New research presented at the European Congress in Liverpool (ECO) beginning today (Sunday 12 May) shows a possible link between obesity and height in childhood and endometrial cancer in adulthood. The research* is by Julie Aarestrup, Institute of Preventive Medicine, Copenhagen University Hospital, Copenhagen, Denmark, and colleagues.

Endometrial cancer is in Europe the fourth most common cancer in women with more than 90,000 new cases diagnosed each year. In adult women, a high body mass index (BMI) is associated with an increased risk of endometrial cancer, whereas associations with height are limited. It is largely unknown, however, whether any of the risk originates in childhood. In this new study, the researchers investigated if childhood BMI and height at each age from 7-13 years were associated with risk of endometrial cancer in adulthood.

The total cohort consisted of 158,459 women from the Copenhagen School Health Records Register with data on measured heights and weights at 7-13 years who were born from between 1930 and 1989. BMI and height were transformed into age-specific z-scores, a method for comparing how large or tall a child is compared to a reference population. Follow-up occurred by linkage via a personal identification number to the Danish Cancer Registry, the Hospital Discharge Register (hysterectomy information), and the vital statistics register. Subjects were followed until a diagnosis of endometrial cancer, hysterectomy, death, emigration, loss-to-follow-up, or December 31, 2010; whichever came first.

The researchers found 940 diagnoses of endometrial cancer occurred during follow-up. At age 7 the risk of endometrial cancer in adulthood increased 18% per increase in BMI z-score and by 12% per increase in height z-score. To put this in perspective, compared to an average height and weight girl born in the late 1950s (122.4 cm, 22.9kg), another girl of the same height but who weighed 3.3 kg more would have an 18% higher risk of endometrial cancer. Further, height also increased the risk; compared to the same average girl, another girl of the same age but who was 5.2cm taller had a 12% increased risk of endometrial cancer. When looking at a girl aged 13 years born in the late 1950s compared to an average height and weight girl (156.7cm, 44.6 kg), another girl of the same height but who weighed 6.8kg more had a 24% increased risk of endometrial cancer; and another girl of the same age but who was 6.9cm taller had a 15% increased risk of endometrial cancer.

The peak age of endometrial cancer diagnosis is approximately 65 years. Therefore girls born in the 1950s are approaching their highest risk years. As the cohort members from later birth years continue to age, the study will continue to follow them in order to assess their risk of endometrial cancer.

Aarestrup concludes: "Higher BMI and height during childhood are associated with an increased risk of endometrial cancer in adulthood. These results suggest that some risk of endometrial cancer observed in adult women has its origins in childhood."

Research is ongoing to refine these results by subtypes of endometrial cancer. This project forms part of a series of studies led by Dr. Jennifer L. Baker, also of the Institute of Preventive Medicine, that are exploring associations between childhood body size and the later risk of cancers including those of the liver, prostate and thyroid. *This study is part of the European Research Council (ERC) project 'Childgrowth2cancer: Childhood body size, growth and pubertal timing and the risk of cancer in adulthood' which is run by Associate Professor Jennifer L. Baker.