Ovarian cancer risk tracks how many times a woman has ovulated
Every ovulation prompts cells in and around the ovary to divide, and each round of division is a small chance for something to go wrong. That is why ovarian cancer risk rises with the number of ovulatory cycles over a lifetime, and why pregnancy, breastfeeding and hormonal contraception, which pause ovulation, are linked to lower risk.
The pattern shows up clearly in the numbers. Starting periods early and reaching menopause late both add cycles, and women who have never given birth face roughly twice the risk of those who have. Most cases arise after menopause, with diagnosis typically around age 63. Despite the name, many tumours begin not in the ovary itself but in nearby tissue such as the fallopian tubes or the lining of the abdomen, and epithelial cancers make up more than 90 per cent of cases, most commonly a subtype called high-grade serous carcinoma.
Genes play a sizeable role. About 10 per cent of cases involve an inherited mutation in BRCA1, BRCA2 or DNA repair genes, and a single faulty copy is enough to raise risk substantially. Because carriers begin with one mutation already in place, their cancers tend to appear about 15 years earlier than sporadic ones. In the United States, women with one first-degree relative who had the disease face about triple the usual risk.
Its danger lies in stealth. The ovaries sit deep in the pelvis, early disease is often painless, and symptoms such as bloating, pelvic discomfort, feeling full quickly or changes in bowel habits are vague enough to be mistaken for irritable bowel syndrome, often persisting for months before diagnosis. As a result, most tumours are large and advanced by the time they are found. Routine screening of women at average risk has not been shown to reduce deaths, and false positives can lead to unnecessary surgery. Caught early, however, the disease is often curable.
Globally about 313,000 women were diagnosed in 2020. In the United States it is the second most common gynaecological cancer yet the deadliest cancer of the female reproductive system, fifth among cancer deaths in women, with an overall five-year survival rate of 52 per cent. Deaths worldwide rose 84.2 per cent between 1990 and 2017.
Source: Ovarian cancer
