Ovarian Cancer
Ideas about causes of ovarian cancer
Some ovarian cancers are caused by inherited genetic mutations (for example, BRCA1/2, HNPCC) (see 'Family history and genetics'). Though several risk factors have been found in connection with ovarian cancer, the cause of most ovarian cancer is unknown. Noted risk factors of ovarian cancer include:
- obesity and being overweight
- hormone replacement therapy (HRT)
- genetics and family history
- tobacco
- reproductive organ surgery (hysterectomy without removal of the ovaries)
- having endometriosis
- having diabetes
- having a history of breast cancer
Many women we interviewed had heard that it seems to be more common in women who have not had children and less common among those who have used oral contraception. Some wondered whether it was connected to the number of menstrual cycles a woman has in her life. Research indicates that having children decreases the risk of ovarian cancer (Cancer Research UK, February 2022) Since these interviews, research has shown that having children, breastfeeding, and taking the contraceptive pill reduces the risk of ovarian cancer, indicating that ovarian cancer may be linked to the number of times an ovary releases an egg (ovulates) (Macmillan Cancer Support, September 2021).
She thought she should have been at low risk of developing ovarian cancer.
She thought she should have been at low risk of developing ovarian cancer.
And do you have any ideas about what might cause ovarian cancer and why you should have got it?
No, none at all. Because I understood if you'd been on the Pill and you had a child, that the risks of ovarian cancer were a lot less. I was on the Pill for many years, I only had one child, but no, I thought I should have been in a very low group, risk group.
Increased risk with hormone therapy and treatment
Stimulation of the ovary by the drugs used during infertility treatment or IVF (in vitro fertilization)was thought to slightly increase the risk of developing ovarian cancer. Women who had such treatment had asked their doctors about this. Since these interviews, it has been found that a risk of ovarian cancer is not directly associated with undergoing IVF treatment, but rather that women who undergo infertility treatment are in a population that has a higher percentage of ovarian cancer risk due to differences in number of children compared with the general population (Cancer Research UK, May 2019).
Wonders about infertility treatment as a possible cause of her ovarian cancer.
Wonders about infertility treatment as a possible cause of her ovarian cancer.
I personally think that it may have been a link in my case although I also think that there may have been an underlying reason for those drugs affecting me because I was in a support group for couples who were trying to have children and having IVF and I know a lot of people and they've had IVF and yet I'm the only one that actually was then diagnosed with ovarian cancer. So statistically, you know, it may be linked but it's possibly still quite small, you know, quite a small chance of it.
Some women wondered whether hormone replacement therapy (HRT) could have increased their chances of developing ovarian cancer. Others asked whether events in their gynaecological history (such as ectopic pregnancy, tubal surgery, endometriosis or untreated ovarian cysts) could have had an effect. A woman regretted not having her ovaries removed when she had her hysterectomy some years before her ovarian cancer developed.
Wonders if HRT might have caused her ovarian cancer.
Wonders if HRT might have caused her ovarian cancer.
HRT is noted as a risk factor for ovarian cancer, with 4% of ovarian cancer cases in the UK caused by post-menopausal hormones and the risk is 37% higher in current or recent users of hormone replacement therapy (HRT). It is noted, however, that the association between HRT and ovarian cancer may be limited to ovarian tumours specifically (Cancer Research UK, June 2018).
Lifestyle factors and ovarian cancer
Many women talked about having had stressful episodes in their lives before their cancer diagnosis. Some believed this had been a possible cause, whilst others were not convinced since stressful life events happen to everyone. One woman felt that it wasn't the stress itself that caused her problems but her tendency to become angry in many situations. Some women felt that stress could have been a contributory rather than a direct cause; for instance, it could have been the final trigger in a series of events needed for cancer to develop, or it could have made them tired and run down, leaving their immune system vulnerable to attack.
Thinks that stress may have triggered her cancer.
Thinks that stress may have triggered her cancer.
I believe that stress is a major cause of disease in general, but talking, thinking about my case in particular yes I've had a lot of stress following the break up of my marriage and subsequent divorce and general stresses that one has in life, but it was a very stressful period of time and last year a very close good friend had a heart attack and died one night. It was an enormous shock and I took it very badly, and I do think that, while it didn't cause my cancer, the cancer was waiting for something like that to happen, and it happened and it's just said 'whoopee chaps, we've got her, another one'.
Several women believed that cancer was caused by a combination of factors such as family history, lifestyle and a trigger such as a virus or stress. One woman described this as like the line-up of three cherries on a fruit machine. A few suspected that an illness (for example a virus, ME, pleurisy) had weakened their immune systems, or could have been an, as yet unknown, bacterial or viral cause of ovarian cancer. Other ideas of possible causes included deodorants, environmental pollution, radiation, genetic mutations, poverty, poor diet in childhood, and 'everything from talcum powder to yoghurt'.
Other women wondered whether unhealthy aspects of their lifestyle may have been a factor, such as smoking, the Western diet, or being overweight. However, women who said they had lived a healthy life, or did not have any of the known risk factors, sometimes felt cheated because it hadn't stopped them getting cancer. A woman who did not think that ovarian cancer was associated with any particular lifestyle said that at least she did not need to feel guilty because there wasn't anything she should have done to avoid it.
Last reviewed December 2024.
Last updated December 2024.
Copyright © 2024 University of Oxford. All rights reserved.