Cervical cancer is the most common gynecological cancer in high-income countries. In most cases, it starts on the surface of the mucous membrane, and experts then speak of endometrial carcinoma. It is already known that being overweight increases the risk of this type of cancer, but the mechanisms and the actual extent were unclear. The molecular biologist Emma Hazelwood and her colleagues from the University of Bristol have examined the connection in more detail in one of the largest studies to date and published the results in the »Journal BMC Medicine«.
The analyzes showed that obesity can almost double the probability of developing cervical cancer. This is higher than most previous research has suggested, and reflects lifelong development, not just status at a given point in time. More precisely: For every five additional BMI units, the risk increases by 88 percent. Five BMI units is the difference between the categories “overweight” and “obese”. For an adult woman who is 165 centimeters tall, that would be around 13 kilograms.
The body mass index (BMI)
It is calculated by dividing the weight by the square of the height, example: 70kg/(1.70m)2 = 24.2. According to the World Health Organization, young adults with a BMI under 18.5 are considered underweight, over 25 as overweight, and over 30 as severely overweight. What is considered healthy also depends on gender and age: men are allowed to weigh slightly more than women, older people slightly more than younger people. The ideal BMI at the age of 30 is between 20 and 25, and at the age of 60 between 23 and 28.
To find out what molecular mechanisms are behind it, the researchers took gene samples from around 120,000 women from Australia, Belgium, Germany, Poland, Sweden, the United Kingdom and the USA. About 13,000 of the study participants had cervical cancer. The team collected 14 genetic risk markers associated with metabolism, hormone balance and inflammatory processes in the body. With insulin, testosterone and the sex hormone-binding globulin (SHBG), the scientists have identified three hormones that on the one hand increase the risk of a cancer diagnosis and on the other hand partially explain the connection with obesity. It is already known that adipose tissue has an important endocrine function and is involved, among other things, in the metabolism of steroids, which include sex hormones.