Ovarian Cancer and Obesity – Weighing the Risks

A recent research study reports an increased risk of ovarian cancer among obese women.

Since every woman I know thinks she is fat, this report is sure to raise anxiety levels across the board. So let’s see if I can calm things down a bit by placing the data in perspective.

First off, you need to know your BMI. Go here and calculate it , then come back. For those of you who are too lazy to click the link, you can think of it this way – your BMI is 30 if you are 5’2″ and 150 lbs, 5’5″ and 180 lbs or 5’8″ and 200 lbs.

Got your BMI? Okay. Here’s the data –

Women with a BMI of 30 or more had a relative risk of 1.6 for ovarian cancer compared to women whose BMI is < 25. That means for every 1 case of ovarian cancer in the thin women, there were 1.6 cases among the obese women. Almost double the rate. Sounds pretty bad, right?

Well, that depends on how risky ovarian cancer is to start with. Turns out ovarian cancer is not that common, whether you are thin or fat. The risk in this study was less than 1% over the 7 years of the study.

Here’s how it looks visually – There are 1000 dots in each group, representing 1000 women. The red dots represent the women who got ovarian cancer in the 7 years of the study.

What about the risk among HRT users? Well, in that group, obese women’s risk for ovarian cancer was no higher than thinner women’s risk, because thinner women on HRT have a higher risk of ovarian cancer than their thin counterparts who don’t use HRT. How high?  For every 1000 women on HRT there were 3-4 cases of ovarian cancer. Same as with obese women.

Bottom Line

Obesity increases your risk for ovarian cancer. Fortunately, that risk is still quite low – certainly not high enough to warrant anything other than routine screening.

But add it to the increased risks of diabetes, hypertension, hyperlipidemia, heart disease and breast cancer associated with obesity, and maybe it’s enough to get you thinking more seriously about losing  weight. Not to mention the improvement in your quality of like when you can sleep without snoring or apnea, exercise comfortably, wear the clothes you love and just plain feel better.

8 Responses to Ovarian Cancer and Obesity – Weighing the Risks

  1. I like the way you graphically showed how small women’s risks are for ovarian cancer. That study, however, actually found no increased risk among “obese” women – all of the relative risks were no better than chance. But the greatest flaw in that study was that it was not a clinical study at all, but looked at AARP member questionnaires that had been filled out 14 years ago!

  2. Anonymous –

    You are correct – the results were only significant on subgroup analysis.

    I actually thought the study design, using baseline data form a questionnaire 14 yrs ago, was not so bad. Getting longitudinal data is very difficult, and researchers must be resourceful in this regard. Matching up the names in the database with cancer databases was a clever way of getting the data.

    Thanks for your thoughtful comments.

  3. Bardiac –
    Yes, it was time. Just passed ny three year blogiversarry. Feels good to be out of the closet 🙂

  4. Interesting that obesity seemed to have no influence on risk for women with a family history; I suppose the substantially larger genetic risk simply overwhelmed the tiny increase in risk associated with obesity.

  5. I had a cousin and then a friend die from ovarian cancer eight months apart form each other. One fought it for three months and the other for three years. I’m in the over weight section but know because of my cousin I have a higher risk for ovarian cancer and that also raises the risk for breast cancer.

    Interesting charts. There is less written about ovarian cancer. I did a maraton in DC with a group from Johns Hopkins to raise money for better treatment and quality of life for it. Are sonograms still the best testing for it?

  6. I found a BMI chart for children after computing my own, I did my son’s BMI for kicks. He is a super skinny, almost 4 yo (in the 35% for height), but with a large head. He came back as overweight. How accurate is that scale for children? I’m trying to feed him more, especially a glass of milk at dinner, etc.

  7. Amanda –

    The BMI charts are for adults. For kids use the pediatric growth charts – talk to your pediatrician before making any change in your child’s diet.

    Thanks for reading.

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