Ovarian cancer ranks as the sixth most common cause of cancer death in women and is the cause of 5% of all cancer deaths in Australian women. Despite advances in screening and treatment, ovarian cancer has a poor prognosis, with a 5-year survival rate of less than 30%.
Reproductive factors such as early menarche, late menopause and not having children are several of the many influences linked to increasing the risk of ovarian cancer. Being over 50, having a past history of breast cancer or having a family history of ovarian cancer are also recognised risk factors for ovarian cancer.
Conversely, multiple births and prolonged breastfeeding practices are linked to lowering the risk of ovarian cancer, as each can lessen lifetime exposure to reproductive hormones.
Not much is known about modifiable lifestyle risk factors for ovarian cancer but physical activity has been raised as an important one. Physical activity is linked to the reduction in risk of many forms of cancer, so researchers are exploring if ovarian cancer can be added to the list.
In a recent study of almost 7,000 women with ovarian cancer, those who reported that they were inactive in the years leading up to the diagnosis were between 22% and 34% more likely to die of the disease compared to women were regularly active.
The link between physical inactivity and ovarian cancer mortality was not altered by the degree of a woman’s weight (overweight or obese), menopause status or degree of tumour advancement.
In a similar study from the same research team, the risk of developing ovarian cancer at all was investigated. Of 8,300 women with ovarian cancer, those who said that they were not recreationally physically active during their lives had a 34% higher risk of being diagnosed with ovarian cancer than those who exercised regularly.
While neither of the studies can prove that exercise can prevent ovarian cancer or delay death from it, they fit within the scientific narrative of the benefits of physical activity as a powerful ‘cancer prevention’ habit.
If the apparent association between physical inactivity and ovarian cancer risk is substantiated, additional work via targeted interventions could be considered to help mitigate the risk of this highly fatal disease.