Does PCOS Increase Your Risk of Cancer?

Have you ever wondered whether PCOS could cause an increased risk of female-related cancers?

There has been relatively little research on this important topic. However, the Aberdeen Royal Infirmary in the UK went through the medical databases and found eight studies that appeared to be relevant.

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After reviewing these studies, the researchers commented that "women with PCOS appear to be three times more likely to develop endometrial cancer but are not at increased risk of breast cancer."

They also said there was not enough evidence to implicate polycystic ovary syndrome in the development of vaginal, vulval, cervical or ovarian cancers.

So it appears that endometrial cancer might be your biggest risk. It is the most common type of uterine cancer.

The relationship between polycystic ovarian syndrome and cancers in general is not completely clear, although women who are overweight are more likely to get some kind of cancer. Women who are infertile (whether they have PCOS or not) are more likely than fertile women to get a cancer of the reproductive system.

The 3 types of cancers we're concerned about are:

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The strongest link between a cancer and PCOS is endometrial cancer. A few studies have suggested a correlation between polycystic ovarian syndrome and breast cancer, while some have not. There doesn't seem to be any obvious relationship between polycystic ovarian syndrome and ovarian cancer.

Breast cancer and endometrial cancer are described as "estrogen-sensitive" cancers, meaning that the presence of estrogen may cause these cancer cells to multiply.

The risk of estrogen-sensitive cancers is relevant to PCOS women because many have "estrogen dominance" or "unopposed estrogen", which means there is too much estrogen available to the cells, and there is too much estrogen in relation to progesterone.

There are three aspects of estrogen to be concerned about:

Too much total estrogen.
Imbalance of individual estrogens.
Poor metabolism of estrogens.

In addition to having an excessive level of total estrogen, you could also have an imbalance of the individual estrogens that make up the total estrogen level. The 3 primary estrogens are: estradiol, estrone, and estriol. Some women are low in estriol, which means they may have high estradiol and estrone, even though their total estrogen level is "normal".

An estrogen imbalance is significant for endometrial cancer, because the cells of the endometrium (lining of the uterus) have receptors for estradiol but not for estriol. Therefore, estriol cannot stimulate endometrial cancer cells. A woman with excessively high levels of estradiol and low levels of estriol has an increased cancer risk. Seeking the optimal balance of individual estrogens is a significant but overlooked health-building tactic.

Other Factors Contributing to Overall Estrogen Dominance

Any number of factors can contribute to estrogen dominance, such as:

Too much testosterone, which can be converted into estrogen.
Insufficient production of progesterone.
Insulin resistance.
Obesity.
Exposure to estrogenic environmental chemicals.
Liver disease (surprisingly common in PCOS).

If you can correct the above problems, you're taking a big step towards reducing cancer risk. Of course, an excellent place to get started is to improve your diet and increase your exercise.

Metabolism of Estrogen (A Problem in PCOS)

The third aspect of estrogen to be concerned about is estrogen metabolism (how it is processed in your body).

Estrogen can be metabolized in two ways. Along one metabolic pathway, it is converted into a powerful metabolite, 16alpha-hydroxyestrone (16alpha-OHE1) that acts to stimulate target tissues. Levels of 16alpha-OHE1 can rise in response to obesity, alcohol consumption or toxic exposure.

Alternately, the body can break down estrogen into a much weaker metabolite, called 2-hydroxyestrone (2-OHE1). This hormone metabolite binds weakly to cell receptors and may slow cell proliferation.

High levels of 16alpha-OHE1 and low levels of 2-OHE1 have been linked to breast cancer, uterine cancer, cervical cancer and lupus. However, excessively high levels of 2-OHE1 may increase the risk of developing conditions associated with estrogen deficiency, such as heart disease, depression, and osteoporosis.

There are things you can do to achieve a healthy balance of 2-OHE1 and 16alpha-OHE1 estrogen metabolites. A healthy diet, healthy lifestyle, good liver function, clean environment, weight control, good bowel function, and selected supplements can all help you to metabolize estrogen in a healthy way.

What we've just discussed is pretty technical and may be hard to understand. But even if it's hard to understand, we think it's important to give you information that you may not be getting from other sources. PCOS is a very complex hormonal and metabolic disorder that represents a threat to your good health. We think a simplistic approach of just taking birth control pills is not the answer to PCOS and infertility. Whether chronic consumption of birth control pills will reduce your risk of cancer, cardiovascular disease or diabetes is questionable.

Will Plant Estrogens Increase My Risk of Cancer?

Question: "Since people with PCOS already have long menstrual cycles and their uterus and breasts are subject to longer exposures to estrogens, thus increasing their risk of cancer, should they avoid foods high in phytoestrogens, e.g., soy products?"

Answer: "Phytoestrogens" is the name given to a family of plant compounds that have both estrogenic and anti-estrogenic properties. Flaxseed, soy, alfalfa are examples of plants containing phytoestrogens.

Research indicates that these plants, and isolated lignans (proteins) from these plants, have many protective effects in the body. Consumption of flaxseed and its lignans increases SHBG (sex hormone binding globulin) synthesis, as well as reduce breast tumor formation and growth. SHBG inhibits the action of testosterone. Excessive testosterone contributes to infertility, hirsutism, and acne.

Hundreds of research studies demonstrate that soy foods are safe. Soy has a moderating influence on both estrogen and testosterone.

There is some evidence to suggest that the more the food has been processed to be drug-like, the more likely there could be adverse effects. Therefore, eating soy beans in chile, putting ground flax seed in your smoothie, or having a tofu scramble for breakfast, is preferable to taking capsules of isolated soy proteins.

Sources:
Chittenden BG et al, Polycystic ovary syndrome and the risk of gynaecological cancer: a systematic review, Reprod Biomed Online. 2009 Sep;19(3):398-405
Wild, S et al, Long-term consequences of polycystic ovary syndrome: results of a 31 year follow-up study, Hum Fertil, 2000, 3(2):101-105
Balen, A, polycystic ovary syndrome and cancer, Hum Reprod Update, 2001, 7(6):522-5
Lord, RS et al, Estrogen metabolism and the diet-cancer connection: rationale for assessing the ratio of urinary hydroxylated estrogen metabolites, Altern Med Rev, 2002, 7(2):112-29