Exercise has been shown to help prevent uterine cancer. Women with fibroids worry that they can be or become cancerous, but fibroids are a non-cancerous growth of the muscle, and it's common for them to grow but not common (1/30,000) for them to become cancerous.
The uterine wall is a muscle, and the lining tissue is very different stuff; it’s called the endometrium. Endometrium is shed monthly and it regenerates: this propensity to grow, develop and respond to estrogen makes this vulnerable to factors that can create a malignancy.
Most cancers of the uterus thus occur in the lining or endometrium. So it’s important to keep that lining healthy. The strategies as to how to keep the lining healthy are complex for many women, but simple for others. Having a baby, using hormonal birth control, and keeping your weight down, actually are all strategies to prevent the pre-cancerous and cancerous changes that can occur in the lining, as well as the exercise strategy!
We don’t know yet what other metabolism changes affect this: it may be that both diabetes and high blood pressure are also specific risk factors. And we do know that the lining of the uterus changes long before it becomes cancerous. Pre-cancerous changes in the lining do not often become cancerous. And the accuracy of transvaginal ultrasound and operative hysteroscopy (looking in the uterus) has enabled us to learn a lot about the changes of the lining to help you understand what could be done and what should be done.
Lining changes that are specifically a thick lining or accompanied by polyps of the lining are the changes that are most often seen. And polyps are often what your gyno worries will become a lining cancer of the uterus. The old standard recommendation is that if you are young, and if the polyps are small, meaning less than 1 cm, they may resolve on their own or with medical treatments, and if the tissue that is polyp shaped on transvaginal ultrasound is greater than 1 cm, it may be a precancerous or cancerous growth. Rarely is the growth cancerous.
Newest information from multiple studies does confirm that if you are older, particularly past menopause, it is more likely the polyp growth is more serious. It is now calculated that if you do have a polyp, your chance of having lining cancer is about 3.5%. We don’t know how to recalculate risks if you also have the factors mentioned above: obesity, diabetes, high blood pressure.
Preventing cancer may mean surgically removing the polyp and treating with medication to prevent cancer. If you have medical reasons you cannot take the hormones (usually progesterones) that are used to treat polyps, then it is more likely you will benefit from a surgical solution. As I often gab about: accuracy in diagnosis is important and proper tests to determine the extent of the lining changes should be done before coming up with the plan of management.