are linked to Lynch syndrome?

There are four genes associated with Lynch syndrome: MLH1, MSH2, MSH6, and PMS2. 

Does everyone with lynch syndrome get cancer?

No, it does not mean that you will get cancer absolutely, but you are at increased risk.

What are five potential silent symptoms of ovarian cancer? 

If you experience bloating frequently, suffer from abdominal and pelvic pain, experience difficulty in eating or feeling full quickly, have changes in bowel habits, and frequent urination.

How do we detect ovarian cancer at an early stage? 

Although there has been a lot of research for a screening test, there has not been success. The two most used tests, in addition to pelvic exams, are transvaginal ultrasound (TVUS) and the CA-125 blood test.

Can birth control pills help reduce the risk of ovarian cancer?

Yes, taking the birth control pill for 5 years reduces the risk by half.

Where does most high-grade serous ovarian cancer(HGSOC) originate from?

 Recent cases have confirmed that it originates from the fallopian tubes.

Summary

Ovarian cancer is one of the most common cancers in women after menopause. Although age-related risk factors cannot be avoided, we can be aware of our family history and symptoms commonly associated and take necessary steps for early detection and to follow a healthy lifestyle, diet, and maintain our weight. Also, ovarian cancer is reduced in women who have pregnancies and breastfeed their children for more than a year. It has a good prognosis in women taking birth control pills and having tubal ligation. There is also a potential risk from chemicals and environmental factors for ovarian cancers, and there is continuous research going on regarding this.