Ovarian cancer refers to harmful growth appearing in different parts of the ovaries. The ovaries are part of a woman’s reproductive system where the eggs are developed. Most ovarian cancers are a type of cancer called ‘epithelial’ – cancer starting from the surface of the ovary. Other types start from the egg cells (germ cell tumour) or supporting cells (sex cord-stromal tumour).
Risk factors and causes of ovarian cancer
The risk factors of ovarian cancer include:
- Late pregnancy
- Early start of menstruation
- Late menopause
- Never had children
- History of breast cancer
- Family history of the cancer
- Endometriosis, where tissue that normally lines the inside of the uterus grows outside instead
Ovarian cancer is the 5th most common cancer among women in Singapore and is the second most common female genital tract cancer. According to the Singapore Cancer Registry Annual Report 2018, it also has the 3rd lowest age-standardised relative survival rate (ASRS) among the common cancers diagnosed in females at 42.7%.
Ovarian cancer onset age
Epithelial ovarian cancer usually affects older women than younger women. However, younger women have a higher risk of contracting germ cell cancers of the ovary than older women.
Ovarian cancer is known to run in some families with BRCA gene defects or Lynch syndrome. Families with BRCA gene defects may have a higher risk of getting ovarian, breast and uterine cancer. Families with Lynch syndrome may have a higher risk of getting ovarian, uterine and colorectal cancer. For example, a woman with a sister or mother with Lynch syndrome is 20 times more likely to develop ovarian cancer. Ovarian cancer also runs in certain families with a history of breast and colon cancers. There is now evidence to suggest that certain genes are involved in causing these diseases.