Ovarian cancer prevention: What high-risk women need to know

19 Aug 2021

We spoke to Dr Gregory Gard, a certified gynaecological oncologist, who is principally based at Royal North Shore Hospital, to help us understand what’s new in the prevention and detection of ovarian cancer.

First of all, Dr Gard, why is ovarian cancer so difficult to detect and prevent?
“So, the biggest challenge we have really if we go back to the normal anatomy of the uterus and ovaries is that ovarian cancer does not actually arise in the ovary. Most of ovarian cancer that we see probably arises in an area of the tube that opens up to the peritoneal cavity, which is where the egg is released after ovulation. This is where we believe the cancer arises from, this end of the fallopian tube.”

Can you explain a little about risk-reducing surgeries?
“When it comes to the risk-reducing surgery, there are two main types. We have traditionally done risk-reducing salpingo-oophorectomy (salpingo, meaning the tube and oophorectomy, meaning the ovary). So, we remove the ovaries and the tube. The second is a risk-reducing early salpingectomy with delayed oophorectomy. So, what we’re talking about is taking the tubes out early, and then at some stage, perhaps at menopause, between 40 and 50 years of age, we take out the ovaries. Interestingly, in about 2% of risk-reducing surgeries, we’ll actually find microscopic cancers.”

What are your thoughts on taking the tubes out and not the ovaries?
“There are certain limitations to the amount of risk reduction we can get from taking the tubes out and not the ovaries, but we haven’t quantified that reduction in risk. All the studies we have look at risk-reduction by removing tubes and ovaries, we don’t anything that’s really rock-solid telling us that taking the tubes out will provide a certain amount of risk reduction compared to taking both the tubes and ovaries. And, of course, the problem we have is the fimbrial tissue from the tubes is found on the ovarian surface in probably about 10% of patients, at least. Therefore, those people are not going to have that reduction in risk if the sort of tissue we’re trying to remove is actually present on the ovaries as well.”

So this surgery doesn’t affect a patient’s fertility?
“The first thing I’ll say is if we do take the tubes out, we have absolutely no evidence that the ovarian function is affected. In fact, we’ve got very good evidence now to suggest that in fact, the ovarian function is not affected. And this is by looking at something called AMH or anti-Mullerian hormone, which is a hormone we use to try and measure ovarian reserve. In the individual patients, you can see this declining with time but there is no decline when you do a salpingectomy. Of course, taking the tubes out has profound effects on your fertility in the fact that if you try to spontaneously get pregnant, it isn’t going to happen. But it’s certainly thought by the IVF community that taking the tubes out does not affect future fertility if you’re doing IVF.  The success rates are very good, particularly with people who don’t have any other particular fertility issues, they just don’t have any tubes. You’re looking at a success rate of about 40% per cycle, but of course, you have to go through an IVF cycle to get there.”

What’s the relationship of risk-reducing surgery and menopause?
“Well, we know that if you do take out the ovaries, you’re going to be menopausal. So, we’re actually reducing the number of steroid hormones, namely estrogen and progesterone, which are usually produced by the ovary. These hormones actually perform certain functions in the rest of the body. Estrogen, for example, is actually a very primitive hormone; it’s been in our evolution an awfully long time and even little tiny multicellular organisms seem to produce estrogen. Without it, we get menopausal symptoms, hot flushes, vaginal dryness, headaches, insomnia, and it affects the bone. It can cause osteoporosis, affect the heart and if you actually have premature menopause, you have an increased risk of myocardial infarction [a heart attack] before the age of 50. It seems to affect cognitive function as well.”

After surgery do you recommend taking hormone replacement therapy?
“For people who don’t have a personal history of cancer, but they have the BRCA mutation we would certainly recommend hormone replacement therapy, at least to the natural age of menopause, which is about 51. If women have had triple-negative breast cancer, it’s unlikely to be affected by estrogen. However, I think there’s probably a lot of advantages to taking hormone replacement therapy for those people too. With the BRCA mutation, if you were going to take hormone replacement therapy, it would slightly increase your risk of breast cancer. The good thing about hormone replacement therapies is they can make menopausal symptoms more tolerable. It may not remove them entirely, but it should be making them more tolerable.”

How does hormone replacement therapy affect women sexually?
“There’s certainly improved sexual function with the use of HRT. It’s something that we often feel a little bit awkward talking about with our patients but it’s something that we really need to address. There’s no doubt that there is an element of sexual dysfunction after risk-reducing surgery, and what I mean by that is a decreased frequency of sex alone, especially with vaginal dryness. I guess the good news is that these things are all significantly helped with the use of hormone replacement therapy. To quantify the degree of sexual dysfunction that this surgery can cause, a study found up to 77% of people noted some element of sexual dysfunction with risk-reducing surgery, with up to 30% of those cases being classified as severe.  And it’s something you should be raising with your doctors when you come to making that decision about when you should be having a risk-reducing surgery.”

 What is the standard age that you would recommend having ovaries removed?
“So, with a person with a BRC1 mutation, we’re generally looking at a risk-reducing surgery somewhere between 35 and 40 years of age. Having said that, unfortunately, I have seen women with BCRA 1 mutation with ovarian cancer below the age of 35. It can happen. The majority are a little bit older than that, but essentially, when you have a BRCA mutation, you should be thinking about surgery. And, you know, I wouldn’t make that decision too soon. You want to wait a little while to make sure you’re absolutely certain because taking your ovaries and tubes out is final. You obviously can’t reverse this surgery.”